ZYME Zymeworks Inc

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): July 14, 2022

(604) 678-1388

(Registrant’s telephone number, including area code)

Not Applicable

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

On July 14, 2022, Zymeworks Inc. (“Zymeworks”) entered into a Transaction Agreement (the “Agreement”) by and among Zymeworks Delaware Inc., a Delaware corporation and a direct, wholly-owned subsidiary of Zymeworks (the “Parent”), Zymeworks CallCo ULC, an unlimited liability company existing under the laws of the Province of British Columbia and a direct, wholly-owned subsidiary of Parent (“Callco”), and Zymeworks ExchangeCo Ltd., a company existing under the laws of the Province of British Columbia and a direct, wholly-owned subsidiary of Callco (“ExchangeCo”). The Agreement includes a plan of arrangement (the “Plan of Arrangement”), which will effect the proposed redomicile transactions (the “Redomicile Transaction”) pursuant to an arrangement under the British Columbia Business Corporations Act (the “Arrangement”). On July 15, 2022, Zymeworks announced its intention to complete the Redomicile Transaction, subject to receipt of necessary shareholder, stock exchange, and court approvals. A press release issued by Zymeworks is attached hereto as Exhibit 99.1 and is incorporated herein by reference (the “Press Release”).

As described in greater detail below, the purpose of the Redomicile Transaction is to facilitate a series of transactions which will occur in a specific sequence and as a consequence of which, among other things, (i) holders of Zymeworks common shares (the “Zymeworks Common Shares” and the holders thereof, the “Zymeworks Shareholders”) will receive, at their election and subject to applicable eligibility criteria, for their Zymeworks Common Shares, either (a) shares of Parent common stock (the “Delaware Common Stock”) on a one-for-one basis, or (b) exchangeable shares (the “Exchangeable Shares” and recipients thereof, the “Exchangeable Shareholders”) in the capital of ExchangeCo, on a one-for-one basis, or a mix of Exchangeable Shares and Delaware Common Stock (in such aggregate number that is equal to the number of Zymeworks Common Shares exchanged for them), subject to a cap on the aggregate number of Exchangeable Shares that is equal to 18% of (1) the number of Zymeworks Common Shares issued and outstanding, less (2) the number of Zymeworks Common Shares held by any Zymeworks Shareholders who exercise their dissent rights (the “Dissenting Shareholders”, and with respect to the cap, the “Exchangeable Share Cap”), (ii) Parent, Callco and ExchangeCo will enter into an Exchangeable Share Support Agreement (the “Support Agreement”), which will require, among other things, that Parent issue shares of Delaware Common Stock as consideration when the holder calls for Exchangeable Shares to be retracted by ExchangeCo, when ExchangeCo redeems Exchangeable Shares from the holder, or when Callco purchases Exchangeable Shares from the Exchangeable Shareholder under Callco’s overriding call rights; and (iii) Parent, ExchangeCo, Callco and Computershare Trust Company of Canada, a trust company existing under the laws of Canada (the “Share Trustee”) will enter into a Voting and Exchange Trust Agreement (the “Trust Agreement”), whereby the Share Trustee will hold the Special Voting Stock (as defined below), enabling the Share Trustee to exercise voting rights for the benefit of the Exchangeable Shareholders. Immediately prior to completion of the Redomicile Transaction, the Delaware Common Stock will be listed on the New York Stock Exchange (“NYSE”) under the symbol “ZYME”.

Plan of Arrangement Steps

Pursuant to the Plan of Arrangement, commencing on the Effective Date (as defined below), each of the following events or transactions shall occur and be deemed to occur in the following sequence and five minutes following the event(s) in the immediately preceding section, without any further act or formality, unless specifically noted:

Post-Arrangement Transactions

After the time at which the Arrangement becomes effective on the Effective Date (the “Effective Time”), and as part of the Redomicile Transactions, the following additional steps will take place:

The Redomicile Transaction will be submitted to a vote at a special meeting of Zymeworks securityholders (the “Special Meeting”) and must be approved by the affirmative vote of at least two-thirds of the votes cast at the Special Meeting, in person or by proxy, by both (i) Zymeworks Shareholders, Zymeworks Warrantholders and Zymeworks Incentive Awardholders, voting together as a single class, and (ii) Zymeworks Shareholders, voting separately. In addition, the Redomicile Transaction must be approved by the Supreme Court of British Columbia and the Delaware Common Stock must be approved for listing by the NYSE.

Assuming the special resolution approving the Redomicile Transaction is approved at the Special Meeting, following the Effective Time and completion of the Redomicile Transaction, the stockholders of Parent will be the same persons who were Zymeworks Shareholders immediately prior to the Redomicile Transaction (other than those who have validly exercised their dissent rights and holders of Exchangeable Shares prior to exchanging them for Delaware Common Stock) and Parent will become the direct or indirect owner of all of the assets and liabilities of Zymeworks. As a result, there will be no effective change of control of Zymeworks as a result of the Redomicile Transaction, as ultimate control will remain with the public stockholders.

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The foregoing description of the Agreement, including the Plan of Arrangement, and the transactions contemplated thereby does not purport to be complete and is qualified in its entirety by the actual Transaction Agreement, including the Plan of Arrangement, a copy of which is filed as Exhibit 2.1 to this Current Report on Form 8-K and incorporated herein by reference.

On July 15, 2022, Zymeworks filed a material change report with the Canadian securities regulatory authorities regarding its intention to complete the Redomicile Transaction, subject to receipt of necessary shareholder, stock exchange, and court approvals, as described in the Press Release. A copy of this material change report is furnished as Exhibit 99.2 hereto.

The information under this Item 7.01 of this Current Report on Form 8-K and Exhibit 99.2 attached hereto are being furnished and shall not be deemed “filed” for the purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liability of that section, nor shall such information be deemed incorporated by reference in any filing under the Exchange Act or the Securities Act of 1933, as amended (the “Securities Act”), regardless of the general incorporation language of such filing, except as shall be expressly set forth by specific reference in such filing.

Parent Registration Statement

In connection with the Redomicile Transaction, Zymeworks intends to cause Parent to file the Registration Statement (as defined below), which includes the Proxy Statement/Prospectus, with the SEC on or about July 15, 2022. The information in the Registration Statement, including the information in the Proxy Statement/Prospectus, is subject to completion and amendment.

Important Information for Investors and Securityholders

This communication is not intended to and does not constitute an offer to sell, buy or exchange or the solicitation of an offer to sell, buy or exchange any securities or the solicitation of any vote or approval in any jurisdiction, nor shall there be any sale, purchase, or exchange of securities or solicitation of any vote or approval in any jurisdiction in contravention of applicable law. In connection with the Redomicile Transaction, Zymeworks will cause Parent to file a registration statement on Form S-4 (the “Registration Statement”), which will include Parent’s prospectus as well as Zymeworks’ proxy statement (the “Proxy Statement/Prospectus”), with the U.S. Securities and Exchange Commission (the “SEC”) and the appropriate Canadian securities regulatory authorities. Zymeworks plans to mail the definitive Proxy Statement/Prospectus to its shareholders and holders of its warrants and outstanding equity awards in connection with the Redomicile Transaction. INVESTORS AND SECURITYHOLDERS OF ZYMEWORKS ARE URGED TO READ THE PROXY STATEMENT/PROSPECTUS AND OTHER RELEVANT DOCUMENTS FILED OR TO BE FILED WITH THE SEC AND CANADIAN SECURITIES REGULATORY AUTHORITIES CAREFULLY WHEN THEY BECOME AVAILABLE BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT ZYMEWORKS, PARENT, THE REDOMICLE TRANSACTION, AND RELATED MATTERS. Investors and securityholders will be able to obtain free copies of the Proxy Statement/Prospectus (when available) and other documents filed with the SEC by Zymeworks or Parent through the website maintained by the SEC at www.sec.gov (“EDGAR”). Investors and securityholders will also be able to obtain free copies of the Proxy Statement/Prospectus (when available) and other documents filed with Canadian securities regulatory authorities by Zymeworks, through the website maintained by the Canadian Securities Administrators at www.sedar.com (“SEDAR”). In addition, investors and securityholders will be able to obtain free copies of the documents filed with the SEC and Canadian securities regulatory authorities on Zymeworks’ website at www.zymeworks.com or by contacting Zymeworks’ corporate secretary.

Participants in the Solicitation

Zymeworks and certain of its directors, executive officers and employees may be considered participants in the solicitation of proxies in connection with the Redomicile Transaction. Information regarding the persons who may, under the rules of the SEC, be deemed participants in the solicitation of the securityholders of Zymeworks in connection with the Redomicile Transaction, including a description of their respective direct or indirect interests, by security holdings or otherwise, will be included in the Proxy Statement/Prospectus described above when it is filed with the SEC and Canadian securities regulatory authorities. Additional information regarding Zymeworks’ directors and executive officers is also included in Zymeworks’ Amendment No. 1 to the Annual Report on Form 10-K/A, which was filed with the SEC and Canadian securities regulatory authorities on May 2, 2022. This document is available free of charge as described above.

CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS

This filing and the exhibits hereto include “forward-looking statements” or information within the meaning of applicable securities legislation, including Section 27A of the Securities Act, and Section 21E of the Exchange Act. Forward-looking statements include, but are not limited to, statements that relate to the timing and completion of the Redomicile Transaction; opportunities to enhance long-term value for shareholders as a U.S. corporation; opportunities to expand the institutional investor base; eligibility for inclusion in certain leading indices; Zymeworks’ ability to commercialize zanidatamab in the United States; and other information that is not historical information. When used herein, words such as “intention”, “subject to”, believes”, “will”, “future”, “may”, “anticipates”, “plans”, “potential”, and similar expressions are intended to identify forward-looking statements. In addition, any statements or information that refer to expectations, beliefs, plans, projections, objectives, performance or

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other characterizations of future events or circumstances, including any underlying assumptions, are forward-looking. All forward-looking statements are based upon Zymeworks’ current expectations and various assumptions. Actual results could differ materially from those described or implied by such forward-looking statements as a result of various factors, including, without limitation: the impact of the COVID-19 pandemic on Zymeworks’ business, research and clinical development plans and timelines and results of operations, including impact on its clinical trial sites, collaborators, and contractors who act for or on Zymeworks’ behalf, may be more severe and more prolonged than currently anticipated; the ability to receive, in a timely manner and on satisfactory terms, the required securityholder, stock exchange and court approvals for the Redomicile Transaction; the anticipated last day of trading of Common Shares on the NYSE and the anticipated trading of shares of Delaware Common Stock on the NYSE; and assumptions in corporate guidance. Risks and uncertainties include, but are not limited to: the anticipated benefits of the Redomicile Transaction may not be achieved; the receipt of securityholder, stock exchange and court approvals and satisfaction of other conditions in connection with the Redomicile Transaction may not be obtained; the anticipated tax consequences and impact of the Redomicile Transaction to Zymeworks Shareholders, Zymeworks and Parent may not materialize; risks relating to Parent following the Redomicile Transaction, including triggering provisions in certain agreements that require consent or may result in termination; publicity resulting from the Redomicile Transaction and impacts to the company’s business and share price; the benefits of being a U.S. corporation on efforts to commercialize zanidatamab may not be realized; Zymeworks may ultimately decide to abandon the Redomicile Transaction, even if required approvals are obtained; changes in or interpretation of laws or regulations may prevent the realization of anticipated benefits from the Redomicile Transaction; risks associated with existing or potential lawsuits and regulatory actions; the impact of disputes arising with partners; and other risks and uncertainties as described in Zymeworks’ Annual Report on Form 10-K, as amended, and Quarterly Report on Form 10-Q and as described from time to time in Zymeworks’ other periodic filings as filed on SEDAR and EDGAR.

Although Zymeworks believes that such forward-looking Statements are reasonable, there can be no assurance they will prove to be correct. Investors should not place undue reliance on forward-looking statements. The above assumptions, risks and uncertainties are not exhaustive. Forward-looking statements are made as of the date hereof and, except as may be required by law, Zymeworks undertakes no obligation to update, republish, or revise any forward-looking statements to reflect new information, future events or circumstances or to reflect the occurrences of unanticipated events.

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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

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Exhibit 2.1

TRANSACTION AGREEMENT

BY AND AMONG

ZYMEWORKS DELAWARE INC.

ZYMEWORKS CALLCO ULC

ZYMEWORKS EXCHANGECO LTD.

AND

ZYMEWORKS INC.

DATED AS OF July 14, 2022

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TABLE OF CONTENTS

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TRANSACTION AGREEMENT

THIS TRANSACTION AGREEMENT (this “Agreement”), dated as of July 14, 2022, is made by and among ZYMEWORKS DELAWARE INC., a Delaware corporation (“Parent”), ZYMEWORKS CALLCO ULC, a British Columbia unlimited liability company and a direct, wholly-owned subsidiary of Parent (“CallCo”), ZYMEWORKS EXCHANGECO LTD., a British Columbia corporation and a direct, wholly-owned subsidiary of CallCo (“ExchangeCo”), and ZYMEWORKS INC., a British Columbia company (“Zymeworks”). Parent, CallCo, ExchangeCo and Zymeworks are referred to collectively as the “Parties” and each as a “Party”.

BACKGROUND:

A.    Parent is a wholly-owned subsidiary of Zymeworks and was incorporated as a Delaware corporation on June 30, 2022 for the purpose of consummating the transactions contemplated by this Agreement and the Plan of Arrangement.

B.    The Parties intend that, pursuant to the Plan of Arrangement under Division 5 of Part 9 of the BCBCA, and among other things, Parent shall acquire the Zymeworks Common Shares either directly, or indirectly through ExchangeCo, as more particularly described in this Agreement and in the Plan of Arrangement.

C.    The board of directors of Zymeworks has (i) determined that the Plan of Arrangement is in the best interests of Zymeworks, (ii) approved the entering into of this Agreement and the Transaction Documents to which Zymeworks is a party, the performance of Zymeworks’ obligations under this Agreement and such Transaction Documents, the consummation of the Redomicile Transactions contemplated by this Agreement and the Transaction Documents, and the completion of the Post-Arrangement Matters as contemplated by this Agreement, and (iii) resolved to recommend the approval of the Plan of Arrangement to the Zymeworks Securityholders.

D.    Subject to the terms and conditions set forth in this Agreement, Zymeworks wishes to submit the Redomicile Resolution to the Zymeworks Securityholders for approval at the Special Meeting and to submit the Plan of Arrangement to the Court for approval.

E.    The directors of each of Parent, CallCo and ExchangeCo have approved the entering into of this Agreement and the Transaction Documents to which they are a party, respectively, and the performance of their respective obligations under this Agreement and such Transaction Documents, the consummation of the Redomicile Transactions contemplated by this Agreement and the Transaction Documents, and the completion of the Post-Arrangement Matters to which they are a party as contemplated by this Agreement.

F.    Each of the Parties intends for Canadian Tax purposes that the Canadian Share Exchange will occur on an income tax deferred basis (or partially income tax deferred basis) for certain Eligible Holders under subsection 85(1) or (2) of the Tax Act.

G.    Each of the Parties intends for U.S. federal income tax purposes that the Parent Share Exchange and, if applicable, the Canadian Share Exchange and assumption of Zymeworks Warrants, viewed together, constitute an exchange governed by Section 351 of the Code.

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IN CONSIDERATION of the premises and the mutual promises set forth in this Agreement and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the Parties, each intending to be legally bound, hereby agree as follows:

ARTICLE 1

INTERPRETATION

1.1    Defined Terms. In this Agreement, the following terms will have the meanings set forth below, and any terms defined elsewhere in this Agreement will have the meanings so given to them. A derivative of a defined term will have a corresponding meaning.

“Affiliate” means, with respect to any Person, any other Person who, directly or indirectly, controls, is controlled by, or is under common control with, such Person. For purposes of this definition, the term “control” (including the correlative terms “controlling”, “controlled by” and “under common control with”) means the possession, directly or indirectly, of the power to direct or cause the direction of the management and policies of a Person, whether through the ownership of voting securities, by contract or otherwise. For purposes of this Agreement, with respect to Zymeworks, Parent, ExchangeCo or CallCo, “Affiliate” does not include any stockholders of Parent (other than Zymeworks), or any directors or executive officers of Zymeworks, Parent, ExchangeCo or CallCo.

“Agreement” has the meaning set forth in the introductory paragraph on the first page hereof.

“Arrangement” means an arrangement under Part 9, Division 5 of the BCBCA on the terms and subject to the conditions set forth in the Plan of Arrangement, subject to any amendments or variations to the Plan of Arrangement made in accordance with the terms of this Agreement and the Plan of Arrangement, or made at the direction of the Court in accordance with the Final Order with the prior written consent of Zymeworks.

“Arrangement Effective Time” means the time at which the Arrangement becomes effective on the Effective Date, as determined by Zymeworks in writing under Section 2.1.

“BCBCA” means the Business Corporations Act (British Columbia) and the regulations made thereunder.

“Broker” has the meaning set forth in Section 2.10(c)(i).

“Business Day” means a day on which banks are generally open for the transaction of commercial business in Vancouver, British Columbia, and New York, New York, but does not in any event include a Saturday or Sunday or statutory holiday in Vancouver, British Columbia, or New York, New York.

“CallCo” has the meaning set forth in the introductory paragraph to this Agreement.

“Canadian Share Exchange” means the exchange of Zymeworks Common Shares for Exchangeable Shares, or for a combination of Exchangeable Shares and Delaware Common Stock, in accordance with the Plan of Arrangement.

“Code” means the U.S. Internal Revenue Code of 1986, as amended.

“Consideration” means (i) in the case of a Zymeworks Shareholder who is an Eligible Holder and who validly elects to receive Exchangeable Shares prior to the Election Deadline (as defined in the Plan of Arrangement) in accordance with the Plan of Arrangement, for each Designated Zymeworks Common Share, one Exchangeable Share together with the Contractual Rights, and for each other Zymeworks Common Share (to the extent applicable), one share of Delaware Common Stock, and (ii) in the case of each other Zymeworks Shareholder who does not exercise the Dissent Rights, for each Zymeworks Common Share, one share of Delaware Common Stock.

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“Consideration Shares” means Delaware Common Stock and Exchangeable Shares, as the context may require.

“Contractual Rights” means the benefit of the Support Agreement and the Voting and Exchange Trust Agreement.

“Court” means the Supreme Court of British Columbia.

“Delaware Common Stock” means the shares of Parent’s common stock, par value $0.00001 per share.

“Depositary” means a bank or trust company selected by Zymeworks to perform the duties described in a depositary agreement in form and substance reasonably acceptable to the parties thereto.

“Designated Zymeworks Common Shares” means the Zymeworks Common Shares of an Eligible Holder that are designated by the Eligible Holder under a Letter of Transmittal and Election Form to be exchanged for Exchangeable Shares, as such number of Zymeworks Common Shares may be reduced as a result of the Exchangeable Share Cap, and “Designated Zymeworks Common Share” means any one of them.

“Dissent Rights” means the rights of dissent in respect of the Arrangement described in Section 5.1 of the Plan of Arrangement.

“Effective Date” has the meaning set forth in Section 2.1.

“Eligible Holder” means a Zymeworks Shareholder that is (i) a resident of Canada for purposes of the Tax Act and not exempt from tax under Part I of the Tax Act, or (ii) a partnership, each member of which is a resident of Canada for purposes of the Tax Act and not exempt from tax under Part I of the Tax Act.

“Exchange Act” means the Securities Exchange Act of 1934.

“Exchangeable Share Cap” means, in respect of the number of Zymeworks Common Shares exchangeable for Exchangeable Shares under the Canadian Share Exchange, such number of Zymeworks Common Shares that is equal to 18% of (i) the number of Zymeworks Common Shares issued and outstanding immediately prior to the Arrangement Effective Time, less (ii) the number of Zymeworks Common Shares held by any Zymeworks Shareholders who exercise their Dissent Rights.

“Exchangeable Share Provisions” means the rights, privileges, restrictions and conditions attaching to the Exchangeable Shares, substantially in the form attached as Exhibit E.

“Exchangeable Shares” means the exchangeable shares in the capital of ExchangeCo.

“Governmental Entity” means any United States, Canadian, international or other (i) federal, state, provincial, local, municipal or other government entity, (ii) governmental or quasi-governmental entity of any nature (including any governmental agency, branch, department, official, or entity and any court or other tribunal) or (iii) body exercising or entitled to exercise any administrative, executive, judicial, legislative, police, regulatory, or taxing authority or power of any nature, including any arbitrator or arbitral tribunal (public or private).

“Information Circular” means the notice of the Special Meeting to be sent to the Zymeworks Securityholders, and the accompanying proxy statement/prospectus to be prepared in connection with the Special Meeting, together with any amendments thereto or supplements thereof in accordance with the terms of this Agreement, and substantially in the form included in the Registration Statement.

“Irish Sub Stock” means the issued and outstanding shares of Zymeworks Pharmaceuticals Limited., a corporation incorporated under the laws of Ireland, consisting of 100 ordinary shares, par value EUR 1.00 per share.

“Intended U.S. Tax Treatment” has the meaning set forth in Section 5.1.

“Interim Order” means the interim order of the Court contemplated by Section 2.2 of this Agreement and made pursuant to Section 291 of the BCBCA, in a form acceptable to Zymeworks providing for, among other things, the calling and holding of the Special Meeting, as the same may be amended by the Court, provided that any such amendment is acceptable to Zymeworks.

“Law” means any federal, state, local, provincial, foreign, national or supranational statute, law (including common law), act, statute, ordinance, treaty, rule, code, regulation or other binding directive or guidance issued, promulgated or enforced by a Governmental Entity having jurisdiction over a given matter.

“Letter of Transmittal and Election Form” has the meaning given to it in the Plan of Arrangement.

“Lien” includes any mortgage, pledge, assignment, charge, lien, security interest, adverse interest in property, license or sub-license, charge, or other third-party interest or encumbrance of any kind (including, in the case of any equity securities, any voting, transfer or similar restrictions) whether contingent or absolute, and any agreement, option, right or privilege (whether by law, contract or otherwise) capable of becoming any of the foregoing.

“New Common Shares” has the meaning set forth in Section 3.2(a).

“NYSE” means the New York Stock Exchange.

“Order” means any writ, order, judgment, injunction, decision, determination, award, ruling, subpoena, verdict or decree entered, issued or rendered by any Governmental Entity.

“Other Withholding Agent” has the meaning set forth in Section 2.10(a).

“Parent” has the meaning set forth in the introductory paragraph to this Agreement.

“Parent Share Exchange” means the exchange of Zymeworks Common Shares for Delaware Common Stock in accordance with the Plan of Arrangement, but excluding any such exchange under the Canadian Share Exchange.

“Party” and “Parties” each have the meaning set forth in the introductory paragraph to this Agreement.

“Person” includes an individual, partnership, corporation, limited liability company, joint stock company, unincorporated organization or association, trust, joint venture, trustee, executor, administrator, legal representative, government or any other entity, whether or not a legal entity.

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“Plan of Arrangement” means the Plan of Arrangement in substantially the form attached as Exhibit A with such changes as may be agreed to by Zymeworks.

“Post-Arrangement Matters” means those matters to be completed or otherwise consummated following the implementation of the Arrangement, as more particularly described in Article 3.

“Redomicile Resolution” means a special resolution of the Zymeworks Securityholders in respect of the Arrangement to be considered at the Special Meeting, in substantially the form attached to this Agreement as Exhibit B.

“Redomicile Transactions” means the transactions contemplated by the Plan of Arrangement, the Transaction Documents and this Agreement.

“Registration Statement” means a registration statement of Parent on Form S-4 relating to the Redomicile Transactions and containing a prospectus for the Delaware Common Stock, among other things.

“Required Approval” has the meaning set forth in Section 2.2(b).

“Retraction Request” has the meaning set forth in the Exchangeable Share Provisions.

“SEC” means the U.S. Securities and Exchange Commission.

“Securities Laws” means the Exchange Act, the U.S. Securities Act and the other U.S. federal securities laws and the rules and regulations of the SEC promulgated thereunder or otherwise, and any other applicable foreign and domestic securities or similar Laws (including the applicable Canadian provincial and territorial securities laws).

“Special Meeting” means the meeting of the Zymeworks Securityholders, including any adjournment or postponement thereof in accordance with the terms of this Agreement, that is to be convened as provided by the Interim Order to consider, and if deemed advisable approve, the Redomicile Resolution, and such other matters as are properly brought before the Zymeworks Shareholders at such meeting.

“Support Agreement” means the support agreement to be entered into among Parent, CallCo and ExchangeCo, substantially in the form of Exhibit C, as it may be amended, supplemented or otherwise modified from time to time in accordance with its terms, and to be entered into at or prior to the issuance by ExchangeCo of any Exchangeable Shares.

“Tax” means any and all national, supranational, multinational, federal, provincial, territorial, state, regional, local or municipal taxes, including income, branch, profits, capital gains, gross receipts, windfall profits, value added, severance, ad valorem, property, capital, estimated, utility, recapture, net worth, production, sales, use, license, excise, franchise, environmental, transfer, land transfer, withholding or similar, payroll, employment, employer health, government pension plan premiums and contributions, social security premiums, workers’ compensation premiums, employment/unemployment insurance or compensation premiums or contributions, disability, documentary, registration, stamp, occupation, premium, alternative or add-on minimum, goods and services, harmonized sales, customs duties or other taxes, levies, premiums, excises, fees, assessments, imposts, duties, and other similar charges of any kind whatsoever imposed, assessed, charged or collected by a Governmental Entity and any installments in respect thereof, including any interest, fines, assessments, reassessments, penalties or additions to tax imposed in connection therewith or with respect thereto, and any interest in respect of such additions or penalties, and whether disputed or not.

“Tax Act” means the Income Tax Act (Canada) and the regulations promulgated thereunder.

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“Transaction Documents” means the Support Agreement, the Voting and Exchange Trust Agreement, and each other agreement, document, instrument or certificate that is necessary, desirable or useful (as determined by Zymeworks or Parent) to give effect to the Arrangement.

“U.S. Securities Act” means the U.S. Securities Act of 1933.

“Voting and Exchange Trust Agreement” means the voting and exchange trust agreement to be entered into among Parent, CallCo, ExchangeCo and the Share Trustee (as defined therein) in connection with the Plan of Arrangement substantially in the form of Exhibit D, as it may be amended, supplemented or otherwise modified from time to time in accordance with its terms.

“Withholding Shortfall” has the meaning set forth in Section 2.10(c).

“ZBI Stock” means the issued and outstanding shares of Zymeworks Biopharmaceuticals Inc., a corporation incorporated under the laws of the State of Washington, consisting of 10,000 shares of Common stock.

“Zymeworks” has the meaning set forth in the introductory paragraph to this Agreement.

“Zymeworks Common Shares” means the common shares in the capital of Zymeworks.

“Zymeworks Incentive Awards” means the stock options, incentive stock options, restricted stock units and all other awards and rights to purchase Zymeworks Common Shares granted under the Zymeworks Incentive Plans that are outstanding and unexercised, whether vested or unvested.

“Zymeworks Incentive Plans” means collectively (i) the Amended and Restated Stock Option and Equity Compensation Plan of Zymeworks, (ii) the Amended and Restated Employee Stock Purchase Plan of Zymeworks, (iii) the Inducement Stock Option and Equity Compensation Plan of Zymeworks, and (iv) the Second Amended and Restated Employee Stock Option Plan of Zymeworks, in each case including any schedules or appendices thereto, as amended from time to time, and “Zymeworks Incentive Plan” means any one of them, as applicable.

“Zymeworks Securityholders” means holders of Zymeworks Common Shares, Zymeworks Incentive Awards and Zymeworks Warrants as at the relevant time in question.

“Zymeworks Shareholders” means, collectively, the holders of Zymeworks Common Shares immediately prior to the Arrangement Effective Time.

“Zymeworks Warrants” means, as of any determination time, each pre-funded warrant to purchase Zymeworks Common Shares that is outstanding and unexercised.

1.2    Headings and References. The division of this Agreement into Articles and Sections and the insertion of headings are for convenience of reference only and do not affect the construction or interpretation of this Agreement. Unless otherwise specified, references to Articles and Sections are to Articles and Sections of this Agreement.

1.3    Time Periods. Unless otherwise specified, time periods within, or following, which any payment is to be made, or act is to be done, shall be calculated by excluding the day on which the period commences and including the day on which the period ends and by extending the period to the next Business Day following if the last day of the period is not a Business Day.

1.4    Currency. All sums of money which are referred to in this Agreement are expressed in the lawful currency of the United States unless otherwise specified.

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1.5    Time. Unless otherwise indicated, all times expressed in this Agreement are to local time, Vancouver, British Columbia.

1.6    Construction. In this Agreement:

1.7    Governing Law. This Agreement shall be governed by and construed in accordance with the Laws of the Province of British Columbia and other federal Laws of Canada applicable in British Columbia without giving effect to any choice of law or conflict of law provision or rule (whether of the Province of British Columbia or any other jurisdiction) that would cause the application of the law of any jurisdiction other than the Province of British Columbia.

ARTICLE 2

THE ARRANGEMENT

2.1    The Arrangement. The Parties shall proceed to effect and implement the Arrangement under Part 9, Division 5 of the BCBCA as soon as practicable following the approval of the Final Order by the Court in respect of the Arrangement, on such date and at such time as may be determined by Zymeworks in writing (the “Effective Date”), in accordance with the terms of, and subject to the conditions contained in, this Agreement and the Plan of Arrangement.

2.2    The Interim Order. As soon as reasonably practicable after the Registration Statement is declared effective by the SEC, Zymeworks shall apply under Part 9, Division 5 of the BCBCA and shall prepare, file and pursue an application to the Court for the Interim Order in respect of the Arrangement, which shall provide, among other things, as follows:

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2.3    U.S. Securities Laws Matters. The Parties agree that the Arrangement will be carried out with the intention, and the Parties will use reasonable efforts to ensure, that all Exchangeable Shares issued under the Arrangement will be issued in reliance on the exemption from the registration requirements of the U.S. Securities Act provided by Section 3(a)(10) thereunder. In order to ensure the availability of the exemption under Section 3(a)(10) of the U.S. Securities Act and to facilitate Parent’s compliance with other Securities Laws, the parties agree that the Arrangement will be carried out on the following basis:

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2.4    The Special Meeting. Subject to the terms of this Agreement and the Interim Order, Zymeworks shall convene and conduct the Special Meeting in accordance with the Governing Documents of Zymeworks, applicable Law and the Interim Order as soon as reasonably practicable after the date of the Interim Order to consider the Redomicile Resolution (and for any other proper purpose as may be set out in the notice for the Special Meeting, as determined by Zymeworks). Zymeworks shall use reasonable efforts to obtain the Required Approval in respect of the Redomicile Resolution.

2.5    Information Circular. Zymeworks shall prepare and complete the Information Circular together with any other documents required by applicable Law in connection with the Special Meeting and the Arrangement and shall, as soon as practicable after obtaining the Interim Order, cause the Information Circular and such other documents to be delivered to each Zymeworks Securityholder and any other Person as required by the Interim Order and applicable Law.

2.6    Final Order. Zymeworks shall take all steps necessary or desirable to submit the Arrangement to the Court and diligently pursue an application for the Final Order pursuant to Part 9, Division 5 of the BCBCA, as soon as reasonably practicable after the Required Approval is obtained for the Redomicile Resolution as provided for in the Interim Order.

2.7    Court Proceedings. In connection with all Court proceedings relating to obtaining the Interim Order and the Final Order, Zymeworks shall: (i) diligently pursue the Interim Order and the Final Order; (ii) ensure that all material filed with the Court in connection with the Arrangement is consistent with this Agreement and the Plan of Arrangement; and (iii) subject to this Agreement, oppose any proposal from any Person that the Final Order contain any provision inconsistent with the Plan of Arrangement or this Agreement.

2.8    Zymeworks Incentive Awards & Warrants. The Parties acknowledge that the outstanding Zymeworks Incentive Awards and Zymeworks Warrants shall be treated as provided under the Plan of Arrangement.

2.9    Payment of Consideration. Prior to or concurrently with the Arrangement Effective Time, Parent and ExchangeCo, as applicable, shall deposit, or cause to be deposited, with the Depositary sufficient Delaware Common Stock and Exchangeable Shares to satisfy the aggregate Consideration payable to the Zymeworks Shareholders pursuant to the terms of the Plan of Arrangement.

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ARTICLE 3

POST-ARRANGEMENT MATTERS

3.1    NYSE Listing. Parent shall use reasonable efforts to cause the shares of Delaware Common Stock issuable under the Arrangement (including the Delaware Common Stock issuable pursuant to the exchange or exercise of the Exchangeable Shares) to be listed on the NYSE under the symbol “ZYME” immediately prior to the Arrangement Effective Time, and in connection therewith, to satisfy any applicable initial and continuing listing requirements of NYSE in respect of the Delaware Common Stock. Immediately following the completion of the Arrangement, Zymeworks will cause the Zymeworks Common Shares currently listed on the NYSE to cease to be traded on the NYSE and to be deregistered under the U.S. Exchange Act, and for Canadian Tax purposes will immediately thereafter elect to be treated as a private corporation.

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3.2    Post-Arrangement Transactions. As soon as practicable following the Arrangement Effective Time, the Parties shall use reasonable efforts, and shall take such corporate steps and actions, as may be necessary or desirable to effect and implement the following transactions in the order set forth below:

ARTICLE 4

REPRESENTATIONS AND WARRANTIES

Each of the Parties represents and warrants, for itself only, to the other Parties as follows:

4.1    Organization and Qualification. The Party is a corporation, limited liability company or other applicable business entity duly incorporated, organized or formed, as applicable, validly existing and in good standing (or the equivalent thereof, if applicable, in each case, with respect to the jurisdictions that recognize the concept of good standing or any equivalent thereof) under the Laws of its jurisdiction of incorporation, organization or formation, has the requisite corporate, limited liability company or other applicable business entity power and authority to own, lease and operate its properties, and to carry on its businesses as presently conducted, and is in good standing (or the equivalent thereof, if applicable, in each case, with respect to the jurisdictions that recognize the concept of good standing or any equivalent thereof) in each jurisdiction in which such property and assets owned, leased or operated by it, or the nature of the business conducted by it, makes such qualification or licensing necessary.

4.2    Authority. The Party has the requisite corporate, limited liability company or other applicable business entity power and authority to execute and deliver this Agreement and each Transaction Document to which it is (or will be) a party, to perform its obligations under this Agreement and, subject to obtaining the Interim Order, Final Order and Required Approval, to consummate the Redomicile Transactions, and to complete or consummate the Post-Arrangement Matters to which it is a party. Subject to the receipt of the Interim Order, Final Order and Required Approval of the Redomicile Resolution, the execution and delivery of this Agreement, the Transaction Documents to which the Party is (or will be) a party, and the consummation of the Redomicile Transactions and the Post-Arrangement Matters to which it is a party have been duly authorized by all necessary corporate, limited liability company or other applicable business entity action on the part of the Party. This Agreement and each Transaction Document to which the Party is (or will be) a party has been (or will be) duly and validly executed and delivered by that Party.

4.3    No Violations. None of the execution or delivery by the Party of this Agreement or any Transaction Documents to which it is (or will be) a party, the performance by the Party of its obligations under this Agreement or such Transaction Documents, or the consummation of the Redomicile Transactions and the Post-

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Arrangement Matters to which it is a party will, directly or indirectly (with or without due notice or lapse of time or both) (i) result in a breach of any provision of the Party’s Governing Documents, (ii) violate, or constitute a breach under, any Order or applicable Law to which the Party or any of its properties or assets are bound or (iii) result in the creation of any Lien upon any of the assets or properties of the Party.

ARTICLE 5

COVENANTS

5.1    U.S. Tax Treatment. The Parties intend that, for U.S. federal income tax purposes, the Parent Share Exchange and, if applicable, the Canadian Share Exchange and assumption of Zymeworks Warrants, viewed together, will constitute an exchange governed by Section 351 of the Code (the “Intended U.S. Tax Treatment”). Alternatively, the Parent Share Exchange and, if applicable, the Canadian Share Exchange and assumption of Zymeworks Warrants, viewed together, are intended to constitute a “reorganization” within the meaning of Section 368(a) of the Code, and the Parties are hereby adopting this Agreement as a “plan of reorganization” for purposes of Section 368 of the Code and U.S. Treasury Regulations Section 1.368-2(g). No Party will intentionally do any act or thing that could reasonably be expected to prevent the relevant Redomicile Transactions from qualifying for the Intended U.S. Tax Treatment.

5.2    Section 85 Elections. Each beneficial owner of Zymeworks Common Shares who is an Eligible Holder and who has validly elected (or for whom the registered holder has validly elected on such beneficial owner’s behalf) to receive Exchangeable Shares shall be entitled to make an income tax election pursuant to subsection 85(1) of the Tax Act, or subsection 85(2) of the Tax Act if such beneficial owner is a partnership (and in each case, where applicable, the analogous provisions of provincial income tax Law), with respect to the transfer of its Zymeworks Common Shares to ExchangeCo and the receipt of Exchangeable Shares (or Exchangeable Shares and Delaware Common Stock, as applicable) in respect thereof, subject to and in accordance with the Plan of Arrangement.

5.3    Preparation of Registration Statement. As soon as reasonably practicable following the date of this Agreement, Parent and Zymeworks shall prepare and mutually agree upon, and Parent shall file with the SEC the Registration Statement. Each of Parent and Zymeworks shall use reasonable efforts to (i) cause the Registration Statement to comply in all material respects with the applicable rules and regulations promulgated by the SEC; (ii) have the Registration Statement declared effective under the U.S. Securities Act as soon as reasonably practicable after it is filed with the SEC; and (iii) keep the Registration Statement effective through the Arrangement Effective Time in order to permit the consummation of the Redomicile Transactions.

5.4    Transaction Documents. The Parties shall, at or before the Arrangement Effective Time, execute and deliver the Transaction Documents to which they are a party, and take such other actions as are necessary to give effect to the Arrangement and the Redomicile Transactions.

5.5    Post-Arrangement Matters. Following the completion of the Arrangement, the Parties shall execute and deliver such agreements, instruments, certificates and other documents, and take such other actions and do all such other things as are necessary, desirable or useful to complete, implement and give effect to the Post-Arrangement Matters referred to in Article 3.

ARTICLE 6

CONDITIONS TO CONSUMMATION OF THE REDOMICILE TRANSACTIONS

6.1    Conditions to the Obligations of the Parties. The obligations of the Parties to consummate the Redomicile Transactions under this Agreement are subject to the satisfaction of, or if permitted by applicable Law waiver by, Zymeworks of the following conditions:

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ARTICLE 7

TERMINATION

7.1    Termination. This Agreement may be terminated and the Arrangement and the Redomicile Transactions may be abandoned at any time prior to the Arrangement Effective Time upon written notice by Zymeworks to the other Parties.

7.2    Effect of Termination. In the event of the termination of this Agreement pursuant to Section 7.1, this entire Agreement shall forthwith become void and of no effect, and there shall be no liability or obligation on the part of any of the Parties in respect of this Agreement, or the termination of the Arrangement and the Redomicile Transactions.

ARTICLE 8

MISCELLANEOUS

8.1    Entire Agreement & Assignment. This Agreement (together with the Transaction Documents, once executed and delivered) constitutes the entire agreement among the Parties with respect to the subject matter hereof and supersedes all other prior agreements and understandings, both written and oral, among the Parties with respect to the subject matter hereof. This Agreement may not be assigned by any Party without the prior written approval of the other Parties. Any attempted assignment of this Agreement not in accordance with the terms of this Section 8.1 shall be void.

8.2    Amendment. This Agreement may be amended or modified only by a written agreement executed and delivered by each of the Parties. This Agreement may not be modified or amended except as provided in the immediately preceding sentence and any purported amendment by any Party or Parties effected in a manner which does not comply with this Section 8.2 shall be of no effect.

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8.3    Notices. All notices, requests, claims, demands and other communications under this Agreement shall be in writing and shall be given (and shall be deemed to have been duly given) by delivery in person, by email or by courier to the other Parties as follows:

114 East 4th Avenue, Suite 800

Vancouver, BC, V5T 1G4

Attn: Legal Department

108 Patriot Drive, Suite A

Middletown, DE 19709

with a copy to:

114 East 4th Avenue, Suite 800

Vancouver, BC, V5T 1G4

Attn: Legal Department

114 East 4th Avenue, Suite 800

Vancouver, BC, V5T 1G4

Attn: Legal Department

or to such other address as the Party to whom notice is given may have previously furnished to the others in writing in the manner set forth above.

8.4    Severability. Whenever possible, each provision of this Agreement will be interpreted in such a manner as to be effective and valid under applicable Law, but if any term or other provision of this Agreement is held to be invalid, illegal or unenforceable under applicable Law, all other provisions of this Agreement shall remain in full force and effect so long as the economic or legal substance of the Redomicile Transactions is not affected in any manner materially adverse to any Party. Upon such determination that any term or other provision of this Agreement is invalid, illegal or unenforceable under applicable Law, the Parties shall negotiate in good faith to modify this Agreement so as to effect the original intent of the Parties as closely as possible in an acceptable manner in order that the Redomicile Transactions are consummated as originally contemplated to the greatest extent possible.

8.5    Counterparts & Electronic Signatures. This Agreement may be executed in counterparts, each of which will be deemed to be an original and all of which taken together will be deemed to constitute one and the same instrument. To evidence its execution of an original counterpart of this Agreement, a Party may send a copy of its original signature on the execution page of this Agreement to the other Parties by electronic mail or fax and transmission by electronic mail or fax will constitute delivery of an executed copy of this Agreement to the receiving Party. This Agreement will be valid, binding and enforceable against a Party only when one copy of it has been executed by an authorised individual on behalf of the Party by means of: (i) a DocuSign^® or other electronic signature; (ii) an original, manual signature; or (iii) a faxed, scanned or photocopied manual signature, and (iv) each DocuSign^® or other electronic, faxed, scanned or photocopied manual signature shall for all purposes have the same validity, legal effect and admissibility in evidence as an original manual signature and the Parties hereby waive any objection to the contrary.

[Remainder of page intentionally left blank]

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IN WITNESS WHEREOF, each of the Parties has caused this Transaction Agreement to be duly executed on its behalf as of the day and year first above written.

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EXHIBIT A

PLAN OF ARRANGEMENT

Under Section 288 of the Business Corporations Act (British Columbia)

concerning

Zymeworks Inc.

ARTICLE 1

INTERPRETATION

For the purposes of this Plan of Arrangement, the following terms have the respective meanings set forth below, and any derivatives of the following terms have a corresponding meaning:

“Affected Person” has the meaning set forth in Section 4.5(a) (Withholding Rights).

“Affiliate” means, with respect to any Person, any other Person who, directly or indirectly, controls, is controlled by, or is under common control with, such Person. For purposes of this definition, the term “control” (including the correlative terms “controlling”, “controlled by” and “under common control with”) means the possession, directly or indirectly, of the power to direct or cause the direction of the management and policies of a Person, whether through the ownership of voting securities, by contract or otherwise. For purposes of this Plan of Arrangement, “Affiliate”, with respect to Zymeworks, Parent, ExchangeCo or CallCo, does not include any stockholders of Parent (other than Zymeworks), or any directors or executive officers of Zymeworks, Parent, ExchangeCo or CallCo.

“Arrangement” means an arrangement under Part 9, Division 5 of the BCBCA on the terms and subject to the conditions set forth in this Plan of Arrangement, subject to any amendments or variations to this Plan of Arrangement made in accordance with the terms of the Transaction Agreement and this Plan of Arrangement, or made at the direction of the Court in accordance with the Final Order with the prior written consent of Zymeworks.

“Arrangement Effective Time” or “Effective Time” means the time at which the Arrangement becomes effective on the Effective Date, as determined by Zymeworks under Section 2.1 of the Transaction Agreement.

“BCBCA” means the Business Corporations Act (British Columbia).

“Broker” has the meaning set forth in Section 4.5(b)(i) (Withholding Rights).

“Business Day” means a day on which banks are generally open for the transaction of commercial business in Vancouver, British Columbia, and New York, New York, but does not in any event include a Saturday or Sunday or statutory holiday in Vancouver, British Columbia, or New York, New York.

“CallCo” means Zymeworks CallCo ULC, a British Columbia unlimited liability company and a direct, wholly-owned subsidiary of Parent.

“Canadian Share Exchange” means the exchange of Zymeworks Common Shares for Exchangeable Shares, or for a combination of Exchangeable Shares and Delaware Common Stock, in accordance with Section 3.1(c) (Electing Zymeworks Common Shares) and Section 3.1(d) (Exchangeable Share Exchange Cap).

“Code” means the U.S. Internal Revenue Code of 1986, as amended.

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“Consideration” means (i) in the case of a Zymeworks Shareholder who is an Eligible Holder and who validly elects to receive Exchangeable Shares prior to the Election Deadline (as defined in the Plan of Arrangement) in accordance with the Plan of Arrangement, for each Designated Zymeworks Common Share, one Exchangeable Share together with the Contractual Rights, and for each other Zymeworks Common Share (to the extent applicable), one share of Delaware Common Stock, and (ii) in the case of each other Zymeworks Shareholder who does not exercise the Dissent Rights, for each Zymeworks Common Share, one share of Delaware Common Stock.

“Consideration Shares” means Delaware Common Stock and Exchangeable Shares, as the context may require.

“Contractual Rights” has the meaning set forth in Section 3.1(c) (Electing Zymeworks Common Shares).

“Court” means the Supreme Court of British Columbia.

“Delaware Common Stock” means the shares of Parent’s common stock, par value US$0.00001 per share.

“Depositary” means a bank or trust company selected by Zymeworks to perform the duties described in a depositary agreement in form and substance reasonably acceptable to the parties thereto.

“Designated Zymeworks Common Shares” means the Zymeworks Common Shares of an Eligible Holder that are designated by the Eligible Holder under a Letter of Transmittal and Election Form to be exchanged for Exchangeable Shares, as such number of Zymeworks Common Shares may be reduced as a result of the Exchangeable Share Cap, and “Designated Zymeworks Common Share” means any one of them.

“Dissent Rights” has the meaning set forth in Section 5.1 (Rights of Dissent).

“Dissenting Common Shares” has the meaning set forth in Section 3.1(a) (Dissenting Shareholders).

“Dissenting Shareholder” means any registered Zymeworks Shareholder as of the record date for the Special Meeting who has duly and validly exercised their Dissent Rights in respect of all Zymeworks Common Shares held by that Zymeworks Shareholder, and has not withdrawn or been deemed to have withdrawn such Dissent Rights.

“Effective Date” means the effective date of the Arrangement, as determined by Zymeworks under Section 2.1 of the Transaction Agreement.

“Election Deadline” means 5:00 p.m. (Vancouver time) on the date before the Special Meeting.

“Eligible Holder” means a Zymeworks Shareholder that is: (i) a resident of Canada for purposes of the Tax Act and not exempt from tax under Part I of the Tax Act; or (ii) a partnership, each member of which is a resident of Canada for purposes of the Tax Act and not exempt from tax under Part I of the Tax Act.

“Exchangeable Share Cap” means, in respect of the number of Zymeworks Common Shares exchangeable for Exchangeable Shares under the Canadian Share Exchange, such number of Zymeworks Common Shares that is equal to 18% of (i) the number of Zymeworks Common Shares issued and outstanding immediately prior to the Arrangement Effective Time, less (ii) the number of Zymeworks Common Shares held by any Zymeworks Shareholders who exercise their Dissent Rights.

“Exchangeable Share Document” means (i) a share certificate representing Exchangeable Shares, (ii) a non-transferable acknowledgement of a shareholder’s right to obtain a share certificate representing Exchangeable Shares, or (iii) a direct registration system advice (or similar document) evidencing the electronic registration of the ownership of Exchangeable Shares, as applicable.

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“Exchangeable Share Provisions” means the rights, privileges, restrictions and conditions attaching to the Exchangeable Shares as set forth in the articles of ExchangeCo, and in the form attached to the Transaction Agreement as Exhibit E.

“Exchangeable Shares” means the exchangeable shares in the capital of ExchangeCo.

“ExchangeCo” means Zymeworks ExchangeCo Ltd., a British Columbia company and a direct, wholly-owned subsidiary of CallCo.

“Final Order” means the final order of the Court, as contemplated by Section 2.6 of the Transaction Agreement and made pursuant to Section 291 of the BCBCA approving the Arrangement, in a form acceptable to Zymeworks, as such order may be amended by the Court at any time prior to the Arrangement Effective Time, provided that any such amendment is acceptable to Zymeworks, or if appealed, then, unless such appeal is withdrawn, abandoned or denied, as affirmed or as amended, on appeal, provided that any such amendment is acceptable to Zymeworks.

“Governmental Entity” means any United States, Canadian, international or other (i) federal, state, provincial, local, municipal or other government entity, (ii) governmental or quasi-governmental entity of any nature (including any governmental agency, branch, department, official, or entity and any court or other tribunal) or (iii) body exercising or entitled to exercise any administrative, executive, judicial, legislative, police, regulatory, or taxing authority or power of any nature, including any arbitrator or arbitral tribunal (public or private).

“Holders”, when used with reference to (i) the Zymeworks Common Shares, means the holders thereof shown from time to time in the central securities registers of Zymeworks maintained by or on behalf of Zymeworks and, where the context so provides, includes joint holders of such Zymeworks Common Shares, (ii) the Zymeworks Incentive Awards, means the holders thereof shown from time to time in the register or other similar records maintained by or on behalf of Zymeworks in respect of Zymeworks Incentive Awards, and (iii) the Zymeworks Warrants, means the holders thereof shown from time to time in the register or other similar records maintained by or on behalf of Zymeworks in respect of Zymeworks Warrants.

“Information Circular” means the notice of the Special Meeting to be sent to the Zymeworks Securityholders, and the accompanying proxy statement/prospectus to be prepared in connection with the Special Meeting, together with any amendments thereto or supplements thereof in accordance with the terms of the Transaction Agreement.

“Interim Order” means the interim order of the Court as contemplated by Section 2.2 of the Transaction Agreement and made pursuant to Section 291 of the BCBCA, in a form acceptable to Zymeworks providing for, among other things, the calling and holding of the Special Meeting, as the same may be amended by the Court, provided that any such amendment is acceptable to Zymeworks.

“Law” means any federal, state, local, provincial, foreign, national or supranational statute, law (including common law), act, statute, ordinance, treaty, rule, code, regulation or other binding directive or guidance issued, promulgated or enforced by a Governmental Entity having jurisdiction over a given matter.

“Letter of Transmittal and Election Form” means the letter of transmittal and election form(s) for use by registered Zymeworks Shareholders, in the form accompanying the Information Circular or in any other form acceptable to Zymeworks, providing for, among other things, the Eligible Holder’s election with respect to the Consideration (and setting forth the number of Designated Zymeworks Common Shares, which number may be less than the number of Zymeworks Common Shares held by that Eligible Holder), and which shall specify that delivery shall be effected, and risk of loss and title to the applicable Zymeworks Common Shares shall pass, only upon proper delivery of such certificates or other documents to the Depositary and which shall be in such form and have such other customary provisions as Zymeworks may specify (or, if such Zymeworks Common Shares

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are held in book-entry or other uncertificated form, upon the entry through a book-entry transfer agent of the surrender of such Zymeworks Common Shares on a book-entry account statement, it being understood that any reference herein to “certificates” shall be deemed to include references to book-entry account statements relating to the ownership of Zymeworks Common Shares).

“Lien” includes any mortgage, pledge, assignment, charge, lien, security interest, adverse interest in property, license or sub-license, charge, or other third-party interest or encumbrance of any kind (including, in the case of any equity securities, any voting, transfer or similar restrictions) whether contingent or absolute, and any agreement, option, right or privilege (whether by law, contract or otherwise) capable of becoming any of the foregoing.

“Non-Electing Zymeworks Common Shares” has the meaning set forth in Section 3.1(b) (Non-Electing Zymeworks Common Shares).

“Other Withholding Agent” has the meaning set forth in Section 4.5(a) (Withholding Rights).

“Parent” means Zymeworks Delaware Inc., a Delaware corporation and a direct, wholly-owned subsidiary of Zymeworks.

“Parent Incentive Awards” means the stock options, incentive stock options, restricted stock units, stock purchase rights, and all other awards and rights to purchase Delaware Common Stock to be assumed pursuant to the Parent Incentive Plans pursuant to the Arrangement in full and complete exchange and substitution for the Zymeworks Incentive Awards, and “Parent Incentive Award” means any one of them, as applicable.

“Parent Incentive Plans” means collectively (i) the Amended and Restated Stock Option and Equity Compensation Plan of Parent, (ii) the Amended and Restated Employee Stock Purchase Plan of Parent, (iii) the Inducement Stock Option and Equity Compensation Plan of Parent, and (iv) the Second Amended and Restated Employee Stock Option Plan of Parent, in each case including any schedules or appendices thereto, as assumed by Parent under this Plan of Arrangement, as amended from time to time, and “Parent Incentive Plan” means any one of them, as applicable.

“Person” includes an individual, partnership, corporation, limited liability company, joint stock company, unincorporated organization or association, trust, joint venture, trustee, executor, administrator, legal representative, government or any other entity, whether or not a legal entity.

“Plan of Arrangement”, “hereof”, “herein”, “hereunder”, and similar expressions refer to this plan of arrangement and not to any particular Article, Section or other portion hereof and includes any agreement or instrument supplementary or ancillary hereto.

“Redomicile Resolution” means a special resolution of the Zymeworks Securityholders in respect of the Arrangement to be considered at the Special Meeting, in substantially the form attached to the Transaction Agreement as Exhibit B.

“Share Trustee” means a trustee chosen by Zymeworks to act as trustee under the Voting and Exchange Trust Agreement and any successor trustee appointed under the Voting and Exchange Trust Agreement.

“Special Meeting” means the meeting of the Zymeworks Securityholders, including any adjournment or postponement thereof in accordance with the terms of the Transaction Agreement, that is to be convened as provided by the Interim Order to consider, and if deemed advisable approve, the Redomicile Resolution, and such other matters as are properly brought before Zymeworks Securityholders or Zymeworks Shareholders at such meeting.

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“Special Voting Stock” means the share of preferred stock of Parent, issued by Parent to and deposited with the Share Trustee, which, at any time, entitles the holder of record to that number of votes at meetings of holders of Parent shares equal to the number of Exchangeable Shares outstanding as of the record date for such meeting (excluding Exchangeable Shares held by Parent, CallCo and their Affiliates) multiplied by the Exchangeable Share Exchange Ratio (as defined in the Exchangeable Share Provisions), rounded down to the nearest whole vote.

“Support Agreement” means an agreement to be made among Parent, CallCo and ExchangeCo on the Effective Date and in connection with this Plan of Arrangement, in substantially the form attached to the Transaction Agreement as Exhibit C, as the same may be amended, supplemented or otherwise modified from time to time in accordance with the terms thereof.

“Tax” has the meaning set forth in the Transaction Agreement.

“Tax Act” means the Income Tax Act (Canada) and the regulations promulgated thereunder.

“Transaction Agreement” means the Transaction Agreement dated July 14, 2022 by and among Parent, Zymeworks, CallCo and ExchangeCo as the same may be amended, modified or supplemented from time to time in accordance therewith, prior to the Arrangement Effective Time, providing for, among other things, the Arrangement.

“Voting and Exchange Trust Agreement” means an agreement to be made between Parent, ExchangeCo, CallCo and the Share Trustee in connection with this Plan of Arrangement, in substantially the form attached to the Transaction Agreement as Exhibit D, as the same may be amended, supplemented or otherwise modified from time to time in accordance with the terms thereof.

“Withholding Obligation” has the meaning set forth in Section 4.5(a) (Withholding Rights).

“Zymeworks” means Zymeworks Inc., a company existing under the BCBCA.

“Zymeworks Common Shares” means the common shares in the capital of Zymeworks.

“Zymeworks Incentive Awards” means the stock options, incentive stock options, restricted stock units, stock purchase rights, and all other awards and rights to purchase Zymeworks Common Shares granted under the Zymeworks Incentive Plans that are outstanding and unexercised, whether vested or unvested.

“Zymeworks Incentive Plans” means collectively (i) the Amended and Restated Stock Option and Equity Compensation Plan of Zymeworks, (ii) the Amended and Restated Employee Stock Purchase Plan of Zymeworks, (iii) the Inducement Stock Option and Equity Compensation Plan of Zymeworks, and (iv) the Second Amended and Restated Employee Stock Option Plan of Zymeworks, in each case including any schedules or appendices thereto, as amended from time to time, and “Zymeworks Incentive Plan” means any one of them, as applicable.

“Zymeworks Securityholders” means Holders of Zymeworks Common Shares, Zymeworks Incentive Awards and Zymeworks Warrants.

“Zymeworks Shareholders” means Holders of Zymeworks Common Shares as of any determination time prior to the Arrangement Effective Time.

“Zymeworks Warrants” means, as of any determination time, each pre-funded warrant to purchase Zymeworks Common Shares that is outstanding and unexercised.

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The division of this Plan of Arrangement into Articles and Sections and the insertion of headings are for convenience of reference only and do not affect the construction or interpretation of this Plan of Arrangement. Unless otherwise specified, references to Articles and Sections are to Articles and Sections of this Plan of Arrangement.

Unless otherwise specified, time periods within, or following, which any payment is to be made, or act is to be done, shall be calculated by excluding the day on which the period commences and including the day on which the period ends and by extending the period to the next Business Day following if the last day of the period is not a Business Day.

All sums of money which are referred to in this Plan of Arrangement are expressed in the lawful currency of the United States unless otherwise specified.

Unless otherwise indicated, all times expressed in this Plan of Arrangement or in any Letter of Transmittal and Election Form are to local time, Vancouver, British Columbia.

In this Plan of Arrangement:

This Plan of Arrangement shall be governed by and construed in accordance with the BCBCA, and the Laws of the Province of British Columbia and other federal Laws of Canada applicable in British Columbia.

ARTICLE 2

PURPOSE AND EFFECT OF THE PLAN OF ARRANGEMENT

This Plan of Arrangement is made pursuant to, is subject to the provisions of and forms part of, the Transaction Agreement, except in respect of the sequence of the steps comprising the Arrangement, which shall occur in the order set out in this Plan of Arrangement.

This Plan of Arrangement and the Arrangement shall become effective, and shall be binding, at and after the times referred to in Section 3.1 (Arrangement) on: (i) Zymeworks, (ii) Parent, (iii) ExchangeCo, (iv) CallCo,

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(v) all Zymeworks Securityholders (including Dissenting Shareholders), (vi) all holders of Exchangeable Shares, (vii) the Depositary, (viii) the Share Trustee, and (ix) all other Persons, in each case without any further authorization, act or formality on the part of the Court or any Person from and after the Arrangement Effective Time.

ARTICLE 3

THE ARRANGEMENT

Commencing immediately following the Arrangement Effective Time, pursuant to the Arrangement, the following transactions shall occur and shall be deemed to occur in the order in which they appear without any further act or formality, effective as at five (5) minute intervals (and in each case, unless otherwise specified) starting at the Arrangement Effective Time:

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(A/B) x C, where:

and for greater certainty, the number of outstanding Zymeworks Common Shares held by each such Eligible Holder and specified as Designated Zymeworks Common Shares in the Letter of Transmittal and Election Form of such Eligible Holder that are not exchanged for Exchangeable Shares as a result of the application of the Exchangeable Share Cap under this provision shall be exchanged for Delaware Common Stock under Section 3.1(c) (Electing Zymeworks Common Shares);

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With respect to the transfer and assignment of Zymeworks Common Shares pursuant to Section 3.1(c) (Electing Zymeworks Common Shares):

Each beneficial owner of Zymeworks Common Shares who is an Eligible Holder, and who has validly elected (or for whom the registered holder has validly elected on such beneficial owner’s behalf) to receive Exchangeable Shares shall be entitled to make an income tax election pursuant to subsection 85(1) of the Tax Act, or subsection 85(2) of the Tax Act if such beneficial owner is a partnership (and in each case, where applicable, the analogous provisions of provincial income tax Law), with respect to the transfer of the Eligible Holder’s Zymeworks Common Shares to ExchangeCo and the receipt of Consideration in respect thereof by providing two signed copies of the necessary prescribed election form(s) (or equivalent information through an alternative document or platform, at ExchangeCo’s discretion) to the Depositary within sixty (60) days following the Effective Date, duly completed with the details of the number of Zymeworks Common Shares transferred and the applicable agreed amounts for the purposes of such elections. Thereafter, subject to the election forms being correct and complete and complying with the provisions of the Tax Act (and applicable provincial income tax Law), the forms shall be signed by ExchangeCo and returned to such former Eligible Holder of Zymeworks Common Shares within sixty

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(60) days after the receipt thereof by the Depositary for filing with the Canada Revenue Agency (or the applicable provincial taxing authority) by such former Eligible Holder. ExchangeCo shall not be responsible for the proper completion of any election form and, except for ExchangeCo’s obligation to return (within sixty (60) days after the receipt thereof by the Depositary) duly completed election forms which are received by the Depositary within sixty (60) days of the Effective Date, ExchangeCo shall not be responsible for any Taxes, interest or penalties resulting from the failure by a former Eligible Holder of Zymeworks Common Shares to properly complete or file the election forms in the form and manner and within the time prescribed by the Tax Act (or any applicable provincial legislation).

No fractional Consideration Shares, or any certificates, scrip, electronic record or book entry representing fractional Consideration Shares shall be issued to any Person under the Arrangement, and any such fractional share interests shall not entitle the owner thereof to the rights of a stockholder of Parent or a shareholder of ExchangeCo, as applicable. Any fractional Consideration Shares to be issued in connection with the Arrangement shall be rounded down to the nearest whole number of Consideration Shares, and no payment or other adjustment shall be made with respect to the fractional interest so disregarded.

ARTICLE 4

DELIVERY OF CONSIDERATION

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In the event any physical share certificate which immediately prior to the Arrangement Effective Time represented one or more outstanding Zymeworks Common Shares that were transferred pursuant to Section 3.1 (Arrangement) is lost, stolen or destroyed, upon the making of an affidavit of that fact by the Person claiming such certificate to be lost, stolen or destroyed, the Depositary shall issue in exchange for such lost, stolen or

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destroyed certificate, the Consideration that such Holder has the right to receive in accordance with Section 3.1 (Arrangement), deliverable in accordance with such Holder’s Letter of Transmittal and Election Form. When authorizing such exchange for any lost, stolen or destroyed physical share certificate, the Person to whom such Consideration is to be delivered shall, as a condition precedent to the delivery of such Consideration, give a bond satisfactory to ExchangeCo, Parent, Zymeworks and the Depositary (each acting reasonably) or otherwise indemnify ExchangeCo, Parent, Zymeworks and their respective Affiliates in a manner satisfactory to ExchangeCo, Parent and Zymeworks (each acting reasonably) against any claim that may be made against ExchangeCo, Parent, Zymeworks or their respective Affiliates with respect to the physical share certificate alleged to have been lost, stolen or destroyed.

Any certificate (or, if such Zymeworks Common Shares are held in book-entry or other uncertificated form, upon the entry through a book-entry transfer agent of the surrender of such Zymeworks Common Shares on a book-entry account statement, it being understood that any reference herein to “certificates” shall be deemed to include references to book-entry account statements relating to the ownership of Zymeworks Common Shares) which immediately prior to the Arrangement Effective Time represented outstanding Zymeworks Common Shares that were transferred pursuant to Section 3.1 (Arrangement), and not duly surrendered, with all other instruments required by Section 4.1 (Delivery of Consideration), on or prior to the third (3^rd) anniversary of the Effective Date shall cease to represent a claim or interest of any former Zymeworks Shareholder of any kind or nature against Parent, CallCo, ExchangeCo, Zymeworks or any of their respective Affiliates. On such date, all Consideration to which the former Holder of the certificate referred to in the preceding sentence was ultimately entitled shall be deemed to have been surrendered for no consideration to Parent or ExchangeCo, as applicable, by the Depositary and the Delaware Common Stock and Exchangeable Shares forming part of the Consideration shall be deemed to be cancelled.

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such number of Delaware Common Stock or Exchangeable Shares (or Delaware Common Stock exchanged therefor) delivered or deliverable to such Affected Person pursuant to this Plan of Arrangement or the Exchangeable Share Provisions as is necessary to produce sale proceeds (after deducting commissions payable to the Broker and other costs and expenses) sufficient to fund any Withholding Obligations. Any Exchangeable Shares to be sold in accordance with this Section 4.5 (Withholding Rights) shall first be exchanged for Delaware Common Stock in accordance with their terms and Delaware Common Stock delivered in respect of such Exchangeable Shares shall be sold. Any such sale of Delaware Common Stock shall be affected on a public market and as soon as practicable following the Effective Date. Each of Parent, ExchangeCo, CallCo, Zymeworks, the Depositary, the Broker or any Other Withholding Agent, as applicable, shall act in a commercially reasonable manner in respect of any Withholding Obligation; however, none of Parent, ExchangeCo, CallCo, Zymeworks, the Depositary, the Broker or any Other Withholding Agent shall have or be deemed to have any fiduciary duty to any stockholder of Parent or Holder of Zymeworks Common Shares (other than any Dissenting Shareholder) and shall not be liable for any loss arising out of any sale of such Delaware Common Stock, including any loss relating to the manner or timing of such sales, the prices at which Delaware Common Stock are sold or otherwise.

Any exchange or transfer of securities pursuant to this Plan of Arrangement shall be free and clear if any and all Liens or other claims of third parties of any kind.

From and after the Arrangement Effective Time: (i) this Plan of Arrangement shall take precedence and priority over any and all securities of Zymeworks issued and outstanding prior to the Arrangement Effective Time, including Zymeworks Common Shares, Zymeworks Incentive Awards and Zymeworks Warrants; (ii) the rights and obligations of the Holders (registered or beneficial) of such securities, Parent, CallCo, ExchangeCo, Zymeworks and their respective Affiliates, the Depositary and any transfer agent or other depositary therefor in relation to this Plan of Arrangement shall be solely as provided for in this Plan of Arrangement; and (iii) all actions, causes of action, claims or proceedings (actual or contingent and whether or not previously asserted) based on or in any way relating to any securities of Zymeworks are deemed to have been settled, compromised, released and determined without liability except as set forth herein and in the Transaction Agreement.

All Consideration Shares issued pursuant to this Plan of Arrangement shall be fully paid and non-assessable, and Parent and ExchangeCo, respectively, shall be deemed to have received the full consideration therefor.

ARTICLE 5

RIGHTS OF DISSENT

Registered Holders of Zymeworks Common Shares as of the record date for the Special Meeting may exercise rights of dissent with respect to such Zymeworks Common Shares (“Dissent Rights”) in connection with the Arrangement pursuant to and in the manner set forth in Sections 237 to 247 of the BCBCA as modified by this Article 5 (Rights of Dissent), as the same may be modified by the Interim Order; provided that, notwithstanding

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Subsection 242(1)(a) of the BCBCA, the written objection to the Redomicile Resolution referred to in Subsection 242(1)(a) of the BCBCA must be received by Zymeworks c/o Blake, Cassels & Graydon LLP, Suite 2600 – 595 Burrard Street, Vancouver, B.C., V7X 1L3, Attention: Sean Boyle and Alexandra Luchenko, not later than 11:00 a.m. (Vancouver Time) on the date that is two (2) Business Days immediately prior to the Special Meeting (or any date to which the Special Meeting may be postponed or adjourned). Dissenting Shareholders who:

ARTICLE 6

AMENDMENTS

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This Plan of Arrangement may be withdrawn prior to the Arrangement Effective Time in accordance with the terms of the Transaction Agreement.

ARTICLE 7

FURTHER ASSURANCES

Notwithstanding that the transactions and events set out in this Plan of Arrangement shall occur and be deemed to occur in the order set out in this Plan of Arrangement without any further authorization, act or formality, each of the parties to the Transaction Agreement shall make, do and execute, or cause to be made, done and executed, all such further acts, deeds, agreements, transfers, assurances, instruments or documents as may reasonably be required by any of them in order to further document or evidence any of the transactions or events set out in this Plan of Arrangement.

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EXHIBIT B

REDOMICILE RESOLUTION

RESOLVED THAT:

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EXHIBIT C

EXCHANGEABLE SHARE SUPPORT AGREEMENT

THIS EXCHANGEABLE SHARE SUPPORT AGREEMENT made as of                     , 2022 among Zymeworks Delaware Inc., a corporation existing under the Laws of the State of Delaware (“Parent”), Zymeworks CallCo ULC, a company existing under the Laws of the Province of British Columbia (“CallCo”), and Zymeworks ExchangeCo Ltd., a company existing under the Laws of the Province of British Columbia (“ExchangeCo”).

RECITALS:

IN CONSIDERATION of the foregoing and the mutual agreements contained in this Agreement and for other good and valuable consideration (the receipt and sufficiency of which are acknowledged), the parties hereby agree as follows:

ARTICLE 1

DEFINITIONS AND INTERPRETATION

1.1    Defined Terms. In this Agreement:

1.2    Interpretation Not Affected by Headings. The division of this Agreement into Articles, Sections, subsections and paragraphs and the insertion of headings are for convenience of reference only and shall not affect in any way the meaning or interpretation of this Agreement. Unless the contrary intention appears, references in this Agreement to an Article, Section, subsection, paragraph or Schedule by number or letter or both refer to the Article, Section, subsection, paragraph or Schedule, respectively, bearing that designation in this Agreement.

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1.3    Number and Gender. In this Agreement, unless the contrary intention appears, words importing the singular include the plural and vice versa, and words importing gender shall include all genders.

1.4    Date of any Action. If the date on which any action is required to be taken under this Agreement by any Person is not a Business Day, such action shall be required to be taken on the next succeeding day which is a Business Day.

1.5    Statutes. Any reference to a statute refers to such statute and all rules and regulations made under it, as it or they may have been or may from time to time be amended or re-enacted, unless stated otherwise.

ARTICLE 2

COVENANTS OF PARENT AND EXCHANGECO

2.1    Covenants Regarding Exchangeable Shares. So long as any Exchangeable Shares not owned by Parent or its Affiliates are outstanding, Parent shall:

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2.2    Segregation of Funds. Parent will cause ExchangeCo to deposit a sufficient amount of funds in a separate account of ExchangeCo and segregate a sufficient amount of such other assets and property as is necessary to enable ExchangeCo to pay or otherwise satisfy its obligations with respect to the applicable dividend, Liquidation Amount, Retraction Price or Redemption Price, in each case once such amounts become payable

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under the terms of this Agreement or the Exchangeable Share Provisions. Once such amounts become payable, Parent will transfer such funds to ExchangeCo (through any intermediary entities) and ExchangeCo will use such funds, assets and property so segregated exclusively for the payment of dividends and the payment or other satisfaction of the Liquidation Amount, the Retraction Price or the Redemption Price, as applicable, net of any corresponding withholding tax obligations and for the remittance of such withholding tax obligations.

2.3    Reservation of Delaware Common Stock. Parent hereby represents, warrants and covenants in favour of ExchangeCo and CallCo that Parent has reserved for issuance and shall, at all times while any Exchangeable Shares are outstanding, keep available, free from pre-emptive and other rights, out of its authorized and unissued capital stock such number of Delaware Common Stock (or other shares or securities into which Delaware Common Stock may be reclassified or changed as contemplated by Section 2.7):

2.4    Notification of Certain Events. In order to assist Parent to comply with its obligations under this Agreement and to permit CallCo to exercise the Liquidation Call Right, the Retraction Call Right, the Change of Law Call Right or the Redemption Call Right, as applicable, ExchangeCo shall notify Parent and CallCo of each of the following events at the time set forth below:

2.5    Delivery of Delaware Common Stock. Upon notice from CallCo or ExchangeCo of any event that requires CallCo or ExchangeCo to deliver or cause to be delivered Delaware Common Stock to any holder of Exchangeable Shares, Parent shall forthwith issue and deliver or cause to be delivered the requisite number of shares of Delaware Common Stock for the benefit of CallCo or ExchangeCo, as appropriate, and CallCo or ExchangeCo, as the case may be, shall forthwith cause to be delivered the requisite number of Delaware Common Stock to be received by or for the benefit of the former holder of the surrendered Exchangeable Shares.

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All such Delaware Common Stock shall be duly authorized and validly issued as fully paid, non-assessable, free of preemptive rights and shall be free and clear of any lien, claim or encumbrance.

2.6    Qualification of Delaware Common Stock.

2.7    Economic Equivalence.

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unless, in each case, ExchangeCo issues or distributes the economic equivalent of such rights, options, warrants, securities, shares, evidences of indebtedness or other assets simultaneously to holders of the Exchangeable Shares or makes an adjustment to the Exchangeable Share Exchange Ratio in accordance with the terms of the Exchangeable Share Provisions; provided, however, that, for greater certainty, the above restrictions shall not apply to any securities issued or distributed by Parent in order to give effect to and to consummate the transactions contemplated by, and in accordance with, the Transaction Agreement and the Plan of Arrangement; provided, further, that the foregoing limitations and restrictions set forth in this Section 2.7(1)(a) shall not apply to actions taken by Parent relating to a Preferred Stock Rights Agreement, as that term is defined in the Exchangeable Share Provisions.

unless, in each case, the same or an economically equivalent change is made simultaneously to, or in the rights of the holders of, the Exchangeable Shares; provided, however, that, for greater certainty, the above restrictions shall not apply to any securities issued or distributed by Parent in order to give effect to and to consummate the transactions contemplated by, and in accordance with the Transaction Agreement and the Plan of Arrangement; provided, further, that the foregoing limitations and restrictions set forth in this Section 2.7(1)(b) shall not apply to actions taken by Parent relating to a Preferred Stock Rights Agreement, as that term is defined in the Exchangeable Share Provisions.

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2.8    Tender Offers. In the event that a tender offer, share exchange offer, issuer bid, take-over bid or similar transaction with respect to Delaware Common Stock (an “Offer”) is proposed by Parent or is proposed to Parent or its shareholders and is recommended by the board of directors of Parent, or is otherwise effected or to be effected with the consent or approval of the board of directors of Parent, and the Exchangeable Shares are not redeemed by ExchangeCo or purchased by CallCo pursuant to the Redemption Call Right, Parent and ExchangeCo will use commercially reasonable efforts to take all such actions and do all such things as are necessary or desirable to enable and permit holders of Exchangeable Shares (other than Parent and its Affiliates) to participate in such Offer to the same extent and on an economically equivalent basis as the holders of Delaware Common Stock, without discrimination. Without limiting the generality of the foregoing, Parent and

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ExchangeCo will use commercially reasonable efforts in good faith to ensure that holders of Exchangeable Shares may participate in each such Offer without being required to retract Exchangeable Shares as against ExchangeCo (or, if so required, to ensure that any such retraction shall be effective only upon, and shall be conditional upon, the closing of such Offer and only to the extent necessary to tender or deposit to the Offer). Nothing in this Agreement shall affect the rights of ExchangeCo to redeem, or CallCo to purchase pursuant to the Redemption Call Right, Exchangeable Shares in the event of a Parent Control Transaction.

2.9    Parent & Affiliates Not to Vote Exchangeable Shares. Each of Parent and CallCo covenants and agrees that it shall appoint and cause to be appointed proxyholders with respect to all Exchangeable Shares held by it and its Affiliates for the sole purpose of attending each meeting of holders of Exchangeable Shares in order to be counted as part of the quorum for each such meeting. Each of Parent and CallCo further covenants and agrees that it shall not, and shall cause its Affiliates not to, exercise any voting rights which may be exercisable by holders of Exchangeable Shares from time to time pursuant to the Exchangeable Share Provisions or pursuant to the provisions of the Business Corporations Act (British Columbia) (or any successor or other corporate statute by which ExchangeCo may in the future be governed) with respect to any Exchangeable Shares held by it or by its Affiliates in respect of any matter considered at any meeting of holders of Exchangeable Shares; provided however, for further clarity, that this Section 2.9 shall not in any way restrict the right of Parent or any of its Affiliates to vote their common shares of ExchangeCo in accordance with the articles of ExchangeCo.

2.10    Ordinary Market Purchases. For greater certainty, nothing contained in this Agreement, including without limitation the obligations of Parent contained in Section 2.8, shall limit the ability of Parent (or any of its Affiliates) to make ordinary market or other voluntary purchases of Delaware Common Stock in accordance with applicable Laws and regulatory or stock exchange requirements.

2.11    Ownership of Outstanding Shares. Without the prior approval of ExchangeCo and the prior approval of the holders of the Exchangeable Shares given in accordance with Section 26.11(b) of the Exchangeable Share Provisions, Parent covenants and agrees in favour of ExchangeCo that, as long as any Exchangeable Shares not owned by Parent or its Affiliates are outstanding, Parent will be and remain the direct or indirect beneficial owner of all issued and outstanding common shares in the capital of ExchangeCo and CallCo. Notwithstanding the foregoing, Parent shall not be in violation of this Section 2.11 if any Person or group of Persons acting jointly or in concert acquires all or substantially all of the assets of Parent or the Delaware Common Stock pursuant to any merger or similar transaction involving Parent pursuant to which Parent is not the surviving corporation.

2.12    Reimbursement by Parent. Parent shall reimburse ExchangeCo for, and indemnify and hold ExchangeCo harmless against, any expense or liability incurred by ExchangeCo with respect to the Exchangeable Shares.

ARTICLE 3

PARENT SUCCESSORS

3.1    Certain Requirements in Respect of Combination, etc. Subject to Section 26.7 of the Exchangeable Share Provisions, and Article 4 with respect to a Parent Control Transaction, so long as any Exchangeable Shares not owned by Parent or its Affiliates are outstanding, Parent shall not enter into any transaction (whether by way of reorganization, consolidation, arrangement, amalgamation, merger, combination, transfer, sale, lease or otherwise) whereby all or substantially all of its undertaking, property and assets would become the property of any other Person or, in the case of an amalgamation or merger or combination, of the continuing corporation resulting therefrom, provided that it may do so if:

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3.2    Vesting of Powers in Successor. Whenever the conditions of Section 3.1 have been duly observed and performed, the parties, if required by Section 3.1, shall execute and deliver the supplemental agreement provided for in Section 3.1(a) and thereupon the Parent Successor and such other Person that may then be the issuer of the Delaware Common Stock shall possess and from time to time may exercise each and every right and power of Parent under this Agreement in the name of Parent or otherwise and any act or proceeding by any provision of this Agreement required to be done or performed by the board of directors of Parent or any officers of Parent may be done and performed with like force and effect by the directors or officers of such Parent Successor.

3.3    Wholly-Owned Subsidiaries. Nothing herein shall be construed as preventing (a) the amalgamation or merger or combination of any wholly-owned direct or indirect subsidiary of Parent (other than ExchangeCo or CallCo) with or into Parent, (b) the winding-up, liquidation or dissolution of any wholly-owned direct or indirect subsidiary of Parent (other than ExchangeCo or CallCo), provided that all of the assets of such subsidiary are transferred to Parent or another wholly-owned direct or indirect subsidiary of Parent, (c) any other distribution of the assets of any wholly-owned direct or indirect subsidiary of Parent (other than ExchangeCo or CallCo) among the shareholders of such subsidiary for the purpose of winding up its affairs, and (d) any such transactions are expressly permitted by this Article 3.

3.4    Successorship Transaction. Notwithstanding the foregoing provisions of this Article 3, in the event of a Parent Control Transaction:

then all references in this Agreement to “Parent” shall thereafter be and be deemed to be references to “Other Corporation” and all references in this Agreement to “Delaware Common Stock” shall thereafter be and be deemed to be references to “Other Shares” (with appropriate adjustments if any, as are required to result in a holder of Exchangeable Shares on the exchange, redemption or retraction of such shares pursuant to the Exchangeable Share Provisions or the exchange of such shares pursuant to the Voting and Exchange Trust Agreement immediately subsequent to the Parent Control Transaction being entitled to receive that number of Other Shares equal to the number of Other Shares such holder of Exchangeable Shares would have received if the exchange, redemption or retraction of such shares pursuant to the Exchangeable Share Provisions, or the exchange of such shares pursuant to the Voting and Exchange Trust Agreement had occurred immediately prior to the Parent Control Transaction and the Parent Control Transaction was completed) but subject to subsequent adjustments to reflect any subsequent changes in the share capital of the issuer of the Other Shares, including

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without limitation, any subdivision, consolidation or reduction of share capital, without any need to amend the terms and conditions of the Exchangeable Shares and without any further action required.

ARTICLE 4

CERTAIN RIGHTS OF PARENT & CALLCO TO ACQUIRE EXCHANGEABLE SHARES

4.1    Liquidation Call Right. The parties hereby acknowledge the rights and obligations of CallCo in respect of the Exchangeable Shares as contained in Section 26.17 of the Exchangeable Share Provisions.

4.2    Redemption Call Right. The parties hereby acknowledge the rights and obligations of CallCo in respect of the Exchangeable Shares as contained in Section 26.18 of the Exchangeable Share Provisions.

4.3    Change of Law Call Right. The parties hereby acknowledge the rights and obligations of CallCo in respect of the Exchangeable Shares as contained in Section 26.19 of the Exchangeable Share Provisions.

4.4    Retraction Call Right. The parties hereby acknowledge the rights and obligations of CallCo in respect of the Exchangeable Shares contained in Section 26.6(b) of the Exchangeable Share Provisions.

ARTICLE 5

GENERAL

5.1    Term. This Agreement shall come into force and be effective as of the date hereof and shall terminate and be of no further force and effect at such time as no Exchangeable Shares (or securities or rights convertible into or exchangeable for or carrying rights to acquire Exchangeable Shares) are held by any Person other than Parent and any of its Affiliates.

5.2    Changes in Capital of Parent & ExchangeCo. Notwithstanding the provisions of Section 5.4, at all times after the occurrence of any event contemplated pursuant to Section 2.7 and Section 2.8 or otherwise, as a result of which either Delaware Common Stock or the Exchangeable Shares or both are in any way changed, this Agreement shall forthwith be amended and modified as necessary in order that it shall apply with full force and effect, mutatis mutandis, to all new securities into which Delaware Common Stock or the Exchangeable Shares or both are so changed and the parties shall execute and deliver an agreement in writing giving effect to and evidencing such necessary amendments and modifications.

5.3    Severability. If any term or other provision of this Agreement is invalid, illegal or incapable of being enforced by any rule or Law, or public policy, all other conditions and provisions of this Agreement shall nevertheless remain in full force and effect so long as the economic or legal substance of the transactions contemplated hereby is not affected in any manner materially adverse to any party. Upon such determination that any term or other provision is invalid, illegal or incapable of being enforced, the parties hereto shall negotiate in good faith to modify this Agreement so as to effect the original intent of the parties as closely as possible in an acceptable manner to the end that the transactions contemplated hereby are fulfilled to the fullest extent possible.

5.4    Amendments, Modifications. Subject to Section 5.2, Section 5.3 and Section 5.5, this Agreement may not be amended or modified except by an agreement in writing executed by Parent, CallCo and ExchangeCo and approved by the holders of the Exchangeable Shares in accordance with Section 26.11(b) of the Exchangeable Share Provisions. No amendment or modification or waiver of any of the provisions of this Agreement otherwise permitted hereunder shall be effective unless made in writing and signed by all of the parties hereto.

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5.5    Ministerial Amendments. Notwithstanding the provisions of Section 5.4, the parties to this Agreement may in writing at any time and from time to time, without the approval of the holders of the Exchangeable Shares, amend or modify this Agreement for the purposes of:

5.6    Meeting to Consider Amendments. ExchangeCo, at the request of Parent, shall call a meeting or meetings of the holders of the Exchangeable Shares for the purpose of considering any proposed amendment or modification requiring approval pursuant to Section 5.4. Any such meeting or meetings shall be called and held in accordance with the articles of ExchangeCo, the Exchangeable Share Provisions and all applicable Laws.

5.7    Enurement. This Agreement shall be binding upon and enure to the benefit of the parties hereto and their respective successors and assigns.

5.8    Notices to Parties. Any notice and other communications required or permitted to be given pursuant to this Agreement shall be sufficiently given if delivered in Person or if sent by facsimile transmission or e-mail (provided such transmission is recorded as being transmitted successfully) to the parties at the following addresses:

108 Patriot Drive, Suite A

Middletown, DE 19709

with a copy to:

114 East 4th Avenue, Suite 800

Vancouver, BC, V5T 1G4

Attn: Legal Department

114 East 4th Avenue, Suite 800

Vancouver, BC, V5T 1G4

Attn: Legal Department

and such notice or other communication shall be deemed to have been given and received (x) if delivered on a Business Day prior to 5:00 p.m. (local time in the place where the notice or other communication is received), on

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the date of delivery, or (y) otherwise, on the next Business Day. Either party may change its address for notice by giving notice to the other parties in accordance with the foregoing provisions.

5.9    Counterparts. This Agreement may be executed in counterparts, each of which shall be deemed an original, and all of which taken together shall constitute one and the same instrument.

5.10    Jurisdiction. This Agreement shall be construed and enforced in accordance with the Laws of the Province of British Columbia and the Laws of Canada applicable therein. Each party hereto irrevocably submits to the exclusive jurisdiction of the courts of the Province of British Columbia with respect to any matter arising hereunder or related hereto.

[Remainder of this page left intentionally blank]

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IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be duly executed as of the date first above written.

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EXHIBIT D

VOTING AND EXCHANGE TRUST AGREEMENT

THIS VOTING AND EXCHANGE TRUST AGREEMENT (as it may be amended from time to time, the “Agreement”) made as of                     , 2022 among Zymeworks Delaware Inc., a corporation existing under the laws of the State of Delaware (“Parent”), Zymeworks CallCo ULC, an unlimited liability company existing under the laws of the Province of British Columbia (“CallCo”), Zymeworks ExchangeCo Ltd., a company existing under the laws of the Province of British Columbia (“ExchangeCo”), and Computershare Trust Company of Canada, a trust company existing under the laws of Canada (the “Share Trustee”).

RECITALS:

IN CONSIDERATION of the foregoing and the mutual agreements contained herein and for other good and valuable consideration (the receipt and sufficiency of which are hereby acknowledged), the parties agree as follows:

ARTICLE 1

DEFINITIONS AND INTERPRETATION

In this Agreement, each capitalized term used and not otherwise defined herein shall have the meaning ascribed thereto in the Exchangeable Share Provisions, and the following terms shall have the following meanings:

“1933 Act” has the meaning ascribed thereto in Section 5.10;

“Agreement” has the meaning ascribed thereto in the introductory paragraph;

“Affected Person” has the meaning ascribed thereto in Section 5.13(1);

“Affiliate” means, with respect to any person, any other person who, directly or indirectly, controls, is controlled by, or is under common control with, such person. For purposes of this definition, the term “control” (including the correlative terms “controlling”, “controlled by” and “under common control with”) means the possession, directly or indirectly, of the power to direct or cause the direction of the management and policies of a person, whether through the ownership of voting securities, by contract or otherwise. For purposes of this Agreement, “Affiliate” does not include any stockholders of Parent (other than Zymeworks), or directors or executive officers of Zymeworks, Parent, ExchangeCo or CallCo;

“Automatic Exchange Right” has the meaning ascribed thereto in Section 5.12(2);

“Beneficiaries” means the registered holders from time to time of Exchangeable Shares, other than Parent, CallCo and their Affiliates;

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“Beneficiary Votes” has the meaning ascribed thereto in Section 4.2;

“Broker” has the meaning ascribed thereto in Section 5.13(2)(a);

“CallCo” has the meaning ascribed thereto in the introductory paragraph;

“Electronic Methods” has the meaning ascribed thereto in Section 13.8;

“Equivalent Vote Amount” means, with respect to any matter, proposition, proposal or question on which holders of Delaware Common Stock are entitled to vote, consent or otherwise act, the number of votes to which a holder of one Delaware Common Stock is entitled with respect to such matter, proposition or question;

“Exchange Right” has the meaning ascribed thereto in Section 5.1;

“Exchangeable Share Consideration” has the meaning ascribed thereto in the Exchangeable Share Provisions;

“Exchangeable Share Document” means (i) a share certificate representing Exchangeable Shares, (ii) a non-transferable acknowledgement of a shareholder’s right to obtain a share certificate representing Exchangeable Shares, or (iii) a direct registration system advice (or similar document) evidencing the electronic registration of the ownership of Exchangeable Shares, as applicable;

“Exchangeable Share Exchange Price” has the meaning ascribed thereto in the Exchangeable Share Provisions;

“Exchangeable Share Exchange Ratio” has the meaning ascribed thereto in the Exchangeable Share Provisions;

“Exchangeable Share Provisions” means the rights, privileges, restrictions and conditions attaching to the Exchangeable Shares as set out in the Articles of ExchangeCo, as they may be amended from time to time, a copy of which is attached as Exhibit A, and is current as if the date of this Agreement;

“Exchangeable Shares” has the meaning ascribed thereto in Recital A;

“ExchangeCo” has the meaning ascribed thereto in the introductory paragraph;

“Governmental Entity” means any United States, Canadian, international or other (i) federal, state, provincial, local, municipal or other government entity, (ii) governmental or quasi-governmental entity of any nature (including any governmental agency, branch, department, official, or entity and any court or other tribunal) or (iii) body exercising or entitled to exercise any administrative, executive, judicial, legislative, police, regulatory, or taxing authority or power of any nature, including any arbitrator or arbitral tribunal (public or private);

“Indemnified Parties” has the meaning ascribed thereto in Section 8.1;

“Insolvency Event” means (i) the institution by ExchangeCo of any proceeding to be adjudicated a bankrupt or insolvent or to be dissolved or wound up, or the consent of ExchangeCo to the institution of bankruptcy, insolvency, dissolution or winding-up proceedings against it, (ii) the filing by ExchangeCo of a petition, answer or consent seeking dissolution or winding-up under any bankruptcy, insolvency or analogous laws, including the Companies Creditors’ Arrangement Act (Canada) and the Bankruptcy and Insolvency Act (Canada), or the failure by ExchangeCo to contest in good faith any such proceedings commenced in respect of ExchangeCo within 30 days of becoming aware thereof, or the consent by ExchangeCo to the filing of any such petition or to the appointment of a receiver, (iii) the making by ExchangeCo of a general assignment for the benefit of creditors, or the admission in writing by ExchangeCo of its inability to pay its debts generally as they become due, or (iv) ExchangeCo not being permitted, pursuant to solvency requirements of applicable law, to redeem any Retracted Shares pursuant to Section 26.6(a)(iii) of the Exchangeable Share Provisions specified in a retraction request delivered to ExchangeCo in accordance with Section 26.6 of the Exchangeable Share Provisions;

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“Liquidation Event” has the meaning ascribed thereto in Section 5.12(1)(a);

“Liquidation Event Effective Date” has the meaning ascribed thereto in Section 5.12(2);

“List” has the meaning ascribed thereto in Section 4.6;

“Officer’s Certificate” means, with respect to Parent, CallCo or ExchangeCo, a certificate signed by any one of the respective directors or officers of Parent, CallCo or ExchangeCo;

“Other Corporation” has the meaning ascribed thereto in Section 10.4(c);

“Other Shares” has the meaning ascribed thereto in Section 10.4(c);

“Other Withholding Agent” has the meaning ascribed thereto in Section 5.13(1);

“Parent” has the meaning ascribed thereto in the introductory paragraph;

“Parent Consent” has the meaning ascribed thereto in Section 4.2;

“Parent Meeting” has the meaning ascribed thereto in Section 4.2;

“Parent Successor” has the meaning ascribed thereto in Section 10.1(a);

“person” includes an individual, partnership, corporation, limited liability company, joint stock company, unincorporated organization or association, trust, joint venture, trustee, executor, administrator, legal representative, government or any other entity, whether or not a legal entity, as the context requires;

“Privacy Laws” has the meaning ascribed thereto in Section 6.18;

“Redemption Date” has the meaning ascribed thereto in the Exchangeable Share Provisions;

“Registration Statement” has the meaning ascribed thereto in Section 5.10;

“Retracted Shares” has the meaning ascribed thereto in Section 5.7;

“Special Voting Stock” means the share of preferred stock of Parent, issued by Parent to and deposited with the Share Trustee, which, at any time, entitles the holder of record to that number of votes at meetings of holders of Delaware Common Stock equal to the number of Exchangeable Shares outstanding as of the record date for such meeting (excluding Exchangeable Shares held by Parent, CallCo and their Affiliates) multiplied by the Exchangeable Share Exchange Ratio, and in respect of each Beneficiary, rounded down to the nearest whole vote;

“Support Agreement” means the exchangeable share support agreement dated the date hereof between Parent, CallCo and ExchangeCo, substantially in the form of Exhibit C to the Transaction Agreement;

“Transaction Agreement” has the meaning ascribed thereto in Recital A;

“Trust” means the trust created by this Agreement under the laws of the Province of British Columbia;

“Trust Estate” means the Special Voting Stock, any other securities, the Exchange Right, the Automatic Exchange Right and any money or other property which may be held by the Share Trustee from time to time pursuant to this Agreement;

“Share Trustee” has the meaning ascribed thereto in the introductory paragraph;

“Voting Rights” means the voting rights attached to the Special Voting Stock;

“Withholding Obligation” has the meaning ascribed thereto in Section 5.13(1); and

“Zymeworks” has the meaning ascribed thereto in Recital A.

The division of this Agreement into Articles, Sections, subsections and paragraphs and the insertion of headings are for convenience of reference only and shall not affect in any way the meaning or interpretation of this

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Agreement. Unless the contrary intention appears, references in this Agreement to an Article, Section, subsection, paragraph or Schedule by number or letter or both refer to the Article, Section, subsection, paragraph or Schedule, respectively, bearing that designation in this Agreement.

In this Agreement, unless the contrary intention appears, words importing the singular include the plural and vice versa, and words importing gender shall include all genders.

If the date on which any action is required to be taken hereunder by any person is not a Business Day, such action shall be required to be taken on the next succeeding day which is a Business Day.

Unless otherwise stated, all references in this Agreement to sums of money are expressed in lawful money of the United States and “$” refers to United States dollars.

Any reference to a statute refers to such statute and all rules and regulations made under it, as it or they may have been or may from time to time be amended or re-enacted, unless stated otherwise.

The following are the Exhibits attached to and incorporated in this Agreement by reference and deemed to be a part of this Agreement:

ARTICLE 2

PURPOSE OF AGREEMENT

The purpose of this Agreement is to create the Trust for the benefit of the Beneficiaries as herein provided. Parent, as the settlor of the Trust, hereby appoints the Share Trustee as Share Trustee of the Trust and settles upon the Share Trustee the Special Voting Stock and US$1.00. The Share Trustee shall hold the Special Voting Stock in order to enable the Share Trustee to exercise the Voting Rights and shall hold the Exchange Right and the Automatic Exchange Right in order to enable the Share Trustee to exercise or enforce such rights, in each case as Share Trustee for and on behalf of the Beneficiaries as provided in this Agreement.

ARTICLE 3

SPECIAL VOTING STOCK

Immediately following execution and delivery of this Agreement, Parent shall issue to and deposit with the Share Trustee the Special Voting Stock (and shall deliver the certificate or book-entry evidence representing such share to the Share Trustee) to be hereafter held of record by the Share Trustee as Share Trustee for and on behalf of,

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and for the use and benefit of, the Beneficiaries and in accordance with the provisions of this Agreement. Parent hereby acknowledges receipt from the Share Trustee, as Share Trustee for and on behalf of the Beneficiaries, of intangible consideration (and the adequacy thereof) for the issuance of the Special Voting Stock by Parent to the Share Trustee. During the term of the Trust, and subject to the terms and conditions of this Agreement, the Share Trustee shall possess and be vested with full legal ownership of the Special Voting Stock and shall be entitled to exercise all of the rights and powers of an owner with respect to the Special Voting Stock; provided, however, that:

ExchangeCo shall cause each Exchangeable Share Document representing Exchangeable Shares to bear a legend notifying the Beneficiary of such shares of his, her or its right to instruct the Share Trustee with respect to the exercise of that portion of the Voting Rights which corresponds to the number of Exchangeable Shares held by each such Beneficiary.

The certificate or book-entry evidence representing the Special Voting Stock delivered to the Share Trustee shall at all times be held in safe keeping by the Share Trustee or its duly authorized agent.

ARTICLE 4

EXERCISE OF VOTING RIGHTS

The Share Trustee, as the holder of record of the Special Voting Stock, shall be entitled to exercise all of the Voting Rights, including the right to consent to or vote in person or by proxy the Special Voting Stock, on any matter, question, proposal or proposition whatsoever that may properly come before the stockholders of Parent at a Parent Meeting or in connection with a Parent Consent. The Voting Rights shall be and remain vested in and exercisable by the Share Trustee on behalf of the Beneficiaries as provided in this Agreement. Subject to Section 6.15:

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With respect to all meetings of stockholders of Parent at which holders of Delaware Common Stock are entitled to vote (each, a “Parent Meeting”) and with respect to all written consents, if any, sought by Parent from holders of Delaware Common Stock (each, a “Parent Consent”), each Beneficiary shall be entitled to instruct the Share Trustee to cast and exercise, in the manner instructed, that number of votes equal to the Equivalent Vote Amount for each Exchangeable Share owned of record by such Beneficiary at the close of business on the record date established by Parent or by applicable law for such Parent Meeting or Parent Consent, as the case may be, multiplied by the Exchangeable Share Exchange Ratio, and in respect of each Beneficiary, rounded down to the nearest whole vote (collectively, the “Beneficiary Votes”), in respect of each matter, question, proposal or proposition to be voted on at such Parent Meeting or consented to in connection with such Parent Consent.

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Parent shall deliver to the Share Trustee copies of all proxy materials (including, without limitation, notices of Parent Meetings but excluding proxies to vote Delaware Common Stock), proxy statements, reports (including, without limitation, all interim and annual financial statements) and other written communications that, in each case, are required to be distributed by Parent from time to time to holders of Delaware Common Stock in sufficient quantities and in sufficient time so as to enable the Share Trustee to send or cause to send those materials to each Beneficiary at the same time as such materials are first sent to holders of Delaware Common Stock. The Share Trustee shall mail or otherwise send to each Beneficiary, at the expense of Parent, copies of all such materials (and all materials specifically directed to the Beneficiaries or to the Share Trustee for the benefit of the Beneficiaries by Parent) received by the Share Trustee from Parent contemporaneously with the sending of such materials to holders of Delaware Common Stock. The Share Trustee shall also make available for inspection, on an appointment basis, during regular business hours by any Beneficiary at the Share Trustee’s principal office in Vancouver, British Columbia all proxy materials, information statements, reports and other written communications that are:

Notwithstanding the foregoing, Parent may, at its option, exercise the duties of the Share Trustee to deliver copies of all such materials to all Beneficiaries as required by this Section 4.4 so long as, in each case, Parent delivers a certificate to the Share Trustee stating that Parent has undertaken to perform the obligations of the Share Trustee set forth in this Section 4.4.

As soon as reasonably practicable after receipt by Parent or stockholders of Parent (if such receipt is known by Parent) of any material sent or given by or on behalf of a third party to holders of Delaware Common Stock generally, including proxy statements with respect to contested proposals (and related information and material) and tender offers and exchange offers (and related information and material), provided such material has not been sent to the Beneficiaries by or on behalf of such third party, Parent shall use its reasonable efforts to obtain

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and deliver to the Share Trustee copies thereof in sufficient quantities so as to enable the Share Trustee to forward such material (unless the same has been provided directly to Beneficiaries by such third party) to each Beneficiary as soon as possible thereafter. As soon as reasonably practicable after receipt thereof, the Share Trustee shall mail or otherwise send to each Beneficiary, at the expense of Parent, copies of all such materials received by the Share Trustee from Parent. The Share Trustee shall also make available for inspection, on an appointment basis, during regular business hours by any Beneficiary at the Share Trustee’s principal office in Vancouver, British Columbia copies of all such materials. Notwithstanding the foregoing, Parent may, at its option, exercise the duties of the Share Trustee to deliver copies of all such materials to all Beneficiaries as required by this Section 4.5 so long as, in each case, Parent delivers a certificate to the Share Trustee stating that Parent has undertaken to perform the obligations of the Share Trustee set forth in this Section 4.5.

ExchangeCo shall (a) prior to each annual meeting of stockholders of Parent or other Parent Meeting or the seeking of any Parent Consent, and (b) forthwith upon each request made at any time by the Share Trustee in writing, prepare or cause to be prepared a list (a “List”) of the names and addresses of the Beneficiaries arranged in alphabetical order and showing the number of Exchangeable Shares (multiplied by the Exchangeable Share Exchange Ratio, and in respect of each Beneficiary, rounded down to the nearest whole share) held of record by each such Beneficiary, in each case at the close of business on the date specified by the Share Trustee in such request or, in the case of a List prepared in connection with a Parent Meeting or Parent Consent, at the close of business on the record date established by Parent or pursuant to applicable law for determining the holders of Delaware Common Stock entitled to receive notice of and/or to vote at such Parent Meeting or to give consent in connection with a Parent Consent. Each such List shall be delivered to the Share Trustee promptly after receipt by ExchangeCo of such request or the record date for such meeting or seeking of consent, as the case may be, and, in any event, within sufficient time as to permit the Share Trustee to perform its obligations under this Agreement. Parent agrees to give ExchangeCo notice (with a copy to the Share Trustee) of the calling of any Parent Meeting or the seeking of any Parent Consent, together with the record date therefor, sufficiently prior to the date of the calling of such meeting or seeking of such consent, so as to enable ExchangeCo to perform its obligations under this Section 4.6.

Subject to Section 4.8 and Section 4.11, any Beneficiary named in a List prepared in connection with any Parent Meeting or Parent Consent shall be entitled to (a) instruct the Share Trustee in the manner described in Sections 4.2 and 4.3 with respect to the exercise of the Beneficiary Votes to which such Beneficiary is entitled, (b) attend such meeting and personally exercise thereat (or to exercise with respect to any written consent), as the proxy of the Share Trustee, the Beneficiary Votes to which such Beneficiary is entitled, or (c) appoint a third party as the proxy of the Share Trustee to attend such meeting and exercise thereat the Beneficiary Votes to which such Beneficiary is entitled except, in each case, to the extent that such Beneficiary has transferred the ownership of any Exchangeable Shares in respect of which such Beneficiary is entitled to Beneficiary Votes after the close of business on the record date for such meeting or seeking of consent.

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Any written materials distributed by the Share Trustee to the Beneficiaries pursuant to this Agreement shall be sent by mail or delivered via electronic transmission in a manner contemplated by Section 232 of the Delaware General Corporation Law (or otherwise communicated in the same manner as Parent utilizes in communications to holders of Delaware Common Stock, including without limitation in accordance with the notice and access rules promulgated by the SEC, subject to applicable regulatory requirements and to the Share Trustee being advised in writing of such manner of communications and provided that such manner of communications is reasonably available to the Share Trustee) to each Beneficiary at its address as shown on the register of holders of Exchangeable Shares maintained by the registrar. In connection with each such distribution, ExchangeCo shall provide or cause to be provided to the Share Trustee for purposes of communication, on a timely basis and without charge or other expense, a current List, and upon the request of the Share Trustee, mailing labels to enable the Share Trustee to carry out its duties under this Agreement. ExchangeCo’s obligations under this Section 4.9 shall be deemed satisfied to the extent Parent exercises its option to perform the duties of the Share Trustee to deliver copies of materials to each Beneficiary and ExchangeCo provides the required information and materials to Parent.

Except as otherwise provided in the Exchangeable Share Provisions, all of the rights of a Beneficiary with respect to the Beneficiary Votes exercisable in respect of the Exchangeable Shares held by such Beneficiary, including the right to instruct the Share Trustee as to the voting of or to vote personally such Beneficiary Votes, shall lapse and be deemed to be surrendered by the Beneficiary to Parent or CallCo, as the case may be, and such Beneficiary Votes and the Voting Rights represented thereby shall cease immediately upon:

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The Share Trustee or ExchangeCo shall be entitled to require any Beneficiary or any person whom the Share Trustee or ExchangeCo, as the case may be, knows or has reasonable cause to believe holds any interest whatsoever in an Exchangeable Share to (a) confirm that fact, or (b) give the Share Trustee or ExchangeCo such details as to whom has an interest in such Exchangeable Share, in each case as would be required (if the Exchangeable Shares were a class of “equity securities” of ExchangeCo) under Section 5.2 of National Instrument 62-104 Take-Over Bids and Issuer Bids or as would be required under the governing documents of Parent or any laws or regulations, or pursuant to the rules or regulations of any regulatory agency, if and only to the extent that the Exchangeable Shares (as multiplied by the Exchangeable Share Exchange Ratio) were Delaware Common Stock. If a Beneficiary does not provide the information required to be provided by such Beneficiary pursuant to this Section 4.11, the board of directors of Parent may take any action permitted under the certificate of incorporation or by-laws of Parent or any laws or regulations, or pursuant to the rules or regulations of any regulatory agency, with respect to the Voting Rights relating to the Exchangeable Shares held by such Beneficiary as if, and only to the extent that, the Exchangeable Shares (as multiplied by the Exchangeable Share Exchange Ratio) were Delaware Common Stock.

ARTICLE 5

EXCHANGE AND AUTOMATIC EXCHANGE

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ExchangeCo shall cause each Exchangeable Share Document to bear a legend notifying the Beneficiary in respect of the Exchangeable Shares represented by such Exchangeable Share Document of (a) his, her or its right to instruct the Share Trustee with respect to the exercise of the Exchange Right in respect of the Exchangeable Shares held by such Beneficiary and (b) the Automatic Exchange Right.

The Exchange Right shall be and remain vested in and exercisable by the Share Trustee. Subject to Section 6.15, the Share Trustee shall exercise the Exchange Right only on the basis of instructions received pursuant to this Article 5 from Beneficiaries entitled to instruct the Share Trustee as to the exercise thereof. To the extent that no instructions are received from any Beneficiary with respect to the Exchange Right, the Share Trustee shall not exercise or permit the exercise of the Exchange Right.

The purchase price payable by Parent or CallCo, as the case may be, for each Exchangeable Share to be purchased by Parent or CallCo, as the case may be, pursuant to the exercise of the Exchange Right shall be an amount per share equal to the Exchangeable Share Price on the last Business Day prior to the day of the closing of the purchase and sale of such Exchangeable Share pursuant to such exercise of the Exchange Right, which price may be satisfied only by Parent or CallCo, as the case may be, delivering or causing to be delivered to the Share Trustee, on behalf of the relevant Beneficiary, the Exchangeable Share Consideration representing such Exchangeable Share Price. In connection with each exercise of the Exchange Right, Parent or CallCo, as the case may be, shall provide to the Share Trustee an Officer’s Certificate setting forth the calculation of the Exchangeable Share Price. Upon payment by Parent or CallCo, as the case may be, of the Exchangeable Share Price, the relevant Beneficiary shall cease to have any right to be paid any amount in respect of declared and unpaid dividends on each such Exchangeable Share by ExchangeCo and ExchangeCo shall cease to be obligated to pay any amount in respect of such dividends.

Subject to the terms and conditions set forth herein, a Beneficiary shall be entitled upon the occurrence and during the continuance of an Insolvency Event, to instruct the Share Trustee to exercise the Exchange Right with respect to all or any part of the Exchangeable Shares registered in the name of such Beneficiary. In order to cause the Share Trustee to exercise the Exchange Right with respect to all or any part of the Exchangeable Shares registered in the name of a Beneficiary, such Beneficiary shall deliver to the Share Trustee, in person or by certified or registered mail, at its principal office in Vancouver, British Columbia or at such other place as the Share Trustee may from time to time designate by written notice to the Beneficiaries, the Exchangeable Share Documents representing the Exchangeable Shares which such Beneficiary desires Parent or CallCo to purchase, duly endorsed in blank for transfer, and accompanied by such other documents and instruments as may be required to effect a transfer of the Exchangeable Shares under the Business Corporations Act (British Columbia), the articles of ExchangeCo and such additional documents and instruments as Parent, ExchangeCo or the Share Trustee may reasonably require together with:

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provided that if only a part of the Exchangeable Shares represented by any Exchangeable Share Documents delivered to the Share Trustee are to be purchased by Parent or CallCo pursuant to the exercise of the Exchange Right, a new Exchangeable Share Document for the balance of such Exchangeable Shares shall be issued to the holder at the expense of ExchangeCo.

Promptly after the receipt by the Share Trustee of the Exchangeable Share Document representing the Exchangeable Shares which a Beneficiary desires Parent or CallCo to purchase pursuant to the exercise of the Exchange Right, together with a notice of exercise and such other documents and instruments specified by Section 5.5, the Share Trustee shall notify Parent, CallCo and ExchangeCo of its receipt of the same, which notice to Parent, CallCo and ExchangeCo shall constitute exercise of the Exchange Right by the Share Trustee on behalf of such Beneficiary in respect of such Exchangeable Shares, and Parent or CallCo, as the case may be, shall promptly thereafter deliver or cause to be delivered to the Share Trustee, for delivery to such Beneficiary (or to such other persons, if any, properly designated by such Beneficiary) the Exchangeable Share Consideration deliverable in connection with such exercise of the Exchange Right; provided, however, that no such delivery shall be made unless and until the Beneficiary requesting the same shall have paid (or provided evidence satisfactory to Parent, CallCo, ExchangeCo and the Share Trustee of the payment of) the taxes (if any) payable as contemplated by Section 5.8 of this Agreement. Immediately upon the giving of notice by the Share Trustee to Parent, CallCo and ExchangeCo of any exercise of the Exchange Right, as provided in this Section 5.6, the closing of the transaction of purchase and sale contemplated by the Exchange Right shall be deemed to have occurred, and the Beneficiary in respect of such Exchangeable Shares shall be deemed to have transferred to Parent or CallCo, as the case may be, all of such Beneficiary’s right, title and interest in and to such Exchangeable Shares and in the related interest in the Trust Estate and shall cease to be a holder of such Exchangeable Shares and shall not be entitled to exercise any of the rights of a holder in respect thereof, other than the right to receive the total Exchangeable Share Consideration in respect of such Exchangeable Shares, unless such Exchangeable Share Consideration is not delivered by Parent or CallCo, as the case may be, to the Share Trustee for delivery to such Beneficiary (or to such other person, if any, properly designated by such Beneficiary) within five Business Days of the date of the giving of such notice by the Share Trustee, in which case the rights of the Beneficiary shall remain unaffected until such Exchangeable Share Consideration is so delivered. Upon delivery of such Exchangeable Share Consideration to the Share Trustee, the Share Trustee shall promptly deliver such Exchangeable Share Consideration to such Beneficiary (or to such other person, if any, properly designated by such Beneficiary). Concurrently with the closing of the transaction of purchase and sale contemplated by such exercise of the Exchange Right, the Beneficiary shall be considered and deemed for all purposes to be the holder of the Delaware Common Stock delivered to it pursuant to such exercise of the Exchange Right.

In the event that a Beneficiary has exercised its retraction right under Section 26.6(a) of the Exchangeable Share Provisions to require ExchangeCo to redeem any or all of the Exchangeable Shares held by the Beneficiary (the “Retracted Shares”) and is notified by ExchangeCo pursuant to Section 26.6(a)(iii) of the Exchangeable Share Provisions that ExchangeCo will not be permitted as a result of solvency requirements of applicable law to redeem all such Retracted Shares, subject to receipt by the Share Trustee of written notice to that effect from ExchangeCo, and provided that CallCo has not exercised its Retraction Call Right with respect to the Retracted Shares and that the Beneficiary shall not have revoked the retraction request delivered by the Beneficiary to ExchangeCo pursuant to Section 26.6(a)(iv) of the Exchangeable Share Provisions, the retraction request will constitute and will be deemed to constitute notice from the Beneficiary to the Share Trustee instructing the Share Trustee to exercise the Exchange Right with respect to those Retracted Shares that ExchangeCo is unable to

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redeem. In any such event, ExchangeCo hereby agrees with the Share Trustee, and in favour of the Beneficiary, promptly to notify the Share Trustee of such prohibition against ExchangeCo and to forward or cause to be forwarded to the Share Trustee all relevant materials delivered by the Beneficiary to ExchangeCo or to the Transfer Agent in connection with such proposed redemption of the Retracted Shares and the Share Trustee will thereupon exercise the Exchange Right with respect to the Retracted Shares that ExchangeCo is not permitted to redeem and will require Parent or, at the option of Parent, CallCo to purchase such shares in accordance with the provisions of this Article 5.

Upon any sale or transfer of Exchangeable Shares to Parent or CallCo pursuant to the exercise of the Exchange Right or the Automatic Exchange Right, the share certificate or certificates or book-entry evidence representing the Delaware Common Stock to be delivered in connection with the payment of the purchase price therefor shall be issued in the name of the Beneficiary in respect of the Exchangeable Shares so sold or transferred or in such names as such Beneficiary may otherwise direct in writing without charge to the holder of the Exchangeable Shares so sold or transferred; provided, however, that such Beneficiary (a) shall pay (and none of Parent, CallCo, ExchangeCo or the Share Trustee shall be required to pay) any documentary, stamp, transfer or other taxes or duties that may be payable in respect of any sale or transfer involved in the issuance or delivery of such shares to a person other than such Beneficiary including, without limitation, in the event that Exchangeable Shares are being delivered, sold or transferred in the name of a clearing service or depositary or a nominee thereof, or (b) shall have evidenced to the satisfaction of Parent, CallCo, ExchangeCo and the Share Trustee that such taxes or duties (if any) have been paid.

As soon as practicable following the occurrence of an Insolvency Event or any event that with the giving of notice or the passage of time or both would be an Insolvency Event, Parent and ExchangeCo shall give written notice thereof to the Share Trustee. As soon as practicable after receiving notice from Parent or ExchangeCo of the occurrence of an Insolvency Event, or upon the Share Trustee otherwise becoming aware of an Insolvency Event, the Share Trustee shall mail to each Beneficiary, at the expense of Parent (such funds to be received in advance), a notice of such Insolvency Event in the form provided by Parent, which notice shall contain a brief statement of the rights of the Beneficiaries with respect to the Exchange Right.

Parent covenants and agrees that it shall use its commercially reasonable efforts to:

Without limiting the generality of the foregoing, Parent and CallCo each covenant and agree that it will take all such actions and do all such things as are reasonably necessary or desirable to make such filings and seek such regulatory consents and approvals as are necessary so that the Delaware Common Stock to be issued or delivered

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to holders of Exchangeable Shares by Parent or CallCo pursuant to the terms of the Exchangeable Share Provisions, the Support Agreement and this Agreement will be offered, sold, issued and delivered in compliance with the 1933 Act and all applicable state securities laws, and applicable securities laws in Canada and will use commercially reasonable efforts to ensure that the Delaware Common Stock will not be subject to any hold period as contemplated by Rule 144 under the 1933 Act or subject to any “hold period” resale restriction under National Instrument 45-102 Resale of Securities. Parent will in good faith expeditiously take all such actions and do all such things as are reasonably necessary or desirable to cause all Delaware Common Stock to be delivered to holders of Exchangeable Shares pursuant to the terms of the Exchangeable Share Provisions, the Support Agreement and this Agreement to be listed, quoted and posted for trading on all stock exchanges and quotation systems on which outstanding Delaware Common Stock have been listed by Parent and remain listed and are quoted or posted for trading at such time.

Parent hereby represents, warrants and covenants that the Delaware Common Stock deliverable as described herein will be duly authorized and validly issued as fully paid and non-assessable and shall be free and clear of any lien, claim or encumbrance.

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such number of shares of Delaware Common Stock or Exchangeable Shares (or shares of Delaware Common Stock exchanged therefor) delivered or deliverable to such Affected Person pursuant to this Agreement as is necessary to produce sale proceeds (after deducting commissions payable to the Broker and other costs and expenses)

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sufficient to fund any Withholding Obligations. Any Exchangeable Shares to be sold in accordance with this Section 5.13 shall first be exchanged for Delaware Common Stock in accordance with their terms and Delaware Common Stock delivered in respect of such Exchangeable Shares shall be sold. Any such sale of Delaware Common Stock shall be affected on a public market and as soon as practicable. Each of Parent, ExchangeCo, CallCo, the Share Trustee, the Broker or any Other Withholding Agent, as applicable, shall act in a commercially reasonable manner in respect of any withholding obligation; however, none of Parent, ExchangeCo, CallCo, the Share Trustee, the Broker or any Other Withholding Agent shall have or be deemed to have any fiduciary duty to any Beneficiary and shall not be liable for any loss arising out of any sale of such Delaware Common Stock, including any loss relating to the manner or timing of such sales, the prices at which Delaware Common Stock are sold or otherwise.

A holder of an Exchangeable Share shall not be entitled to any fraction of a Delaware Common Stock upon the exercise of the Exchange Right or Automatic Exchange Right hereunder and no certificates or book-entry evidence representing any such fractional interest shall be issued.

ARTICLE 6

CONCERNING THE SHARE TRUSTEE

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The Share Trustee represents to Parent, CallCo and ExchangeCo that, at the date of execution and delivery of this Agreement, there exists no material conflict of interest in the role of the Share Trustee as a fiduciary hereunder and the role of the Share Trustee in any other capacity. If the Share Trustee has a material conflict of interest in the role of the Share Trustee as a fiduciary hereunder and the role of the Share Trustee in any other capacity the validity and enforceability of this Agreement shall not be affected in any manner whatsoever by reason only of the existence of such material conflict of interest. If the Share Trustee contravenes the foregoing provisions of this Section 6.2, any interested party may apply to the Supreme Court of British Columbia for an order that the Share Trustee be replaced as Share Trustee hereunder. Notwithstanding the foregoing, if Parent determines (acting reasonably and in good faith) that there exists a material conflict of interest in the role of the Share Trustee as a fiduciary hereunder and the role of the Share Trustee in any other capacity, then at the written request of Parent (which written request shall set forth the nature of such material conflict of interest), the Share Trustee shall resign in the manner and with the effect specified in Article 9.

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The Share Trustee shall keep available for inspection during regular business hours by Parent, CallCo and ExchangeCo at the Share Trustee’s principal office in Vancouver, British Columbia correct and complete books and records of account relating to the Trust created by, and Share Trustee’s actions under, this Agreement, including all relevant data relating to mailings and instructions to and from Beneficiaries and all transactions pursuant to the Exchange Right and the Automatic Exchange Right. On or before [MMM DD, YYYY], and on or before [MMM DD] in every year thereafter, so long as the Special Voting Stock is registered in the name of the Share Trustee, the Share Trustee shall transmit to Parent, CallCo and ExchangeCo a brief report, dated as of the preceding December 31, with respect to:

The Share Trustee shall, when directed by Parent, prepare and file, or cause to be prepared and filed, on behalf of the Trust appropriate Canadian income tax returns and any other returns or reports as may be required by applicable law, by any court, tribunal, government, governmental or regulatory agency or public official, or pursuant to the rules and regulations of any securities exchange or other trading system through which the Exchangeable Shares are traded. In connection therewith, the Share Trustee may obtain the advice and assistance of such experts or advisors (who may be experts or advisors to Parent, CallCo and/or ExchangeCo) as the Share Trustee considers necessary or advisable. If requested by the Share Trustee, Parent shall retain or caused to be retained qualified experts or advisors for the purpose of providing such tax advice or assistance.

No Beneficiary shall have the right to institute any action, suit or proceeding or to exercise any other remedy authorized by this Agreement for the purpose of enforcing any of its rights or for the execution of any trust or power hereunder unless the Beneficiary has requested the Share Trustee to take or institute such action, suit or proceeding and furnished the Share Trustee with the funding, security or indemnity referred to in Section 6.6 and the Share Trustee shall have failed to act within a reasonable time thereafter. In such case, but not otherwise, the

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Beneficiary shall be entitled to take proceedings in any court of competent jurisdiction such as the Share Trustee might have taken; it being understood and intended that no one or more Beneficiaries shall have any right in any manner whatsoever to affect, disturb or prejudice the rights hereby created by any such action, or to enforce any right hereunder or the Voting Rights, the Exchange Right or the Automatic Exchange Right except subject to the conditions and in the manner herein provided, and that all powers and trusts hereunder shall be exercised and all proceedings at law shall be instituted, had and maintained by the Share Trustee, except only as herein provided, and in any event for the equal benefit of all Beneficiaries.

The Share Trustee shall not be considered to be in contravention of any of its rights, powers, duties and authorities hereunder if, when required, it acts and relies in good faith upon statutory declarations, certificates, opinions or reports furnished pursuant to the provisions hereof or required by the Share Trustee to be furnished to it in the exercise of its rights, powers, duties and authorities hereunder if such statutory declarations, certificates, opinions or reports comply with the provisions of Section 6.9, if applicable, and with any other applicable provisions of this Agreement.

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The Share Trustee may:

Unless otherwise provided in this Agreement, any moneys held by or on behalf of the Share Trustee which under the terms of this Agreement may or ought to be invested or which may be on deposit with the Share Trustee or which may be in the hands of the Share Trustee may be invested or reinvested in the name or under the control of the Share Trustee in securities in which, under the laws of the Province of British Columbia, trustees are authorized to invest trust moneys, or as otherwise agreed upon in writing by the Share Trustee and ExchangeCo, provided that such securities are stated to mature within two years after their purchase by the Share Trustee and the Share Trustee shall so invest such money on the written direction of ExchangeCo. Pending the investment of any money as herein provided, such moneys may be deposited in the name of the Share Trustee in any chartered bank in Canada or, with the consent of ExchangeCo, in the deposit department of the Share Trustee or any other specified loan or trust company authorized to accept deposits under the laws of Canada or any province thereof at the rate of interest then current on similar deposits. The Share Trustee shall not be held liable for any losses incurred in the investment of any funds as herein provided and all interest on monies held by or on behalf of the Share Trustee shall be for the account of ExchangeCo and held by the Share Trustee for the benefit of ExchangeCo.

The Share Trustee shall not be required to give any bond or security in respect of the execution of the trusts, rights, duties, powers and authorities of this Agreement or otherwise in respect of the premises.

Except as in this Agreement otherwise specifically provided, the Share Trustee shall not be bound to act in accordance with any direction or request of Parent, CallCo and/or ExchangeCo or of the respective directors thereof until a duly authenticated copy of the instrument or resolution containing such direction or request shall have been delivered to the Share Trustee, and the Share Trustee shall be empowered to act upon any such copy purporting to be authenticated and believed by the Share Trustee to be genuine. The Share Trustee shall have the right not to act and shall not be liable for refusing to act if, due to a lack of information or for any other reason

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whatsoever, the Share Trustee, in its sole judgment, determines that such act might cause it to be in non-compliance with any applicable anti-money laundering or anti-terrorist or economic sanction legislation or regulation. Further, should the Share Trustee, in its sole judgment, determine at any time that its acting under this Agreement has resulted in its being in non-compliance with any applicable anti-money laundering, anti-terrorist or economic sanctions legislation or regulation or guideline, then it shall have the right to resign on ten days written notice to the other parties to this Agreement, provided that (a) the Share Trustee’s written notice shall describe the circumstances of such non-compliance and (b) if such circumstances are rectified to the Share Trustee’s satisfaction within such ten day period, such resignation shall not be effective.

The Share Trustee represents to Parent, CallCo and ExchangeCo that, at the date of execution and delivery by it of this Agreement, it is authorized to carry on the business of a trust company in each of the provinces and territories of Canada but if, notwithstanding the provisions of this Section 6.14, it ceases to be so authorized to carry on business, the validity and enforceability of this Agreement and the Voting Rights, the Exchange Right and the Automatic Exchange Right and the other rights granted in or resulting from the Share Trustee being a party to this Agreement shall not be affected in any manner whatsoever by reason only of such event but the Share Trustee shall, within 90 days after ceasing to be authorized to carry on the business of a trust company in any province or territory of Canada, either become so authorized or resign in the manner and with the effect specified in Article 9.

The Share Trustee hereby accepts the Trust created and provided for, by and in this Agreement and agrees to perform the same upon the terms and conditions herein set forth and to hold all rights, privileges and benefits conferred hereby and by law in trust for the various persons who shall from time to time be Beneficiaries, subject to all the terms and conditions herein set forth.

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Each party to this Agreement hereby represents to the Share Trustee that any account to be opened by, or interest to be held by the Share Trustee in connection with this Agreement, for or to the credit of such party, either (a) is not intended to be used by or on behalf of any third party, or (b) is intended to be used by or on behalf of a third party, in which case such party hereto agrees to complete and execute forthwith a declaration in the Share Trustee’s prescribed form as to the particulars of such third party.

The parties acknowledge that Canadian federal and/or provincial legislation that addresses the protection of individuals’ personal information (collectively, “Privacy Laws”) applies to obligations and activities under this Agreement. Despite any other provision of this Agreement, no party shall take or direct any action that would contravene, or cause the others to contravene, applicable Privacy Laws. The parties shall, prior to transferring or causing to be transferred personal information to the Share Trustee, obtain and retain required consents of the relevant individuals to the collection, use and disclosure of their personal information, or shall have determined that such consents either have previously been given upon which the parties can rely or are not required under the Privacy Laws. The Share Trustee shall use commercially reasonable efforts to ensure that its services hereunder comply with Privacy Laws. Specifically, the Share Trustee agrees (a) to have a designated chief privacy officer, (b) to maintain policies and procedures to protect personal information and to receive and respond to any privacy complaint or inquiry, (c) to use personal information solely for the purposes of providing its services under or ancillary to this Agreement and not to use it for any other purpose except with the consent of or direction from the other parties or the individual involved, (d) not to sell or otherwise improperly disclose personal information to any third party, and (e) to employ administrative, physical and technological safeguards to reasonably secure and protect personal information against loss, theft, or unauthorized access, use or modification.

ARTICLE 7

COMPENSATION

Parent, CallCo and ExchangeCo jointly and severally agree to pay the Share Trustee reasonable compensation for all of the services rendered by it under this Agreement and shall reimburse the Share Trustee for all reasonable expenses (including, but not limited to, taxes (other than taxes based on the net income or capital of the Share Trustee), fees paid to legal counsel and other experts and advisors and agents and reasonable travel expenses) and disbursements, including the reasonable cost and expense of any suit or litigation of any character and any proceedings before any governmental agency, in each case reasonably incurred by the Share Trustee in connection with its duties under this Agreement; provided, however, that Parent, CallCo and ExchangeCo shall have no obligation to reimburse the Share Trustee for any expenses or disbursements paid, incurred or suffered by the Share Trustee in any suit or litigation or any such proceedings in which the Share Trustee is determined to have acted in bad faith or with gross negligence, fraud or willful misconduct.

ARTICLE 8

INDEMNIFICATION AND LIMITATION OF LIABILITY

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No party shall be liable to the other, or held in breach of this Agreement, if prevented, hindered or delayed in the performance or observance of any provision contained herein by reason of act of god, riots, terrorism, acts of war, epidemics or pandemics, governmental action or judicial order, earthquakes, or any other similar causes

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(including, but not limited to, mechanical, electronic or communication interruptions, disruptions or failures). Performance times under this Agreement shall be extended for a period of time equivalent to the time lost because of any delay that is excusable under this Section 8.3.

ARTICLE 9

CHANGE OF SHARE TRUSTEE

The Share Trustee, or any Share Trustee hereafter appointed, may at any time resign by giving written notice of such resignation to Parent, CallCo and ExchangeCo specifying the date on which it desires to resign, provided that such notice shall not be given less than 30 days before such desired resignation date unless Parent, CallCo and ExchangeCo otherwise agree and provided further that such resignation shall not take effect until the date of the appointment of a successor Share Trustee and the acceptance of such appointment by the successor Share Trustee. Upon receiving such notice of resignation, Parent, CallCo and ExchangeCo shall promptly appoint a successor Share Trustee, which successor Share Trustee shall be a corporation organized and existing under the laws of Canada and authorized to carry on the business of a trust company in all provinces and territories of Canada, by written instrument in duplicate, one copy of which shall be delivered to the resigning Share Trustee and one copy to the successor Share Trustee. Failing the appointment and acceptance of a successor Share Trustee, a successor Share Trustee may be appointed by order of a court of competent jurisdiction upon application of one or more of the parties to this Agreement. If the retiring Share Trustee is the party initiating an application for the appointment of a successor Share Trustee by order of a court of competent jurisdiction, Parent, CallCo and ExchangeCo shall be jointly and severally liable to reimburse the retiring Share Trustee for its legal costs and expenses in connection with same.

The Share Trustee, or any Share Trustee hereafter appointed, may (provided a successor Share Trustee is appointed) be removed at any time on not less than 30 days’ prior notice by written instrument executed by Parent, CallCo and ExchangeCo, in duplicate, one copy of which shall be delivered to the Share Trustee so removed and one copy to the successor Share Trustee, provided that such removal shall not take effect until the date of acceptance of appointment by the successor Share Trustee.

Any successor Share Trustee appointed as provided under this Agreement shall execute, acknowledge and deliver to Parent, CallCo and ExchangeCo and to its predecessor Share Trustee an instrument accepting such appointment. Thereupon the resignation or removal of the predecessor Share Trustee shall become effective and such successor Share Trustee, without any further act, deed or conveyance, shall become vested with all the rights, powers, duties and obligations of its predecessor under this Agreement, with the like effect as if originally named as Share Trustee in this Agreement. However, on the written request of Parent, CallCo and ExchangeCo or of the successor Share Trustee, the Share Trustee ceasing to act shall, upon payment of any amounts then due to it pursuant to the provisions of this Agreement, execute and deliver an instrument transferring to such successor Share Trustee all the rights and powers of the Share Trustee so ceasing to act. Upon the request of any such successor Share Trustee, Parent, CallCo, ExchangeCo and such predecessor Share Trustee shall execute any and all instruments in writing for more fully and certainly vesting in and confirming to such successor Share Trustee all such rights and powers.

Upon acceptance of appointment by a successor Share Trustee as provided herein, Parent, CallCo and ExchangeCo shall cause to be mailed notice of the succession of such Share Trustee hereunder to each Beneficiary specified in a List. If Parent, CallCo or ExchangeCo shall fail to cause such notice to be mailed

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within ten days after acceptance of appointment by the successor Share Trustee, the successor Share Trustee shall cause such notice to be mailed at the expense of Parent, CallCo and ExchangeCo.

ARTICLE 10

PARENT SUCCESSORS

So long as any Exchangeable Shares not owned by Parent or its Affiliates are outstanding, Parent shall not enter into any transaction (whether by way of reorganization, consolidation, arrangement, amalgamation, merger, transfer, sale for otherwise) whereby all or substantially all of its undertaking, property and assets would become the property of any other person or, in the case of an amalgamation or merger, of the continuing corporation resulting therefrom, provided that it may do so if as a result of such transactions, and concurrently therewith, the Exchangeable Shares held by the Beneficiaries are exchanged for Delaware Common Stock in accordance with their terms, and in any other case:

Whenever the conditions of Section 10.1 have been duly observed and performed, the parties, if required by Section 10.1, shall execute and deliver the supplemental trust agreement provided for in Section 10.1(a) and thereupon the Parent Successor and such other person that may then be the issuer of the Delaware Common Stock shall possess and from time to time may exercise each and every right and power of Parent under this Agreement in the name of Parent or otherwise and any act or proceeding by any provision of this Agreement required to be done or performed by the board of directors of Parent or any officers of Parent may be done and performed with like force and effect by the directors or officers of such Parent Successor.

Nothing herein shall be construed as preventing (a) the amalgamation or merger of any wholly-owned direct or indirect subsidiary of Parent (other than ExchangeCo or CallCo) with or into Parent, (b) the winding-up, liquidation or dissolution of any wholly-owned direct or indirect subsidiary of Parent (other than ExchangeCo or CallCo), provided that all of the assets of such subsidiary are transferred to Parent or another wholly-owned direct or indirect subsidiary of Parent, (c) the conversion of Parent as contemplated by Section 266 of the Delaware General Corporation Law, as it may be amended from time to time, (d) any other distribution of the assets of any wholly-owned direct or indirect subsidiary of Parent among the stockholders of such subsidiary for the purpose of winding up its affairs, and (e) any such transactions which are expressly permitted by this Article 10.

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Notwithstanding the foregoing provisions of this Article 10, in the event of a Parent Control Transaction:

then, (i) all references herein to “Parent” shall thereafter be and be deemed to be references to “Other Corporation” and all references herein to “Delaware Common Stock” shall thereafter be and be deemed to be references to “Other Shares” (with appropriate adjustments, if any, as are required to result in a holder of Exchangeable Shares on the exchange, redemption or retraction of such shares pursuant to the Exchangeable Share Provisions or the Plan of Arrangement or the exchange of such shares pursuant to this Agreement immediately subsequent to the Parent Control Transaction being entitled to receive that number of Other Shares equal to the number of Other Shares such holder of Exchangeable Shares would have received if the exchange, redemption or retraction of such shares pursuant to the Exchangeable Share Provisions or the Plan of Arrangement, or the exchange of such shares pursuant to this Agreement had occurred immediately prior to the Parent Control Transaction and the Parent Control Transaction was completed) but subject to subsequent adjustments to reflect any subsequent changes in the share capital of the issuer of the Other Shares, including without limitation, any subdivision, consolidation or reduction of share capital, without any need to amend the terms and conditions of this Agreement and without any further action required, and (ii) Parent shall cause the Other Corporation to deposit one or more voting securities of such Other Corporation to allow Beneficiaries to exercise voting rights in respect of the Other Corporation substantially similar to those provided for in this Agreement.

ARTICLE 11

AMENDMENTS AND SUPPLEMENTAL TRUST AGREEMENTS

Subject to Section 11.2, 11.4 and 13.1 this Agreement may not be amended or modified except by an agreement in writing executed by Parent, CallCo, ExchangeCo and the Share Trustee and approved by the Beneficiaries in accordance with Section 26.11(b) of the Exchangeable Share Provisions.

Notwithstanding the provisions of Section 11.1, the parties to this Agreement may in writing, at any time and from time to time, without the approval of the Beneficiaries, amend or modify this Agreement for the purposes of:

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ExchangeCo, at the request of Parent, shall call a meeting or meetings of the Beneficiaries for the purpose of considering any proposed amendment or modification requiring approval of ExchangeCo pursuant hereto. Any such meeting or meetings shall be called and held in accordance with the articles of ExchangeCo, the Exchangeable Share Provisions and all applicable laws.

Notwithstanding the provisions of Section 11.1, at all times after the occurrence of any event contemplated pursuant to Section 2.7 or 2.8 of the Support Agreement or otherwise, as a result of which either Delaware Common Stock or the Exchangeable Shares or both are in any way changed, this Agreement shall forthwith be amended and modified as necessary in order that it shall apply with full force and effect, mutatis mutandis, to all new securities into which Delaware Common Stock or the Exchangeable Shares or both are so changed and the parties hereto shall execute and deliver a supplemental trust agreement giving effect to and evidencing such necessary amendments and modifications.

No amendment to or modification or waiver of any of the provisions of this Agreement otherwise permitted hereunder shall be effective unless made in writing and signed by all of the parties hereto. Notwithstanding the provisions of Section 11.1, from time to time Parent, CallCo and ExchangeCo (in each case, when authorized by a resolution of its board of directors) and the Share Trustee may, subject to the provisions of these presents, and they shall, when so directed by these presents, execute and deliver by their proper officers, trust agreements or other instruments supplemental hereto, which thereafter shall form part hereof, for any one or more of the following purposes:

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ARTICLE 12

TERMINATION

The Trust created by this Agreement shall continue until the earliest to occur of the following events, and upon the occurrence thereof, the Share Trustee shall surrender the electronic registration of Special Voting Stock, and the Special Voting Share shall be cancelled by Parent without a return of capital:

This Agreement shall survive any termination of the Trust and shall continue until there are no Exchangeable Shares outstanding held by a Beneficiary; provided, however, that the provisions of Article 7 and Article 8 shall survive any such termination of this Agreement.

ARTICLE 13

GENERAL

If any term or other provision of this Agreement is invalid, illegal or incapable of being enforced by any rule or law, or public policy, all other conditions and provisions of this Agreement shall nevertheless remain in full force and effect so long as the economic or legal substance of the transactions contemplated hereby is not affected in any manner materially adverse to any party. Upon such determination that any term or other provision is invalid, illegal or incapable of being enforced, the parties hereto shall negotiate in good faith to modify this Agreement so as to effect the original intent of the parties as closely as possible in an acceptable manner to the end that the transactions contemplated hereby are fulfilled to the fullest extent possible.

This Agreement shall be binding upon and enure to the benefit of the parties hereto and their respective successors and assigns and, subject to the terms hereof, to the benefit of the Beneficiaries.

Any notice and other communications required or permitted to be given pursuant to this Agreement shall be sufficiently given if delivered in person or if sent by electronic transmission to the parties at the following addresses:

114 East 4th Avenue, Suite 800

Vancouver, BC, V5T 1G4

Attention: Daniel Dex

Email: daniel.dex@zymeworks.com

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with copies (which shall not constitute notice) to:

Attention: Bryan King

Email:     bking@wsgr.com

and to:

Attention:  Joseph Garcia

Email: joseph.garcia@blakes.com

Computershare Trust Company of Canada

Attention:          General Manager, Corporate Trust

Email: corporatetrust.vancouver@computershare.com

and such notice or other communication shall be deemed to have been given and received (x) if delivered on a Business Day prior to 4:30 p.m. (local time in the place where the notice or other communication is received), on the date of delivery, or (y) otherwise, on the next Business Day. Either party may change its address for notice by giving notice to the other parties in accordance with the foregoing provisions.

Any notice, request or other communication to be given to a Beneficiary shall be given or sent (in writing or by electronic transmission) to the address of the holder recorded in the securities register of ExchangeCo or, in the event of the address of any such holder not being so recorded, then at the last known address of such holder, in any manner permitted by the articles of ExchangeCo, and shall be deemed received at the time specified by such articles. Accidental failure or omission to give any notice, request or other communication to one or more holders of Exchangeable Shares, or any defect in such notice, shall not invalidate or otherwise alter or affect any action or proceeding to be taken pursuant thereto.

This Agreement may be executed in counterparts, each of which shall be deemed an original, but all of which taken together shall constitute one and the same instrument.

This Agreement shall be construed and enforced in accordance with the laws of the Province of British Columbia and the laws of Canada applicable therein.

Each of Parent, CallCo, ExchangeCo and the Share Trustee agrees that any action or proceeding arising out of or relating to this Agreement may be instituted in the courts of British Columbia, waives any objection which it may have now or hereafter to the venue of any such action or proceeding, irrevocably submits to the non-exclusive jurisdiction of the said courts in any such action or proceeding, agrees to be bound by any judgement of the said courts and not to seek, and hereby waives, any review of the merits of any such judgement by the courts of any other jurisdiction, and Parent hereby appoints ExchangeCo at its registered office in the Province of British Columbia as attorney for service of process.

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The Share Trustee shall be entitled to treat a facsimile, pdf or e-mail communication or communication by other similar electronic means in a form satisfactory to the Share Trustee (“Electronic Methods”) from a person purporting to be (and whom the Share Trustee, acting reasonably, believes in good faith to be) the authorized representative of a party, as sufficient instructions and authority of the party for the Share Trustee to act and shall have no duty to verify or confirm that such person is so authorized. The parties hereto acknowledges that they are fully informed of the protections and risks associated with the various methods of transmitting instructions to the Share Trustee and that there may be more secure methods of transmitting instructions than Electronic Methods.

[Remainder of this page left intentionally blank]

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IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be duly executed as of the date first above written.

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EXHIBIT A

EXCHANGEABLE SHARE PROVISIONS

ARTICLE 26

SPECIAL RIGHTS OR RESTRICTIONS ATTACHED TO THE EXCHANGEABLE SHARES

The Exchangeable Shares of the Company shall have the following rights, privileges, restrictions and conditions:

26.1 Interpretation

“affiliate” means, with respect to any person, any other person who, directly or indirectly, controls, is controlled by, or is under common control with, such person. For purposes of this definition, the term “control” (including the correlative terms “controlling”, “controlled by” and “under common control with”) means the possession, directly or indirectly, of the power to direct or cause the direction of the management and policies of a person, whether through the ownership of voting securities, by contract or otherwise. For purposes of this Article 26, “affiliate” does not include any stockholders of Parent (other than Zymeworks Inc.), or directors or executive officers of Zymeworks Inc., Parent, the Company or CallCo.

“Automatic Exchange Right” has the meaning ascribed thereto in the Voting and Exchange Trust Agreement.

“BCBCA” means the Business Corporations Act (British Columbia) and the regulations made thereunder, as now in effect and as they may be promulgated or amended from time to time.

“Board of Directors” means the board of directors of the Company.

“Broker” has the meaning ascribed thereto in Section 26.14(c).

“Business Day” means a day on which banks are generally open for the transaction of commercial business in Vancouver, British Columbia, and New York, New York, but does not in any event include a Saturday or Sunday or statutory holiday in Vancouver, British Columbia, or New York, New York.

“CallCo” means Zymeworks CallCo ULC, a corporation existing under the laws of the Province of British Columbia.

“Canadian Resident” means either (i) a person who, at the relevant time, is a resident of Canada for purposes of the Income Tax Act (Canada), or (ii) a partnership that is a “Canadian partnership” for purposes of the Income Tax Act (Canada).

“Change of Law” means any amendment to the Income Tax Act (Canada) and other applicable provincial income Tax Laws that permits Canadian Resident holders of the Exchangeable Shares, who hold the Exchangeable Shares as capital property and deal at arm’s length with Parent and the Company (all for the purposes of the Income Tax Act (Canada) and other applicable provincial income Tax Laws), to exchange their Exchangeable Shares for Delaware Common Stock on a basis that will not require such holders to recognize any income, gain or loss or any actual or deemed dividend in respect of such exchange for the purposes of the Income Tax Act (Canada) or applicable provincial income Tax Laws.

“Change of Law Call Date” has the meaning ascribed thereto in Section 26.20(b).

“Change of Law Call Purchase Price” has the meaning ascribed thereto in Section 26.20(a).

“Change of Law Call Right” has the meaning ascribed thereto in Section 26.20(a).

“Common Shares” means the common shares in the capital of the Company.

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“Current Market Price” means, in respect of Delaware Common Stock on any date, the average closing price of a share of Delaware Common Stock on the NYSE during the period of 20 consecutive trading days ending on the third trading day immediately before such date or, if the Delaware Common Stock are not then listed on the NYSE, on such other stock exchange or automated quotation system on which the Delaware Common Stock are listed or quoted, as the case may be, as may be selected by the Board of Directors for such purpose; provided, however, that if in the opinion of the Board of Directors the public distribution or trading activity of Delaware Common Stock during such period does not reflect the fair market value of a share of Delaware Common Stock, then the Current Market Price of a share of Delaware Common Stock shall be determined by the Board of Directors, based upon the advice of such qualified independent financial advisors as the Board of Directors may deem to be appropriate; and provided further that any such selection, opinion or determination by the Board of Directors shall be conclusive and binding, absent manifest error.

“Delaware Common Stock” means shares of Parent’s common stock, par value US$0.00001 per share.

“Effective Date” has the meaning ascribed thereto in the Plan of Arrangement.

“Exchangeable Share Consideration” means, with respect to each Exchangeable Share, for any acquisition of, redemption of or distribution of assets of the Company in respect of such Exchangeable Share, or purchase of such Exchangeable Share pursuant to these Exchangeable Share Provisions or the Support Agreement or the Voting and Exchange Trust Agreement:

provided that: (A) the part of the consideration which represents (i) above shall be fully paid and satisfied by the delivery of Delaware Common Stock, such shares to be duly issued, fully paid and nonassessable; (B) the part of the consideration which represents (iii) above shall be fully paid and satisfied by delivery of such non-cash items; (C) in each case, any such consideration shall be delivered free and clear of any lien, claim, encumbrance, security interest or adverse claim or interest; and (D) in each case, any such consideration shall be paid without interest and less any tax required to be deducted and withheld therefrom.

“Exchangeable Share Document” means (i) a share certificate representing Exchangeable Shares, (ii) a non-transferable acknowledgement of a shareholder’s right to obtain a share certificate representing Exchangeable Shares, or (iii) a direct registration system advice (or similar document) evidencing the electronic registration of the ownership of Exchangeable Shares, as applicable.

“Exchangeable Share Exchange Ratio” means, at any time and in respect of each Exchangeable Share, an amount equal to 1.00000, as at the Effective Date, as cumulatively adjusted from time to time thereafter by increasing the Exchangeable Share Exchange Ratio on each date after the Effective Date on which the board of directors of Parent pays any dividend or other distribution on the Delaware Common Stock (but excluding any dividends or distributions pursuant to a Preferred Stock Rights Agreement) by an amount, rounded to the nearest five decimal places, equal to (a)(i) the amount of such dividend or other distribution (which, in the case of a non-cash dividend, shall equal the fair value as determined by the Board of Directors in good faith and in its sole discretion), expressed on a per

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Delaware Common Stock per share basis, multiplied (ii) by the Exchangeable Share Exchange Ratio in effect on the Business Day immediately preceding the record date set for such dividend or other distribution, divided by (b) the Current Market Price on the record date set for such dividend or other distribution, and any such adjustment shall be determined by the Board of Directors in good faith and in its sole discretion and any such determination by the Board of Directors shall be conclusive and binding; provided, however, that the Exchangeable Share Exchange Ratio shall only be so adjusted to the extent that the Board of Directors determines in good faith and in its sole discretion that the Company would be liable for any unrecoverable tax as a result of paying any such dividend or distribution and determines to adjust the Exchangeable Share Exchange Ratio in lieu of paying an equivalent dividend or other distribution on the Exchangeable Shares in accordance with these Exchangeable Share Provisions.

“Exchangeable Share Price” means, at any time, for each Exchangeable Share, an amount equal to the aggregate of the following:

“Exchangeable Share Provisions” means the rights, privileges, restrictions and conditions set out in this Article 26.

“Exchangeable Shares” means the exchangeable shares in the capital of the Company, having the rights, privileges, restrictions and conditions set forth in this Article 26.

“Governmental Authority” means any nation or government or any agency, public or regulatory authority, taxing authority, self-regulatory organization (including stock exchanges), instrumentality, department, commission, court, arbitrator (public or private), ministry, tribunal or board of any nation, government or political subdivision or delegated authority thereof, in each case, whether foreign or domestic and whether national, supranational, multinational, federal, provincial, territorial, state, regional, local or municipal.

“Law” means applicable statutes, common laws, rules, ordinances, regulations, codes, orders, judgments, injunctions, writs, decrees, governmental guidelines or interpretations having the force of Law or bylaws, in each case, of a Governmental Authority.

“Liquidation Amount” has the meaning ascribed thereto in Section 26.5(a).

“Liquidation Call Purchase Price” has the meaning ascribed thereto in the Section 26.18(a).

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“Liquidation Call Right” has the meaning ascribed thereto in the Section 26.18(a).

“Liquidation Date” has the meaning ascribed thereto in Section 26.5(a).

“NYSE” means the New York Stock Exchange.

“Other Withholding Agent” has the meaning ascribed thereto in Section 26.14(c).

“Parent” means Zymeworks Delaware Inc., a corporation existing under the Laws of the State of Delaware.

“Parent Control Transaction” shall be deemed to have occurred if:

“Parent Dividend Declaration Date” means the date on which the board of directors of Parent declares any dividend or other distribution on the Delaware Common Stock (but excluding any dividends or distributions pursuant to a Preferred Stock Rights Agreement).

“person” includes an individual, partnership, association, body corporate, trustee, executor, administrator, legal representative, government or any other entity, whether or not having legal status.

“Plan of Arrangement” means the plan of arrangement substantially in the form and content of Exhibit A to the Transaction Agreement, including any appendices thereto, and any amendments, modifications or supplements thereto made from time to time in accordance with its terms.

“Preferred Stock Rights Agreement” means any preferred stock rights agreement that may now or in the future be adopted and entered into by Parent in respect of the Delaware Common Stock, to protect stockholders of Parent from coercive or otherwise unfair takeover tactics, in such form and substance as Parent may determine in its sole discretion.

“Redemption Call Purchase Price” has the meaning ascribed thereto in Section 26.19(a).

“Redemption Call Right” has the meaning ascribed thereto in Section 26.19(a).

“Redemption Date” means the date for the redemption by the Company of all but not less than all of the outstanding Exchangeable Shares (other than Exchangeable Shares held by Parent and its affiliates), which date shall be the earlier of (a) the Sunset Date, and (b) the date, if any, established by the Board of Directors following the occurrence of any of the following:

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provided, however, that the accidental failure or omission to give any notice of redemption under clauses (i) or (ii) above to any of the holders of Exchangeable Shares shall not affect the validity of any such redemption.

“Redemption Price” has the meaning ascribed thereto in Section 26.7(a).

“Retracted Shares” has the meaning ascribed thereto in Section 26.6(a)(i)(A).

“Retraction Call Notice” has the meaning ascribed thereto in Section 26.6(b)(ii).

“Retraction Call Right” has the meaning ascribed thereto in Section 26.6(a)(i)(C).

“Retraction Call Right Purchase Price” has the meaning ascribed thereto in Section 26.6(b)(i).

“Retraction Date” has the meaning ascribed thereto in Section 26.6(a)(i)(B).

“Retraction Price” has the meaning ascribed thereto in Section 26.6(a)(i).

“Retraction Request” has the meaning ascribed thereto in Section 26.6(a)(i).

“Share Trustee” means the trustee chosen by Parent and Zymeworks Inc. to act as trustee under the Voting and Exchange Trust Agreement, being a corporation organized and existing under the Laws of Canada or any Province thereof and authorized to carry on the business of a trust company in all the provinces of Canada, and any successor trustee appointed under the Voting and Exchange Trust Agreement.

“Sunset Date” means the seventh anniversary of the Effective Date, as it may be extended from time to time by the Board of Directors.

“Support Agreement” means the support agreement to be entered into at or prior to the issuance by the Company of any Exchangeable Shares among Parent, CallCo and the Company substantially in the form of Exhibit C to the Transaction Agreement, as it may be amended, supplemented or otherwise modified from time to time in accordance with its terms.

“Tax” means any and all national, supranational, multinational, federal, provincial, territorial, state, regional, local or municipal taxes, including income, branch, profits, capital gains, gross receipts, windfall profits, value added, severance, ad valorem, property, capital, estimated, utility, recapture, net worth, production, sales, use, license, excise, franchise, environmental, transfer, land transfer, withholding or similar, payroll, employment, employer health, government pension plan premiums and

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contributions, social security premiums, workers’ compensation premiums, employment/unemployment insurance or compensation premiums or contributions, disability, documentary, registration, stamp, occupation, premium, alternative or add-on minimum, goods and services, harmonized sales, customs duties or other taxes, levies, premiums, excises, fees, assessments, imposts, duties, and other similar charges of any kind whatsoever imposed, assessed, charged or collected by a Governmental Authority and any installments in respect thereof, including any interest, fines, assessments, reassessments, penalties or additions to tax imposed in connection therewith or with respect thereto, and any interest in respect of such additions or penalties, and whether disputed or not.

“Tax Law” means any Law in respect of Taxes.

“Transaction Agreement” means the transaction agreement dated July 14, 2022 among Parent, CallCo, the Company and Zymeworks Inc., as amended, supplemented or otherwise modified from time to time in accordance with its terms.

“Transfer Agent” means Computershare Investor Services Inc. or such other person as may from time to time be appointed by the Company as the registrar and transfer agent for the Exchangeable Shares.

“Voting and Exchange Trust Agreement” means the voting and exchange trust agreement to be made among Parent, CallCo, the Company and the Share Trustee in connection with the Plan of Arrangement substantially in the form of Exhibit D to the Transaction Agreement, as may be amended, supplemented or otherwise modified from time to time in accordance with its terms.

“Withholding Shortfall” has the meaning ascribed thereto in Section 26.14(c).

26.2 Ranking of Exchangeable Shares. The Exchangeable Shares shall be entitled to a preference over the Common Shares and any other shares ranking junior to the Exchangeable Shares: (a) with respect to the payment of dividends or other distributions as and to the extent provided in Section 26.3 and (b) with respect to the distribution of assets in the event of the liquidation, dissolution or winding-up of the Company, whether voluntary or involuntary, or any other distribution of the assets of the Company among its shareholders for the purpose of winding up its affairs as and to the extent provided in Section 26.5.

26.3 Dividends and Distributions.

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such dividends or other distributions shall be paid out of money, assets or property of the Company properly applicable to the payment of dividends or other distributions, out of authorized but unissued shares of the Company or through the subdivision of outstanding Exchangeable Shares, as applicable; provided, that the Board of Directors may determine, in its sole discretion, to adjust the Exchangeable Share Exchange Ratio as provided herein in lieu of paying any such dividend or other distribution on the Exchangeable Shares, and provided further, however, that the Exchangeable Share Exchange Ratio shall only be so adjusted to the extent that the Board of Directors determines in good faith and in its sole discretion that the Company would be liable for any unrecoverable tax as a result of paying any such dividend or distribution. The holders of Exchangeable Shares shall not be entitled to any dividends or other distributions other than or in excess of the dividends or other distributions referred to in this Section 26.3(a).

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26.4 Certain Restrictions. So long as any of the Exchangeable Shares are outstanding, the Company shall not at any time without, but may at any time with, the approval of the holders of the Exchangeable Shares given as specified in Section 26.11(b):

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provided, however, that the restrictions in this Section 26.4 shall not apply if, in connection with all dividends or other distributions declared and paid on the Delaware Common Stock (but excluding any dividends or distributions pursuant to a Preferred Stock Rights Agreement): (i) all dividends or other distributions on the outstanding Exchangeable Shares shall have been declared and paid in full on the Exchangeable Shares, or (ii) the Exchangeable Share Exchange Ratio shall have been adjusted in accordance with these Exchangeable Share Terms, in each case, prior to or as at the date of any such event referred to in this Section 26.4.

26.5 Liquidation.

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26.6 Retraction of Exchangeable Shares.

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26.7 Redemption of Exchangeable Shares by the Company.

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26.8 Purchase by Private Agreement. Subject to applicable Laws and the articles of the Company, and notwithstanding Section 26.7(b), the Company may at any time and from time to time purchase for cancellation all or any part of the Exchangeable Shares by private agreement with the holder thereof.

26.9 Voting Rights. Except as required by applicable Laws and by Section 26.11, the holders of the Exchangeable Shares shall not be entitled as such to receive notice of or to attend any meeting of the shareholders of the Company or to vote at any such meeting. Without limiting the generality of the foregoing, the holders of the Exchangeable Shares shall not be entitled to class votes except as required by applicable Law.

26.10 Specified Amount. The “specified amount” for the purposes of subsection 191(4) of the Income Tax Act (Canada) in respect of each Exchangeable Share shall be the amount specified by a director or officer of the Company in a resolution that is entered into in connection with the issuance of the Exchangeable Shares of the Company (expressed as a dollar amount).

26.11 Amendment and Approval.

26.12 Reciprocal Changes in Respect of Delaware Common Stock.

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unless, in each case, the Company issues or distributes the economic equivalent of such rights, options, warrants, securities, shares, evidences of indebtedness or other assets simultaneously to holders of the Exchangeable Shares; provided, however, that, for greater certainty, the above restrictions shall not apply to any securities issued or distributed by Parent in order to give effect to and to consummate the transactions contemplated by, and in accordance with, the Transaction Agreement and the Plan of Arrangement; provided, further, that the foregoing limitations and restrictions set forth in this Section 26.12(a) shall not apply to actions taken by Parent relating to a Preferred Stock Rights Agreement.

unless, in each case, the same or an economically equivalent change is made simultaneously to, or in the rights of the holders of, the Exchangeable Shares; provided, however, that, for greater certainty, the above restrictions shall not apply to any securities issued or distributed by Parent in order to give effect to and to consummate the transactions contemplated by, and in accordance with the Transaction Agreement and the Plan of Arrangement; provided, further, that the foregoing limitations and restrictions set forth in this Section 26.12(b) shall not apply to actions taken by Parent relating to a Preferred Stock Rights Agreement. The Support Agreement further provides, in part, that the above noted provisions of the Support Agreement shall not be changed without the approval of the holders of the Exchangeable Shares given in accordance with Section 26.11(b). Accordingly, and notwithstanding any provision to the contrary contained elsewhere in these Articles, the Company may, by way of a

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resolution of the Board of Directors (i) subdivide, redivide or change the then outstanding Exchangeable Shares into a greater number of Exchangeable Shares, or (ii) reduce, combine, consolidate or change the then outstanding Exchangeable Shares into a lesser number of Exchangeable Shares, to give effect to an economically equivalent change in the rights of the holders of the Exchangeable Shares to any similar change made to the Delaware Common Stock under Sections 26.12(b)(i) or 26.12(b)(ii) respectively, as applicable.

then all references herein to “Parent” shall thereafter be and be deemed to be references to “Other Corporation” and all references herein to “Delaware Common Stock” shall thereafter be and be deemed to be references to “Other Shares” (with appropriate adjustments, if any, as are required to result in a holder of Exchangeable Shares on the exchange, redemption, retraction or purchase of shares pursuant to these Exchangeable Share Provisions, the Support Agreement and the Voting and Exchange Trust Agreement (as applicable) immediately subsequent to the Parent Control Transaction, being entitled to receive that number of Other Shares equal to the number of Other Shares such holder of Exchangeable Shares would have received if the exchange, redemption, retraction or purchase of such shares pursuant to these Exchangeable Share Provisions, the Support Agreement and the Voting and Exchange Trust Agreement (as applicable), had occurred immediately prior to the Parent Control Transaction and the Parent Control Transaction was completed), but subject to subsequent adjustments to reflect any subsequent changes in the share capital of the issuer of the Other Shares, including without limitation, any subdivision, consolidation or reduction of share capital, without any need to amend the terms and conditions of the Exchangeable Shares and without any further action required.

26.13 Actions by the Company under Support Agreement and the Voting and Exchange Trust Agreement

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26.14 Legend; Call Rights; Withholding Rights.

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26.15 Notices.

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