ATHX Athersys Inc

Filed Pursuant to Rule 424(b)(5)
Registration No. 333-235945

PROSPECTUS SUPPLEMENT

(To Prospectus dated January 29, 2020)

30,000,000 Shares of Common Stock

Pre-Funded Warrants to Purchase up to 18,000,000 Shares of Common Stock

Warrants to Purchase up to 48,000,000 Shares of Common Stock

Up to 66,000,000 Shares of Common Stock underlying such Pre-Funded Warrants and Warrants

We are offering 30,000,000 shares of our common stock, par value $0.001 per share (the “Common Stock”), pre-funded warrants (the “Pre-Funded Warrants”) to purchase up to 18,000,000 shares of Common Stock and warrants (the “Common Warrants” and, collectively with the Pre-Funded Warrants, the “Warrants”) to purchase up to 48,000,000 shares of Common Stock. The shares of Common Stock and Common Warrants will be sold in units, with each unit consisting of one share of Common Stock and a Common Warrant to purchase one share of Common Stock. The Common Warrants will have an initial exercise price of $0.2554 per share and will be exercisable upon the sixth-month anniversary of issuance for a five-year period. Each unit will be sold at a negotiated price of $0.25 and will be issued directly to a single institutional investor pursuant to this prospectus supplement, the accompanying prospectus and a securities purchase agreement. The shares of Common Stock and Common Warrants are immediately separable and will be issued separately. The Pre-Funded Warrants and accompanying Common Warrants are identical to the units, except that each Pre-Funded Warrant is immediately exercisable for one share of Common Stock at an exercise price of $0.0001, the purchase price for a Pre-Funded Warrant and accompanying Common Warrant is $0.2499 and the Pre-Funded Warrants do not expire until exercised and are valid until exercised in full.

Our Common Stock is listed on The Nasdaq Capital Market under the symbol “ATHX.” The last sale price of our Common Stock on August 12, 2022, as reported by The Nasdaq Capital Market, was $0.2554 per share. There is no established public trading market for the Pre-Funded Warrants or Common Warrants and we do not expect a market to develop. Without an active trading market, the liquidity of the Pre-Funded Warrants and Common Warrants will be limited. In addition, we do not intend to have the Pre-Funded Warrants or Common Warrants admitted to trading on The Nasdaq Capital Market or listed on any other national securities exchange or any other trading system.

Investing in any of our securities involves risk. Please read carefully the section entitled “Risk Factors” beginning on page S-4 of this prospectus supplement and page 1 of the accompanying prospectus.

We have retained A.G.P./Alliance Global Partners (“A.G.P.” or the “Placement Agent”) to act as our exclusive placement agent in connection with the securities offered by this prospectus supplement. A.G.P. is not purchasing or selling any of these securities nor is it required to sell any specific number or dollar amount of securities, but has agreed to use its reasonable best efforts to sell the securities offered by this prospectus supplement. We have agreed to pay A.G.P. a cash fee equal to 7.0% of the aggregate gross proceeds raised in this offering as set forth in the table below.

Delivery of the securities offered pursuant to this prospectus supplement and the accompanying prospectus is expected to be made on or about August 17, 2022, subject to the satisfaction of certain closing conditions.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus supplement or the accompanying prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

Sole Placement Agent

A.G.P.

The date of this prospectus supplement is August 15, 2022.

In addition, a number of known and unknown risks, uncertainties and other factors could affect the accuracy of these statements. Some of the more significant known risks that we face are the risk that we will be unable to raise capital to fund our operations in the near term and long term, including our ability to obtain funding through public or private equity offerings, debt financings, collaborations and licensing arrangements or other sources, on terms acceptable to us or at all, and to continue as a going concern and our ability to successfully resolve the payment issues with our primary contract manufacturer and gain access to our clinical product. The following risks and uncertainties may cause our actual results, levels of activity, performance or achievements to differ materially from any future results, levels of activity, performance or achievements expressed or implied by these forward-looking statements:

S-iii

Any forward-looking statement you read in this prospectus supplement, the accompanying prospectus or any document incorporated by reference herein or therein reflects our current views with respect to future events and is subject to these and other risks, uncertainties and assumptions relating to our operations, operating results, growth strategy and liquidity. Although we currently believe that the expectations reflected in these forward-looking statements are reasonable, we cannot guarantee our future results, levels of activity or performance. You should not place undue reliance on these forward-looking statements because such statements speak only as of the date when made. We undertake no obligation to publicly update forward-looking statements, whether as a result of new information, future events or otherwise, except as otherwise required by law. You are advised, however, to consult any further disclosures we make on related subjects in our reports on Forms 10-Q, 8-K and 10-K furnished to the SEC. You should understand that it is not possible to predict or identify all risk factors. Consequently, you should not consider any such list to be a complete set of all potential risks or uncertainties.

Any document incorporated by reference in this prospectus supplement and the accompanying prospectus may also contain statistical data and estimates we obtained from industry publications and reports generated by third parties. Although we believe that such publications and reports are reliable, we have not independently verified their data.

S-iv

S-1

INFORMATION WE INCORPORATE BY REFERENCE

The SEC allows us to “incorporate by reference” into this prospectus supplement and the accompanying prospectus the information in documents we file with it, which means that we can disclose important information to you by referring you to those documents. The information incorporated by reference is considered to be a part of this prospectus supplement and the accompanying prospectus, and information that we file later with the SEC will automatically update and supersede this information. Any statement contained in any document incorporated or deemed to be incorporated by reference herein shall be deemed to be modified or superseded for purposes of this prospectus supplement and the accompanying prospectus to the extent that a statement contained in or omitted from this prospectus supplement or the accompanying prospectus, or in any other subsequently filed document which also is or is deemed to be incorporated by reference herein or therein, modifies or supersedes such statement. Any such statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this prospectus supplement or the accompanying prospectus.

We incorporate by reference the documents listed below and any future documents that we file with the SEC (excluding any portion of such documents that are furnished and not filed with the SEC) under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act after the date of this prospectus supplement until the offering of the securities is terminated:

We will not, however, incorporate by reference in this prospectus supplement or the accompanying prospectus any documents or portions thereof that are not deemed “filed” with the SEC, including any information furnished pursuant to Item 2.02 or Item 7.01 of our current reports on Form 8-K unless, and except to the extent, specified in such current reports.

We will provide you with a copy of any of these filings (other than an exhibit to these filings, unless the exhibit is specifically incorporated by reference into the filing requested) at no cost, if you submit a request to us by writing or telephoning us at the following address and telephone number:

Athersys, Inc.

3201 Carnegie Avenue

Cleveland, Ohio 44115-2634

(216) 431-9900

Attn: Secretary

S-15

PROSPECTUS

$100,000,000

Common Stock

Preferred Stock

Depositary Shares

Warrants

Subscription Rights

Contingent Value Rights

Debt Securities

Purchase Contracts

Units

We may offer and sell from time to time our common stock, preferred stock, depositary shares, warrants, subscription rights, contingent value rights, debt securities and purchase contracts, as well as units that include any of these securities. We may sell any combination of these securities in one or more offerings with an aggregate initial offering price of $100,000,000 or the equivalent amount in other currencies or currency units.

We will provide the specific terms of the securities to be offered in one or more supplements to this prospectus. You should read this prospectus and the applicable prospectus supplement carefully before you invest in our securities. This prospectus may not be used to offer and sell our securities unless accompanied by a prospectus supplement describing the method and terms of the offering of those offered securities.

We may sell the securities directly or to or through underwriters or dealers, and also to other purchasers or through agents. The names of any underwriters or agents that are included in a sale of securities to you, and any applicable commissions or discounts, will be stated in an accompanying prospectus supplement.

Investing in any of our securities involves risk. Please read carefully the section entitled “Risk Factors” beginning on page 1 of this prospectus.

Our common stock is listed on the NASDAQ Capital Market under the symbol “ATHX.” On January 15, 2020, the closing price of our common stock on the NASDAQ Capital Market was $1.30 per share. None of the other securities that we may offer under this prospectus are currently publicly traded.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus is January 29, 2020.

TABLE OF CONTENTS

-i-

ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement that we filed with the Securities and Exchange Commission, or the “SEC,” using a “shelf” registration process. Under this shelf process, we may from time to time sell any combination of the securities described in this prospectus in one or more offerings up to an aggregate initial offering price of $100,000,000 or the equivalent amount in other currencies or currency units.

This prospectus provides you with a general description of the securities we may offer. Each time we sell securities, we will provide a prospectus supplement that will contain specific information about the terms of that offering. For a more complete understanding of the offering of the securities, you should refer to the registration statement, including its exhibits. The prospectus supplement may also add, update or change information contained in this prospectus. You should read both this prospectus and any prospectus supplement together with additional information under the heading “Where You Can Find More Information” and “Information We Incorporate By Reference.”

We have not authorized anyone to provide you with different information from the information contained or incorporated by reference in this prospectus and in any prospectus supplement or in any free writing prospectus that we may provide you. You should not assume that the information contained in this prospectus, any prospectus supplement, any document incorporated by reference or any free writing prospectus is accurate as of any date, other than the date mentioned on the cover page of these documents. We are not making offers to sell the securities in any jurisdiction in which an offer or solicitation is not authorized or in which the person making such offer or solicitation is not qualified to do so or to anyone to whom it is unlawful to make an offer or solicitation.

References in this prospectus to the terms “we,” “us” or “the Company” or other similar terms mean Athersys, Inc. and its consolidated subsidiaries, unless we state otherwise or the context indicates otherwise.

WHERE YOU CAN FIND MORE INFORMATION

We are subject to the informational reporting requirements of the Securities Exchange Act of 1934, or the “Exchange Act.” We file reports, proxy statements and other information with the SEC. Our SEC filings are available at the SEC’s website at http://www.sec.gov. We make available, free of charge, on our website at http://www.athersys.com, our annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K and amendments to those reports and statements as soon as reasonably practicable after they are filed with the SEC. The contents of our website are not part of this prospectus, and the reference to our website does not constitute incorporation by reference into this prospectus of the information contained at that site, other than documents we file with the SEC that are incorporated by reference into this prospectus.

i

INFORMATION WE INCORPORATE BY REFERENCE

The SEC allows us to “incorporate by reference” into this prospectus the information in documents we file with it, which means that we can disclose important information to you by referring you to those documents. The information incorporated by reference is considered to be a part of this prospectus, and information that we file later with the SEC will automatically update and supersede this information. Any statement contained in any document incorporated or deemed to be incorporated by reference herein shall be deemed to be modified or superseded for purposes of this prospectus to the extent that a statement contained in or omitted from this prospectus or any accompanying prospectus supplement, or in any other subsequently filed document that also is or is deemed to be incorporated by reference herein, modifies or supersedes such statement. Any such statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this prospectus.

We incorporate by reference the documents listed below and any future documents that we file with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act (1) after the date of the initial filing of the registration statement of which this prospectus forms a part prior to the effectiveness of the registration statement and (2) after the date of this prospectus until the offering of the securities is terminated:

We will not, however, incorporate by reference in this prospectus any documents or portions thereof that are not deemed “filed” with the SEC, including any information furnished pursuant to Item 2.02 or Item 7.01 of our current reports on Form 8-K unless, and except to the extent, specified in such current reports.

We will provide you with a copy of any of these filings (other than an exhibit to these filings, unless the exhibit is specifically incorporated by reference into the filing requested) at no cost, if you submit a request to us by writing or telephoning us at the following address and telephone number:

Athersys, Inc.

3201 Carnegie Avenue

Cleveland, Ohio 44115-2634

Phone: (216) 431-9900

Attention: Secretary

ii

THE COMPANY

We are an international biotechnology company that is focused primarily in the field of regenerative medicine. Our MultiStem^® cell therapy, a patented and proprietary allogeneic stem cell product, is our lead platform product and is currently in clinical development in several areas, the most advanced of which is an ongoing Phase 3 clinical trial for treatment of ischemic stroke. Our current clinical development programs are focused on treating neurological conditions, cardiovascular disease, inflammatory and immune disorders, certain pulmonary conditions and other conditions where the current standard of care is limited or inadequate for many patients, particularly in the critical care stage.

CORPORATE INFORMATION

We are incorporated under the laws of the State of Delaware. Our principal executive offices are located at 3201 Carnegie Avenue, Cleveland, Ohio 44115-2634. Our telephone number is (216) 431-9900. Our website is http://www.athersys.com. The information contained on or accessible through our website is not part of this prospectus, other than the documents that we file with the SEC that are specifically incorporated by reference into this prospectus.

Any forward-looking statement you read in this prospectus, any prospectus supplement or any document incorporated by reference reflects our current views with respect to future events and is subject to these and other risks, uncertainties and assumptions relating to our operations, operating results growth strategy and liquidity. You should not place undue reliance on these forward-looking statements because such statements speak only as of the date when made. We undertake no obligation to publicly update forward-looking statements, whether as a result of new information, future events or otherwise, except as otherwise required by law. You are advised, however, to consult any further disclosures we make on related subjects in our reports on Forms 10-Q, 8-K and

2

10-K furnished to the SEC. You should understand that it is not possible to predict or identify all risk factors. Consequently, you should not consider any such list to be a complete set of all potential risks or uncertainties.

Any document incorporated by reference or any prospectus supplement may also contain statistical data and estimates we obtained from industry publications and reports generated by third parties. Although we believe that the publications and reports are reliable, we have not independently verified their data.

Voting the Preferred Stock

Upon receipt of notice of any meeting at which the holders of the preferred stock represented by depositary shares are entitled to vote, the bank depositary will mail the notice to the record holders of the depositary shares relating to the preferred stock. Each record holder of these depositary shares on the record date (which will be the same date as the record date for the preferred stock) may instruct the bank depositary as to how to vote the preferred stock represented by this holder’s depositary shares. The bank depositary will endeavor, insofar as practicable, to vote the amount of the preferred stock represented by such depositary shares in accordance with these instructions, and we will take all action which the bank depositary deems necessary in order to enable the bank depositary to do so. The bank depositary will abstain from voting shares of the preferred stock to the extent it does not receive specific instructions from the holders of depositary shares representing this preferred stock.

Amendment and Termination of the Depositary Agreement

The form of depositary receipt evidencing the depositary shares and any provision of the depositary agreement may be amended by agreement between the bank depositary and us. However, any amendment that materially and adversely alters the rights of the holders of depositary shares will not be effective unless this amendment has been approved by the holders of at least a majority of the depositary shares then outstanding. The depositary agreement may be terminated by the bank depositary or us only if:

Charges of Bank Depositary

We will pay all transfer and other taxes and governmental charges arising solely from the existence of the depositary arrangements. We will pay charges of the bank depositary in connection with the initial deposit of the preferred stock and any redemption of the preferred stock. Holders of depositary receipts will pay other transfer, tax and governmental charges and any other charges, including a fee for the withdrawal of shares of preferred stock upon surrender of depositary receipts, as are expressly provided in the depositary agreement to be for their accounts.

Withdrawal of Preferred Stock

Except as may be provided otherwise in the applicable prospectus supplement, upon surrender of depositary receipts at the principal office of the bank depositary, subject to the terms of the depositary agreement, the owner of the depositary shares may demand delivery of the number of whole shares of preferred stock and all money and other property, if any, represented by those depositary shares. Fractional shares of preferred stock will not be issued. If the depositary receipts delivered by the holder evidence a number of depositary shares in excess of the number of depositary shares representing the number of whole shares of preferred stock to be withdrawn, the bank depositary will deliver to this holder at the same time a new depositary receipt evidencing the excess number of depositary shares. Holders of preferred stock thus withdrawn may not thereafter deposit those shares under the depositary agreement or receive depositary receipts evidencing depositary shares therefor.

Miscellaneous

The bank depositary will forward to holders of depositary receipts all reports and communications from us that are delivered to the bank depositary and that we are required to furnish to the holders of preferred stock.

5

Neither the bank depositary nor we will be liable if we are prevented or delayed by law or any circumstance beyond our control in performing our obligations under the depositary agreement. The obligations of the bank depositary and us under the depositary agreement will be limited to performance in good faith of our duties thereunder, and we will not be obligated to prosecute or defend any legal proceeding in respect of any depositary shares or shares of preferred stock unless satisfactory indemnity is furnished. We may rely upon written advice of counsel or accountants, or upon information provided by persons presenting shares of preferred stock for deposit, holders of depositary receipts or other persons believed to be competent and on documents believed to be genuine.

Resignation and Removal of Bank Depositary

The bank depositary may resign at any time by delivering to us notice of its election to do so, and we may at any time remove the bank depositary. Any such resignation or removal will take effect upon the appointment of a successor bank depositary and the successor’s acceptance of this appointment. The successor bank depositary must be appointed within 60 days after delivery of the notice of resignation or removal and must be a bank or trust company meeting the requirements of the depositary agreement.

Stock Warrants

The prospectus supplement relating to a particular issue of warrants to issue common stock, preferred stock or depositary shares will describe the terms of the common stock warrants and preferred stock warrants, including the following:

7

Exercise of Warrants

Each warrant will entitle the holder of the warrant to purchase at the exercise price set forth in the applicable prospectus supplement the number of shares of common stock, preferred stock or depositary shares or the principal amount of debt securities being offered. Holders may exercise warrants at any time up to the close of business on the expiration date set forth in the applicable prospectus supplement. After the close of business on the expiration date, unexercised warrants are void. Holders may exercise warrants as set forth in the prospectus supplement relating to the warrants being offered.

Until a holder exercises the warrants to purchase our common stock, preferred stock, depositary shares or debt securities, the holder will not have any rights as a holder of our common stock, preferred stock, depositary shares or debt securities, as the case may be, by virtue of ownership of warrants.

DESCRIPTION OF SUBSCRIPTION RIGHTS

We may issue to our shareholders subscription rights to purchase our common stock, preferred stock, depositary shares, contingent value rights or debt securities. The following description sets forth certain general terms and provisions of the subscription rights that we may offer pursuant to this prospectus. The particular terms of the subscription rights and the extent, if any, to which the general terms and provisions may apply to the subscription rights so offered will be described in the applicable prospectus supplement.

Subscription rights may be issued independently or together with any other security offered by this prospectus and may or may not be transferable by the shareholder receiving the rights in the rights offering. In connection with any rights offering, we may enter into a standby underwriting agreement with one or more underwriters pursuant to which the underwriter will purchase any securities that remain unsubscribed for upon completion of the rights offering, or offer these securities to other parties who are not our shareholders. A copy of the form of subscription rights certificate will be filed with the SEC each time we issue subscription rights, and you should read that document for provisions that may be important to you. For more information on how you can obtain a copy of any subscription rights certificate, see “Where You Can Find More Information.”

8

The applicable prospectus supplement relating to any subscription rights will describe the terms of the offered subscription rights, including, where applicable, the following:

DESCRIPTION OF CONTINGENT VALUE RIGHTS

We may issue contingent value rights pursuant to an agreement to be entered into by and between the Company and a trustee, agent and/or the purchasers (or representative(s) thereof) of such contingent value rights (the “CVR Agreement”). The contingent value rights will entitle the holder to a potential cash payment upon the satisfaction of one or more conditions set forth in the CVR Agreement. The following description sets forth certain general terms and provisions of the contingent value rights that we may offer pursuant to this prospectus. The particular terms of the contingent value rights and the extent, if any, to which the general terms and provisions may apply to the contingent value rights so offered will be described in the applicable prospectus supplement.

Contingent value rights may be issued independently or together with any other security offered by this prospectus. A copy of the form of contingent value rights certificate will be filed with the SEC each time we issue contingent value rights, and you should read that document for provisions that may be important to you. For more information on how you can obtain a copy of any contingent value rights certificate, see “Where You Can Find More Information.”

The applicable prospectus supplement relating to any contingent value rights will describe the terms of the offered contingent value rights, including, where applicable, the following:

9

The foregoing is not intended to be an exclusive list of the terms that may be applicable to any offered contingent value rights.

We will set forth in a prospectus supplement relating to any debt securities being offered, the aggregate principal amount and the following terms of the debt securities, if applicable:

11

The foregoing is not intended to be an exclusive list of the terms that may be applicable to any offered debt securities.

In addition, the indenture does not limit our ability to issue convertible, exchangeable or subordinated debt securities. Any conversion, exchange or subordination provisions of debt securities will be described in the relevant prospectus supplement. Such terms may include provisions for conversion or exchange, either mandatory, at the option of the holder or at our option, in which case the number of shares of common stock or other securities to be received by the holders of debt securities would be calculated as of a time and in the manner stated in the prospectus supplement.

We may issue debt securities that provide for an amount less than their stated principal amount to be due and payable upon declaration of acceleration of their maturity pursuant to the terms of the indenture. We will provide you with information on the U.S. federal income tax considerations and other special considerations applicable to any of these debt securities in the applicable prospectus supplement.

If we denominate the purchase price of any of the debt securities in a foreign currency or currencies or a foreign currency unit or units, or if the principal of, and any premium and interest on, any series of debt securities is payable in a foreign currency or currencies or a foreign currency unit or units, we will provide you with information on the restrictions, elections, general tax considerations, specific terms and other information with respect to that issue of debt securities and such foreign currency or currencies or foreign currency unit or units in the applicable prospectus supplement.

Exchange and Transfer

Debt securities may be transferred or exchanged at the office of the registrar or co-registrar designated by us.

We will not impose a service charge for any transfer or exchange, but we may require holders to pay any tax or other governmental charges associated with any transfer or exchange.

In the event of any redemption of debt securities of any series, we will not be required to:

12

We may initially appoint the trustee as the registrar. Any transfer agent, in addition to the registrar initially designated by us, will be named in the prospectus supplement. We may designate additional transfer agents or change transfer agents or change the office of the transfer agent. However, we will be required to maintain a transfer agent in each place of payment for the debt securities of each series.

Global Securities

The debt securities of any series may be represented, in whole or in part, by one or more global securities. Each global security will:

No global security may be exchanged in whole or in part for debt securities registered in the name of any person other than the depositary or any nominee unless:

As long as the depositary, or its nominee, is the registered owner of a global security, the depositary or nominee will be considered the sole owner and holder of the debt securities represented by the global security for all purposes under the indenture. Except in the above limited circumstances, owners of beneficial interests in a global security:

Payments on a global security will be made to the depositary or its nominee as the holder of the global security. Some jurisdictions have laws that require that certain purchasers of securities take physical delivery of such securities in definitive form. These laws may impair the ability to transfer beneficial interests in a global security.

Institutions that have accounts with the depositary or its nominee are referred to as “participants.” Ownership of beneficial interests in a global security will be limited to participants and to persons that may hold beneficial interests through participants. The depositary will credit, on its book-entry registration and transfer system, the respective principal amounts of debt securities represented by the global security to the accounts of its participants. Each person owning a beneficial interest in a global security must rely on the procedures of the depositary (and, if such person is not a participant, on procedures of the participant through which such person owns its interest) to exercise any rights of a holder under the indenture.

13

Ownership of beneficial interests in a global security will be shown on and effected through records maintained by the depositary, with respect to participants’ interests, or by any participant, with respect to interests of persons held by participants on their behalf. Payments, transfers and exchanges relating to beneficial interests in a global security will be subject to policies and procedures of the depositary. The depositary policies and procedures may change from time to time. Neither we nor the trustee will have any responsibility or liability for the depositary’s acts or omissions or any participant’s records with respect to beneficial interests in a global security.

Payment and Paying Agent

The provisions of this subsection will apply to the debt securities unless otherwise indicated in the prospectus supplement. Payment of interest on a debt security on any interest payment date will be made to the person in whose name the debt security is registered at the close of business on the regular record date. Payment on debt securities of a particular series will be payable at the office of a paying agent or paying agents designated by us. However, at our option, we may pay interest by mailing a check to the record holder.

We may also name any other paying agents in the prospectus supplement. We may designate additional paying agents, change paying agents or change the office of any paying agent. However, we will be required to maintain a paying agent in each place of payment for the debt securities of a particular series.

Subject to any applicable abandoned property law, all moneys paid by us to a paying agent for payment on any debt security that remain unclaimed at the end of two years after such payment was due will be repaid to us. Thereafter, the holder may look only to us for such payment.

Consolidation, Merger and Sale of Assets

Except as otherwise set forth in the applicable prospectus supplement, we may not merge or consolidate with or into any other person, in a transaction in which we are not the surviving corporation, or sell, convey, transfer, lease or otherwise dispose of all or substantially all of the properties and assets of us and our subsidiaries, taken as a whole, to any person, unless:

In the event of the above transaction, if there is a successor or transferee, then the successor or transferee will expressly assume all of our obligations under the indenture and automatically be substituted for us in the indenture and as issuer of the debt securities and may exercise every right and power of ours under the indenture with the same effect as if such successor or transferee had been named in our place in the indenture; provided, however, that the predecessor company will not be relieved of the obligation to pay principal and interest on the debt securities except in the case of a sale of all of the assets of us and our subsidiaries.

14

Events of Default

Event of default means, with respect to any series of debt securities, any of the following:

We will promptly deliver to the trustee written notice of any event which with the giving of notice and the lapse of time would become a covenant event of default, or any other event of default provided with respect to debt securities of that series that is described in the applicable prospectus supplement, along with a description of the status and what action we are taking or propose to take with respect to such event of default.

No event of default with respect to a particular series of debt securities (except as to certain events of bankruptcy, insolvency or reorganization) necessarily constitutes an event of default with respect to any other series of debt securities. The occurrence of an event of default may constitute an event of default under our bank credit agreements in existence from time to time. In addition, the occurrence of certain events of default or an acceleration under the indenture may constitute an event of default under certain of our other indebtedness outstanding from time to time.

If an event of default (other than an event of default resulting from certain events of bankruptcy, insolvency or reorganization of our company) with respect to debt securities of any series at the time outstanding occurs and is continuing, then the trustee or the holders of not less than 25% in aggregate principal amount of the outstanding debt securities of that series may, by a notice in writing to us (and to the trustee if given by the holders), declare to be due and payable immediately the principal (or, if the debt securities of that series are discount securities, that portion of the principal amount as may be specified in the terms of that series) of, and accrued and unpaid interest, if any, on all debt securities of that series. In the case of an event of default resulting from certain events of bankruptcy, insolvency or reorganization of our company, the principal (or such specified amount) of and accrued and unpaid interest, if any, on all outstanding debt securities will become and be immediately due and payable without any declaration or other act on the part of the trustee or any holder of outstanding debt securities. At any time after a declaration of acceleration with respect to debt securities of any series has been made, the holders of a majority in aggregate principal amount of the outstanding debt securities of that series may rescind and annul the acceleration if the rescission and annulment would not conflict with any

15

judgment or decree already rendered and if all events of default with respect to that series, other than the non-payment of principal and interest, if any, with respect to debt securities of that series that has become due and payable solely because of the acceleration, have been cured or waived and all sums paid or advanced by the trustee and the reasonable compensation expenses and disbursements of the trustee and its agents and counsel have been paid as provided in the indenture.

The indenture provides that the trustee will be under no obligation to exercise any of its rights or powers under the indenture at the request of any holder of outstanding debt securities, unless the trustee receives security or indemnity satisfactory to it against any loss, liability or expense. Subject to certain rights of the trustee, the holders of a majority in principal amount of the outstanding debt securities of any series will have the right to direct the time, method and place of conducting any proceeding for any remedy available to the trustee or exercising any trust or power conferred on the trustee with respect to the debt securities of that series.

No holder of any debt security of any series will have any right to institute any proceeding, judicial or otherwise, with respect to the indenture or for the appointment of a receiver or trustee, or for any remedy under the indenture, unless:

Notwithstanding the foregoing, the holder of any debt security will have an absolute and unconditional right to receive payment of the principal of, and premium and any interest on, that debt security on or after the due dates expressed in that debt security and to institute suit for the enforcement of such payment.

The indenture requires us, within 120 days after the end of our fiscal year, to furnish to the trustee a statement as to compliance with the indenture. The indenture provides that the trustee may withhold notice to the holders of debt securities of any series of any default or event of default (except in payment on any debt securities of that series) with respect to debt securities of that series if it in good faith determines that withholding notice is in the interest of the holders of those debt securities.

Modification and Waiver

We may amend or modify the indenture without the consent of any holder of debt securities of the series affected by the modifications or amendments in order to:

16

Other amendments and modifications of the indenture or the debt securities issued may be made with the consent of the holders of at least a majority of the aggregate principal amount of the outstanding debt securities of the affected series, and our compliance with any provision of the indenture with respect to the debt securities may be waived by written notice to the trustee by the holders of a majority of the aggregate principal amount of the outstanding debt securities of the affected series. However, no modification or amendment may, without the consent of the holder of each outstanding debt security of the affected series:

Except for certain specified provisions, the holders of at least a majority in principal amount of the outstanding debt securities of an affected series may, on behalf of the holders of all debt securities of such series, waive our compliance with provisions of the indenture. Prior to the acceleration of the maturity of the debt securities of any series pursuant to the terms of the indenture, the holders of a majority in aggregate principal amount of the outstanding debt securities of such series may, on behalf of the holders of all the debt securities of such series, waive any past default under the indenture with respect to such debt securities and its consequences, except (i) a default with respect to such series in the payment of the principal of, or premium or any interest on, the debt securities of such series or (ii) a default or event of default in respect of a covenant or provision that cannot be modified or amended without the consent of all of the holders of the outstanding debt securities of the affected series.

17

Defeasance of Debt Securities and Certain Covenants in Certain Circumstances

Legal Defeasance. The indenture provides that, in certain circumstances, we may be discharged from any and all obligations in respect of the debt securities of any series (except for certain obligations to register the transfer or exchange of debt securities, to replace stolen, lost or mutilated debt securities, and to maintain paying agencies and certain provisions relating to the treatment of funds held by paying agents). We will be so discharged upon the deposit with the trustee, in trust, of money and/or U.S. government obligations that, through the payment of interest and principal in accordance with their terms, will provide money in an amount sufficient in the written opinion of a nationally recognized firm of independent public accountants, a nationally recognized investment bank or a nationally recognized appraisal firm to pay and discharge each installment of principal, premium and interest in accordance with the terms of the indenture and the debt securities of that series.

This discharge may occur only if, among other things, we have delivered to the trustee an opinion of counsel stating that we have received from, or there has been published by, the United States Internal Revenue Service a ruling or, since the date of execution of the indenture, there has been a change in the applicable U.S. federal income tax law, in either case to the effect that, and based thereon such opinion shall confirm that, the beneficial owners of the debt securities of the applicable series will not recognize income, gain or loss for U.S. federal income tax purposes as a result of the deposit, defeasance and discharge and will be subject to U.S. federal income tax on the same amounts and in the same manner and at the same times as would have been the case if the deposit, defeasance and discharge had not occurred.

Defeasance of Certain Covenants. The indenture provides that, upon compliance with certain conditions, we may be released from our obligation to comply with certain covenants set forth in the indenture and any supplemental indenture, and any failure to comply with those covenants will not constitute a default or an event of default with respect to the debt securities of the applicable series, or covenant defeasance. If we exercise our covenant defeasance option with respect to a series of debt securities, payment of such debt securities may not be accelerated because of an event of default related to certain events of bankruptcy, insolvency or reorganization of our significant subsidiaries.

The conditions include:

Governing Law

The indenture and the debt securities will be governed by, and construed in accordance with, the internal laws of the State of New York.

18

DESCRIPTION OF PURCHASE CONTRACTS

We may issue purchase contracts, including contracts obligating holders to purchase from us, and obligating us to sell to the holders, a specified number of common shares or other securities at a future date or dates. The price per security of the securities and the number of securities may be fixed at the time the purchase contracts are issued or may be determined by reference to a specific formula set forth in the purchase contracts. The purchase contracts also may require us to make periodic payments to the holders of the purchase contracts, or vice versa, and those payments may be unsecured or refunded on some basis. The purchase contracts may require holders to secure their obligations thereunder in a specified manner and may provide for the prepayment of all or part of the consideration payable by holders in connection with the purchase of the underlying security or other property pursuant to the purchase contracts.

The securities related to the purchase contracts may be pledged to a collateral agent for our benefit pursuant to a pledge agreement to secure the obligations of holders of purchase contracts to purchase the underlying security or property under the related purchase contracts. The rights of holders of purchase contracts to the related pledged securities will be subject to our security interest therein created by the pledge agreement. No holder of purchase contracts will be permitted to withdraw the pledged securities related to such purchase contracts from the pledge arrangement.

The prospectus supplement relating to any particular issuance of purchase contracts will describe the terms of the purchase contracts. The description in the prospectus supplement will not necessarily be complete, and reference will be made to the purchase contracts, and, if applicable, collateral or depositary arrangements, relating to the purchase contracts, which will be filed with the SEC each time we issue purchase contracts. U.S. federal income tax considerations applicable to the purchase contracts will also be discussed in the prospectus supplement.

PLAN OF DISTRIBUTION

We may sell the offered securities in and outside the United States:

The prospectus supplement will include the following information:

Sale through Underwriters or Dealers

If underwriters are used in the sale, the underwriters will acquire the securities for their own account. The underwriters may resell the securities from time to time in one or more transactions, including negotiated transactions, at a fixed public offering price or at varying prices determined at the time of sale. Underwriters may offer securities to the public either through underwriting syndicates represented by one or more managing underwriters or directly by one or more firms acting as underwriters. Unless we inform you otherwise in the prospectus supplement, the obligations of the underwriters to purchase the securities will be subject to certain conditions, and the underwriters will be obligated to purchase all the offered securities if they purchase any of them. The underwriters may change from time to time any initial public offering price and any discounts or concessions allowed or reallowed or paid to dealers.

If we offer securities in a subscription rights offering to our existing security holders, we may enter into a standby underwriting agreement with dealers, acting as standby underwriters. We may pay the standby underwriters a commitment fee for the securities they commit to purchase on a standby basis. If we do not enter into a standby underwriting agreement, we may retain a dealer-manager to manage a subscription rights offering for us.

20

During and after an offering through underwriters, the underwriters may purchase and sell the securities in the open market. These transactions may include overallotment and stabilizing transactions and purchases to cover syndicate short positions created in connection with the offering. The underwriters may also impose a penalty bid, which means that selling concessions allowed to syndicate members or other broker-dealers for the offered securities sold for their account may be reclaimed by the syndicate if the offered securities are repurchased by the syndicate in stabilizing or covering transactions. These activities may stabilize, maintain or otherwise affect the market price of the offered securities, which may be higher than the price that might otherwise prevail in the open market. If commenced, the underwriters may discontinue these activities at any time.

Some or all of the securities that we offer though this prospectus may be new issues of securities with no established trading market. Any underwriters to whom we sell our securities for public offering and sale may make a market in those securities, but they will not be obligated to do so and they may discontinue any market making at any time without notice. Accordingly, we cannot assure you of the liquidity of, or continued trading markets for, any securities that we offer.

If dealers are used in the sale of securities, we will sell the securities to them as principals. They may then resell those securities to the public at varying prices determined by the dealers at the time of resale. We will include in the prospectus supplement the names of the dealers and the terms of the transaction.

Direct Sales and Sales through Agents

We may sell the securities directly. In this case, no underwriters or agents would be involved. We may also sell the securities through agents designated from time to time at fixed prices or at varying prices determined at the time of sale. In the prospectus supplement, we will name any agent involved in the offer or sale of the offered securities, and we will describe any commissions payable to the agent. Unless we inform you otherwise in the prospectus supplement, any agent will agree to use its reasonable best efforts to solicit purchases for the period of its appointment.

We may sell the securities directly to institutional investors or others who may be deemed to be underwriters within the meaning of the Securities Act with respect to any sale of those securities. We will describe the terms of any sales of these securities in the prospectus supplement.

Remarketing Arrangements

Offered securities may also be offered and sold, if so indicated in the applicable prospectus supplement, in connection with a remarketing upon their purchase, in accordance with a redemption or repayment pursuant to their terms, or otherwise, by one or more remarketing firms, acting as principals for their own accounts or as agents for us. Any remarketing firm will be identified and the terms of its agreements, if any, with us and its compensation will be described in the applicable prospectus supplement.

Delayed Delivery Contracts

If we so indicate in the prospectus supplement, we may authorize agents, underwriters or dealers to solicit offers from certain types of institutions to purchase securities from us at the public offering price under delayed delivery contracts. These contracts would provide for payment and delivery on a specified date in the future. The contracts would be subject only to those conditions described in the prospectus supplement. The prospectus supplement will describe the commission payable for solicitation of those contracts.

General Information

We may have agreements with the agents, dealers, underwriters and remarketing firms to indemnify them against certain civil liabilities, including liabilities under the Securities Act, or to contribute with respect to

21

payments that the agents, dealers, underwriters or remarketing firms may be required to make. Agents, dealers, underwriters and remarketing firms may be customers of, engage in transactions with or perform services for us in the ordinary course of their businesses.

LEGAL MATTERS

Jones Day will pass upon the validity of the securities being offered hereby.

EXPERTS

The consolidated financial statements of Athersys, Inc. appearing in Athersys, Inc.’s Annual Report (Form 10-K) for the year ended December 31, 2018, including the schedule appearing therein, and the effectiveness of Athersys, Inc.’s internal control over financial reporting as of December 31, 2018, have been audited by Ernst & Young LLP, independent registered public accounting firm, as set forth in their reports thereon, included therein, and incorporated herein by reference. Such consolidated financial statements are, and audited financial statements to be included in subsequently filed documents will be, incorporated herein in reliance upon such reports of Ernst & Young LLP pertaining to such financial statements and the effectiveness of our internal control over financial reporting as of the respective dates to the extent covered by consents filed with the Securities and Exchange Commission given on the authority of such firm as experts in accounting and auditing.

22