STML Stemline Therapeutics Inc

PROXY STATEMENT

        This proxy statement and the accompanying proxy card are being made available via internet access, beginning on or about April 29, 2020, to the owners of shares of common stock of Stemline Therapeutics, Inc. (the "Company," "our," "we," or "Stemline") as of April 27, 2020, in connection with the solicitation of proxies by our Board of Directors for our 2020 Annual Meeting of Stockholders (the "Annual Meeting"). On or about April 29, 2020, we sent an "Important Notice Regarding the Availability of Proxy Materials" to our stockholders. If you received this notice by mail, you will not automatically receive by mail our proxy statement and annual report to stockholders for the year ended December 31, 2019. If you would like to receive a printed copy of our proxy statement, annual report and proxy card, please follow the instructions for requesting such materials in the notice. Upon request, we will promptly mail you paper copies of such materials free of charge.

        The Annual Meeting will take place at the offices of our legal counsel, Alston & Bird LLP, located at 90 Park Avenue, New York, New York 10016 on Thursday, June 25, 2020, at 10:00 a.m. ET. Our Board of Directors encourages you to read this document thoroughly and take this opportunity to vote, via proxy, on the matters to be decided at the Annual Meeting. As discussed below, you may revoke your proxy at any time before your shares are voted at the Annual Meeting.

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QUESTIONS AND ANSWERS

Q:

Why did I receive an "Important Notice Regarding the Availability of Proxy Materials"?

A.

In accordance with Securities and Exchange Commission ("SEC") rules, instead of mailing a printed copy of our proxy materials, we may send an "Important Notice Regarding the Availability of Proxy Materials" to stockholders. All stockholders will have the ability to access the proxy materials on a website referred to in the notice or to request a printed set of these materials at no charge. You will not receive a printed copy of the proxy materials unless you specifically request one from us. Instead, the notice instructs you as to how you may access and review all of the important information contained in the proxy materials via the internet and submit your vote via the internet.

Important Notice Regarding the Availability of Proxy Materials for the Stockholder Meeting to Be Held on June 25, 2020. The proxy statement is available at www.edocumentview.com/STML.

Q:

When is the Annual Meeting?

A.

The Annual Meeting will be held on Thursday, June 25, 2020, at 10:00 a.m., Eastern Time.

Q:

Where will the Annual Meeting be held?

A.

The Annual Meeting will be held at the offices of Alston & Bird LLP, our legal counsel, located at 90 Park Avenue, New York, New York 10016.

Q:

What is the purpose of the Annual Meeting?

A.

At the Annual Meeting, our stockholders will act upon the matters outlined in the Notice of 2020 Annual Meeting of Stockholders accompanying this proxy statement, including: (i) the election of three Class II directors, until their successors are elected and qualified, (ii) the ratification of the appointment of Ernst & Young LLP as our independent registered public accounting firm for the year ending December 31, 2020, (iii) the approval of an amendment to our 2016 Equity Incentive Plan to increase the number of authorized shares issuable thereunder by 2,500,000 shares, and (iv) the transaction of any other business that may properly come before the 2020 Annual Meeting or any adjournment thereof.

Q:

How many votes do I have?

A.

On each matter to be voted upon, you have one vote for each share of common stock you own as of the Record Date.

Q:

Who is entitled to vote at our Annual Meeting?

A.

Only stockholders of record at the close of business on April 27, 2020, which we refer to as the Record Date, are entitled to receive notice of the Annual Meeting and to vote the shares that they held on that date at the Annual Meeting, or any adjournment or postponement thereof. As of the close of business on the Record Date, we had 52,472,785 shares of common stock outstanding. Each share of common stock entitles its holder to one vote at the Annual Meeting. A list of stockholders entitled to vote at the Annual Meeting, including the address of and number of shares held by each stockholder of record, will be available for your inspection beginning May 4, 2020, at our offices located at 750 Lexington Avenue, Eleventh Floor, New York, New York 10022, between the hours of 10:00 a.m. and 5:00 p.m., ET, each business day.

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Stockholders of Record: Shares Registered in Your Name.  If on the Record Date your shares were registered directly in your name with our transfer agent, Computershare, then you are a

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stockholder of record. As a stockholder of record, you may vote in person at the Annual Meeting or vote by proxy. Whether or not you plan to attend the Annual Meeting, we urge you to fill out and return the enclosed proxy card, to ensure your vote is counted.

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Beneficial Owner: Shares Registered in the Name of a Broker, Bank, Custodian or Other Nominee.  If on the Record Date your shares were held in an account at a brokerage firm, bank, custodian or other nominee, then you are the beneficial owner of shares held in "street name" and these proxy materials are being forwarded to you by that organization. The organization holding your account is considered the stockholder of record for purposes of voting at the Annual Meeting. As a beneficial owner, you have the right to direct your broker, bank, custodian or other nominee on how to vote the shares in your account. You are also invited to attend the Annual Meeting. However, because you are not the stockholder of record, you may not vote your shares in person at the Annual Meeting unless you request and obtain a valid proxy from your broker, bank, custodian or other nominee.

Q:

How do I vote?

A.

Whether you hold shares directly as the stockholder of record or indirectly as the beneficial owner of shares held for you by a broker or other nominee (i.e., in "street name"), you may direct your vote without attending the Annual Meeting. You may vote by granting a proxy or, for shares you hold in street name, by submitting voting instructions to your broker or nominee. In most instances, you will be able to do this by internet, telephone or by mail. Please refer to the summary instructions below and those included on your proxy card or, for shares you hold in street name, the voting instruction card provided by your broker or nominee.

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By Internet—If you have Internet access, you may authorize your proxy from any location in the world as directed in our "Important Notice Regarding the Availability of Proxy Materials."

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By Telephone—If you are calling from the United States or Canada, you may authorize your proxy by following the "By Telephone" instructions on the proxy card or, if applicable, the telephone voting instructions that may be described on the voting instruction card sent to you by your broker or nominee.

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By Mail—You may authorize your proxy by signing your proxy card and mailing it in the enclosed, postage-prepaid and addressed envelope. For shares you hold in street name, you may sign the voting instruction card included by your broker or nominee and mail it in the envelope provided.

Q:

What is a proxy?

A.

A proxy is a person you appoint to vote your shares of our common stock on your behalf. If you are unable to attend the Annual Meeting, our Board of Directors is seeking your appointment of a proxy so that your shares of our common stock may be voted. If you vote by proxy, you will be designating Ivan Bergstein, our Chairman, President and Chief Executive Officer, and Kenneth Hoberman, our Chief Operating Officer and Corporate Secretary, as your proxies. Dr. Bergstein and/or Mr. Hoberman may act on your behalf and have the authority to appoint a substitute to act as your proxy.

Q:

How will my shares be voted if I vote by proxy?

A.

Your proxy will be voted according to the instructions you provide. If you complete and submit your proxy but do not otherwise provide instructions on how to vote your shares, your shares will be voted: (i) "FOR" the individuals nominated to serve as members of our Board of Directors, (ii) "FOR" the ratification of Ernst & Young LLP as our independent registered public accounting

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firm for the year ending December 31, 2020, and (iii) "FOR" the approval of an amendment to our 2016 Equity Incentive Plan to increase the number of authorized shares issuable thereunder by 2,500,000 shares. Presently, our Board of Directors does not know of any other matter that may come before the Annual Meeting. However, your proxies are authorized to vote on your behalf, using their discretion, on any other business that properly comes before the Annual Meeting.

Q:

Can I change my vote after I return my proxy card?

A.

Yes. You may revoke your proxy at any time before the final vote at the Annual Meeting. If you are the record holder of your shares, you may revoke your proxy in any one of three ways:

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You may send a written notice that you are revoking your proxy to our Corporate Secretary, Kenneth Hoberman, at 750 Lexington Avenue, Eleventh Floor, New York, NY 10022 (so long as we receive such notice no later than the close of business on the day before the Annual Meeting);

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You may submit a later dated proxy card or vote again via the internet as described in the "Important Notice Regarding the Availability of Proxy Materials"; or

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You may attend the Annual Meeting and notify the election officials at the Annual Meeting that you wish to revoke your proxy and vote in person. Simply attending the Annual Meeting will not, by itself, revoke your proxy.

If your shares are held by your broker, bank, custodian or other nominee, you should follow the instructions provided by such broker, bank, custodian or other nominee.

Q:

Is my vote confidential?

A.

Yes. All votes remain confidential, unless you provide otherwise.

Q:

How are votes counted?

A.

Before the Annual Meeting, our Board of Directors will appoint one or more inspectors of election for the meeting. The inspector(s) will determine the number of shares represented at the meeting, the existence of a quorum and the validity and effect of proxies. The inspector(s) will also receive, count, and tabulate ballots and votes and determine the results of the voting on each matter that comes before the Annual Meeting.

Abstentions and votes withheld, and shares represented by proxies reflecting abstentions or votes withheld, will be treated as present for purposes of determining the existence of a quorum at the Annual Meeting. They will not be considered as votes "for" or "against" any matter for which the stockholder has indicated their intention to abstain or withhold their vote. Broker non-votes occur when shares are held indirectly through a broker, bank or other intermediary on behalf of a beneficial owner (referred to as held in "street name") and the broker submits a proxy but does not vote for a matter because the broker has not received voting instructions from the beneficial owner and (i) the broker does not have discretionary voting authority on the matter or (ii) the broker chooses not to vote on a matter for which it has discretionary voting authority. Pursuant to the New York Stock Exchange (the "NYSE"), which governs voting matters at the Annual Meeting, brokers are permitted to exercise discretionary voting authority only on "routine" matters when voting instructions have not been timely received from a beneficial owner.

The following matter up for vote at the Annual Meeting is considered to be "routine": the ratification of Ernst & Young LLP as our independent registered public accounting firm for the year ending December 31, 2020. Brokers that hold your shares, therefore, have discretionary

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authority to vote your shares on this matter unless they receive instructions from you on this matter.

Q:

What constitutes a quorum at the Annual Meeting?

A.

In accordance with Delaware law (the law under which we are incorporated) and our Amended and Restated Bylaws, the presence at the Annual Meeting, by proxy or in person, of the holders of a majority of the shares of our common stock outstanding on the record date constitutes a quorum, thereby permitting the stockholders to conduct business at the Annual Meeting. Abstentions, votes withheld, and broker or nominee non-votes will be included in the calculation of the number of shares considered present at the Annual Meeting for purposes of determining the existence of a quorum.

If a quorum is not present at the Annual Meeting, a majority of the stockholders present in person and by proxy may adjourn the meeting to another date. If an adjournment is for more than 30 days or a new record date is fixed for the adjourned meeting by our Board of Directors, we will provide notice of the adjourned meeting to each stockholder of record entitled to vote at the adjourned meeting. At any adjourned meeting at which a quorum is present, any business may be transacted that might have been transacted at the originally called meeting.

Q:

What vote is required to elect each of our director-nominees?

A.

The affirmative vote of a plurality of the votes of the shares present, in person or by proxy, at the Annual Meeting is required for the election of each of the director nominees. "Plurality" means that the nominees receiving the largest number of votes up to the number of directors to be elected at the Annual Meeting will be duly elected as directors. Abstentions, votes withheld, and broker or nominee non-votes will not affect the outcome of director elections.

Q:

What vote is required to ratify Ernst & Young LLP as our independent registered public accounting firm for the year ending December 31, 2020?

A.

The affirmative vote of a majority of the shares present, in person or by proxy, and entitled to vote at the Annual Meeting is required to approve the ratification of Ernst & Young LLP as our independent registered public accounting firm for the year ending December 31, 2020. Abstentions and votes withheld will have the same effect as a negative vote. However, broker or nominee non-votes, and shares represented by proxies reflecting broker or nominee non-votes, will not have the effect of a vote against this proposal as they are not considered to be present and entitled to vote on this matter.

Q:

What vote is required to approve the amendment to our 2016 Equity Incentive Plan to increase the number of authorized shares issuable thereunder by 2,500,000 shares?

A.

The affirmative vote of a majority of the shares present, in person or by proxy, and entitled to vote at the Annual Meeting is required to approve an amendment to our 2016 Equity Incentive Plan to increase the number of authorized shares issuable thereunder by 2,500,000 shares. Abstentions and votes withheld will have the same effect as a negative vote. However, broker or nominee non-votes, and shares represented by proxies reflecting broker or nominee non-votes, will not have the effect of a vote against this proposal as they are not considered to be present and entitled to vote on this matter.

Q:

What percentage of our outstanding common stock do our directors and executive officers own?

A.

As of April 27, 2020, our directors and executive officers owned, or have the right to acquire, approximately 11.2% of our outstanding common stock. See the discussion under the heading

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"Stock Ownership of Our Directors, Executive Officers, and 5% Beneficial Owners" on page 37 for more details.

Q:

How can I find out the results of the voting at the Annual Meeting?

A.

We will announce preliminary voting results at the Annual Meeting. We will also disclose voting results on a Form 8-K filed with the SEC, within four business days after the Annual Meeting.

Q:

Who was our independent public accountant for the year ended December 31, 2019? Will they be represented at the Annual Meeting?

A.

Ernst & Young LLP is the independent registered public accounting firm that audited our financial statements for the year ended December 31, 2019. We expect a representative of Ernst & Young LLP to be present at the Annual Meeting. The representative will have an opportunity to make a statement and will be available to answer your questions.

Q:

Who is paying for this proxy solicitation?

A.

We will pay the entire cost of preparing, assembling, printing, mailing, and distributing these proxy materials and soliciting votes. If you choose to vote over the internet, you are responsible for internet access charges you may incur. If you choose to vote by telephone, you are responsible for telephone charges you may incur. In addition to the mailing of these proxy materials, the solicitation of proxies or votes may be made in person, by telephone or by electronic communication by our directors, officers and employees, who will not receive any additional compensation for such solicitation activities. Proxies also may be solicited by employees and our directors by mail, telephone, facsimile, e-mail or in person.

Q:

How can I obtain a copy of our annual report on Form 10-K?

A.

We have filed our annual report on Form 10-K for the year ended December 31, 2019, with the SEC. The annual report on Form 10-K is also included in the Annual Report to stockholders. You may obtain, free of charge, a copy of our annual report on Form 10-K, including financial statements and exhibits, by writing to our Corporate Secretary, Kenneth Hoberman. Upon request, we will also furnish any exhibits to the annual report on Form 10-K as filed with the SEC.

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        Our Board of Directors has determined to nominate Ron Bentsur, Darren Cline, and Daniel Hume for re-election to our Board of Directors for a three-year term expiring at the 2023 annual meeting of stockholders.

        Our Board of Directors is divided into three classes. Generally, each director will serve for a term ending on the date of the third annual meeting of stockholders following the annual meeting of stockholders at which such director was elected; provided that the term of each director will continue until the election and qualification of his or her successor and be subject to his or her earlier death, resignation or removal.

        Our Board of Directors does not have a formal policy regarding the separation of the roles of Chief Executive Officer and Chairman of the Board of Directors, as the Board of Directors believes that it is in the best interests of the Company to make that determination based on the direction of the Company and the current membership of the Board of Directors. The Board of Directors has determined that having Dr. Bergstein serve as both Chief Executive Officer and Chairman is in the best interest of the Company's stockholders at this time.

        Stemline has a risk management program overseen by Dr. Bergstein, our President and Chief Executive Officer, Mr. Hoberman, our Chief Operating Officer, and David Gionco, our Chief Accounting Officer and Senior Vice President of Finance. Dr. Bergstein, Mr. Hoberman and Mr. Gionco identify material risks and prioritize them for our Board of Directors. Our Board of Directors regularly reviews information regarding our credit, liquidity and operations, as well as the risks associated with each.

        The corporate governance standards adopted by the Nasdaq Stock Market, or Nasdaq, require that a majority of the members of our Board of Directors be "independent" as Nasdaq defines that term. Additionally, the Nasdaq rules require our Board of Directors to make an affirmative determination as to the independence of each director. Consistent with these rules, our Board of Directors undertook its annual review of director independence in March 2020. During the review, our Board of Directors considered relationships and transactions during 2019 and during the past three fiscal years between each director or any member of his immediate family, on the one hand, and our company and our subsidiaries and affiliates, on the other hand. The purpose of this review was to determine whether any such relationships or transactions were inconsistent with a determination that the director is independent. Based on this review, our Board of Directors determined that Mr. Bentsur, Mr. Cline,

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Mr. Forman, Mr. Hume, Mr. Sard, and Mr. Zuerblis are independent under the criteria established by Nasdaq and by our Board of Directors.

        The following biographies set forth the names of each of our directors (including our director-nominees) and the following additional information: their ages, the year in which they first became directors, their positions with us, their principal occupations and employers for at least the past five years, any other directorships held by them during the past five years in companies that are subject to the reporting requirements of the Securities Exchange Act of 1934, or the Exchange Act, or any company registered as an investment company under the Investment Company Act of 1940, as well as additional information, all of which we believe sets forth each director's qualifications to serve on the Board of Directors. There is no family relationship between and among any of our executive officers or directors. There are no arrangements or understandings between any of our executive officers or directors and any other person pursuant to which any of them are elected as an officer or director.

Director-Nominees

        Ron Bentsur, 54, has served as a member of our Board of Directors since 2009. Mr. Bentsur has more than 15 years of experience in the biotech industry. In 2019, Mr. Bentsur served as an advisor to UroGen Pharma Ltd. He was Chief Executive Officer of UroGen Pharma Ltd. from August 2015 until January 3, 2019 and its Director from October 2015 until January 3, 2019. From 2009 to 2015, Mr. Bentsur served as Chief Executive Officer of Keryx Biopharmaceuticals, Inc. and as a member of its board of directors. Prior to joining Keryx Biopharmaceuticals, Inc., Mr. Bentsur served as Chief Executive Officer of XTL Biopharmaceuticals, Inc. from 2006 to 2009. From 2000 to 2006, Mr. Bentsur was employed by Keryx Biopharmaceuticals, Inc., where he served as Vice President of Finance and Chief Financial Officer from 2003 until 2006. From 1998 to 2000, Mr. Bentsur served as Director of Investment Banking at Leumi Underwriters Ltd. And from 1994 to 1998, Mr. Bentsur was a New York City-based investment banker, primarily at ING Barings Furman Selz. Mr. Bentsur holds a B.A. in Economics and Business Administration with distinction from the Hebrew University of Jerusalem, Israel and an M.B.A., magna cum laude, from NYU's Stern Graduate School of Business. We believe that Mr. Bentsur is qualified to serve on our Board of Directors due to his leadership and management experience, his service as an executive of a public biopharmaceutical company and his knowledge of our business and industry.

        Darren Cline, 55, has served as a member of our Board of Directors since April 2018. Mr. Cline is an accomplished biopharmaceutical executive with over 25 years of commercial experience, focused in the hematology and oncology, orphan and ultra-orphan arenas. Mr. Cline currently serves as US Chief Commercial Officer and member of the Executive Committee for Greenwich Bioscience, the US subsidiary of GW Pharmaceuticals. (Nasdaq: GWPH). In his role he is responsible for all commercial, medical affairs and state government affairs functions. Mr. Cline previously served as Executive Vice President, Commercial at Seattle Genetics (Nasdaq: SGEN), where he oversaw all marketing, sales and managed markets. He was directly involved in the commercial build out for the launch of ADCETRIS, an antibody-based biologic FDA approved for treatment of certain hematologic cancers, and he played an integral role driving ADCETRIS' continued growth to over $475 million in 2018 revenue. Prior to Seattle Genetics, Mr. Cline was at Alexion Pharmaceuticals, where he was part of the initial commercial leadership team for the Soliris launch, helping to build out key sales functions that were instrumental in Soliris becoming a billion-dollar brand. Mr. Cline received his undergraduate degree from San Diego State University and his MBA from Pepperdine University. We believe that Mr. Cline is qualified to serve on our Board of Directors due to his extensive commercial experience in hematology and oncology coupled with his management experience.

        Daniel Hume, 53, has served as a member of our Board of Directors since April 2018. Mr. Hume is currently a managing partner at Kirby McInerney, LLP. Mr. Hume's law practice focuses on securities law regulation, structured finance, antitrust, and civil litigation. Mr. Hume is member of the board of

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directors of TG Therapeutics (Nasdaq: TGTX), a late clinical stage biopharmaceutical company, and National Holdings Corporation (Nasdaq: NHLD), a financial services company. Mr. Hume is admitted to the New York State Bar and federal courts around the country, including the United States Supreme Court. Mr. Hume received a B.A. in philosophy and graduated magna cum laude from the State University of New York at Albany, and earned a J.D. from the Columbia University Law School, where he served as Notes Editor for the Columbia Journal of Environmental Law. We believe that Mr. Hume is qualified to serve on our Board of Directors due to his substantial financial and legal experience as well as his experience on several other Boards, some within the pharmaceutical industry.

Other Board Members

        Ivan Bergstein, M.D., 54, Chairman, Chief Executive Officer and President. Dr. Bergstein is our Chief Executive Officer and Founder. Dr. Bergstein has managed the company's evolution from early-stage research and development to the FDA approval and commercial launch of its lead product, ELZONRIS. Prior to founding Stemline, Dr. Bergstein was Medical Director of Access Oncology, Inc., a clinical stage oncology-focused biotechnology company where he was a key member of a small team responsible for the acquisition and development of the company's clinical stage assets and ultimately the sale of the company to Keryx Biopharmaceuticals, Inc. He received a BA in mathematics from the University of Pennsylvania, was elected to the Pi Mu Epsilon National Mathematics Honor Society, and was captain of the varsity wrestling team at Penn. He then received an MD from the Mount Sinai School of Medicine where he was elected to the Alpha Omega Alpha Honor Medical Society, received the Merck Award for Clinical Excellence, and subsequently completed an internship in general surgery. He then became the Jerome A. Urban Post-Doctoral Research Fellow at the Cornell University Medical College where he studied and published work relating to Wnt genes in human breast cancer. He then completed an internal medicine residency and hematology-oncology fellowship at the New York Presbyterian Hospital—Weill Medical College of Cornell University where he studied and published work on gene therapy manipulations of the sonic hedgehog pathway. We believe Dr. Bergstein is qualified to serve on our Board of Directors due to his leadership, business and management experience and extensive medical, scientific and clinical expertise.

        Alan Forman, 54, has served as a member of our Board of Directors since April 2015. Mr. Forman is a Director of Investments at the Yale University Investments Office, the team charged with managing the University's $29 billion dollar endowment fund. Mr. Forman has been a leader at the Investment Office for more than two decades during which time the office has become one of the top performing institutions in the world. While at the institution, he has executed billions of dollars of transactions across numerous investment cycles and industries. Mr. Forman served on the board of directors of Acadia Realty Trust, a public company, where he served as Chairman of Acadia's Compensation Committee and was a member of the Nominating and Corporate Governance Committees. He worked closely with the CEO and other board members on a wide range of strategic issues with particular emphasis on corporate strategy, company structure, M&A and fund raising, and was instrumental in the company's success. Mr. Forman was also on the board of directors of Kimpton Group Holdings, which was ultimately sold to Intercontinental Hotels Group. He served on the Compensation and Nominating and Governance Committees. After having sourced and structured the original investment, he then joined the board, served as a close advisor to the CEO and CFO, and was a key member of the team that orchestrated the company's successful acquisition. Mr. Forman received his B.A. degree from Dartmouth College and an M.B.A. degree from NYU's Stern Graduate School of Business. We believe Mr. Forman is qualified to serve on our Board of Directors due to his extensive financial and management experience for both public and private entities and his experience serving as member of the board of directors of other companies.

        Mark Sard, 55, has served as a member of our Board of Directors since April 2018. Mr. Sard has a thirty-plus year career in venture capital, private equity, and underwriting. He has been employed for

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the past 12 years as a principal at Frontier Equities VC, since he co-founded the firm in 2007. Frontier is a generalist venture capital firm that invests in early to mid-stage companies across a wide array of sectors. Past investments, with successful exits, include Glaceau/Vitamin Water to Coca Cola and Nurture Inc./Happy Baby to Group Danone. In addition, he has structured more than $3 billion in financing for companies from private start-ups to Fortune 500 corporations. He has managed investments from institutional clients including sovereign wealth funds, insurance companies, public pension funds and other investors. Previously, Mr. Sard was the director of acquisitions for a boutique investment management firm with assets in excess of $2 billion. While at the firm, he sourced over $500 million in institutional investments. He also underwrote more than $1 billion in debt for clients while at Chemical Bank/JP Morgan Chase. Mr. Sard was an early angel investor in Stemline. He holds a B.A. in economics from the University of Pennsylvania, with additional coursework in advanced applied mathematics.

        Kenneth Zuerblis, 61, has served as a member of our Board of Directors since March 2012. Prior to joining Stemline, Mr. Zuerblis served as Executive Vice President and Chief Financial Officer of Savient Pharmaceuticals, Inc. from September 2011 until May 2012. Prior to joining Savient, Mr. Zuerblis served as Chief Financial Officer and Senior Vice President at ImClone Systems from 2008 through 2009. In that role, he was responsible for the strategic planning and leadership of finance and related operations and helped lead all aspects of the sale of the company to Eli Lilly and Company. From 1994 through 2005, Mr. Zuerblis served as Chief Financial Officer of Enzon Pharmaceuticals, Inc., and held the position of Corporate Controller from 1991 through 1994. Enzon developed the first three FDA approved products using PEGylation technology. Most notably during Mr. Zuerblis' 14 year tenure, Enzon transformed from an early stage biotechnology company into a fully integrated biopharmaceutical company with five marketed products. He began his career at KPMG, LLP in 1982 where he held management positions of increasing responsibility over a ten-year period. Mr. Zuerblis previously served on the board of directors of Immunomedics, Inc. and XTL Biopharmaceuticals, Inc. Mr. Zuerblis currently serves on the board of directors of Resverlogix Corp., which is publicly traded on the Toronto Stock Exchange, and Zenith Epigenetics, Inc., a private biotechnology company based in Calgary, Canada. Mr. Zuerblis brings nearly 30 years of proven leadership and expertise in building fully integrated biopharmaceutical organizations and has an established track record of managing complex commercial and research organizations, raising capital, overseeing multifaceted merger and acquisition transactions, and directing all investor and stockholder relations. Mr. Zuerblis earned his B.S. in Accounting from Seton Hall University and is a Certified Public Accountant in the State of New Jersey. We believe Mr. Zuerblis is qualified to serve on our Board of Directors due to his extensive accounting and financial experience and years of executive leadership in the biopharmaceutical industry.

        During 2019, our Board of Directors held five (5) meetings and took two (2) actions by unanimous written consent. Also in 2019, each incumbent director standing for election attended at least 75% of the meetings of the Board of Directors and the meetings of those committees on which each incumbent director served, in each case during the period that such person was a director. The permanent committees established by our Board of Directors are the Audit Committee, the Compensation Committee, and the Nominating and Corporate Governance Committee, descriptions of which are set forth in more detail below. Our directors are expected to attend each Annual Meeting of Stockholders, and it is our expectation that all of the directors standing for election will attend this year's Annual Meeting.

Communicating with the Board of Directors

        Our Board of Directors has established a process by which stockholders can send communications to the Board of Directors. You may communicate with the Board of Directors as a group, or to specific directors, by writing to Kenneth Hoberman, our Corporate Secretary, at 750 Lexington Avenue,

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Eleventh Floor, New York, NY 10022. The Corporate Secretary will review all such correspondence and regularly forward to the Board of Directors a summary of all correspondence and copies of all correspondence that, in the opinion of the Corporate Secretary, deals with the functions of the Board of Directors or committees thereof or that he otherwise determines requires their attention. Directors may at any time review a log of all correspondence we receive that is addressed to members of our Board of Directors and request copies of any such correspondence. Concerns relating to accounting, internal controls, or auditing matters may be communicated in this manner, or may be submitted on an anonymous basis via e-mail at audit@stemline.com. These concerns will be immediately brought to the attention of our Audit Committee and handled in accordance with procedures established by our Audit Committee.

Audit Committee

        The Audit Committee currently consists of Ron Bentsur, Darren Cline, Alan Forman, Mark Sard and Kenneth Zuerblis. Mr. Zuerblis chairs the Audit Committee.

        The Audit Committee held seven (7) meetings and took one (1) action by unanimous written consent during the fiscal year ended December 31, 2019. The duties and responsibilities of the Audit Committee are set forth in the Charter of the Audit Committee which was recently reviewed and updated by our Audit Committee. A copy of the Charter of the Audit Committee is available on our website, located at www.stemline.com. Among other things, the duties and responsibilities of the Audit Committee include reviewing and monitoring our financial statements and internal accounting procedures, the selection of our independent registered public accounting firm and consulting with and reviewing the services provided by our independent registered public accounting firm. Our Audit Committee has sole discretion over the retention, compensation, evaluation and oversight of our independent registered public accounting firm. The SEC and Nasdaq have established rules and regulations regarding the composition of audit committees and the qualifications of audit committee members. Our Board of Directors has examined the composition of our Audit Committee and the qualifications of our Audit Committee members in light of the current rules and regulations governing audit committees. Based upon this examination, our Board of Directors has determined that each member of our Audit Committee is independent and is otherwise qualified to be a member of our Audit Committee in accordance with the rules of the SEC and Nasdaq.

        Additionally, the SEC requires that at least one member of the Audit Committee have a "heightened" level of financial and accounting sophistication. Such a person is known as the "audit committee financial expert" under the SEC's rules. Our Board of Directors has determined that Mr. Zuerblis is an "audit committee financial expert," as the SEC defines that term, and is an independent member of our Board of Directors and our Audit Committee. Please see Mr. Zuerblis' biography under "Corporate Governance—Our Board of Directors" beginning on page 6 for a description of his relevant experience.

        The report of the Audit Committee can be found on page 15 of this proxy statement.

Compensation Committee

        The Compensation Committee currently consists of Ron Bentsur, Alan Forman, Daniel Hume and Mark Sard. Mr. Bentsur chairs the Compensation Committee.

        The Compensation Committee held two (2) meetings and took one (1) action by unanimous written consent during the fiscal year ended December 31, 2019. The duties and responsibilities of the Compensation Committee are set forth in the Charter of the Compensation Committee. A copy of the Charter of the Compensation Committee is available on our website, located at www.stemline.com. As discussed in its Charter, among other things, the duties and responsibilities of the Compensation Committee include evaluating the performance of our executive officers, determining the overall

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compensation of our executive officers, administering all executive compensation programs, including, but not limited to, our incentive and equity-based plans, and reviewing and making recommendations to the Board of Directors with respect to director compensation. The Compensation Committee evaluates the performance of our executive officers on an annual basis and reviews and approves on an annual basis all compensation programs and awards relating to such officers. The Compensation Committee applies discretion in the determination of individual executive compensation packages to ensure compliance with the Company's compensation philosophy. Our Chief Executive Officer makes recommendations to the Compensation Committee with respect to the compensation packages for officers other than himself. The Compensation Committee may delegate its authority to grant awards to certain employees to a special committee consisting of one or more directors who may but need not be officers of the Company. The Compensation Committee has delegated authority to Dr. Bergstein to make certain grants to non-executive employees.

        Nasdaq has established rules and regulations regarding the composition of compensation committees and the qualifications of compensation committee members. Our Board of Directors has examined the composition of our Compensation Committee and the qualifications of our Compensation Committee members in light of the current rules and regulations governing compensation committees. Based upon this examination, our Board of Directors has determined that each member of our Compensation Committee is independent and is otherwise qualified to be a member of our Compensation Committee in accordance with such rules.

        The report of the Compensation Committee can be found on page 24 of this proxy statement.

Nominating and Corporate Governance Committee

        The Nominating and Corporate Governance Committee, or the Nominating Committee, currently consists of Alan Forman, Daniel Hume, Mark Sard and Kenneth Zuerblis. Alan Forman chairs the Nominating Committee. The Nominating Committee held one (1) meeting during the fiscal year ended December 31, 2019. The duties and responsibilities of the Nominating Committee are set forth in the Nominating and Corporate Governance Committee Charter. A copy of the Nominating and Corporate Governance Committee Charter is available on our website at www.stemline.com. Among other things, the duties and responsibilities of the Nominating Committee include identifying individuals qualified to become Board members, evaluating the overall effectiveness of the Board, developing, mentoring and evaluating applicable corporate governance practices of the Company, and performing such other duties as enumerated in and consistent with the Charter.

        Our Nominating Committee will also consider candidates recommended by stockholders for nomination to our Board of Directors. A stockholder who wishes to recommend a candidate for nomination to our Board of Directors must submit such recommendation to our Corporate Secretary, Kenneth Hoberman, at 750 Lexington Avenue, Eleventh Floor, New York, New York 10022. Any recommendation must be received not less than 90 calendar days nor more than 120 calendar days before the anniversary date of the previous year's annual meeting. All stockholder recommendations of candidates for nomination for election to our Board of Directors must be in writing and must set forth the following: (i) the candidate's name, age, business address, and other contact information, (ii) the number of shares of Stemline common stock beneficially owned by the candidate, (iii) a complete description of the candidate's qualifications, experience, background and affiliations, as would be required to be disclosed in the proxy statement pursuant to Schedule 14A under the Exchange Act, (iv) a sworn or certified statement by the candidate in which he or she consents to being named in the proxy statement as a nominee and to serve as director if elected, and (v) the name and address of the stockholder(s) of record making such a recommendation and the number of shares owned by the recommending stockholders.

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        We believe that our Board of Directors as a whole should encompass a range of talent, skill, and expertise enabling it to provide sound guidance with respect to our operations and interests. Our Nominating Committee evaluates all candidates to our Board of Directors by reviewing their biographical information and qualifications. If the independent directors determine that a candidate is qualified to serve on our Board of Directors, such candidate is interviewed by at least one of the independent directors and our Chief Executive Officer. Other members of the Board of Directors also have an opportunity to interview qualified candidates. The independent directors then determine, based on the background information and the information obtained in the interviews, whether to recommend to the Board of Directors that the candidate be nominated for approval by the stockholders to fill a directorship. With respect to an incumbent director whom the independent directors are considering as a potential nominee for re-election, the independent directors review and consider the incumbent director's service during his or her term, including the number of meetings attended, level of participation, and overall contribution to the Board of Directors. The manner in which the independent directors evaluate a potential nominee will not differ based on whether the candidate is recommended by our directors or stockholders.

        Nasdaq has established rules and regulations regarding the composition of nominating committees and the qualifications of nominating committee members. Our Board of Directors has examined the composition of our Nominating Committee and the qualifications of our Nominating Committee members in light of the current rules and regulations governing nominating committees. Based upon this examination, our Board of Directors has determined that each member of our Nominating Committee is independent and is otherwise qualified to be a member of our Nominating Committee in accordance with such rules.

        We do not have a formal policy in place with regard to the consideration of diversity in considering candidates for our Board of Directors, but the Board of Directors strives to nominate candidates with a variety of complementary skills so that, as a group, the Board of Directors will possess the appropriate talent, skills and expertise to oversee our business.

Code of Business Conduct and Ethics

        We have adopted a written code of business conduct and ethics that applies to our directors, officers and employees, including our principal executive officer and principal financial officer. A current copy of the code is posted on the Corporate Governance section of our website at www.stemline.com.

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INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM FEES AND OTHER MATTERS

        Ernst & Young LLP, the independent registered public accounting firm that audited our financial statements for the years ended December 31, 2019 and December 31, 2018, has served as our independent registered public accounting firm since 2011. We expect a representative of Ernst & Young LLP to be present at the Annual Meeting. The representative will have an opportunity to make a statement and will be available to answer your questions.

        Our Board of Directors has asked the stockholders to ratify the selection of Ernst & Young LLP as our independent registered public accounting firm. See Proposal Two: Ratification of Appointment of Ernst & Young LLP as Our Independent Registered Public Accounting Firm on page 41 of this proxy statement. The Audit Committee has reviewed the fees described below and concluded that the payment of such fees is compatible with maintaining Ernst & Young LLP's independence. All proposed engagements of Ernst & Young LLP, whether for audit services, audit-related services, tax services, or permissible non-audit services, were pre-approved by our Audit Committee.

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Pre-Approval of Services

        Our Audit Committee sets forth the procedures under which services provided by our independent registered public accounting firm will be pre-approved by our Audit Committee. The potential services that might be provided by our independent registered public accounting firm fall into two categories:

•

Services that are permitted, including the audit of our annual financial statements, the review of our quarterly financial statements, related attestations, benefit plan audits and similar audit reports, financial and other due diligence on acquisitions, and federal, state, and non-US tax services; and



•

Services that may be permitted, subject to individual pre-approval, including compliance and internal-control reviews, indirect tax services such as transfer pricing and customs and duties, and forensic auditing.

        Services that our independent registered public accounting firm may not legally provide include such services as bookkeeping, certain human resources services, internal audit outsourcing, and investment or investment banking advice.

        All proposed engagements of our independent registered public accounting firm, whether for audit services or permissible non-audit services, are pre-approved by the Audit Committee. We jointly prepare a schedule with our independent registered public accounting firm that outlines services that we reasonably expect we will need from our independent registered public accounting firm, and categorize them according to the classifications described above. Each service identified is reviewed and approved or rejected by the Audit Committee.

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