UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a)
of
the Securities Exchange Act of 1934 (Amendment No.          )

Filed by the Registrant x                                        Filed by a Party other than the Registrant ¨

Check the appropriate box:

SELLAS LIFE SCIENCES GROUP, INC.

(Name of Registrant as Specified In Its Charter)

(Name of Person(s) Filing Proxy Statement if Other Than the Registrant)

Payment of Filing Fee (Check the appropriate box):

August 7, 2019April 23, 2021

Dear FellowTo Our Stockholders:

You are cordially invited to attend the 2021 annual meeting of stockholders of SELLAS Life Sciences Group, Inc. (the “Company”) to be held at 8:30 a.m. Eastern Time on June 8, 2021 (the “2021 Annual Meeting”) via live webcast. In light of public health restrictions and recommendations relating to the ongoing coronavirus (COVID-19) pandemic, we will hold the 2021 Annual Meeting virtually via live webcast. You will be able to attend and participate in the 2021 Annual Meeting online via the live webcast and vote your shares electronically by visiting: www.meetingcenter.io/287191590. The password for the meeting is: SLS2021. There is no physical location for the 2021 Annual Meeting.

The enclosed Notice of Annual Meeting of Stockholders sets forth the proposals that will be presented at the 2021 Annual Meeting, which are described in more detail in the enclosed Proxy Statement. Our Board of Directors recommends that you vote “FOR” Proposals 1, 2, 3 and 4 as set forth in the Proxy Statement.

Under Securities and Exchange Commission rules that allow companies to furnish proxy materials to stockholders over the Internet, we have elected to deliver our proxy materials to our stockholders over the Internet, unless a stockholder requests printed materials. This delivery process allows us to provide stockholders with the information they need, while at the same time conserving natural resources and lowering the cost of delivery. On or about April 26, 2021, we intend to begin sending to our stockholders a Notice of Internet Availability of Proxy Materials (the “Notice”) containing instructions on how to access our Proxy Statement for the 2021 Annual Meeting and our 2020 annual report to stockholders. The Notice also provides instructions on how to vote online and how to receive a paper copy of the proxy materials by mail.

We hope you will be able to attend the 2021 Annual Meeting. Whether you plan to attend the 2021 Annual Meeting or not, it is important that you cast your vote. You may vote over the Internet as well as by telephone or by mail. When you have finished reading the Proxy Statement, you are urged to vote in accordance with the instructions set forth in the Proxy Statement. We encourage you to vote by proxy so that your shares will be represented and voted at the meeting, whether or not you can attend.

On behalf of the Board and the management team, we thank you for your ongoing support of, Directors (the "Board") ofand continued interest in, SELLAS Life Sciences Group, Inc. (the "Company"), you are cordially invited to attend a Special Meeting of Stockholders to be held at 8:30 a.m., local time, on September 10, 2019, at 15 West 38^th Street, 4^th Fl., New York, New York 10018.

At the Special Meeting, stockholders will consider and vote on

The proxy statement attached to this letter provides you with information regarding the above three proposals. Please read the entire proxy statement carefully. You may obtain additional information about the Company from documents we file with the Securities and Exchange Commission.

It is important that your shares be represented and voted at the meeting. Please vote as soon as possible even if you plan to attend the Special Meeting. We appreciate your continued ownership of the Company shares and your support regarding this matter.

	Very truly yours,
	Angelos M. Stergiou, M.D., Sc.D. h.c.
	President and Chief Executive Officer

SELLAS LIFE SCIENCES GROUP, INC.

15 West 38^th Street, 10^th FloorTimes Square Tower, 7 Times Square, Suite 2503

New York, New York 1001810036

NOTICE OF SPECIAL2021 ANNUAL MEETING OF STOCKHOLDERS
To Be Held on September 10, 2019

PURPOSES:

WHO MAY VOTE:

The close of business on July 12, 2019 has been fixed asYou may vote if you were the record date for determining those stockholders entitled to vote atowner of the Special Meeting. Accordingly, only stockholders of recordCompany’s common stock at the close of business on that dateTuesday, April 13, 2021. A list of stockholders of record will receive this notice of, and be eligible to voteavailable at the Special2021 Annual Meeting and, any adjournment or postponement ofduring the Special Meeting. The above items of business for10 days prior to the Special2021 Annual Meeting, are more fully described in the proxy statement that accompanies this notice.at our principal executive offices located at Times Square Tower, 7 Times Square, Suite 2503, New York, NY 10036.

 Your vote is important.    Please readAll stockholders are cordially invited to attend the proxy statement and the instructions on the enclosed proxy card and then, whether or not2021 Annual Meeting. Whether you plan to attend the Special2021 Annual Meeting or not, we urge you to vote promptly in person, and no matter how many shares you own, please submit your proxy promptly by telephone or viaorder to ensure the Internet in accordance with the instructions on the enclosed proxy card, or by completing, dating and returning your proxy card in the envelope provided. This will not prevent you from voting in person at the Special Meeting. It will, however, help to assurepresence of a quorum and to avoid added proxy solicitation costs.

quorum. You may change or revoke your proxy at any time before the voteit is taken by delivering to the Secretary of the Company a written revocation or a proxy with a later date (including a proxy by telephone or via the Internet) or by voting your shares in personvoted at the Special Meeting, in which case your prior proxy would be disregarded.meeting.

	By orderOrder of the Board of Directors,
	Barbara A. Wood
	Executive Vice President, General Counsel and Corporate Secretary
	New York, New York
	August 7, 2019

New York, New York

April 23, 2021

TABLE OF CONTENTS

SELLAS LIFE SCIENCES GROUP, INC.

15 West 38^th Street, 10^th FloorTimes Square Tower, 7 Times Square, Suite 2503

New York, New York 1001810036

PROXY STATEMENT

FOR THE SPECIAL2021 ANNUAL MEETING OF STOCKHOLDERS TO BE HELD ON

Friday, September 10, 2019Tuesday, June 8, 2021

This Proxy Statement, along with the accompanying notice of 2021 Annual Meeting, contains information about the annual meeting of stockholders of SELLAS Life Sciences Group, Inc., including any adjournments or postponements of the 2021 Annual Meeting. We are holding the 2021 Annual Meeting at 8:30 a.m., Eastern Time, on June 8, 2021 via live webcast. There will be no physical location for the 2021 Annual Meeting. We refer, in this Proxy Statement, to SELLAS Life Sciences Group, Inc. as “SELLAS,” “the Company,” “we” and “us,” or “our.”

This Proxy Statement relates to the solicitation of proxies by our Board of Directors for use at the 2021 Annual Meeting.

On or about April 26, 2021, we intend to begin sending to our stockholders the Important Notice Regarding the Availability of Proxy Materials for the Special Meetingcontaining instructions on how to be Held on September 10, 2019:

Theaccess our proxy statement is available at
www.envisionreports.com/SLS

This proxy statement is being furnished to you by the Board of Directors (the "Board" or "Board of Directors") of SELLAS Life Sciences Group, Inc. (the "Company") to solicit your proxy to vote your shares atfor our Special2021 Annual Meeting of Stockholders (the "Special Meeting"). The Special Meeting will be held on September 10, 2019 at 8:30 a.m., local time, at 15 West 38^th Street, 4^th Floor, New York, New York 10018.

This proxy statement, the foregoing notice and the accompanying proxy card are first being made available on or about August [5], 2019 to all holders of our common stock entitled to vote at the Special Meeting.

Purpose of the Special Meeting 

The purpose of the Special Meeting is to consider and vote on the following proposals:

If the Reverse Stock Split proposal is approved by the Company's stockholders at the Special Meeting, it will be effected, if at all, only upon a subsequent determination by the Board, not later than the date that is within one year from the date of the Special Meeting, that the Reverse Stock Split is in the best interests of the Company and our stockholders. The Board may make this determination as soon as immediately following the conclusion of the Special Meeting, and the Reverse Stock Split could become effective as soon as the business day immediately following the Special Meeting.

Notwithstanding approval of the Reverse Stock Split proposal by our stockholders, the Board reserves its right2020 annual report to elect not to proceed with implementing the Reverse Stock Split proposal at any time prior to the date on which the amendment to our Amended and Restated Certificate of Incorporation becomes effective under Delaware law, if it determines, in its sole discretion, that the Reverse Stock Split is no longer in the best interests of the Company or its stockholders.

QUESTIONS AND ANSWERS ABOUT THE SPECIAL MEETING THESE PROXY MATERIALS AND VOTING

WhoWhy is entitledthe Company Soliciting My Proxy?

Our Board of Directors is soliciting your proxy to vote at the Special Meeting?2021 Annual Meeting to be held via live webcast, on June 8, 2021, at 8:30 a.m., Eastern Time, and any adjournments or postponements of the meeting, which we refer to as the 2021 Annual Meeting. This proxy statement, along with the accompanying Notice of Annual Meeting of Stockholders, summarizes the purposes of the meeting and the information you need to know to vote at the 2021 Annual Meeting.

HoldersWe have made available to you on the Internet or have sent you this proxy statement, the Notice of Annual Meeting of Stockholders, the proxy card and a copy of our Annual Report on Form 10-K for the fiscal year ended December 31, 2020, because you owned shares of our common stock on April 13, 2021, or the Record Date. We intend to commence distribution of the Company’s common stockImportant Notice Regarding the Availability of Proxy Materials, which we refer to throughout this proxy statement as the Notice, and, if applicable, proxy materials, to stockholders on or about April 26, 2021.

Why Did I Receive a Notice in the Mail Regarding the Internet Availability of Proxy Materials Instead of a Full Set of Proxy Materials?

As permitted by the rules of the U.S. Securities and Exchange Commission, or the SEC, we may furnish our proxy materials to our stockholders by providing access to such documents on the Internet, rather than mailing printed copies of these materials to each stockholder. Stockholders will not receive printed copies of the proxy materials unless they request them. We believe that this process will expedite stockholders’ receipt of proxy materials, lower the costs of the 2021 Annual Meeting and help to conserve natural resources. If you received the Notice by mail or electronically, you will not receive a printed or email copy of the proxy materials, unless you request one by following the instructions included in the Notice. Instead, the Notice instructs you as to how you may access and review all of the proxy materials and submit your proxy on the Internet. If you requested a paper copy of the proxy materials, you may authorize the voting of your shares by following the instructions on the proxy card, in addition to the other methods of voting described in this proxy statement.

How do I attend the 2021 Annual Meeting?

The 2021 Annual Meeting will be held on Tuesday, June 8, 2021, at 8:30 a.m., Eastern Time, via live webcast. You will be able to attend and participate in the 2021 Annual Meeting online via live webcast and vote your shares electronically by visiting: www.meetingcenter.io/287191590 on the meeting date and time described in this Proxy Statement. The password for the meeting is: SLS2021. There is no physical location for the 2021 Annual Meeting. You are entitled to participate in the 2021 Annual Meeting only if you were a stockholder of the Company as of the close of business on the record date, July 12, 2019,Record Date or if you hold a valid proxy for the 2021 Annual Meeting.

How do I submit questions?

You may submit questions in advance of the 2021 Annual Meeting by emailing the questions, along with proof of ownership, to questions2021@sellaslife.com prior to 8:30 a.m. Eastern Time on June 7, 2021. You may also submit questions during the 2021 Annual Meeting by visiting: www.meetingcenter.io/287191590. We will, receive noticesubject to time constraints, answer all questions that are pertinent to the business of the 2021 Annual Meeting and be eligiblewill give priority to questions submitted in advance.

Who can vote at the Special Meeting and any adjournment or postponement2021 Annual Meeting?

Only stockholders of the Special Meeting. Atrecord at the close of business on the record date, the Company had outstanding andRecord Date will be entitled to vote 210,092,687 shares of common stock. No other shares of the Company’s capital stock are entitled to notice of and to vote at the Special2021 Annual Meeting. On the Record Date, there were 15,084,754 shares of common stock issued and outstanding. Our common stock is our only class of voting stock.

How Do I Vote?

How do I attend the Special Meeting?

All stockholders of record on July 12, 2019 are invited to attend the Special Meeting. You must bring proof of your identity to attend the special meeting. If you are the beneficial owner of shares held in the name of your broker, bank or other nominee, you must bring both proof of ownership of shares as of the record date (e.g., a broker's statement) and a photo ID in order to be admitted to the meeting. IfWhether you plan to attend the meeting,2021 Annual Meeting or not, we will have representatives onsiteurge you to assist with registration for the event.

What mattersvote by proxy. All shares represented by valid proxies that we receive through this solicitation, and that are not revoked, will be voted in accordance with your instructions on the proxy card or as instructed via the Internet or telephone. You may specify (i) whether your shares should be voted FOR or WITHHELD for Proposal 1, our nominee for Class II director, and (ii) whether your shares should be voted for, against or abstain with respect to Proposals 2, 3 and 4. If you properly submit a proxy without giving specific voting instructions, your shares will be voted in accordance with our Board of Directors’ recommendations as noted below. Voting by proxy will not affect your right to attend the 2021 Annual Meeting. You may vote by one of the following methods:

	By Internet: If you have Internet access, you may submit your vote from any location in the world by following the instructions in the Notice or following the instructions on the proxy card or voting instruction card sent to you.
	By Telephone: You may submit your vote by following the telephone voting instructions on the proxy card or voting instruction card sent to you.
	By Proxy by Mail: You may vote by mail by requesting a full paper copy of the Proxy Statement materials as instructed in the Notice of Internet Availability and marking, dating and signing your proxy card or, for shares held in street name, the voting instruction card provided to you by your broker or nominee, and mailing it in the enclosed, self-addressed, postage prepaid envelope.

Telephone and Internet voting facilities for stockholders of record will be available 24 hours a day and will close at the Special Meeting?1:00 a.m. Eastern Time on June 8, 2021.

The three proposals that are scheduled to be considered and voted on at the Special Meeting are the Reverse Stock Split proposal, the 2019 Equity Plan proposal and the adjournment proposal.

What are the Board's voting recommendations?

The Board recommends that you vote "FOR" the Reverse Stock Split proposal, “FOR” the 2019 Equity Plan proposal and "FOR" the adjournment proposal.

Why does the Company need stockholders to vote on the Reverse Stock Split?

On May 31, 2019, we received a written notification from The Nasdaq Stock Market LLC (“Nasdaq”) indicating that the Company was not in compliance with Nasdaq Listing Rule 5550(a)(2) because the minimum bid price of the Company’s shares of common stock was below $1.00 per share for the previous 30 consecutive business days. We have been provided an initial period of 180 calendar days, or until November 27, 2019, to regain compliance with the minimum bid price rule. To regain compliance, the closing bid price of the Company’s shares of common stock must meet or exceed $1.00 per share for at least ten consecutive business days during this 180-day grace period. If we do not regain compliance with the minimum bid price rule by November 27, 2019, we may be eligible for an additional compliance period of 180 calendar days; however, such extension is at the discretion of Nasdaq and there can be no assurance that Nasdaq will grant the extension. If we do not regain compliance with the minimum bid price rule by November 27, 2019 and are not granted an additional compliance period at that time, Nasdaq will provide written notification to us that our common stock may be delisted. At that time, we may appeal Nasdaq’s delisting determination to a Nasdaq hearings panel. If we timely appeal, our common stock would remain listed pending the panel’s decision. There can be no assurance that, if we do appeal the delisting determination by Nasdaq to the panel, such appeal would be successful.

The Board has determined that an amendment to our Amended and Restated Certificate of Incorporation to effect the Reverse Stock Split is necessary to the continued listing of our common stock on Nasdaq and is in the best interests of our stockholders. If approved and implemented, the Board will select a Reverse Stock Split ratio of not less than 1-for-20 and not greater than 1-for-60, with the exact ratio and effective time of the Reverse Stock Split to be determined by the Board at any time within one year of the date of the Special Meeting based on various factors, including the then prevailing market conditions and the existing and expected per share trading prices of our common stock. Pursuant to the law of our state of incorporation, Delaware, the Board must adopt any amendment to our Amended and Restated Certificate of Incorporation and submit the amendment to stockholders for approval. Accordingly, the Board is requesting your proxy to vote "FOR" the Reverse Stock Split proposal and "FOR" the adjournment proposal.

In addition to bringing the per share trading price of our common stock back above $1.00, we also believe that the Reverse Stock Split will make our common stock more attractive to a broader range of institutional and other investors, as we have been advised that the current per share trading price of our common stock may affect its acceptability to certain institutional investors, professional investors and other members of the investing public. Many brokerage houses and institutional investors have internal policies and practices that either prohibit them from investing in low-priced stocks or tend to discourage individual brokers from recommending low-priced stocks to their customers. In addition, some of those policies and practices may function to make the processing of trades in low-priced stocks economically unattractive to brokers.

What is the difference between holding shares as a stockholder of record and as a beneficial owner?

If on the Record Date your shares were registered directly in your name with our transfer agent, Computershare, Inc.,then you are considered the "stockholdera stockholder of record" with respect to those shares.

record. If on the Record Date your shares were not held instead in your name, but rather in an account at a stock brokerage account or by afirm, bank, dealer or other nominee, those shares are held in "street name" andsimilar organization, then you are considered the "beneficial owner" of the shares. As the beneficial owner of those shares you haveheld in “street name.” You must follow the right to direct your broker, bank or nominee how to vote your shares, and you will receive separate instructions from your broker, bank or otherof the holder of record describing howin order for your shares to vote your shares.be voted.

How can I vote my shares before the Special Meeting?Stockholder of Record: Shares Registered in Your Name

If you are a stockholder of record, you may submit avote during the 2021 Annual Meeting, vote by proxy byover the telephone viaor through the Internet, or vote by mail.

·Submitting a Proxy by Telephone:  You can submitproxy using a proxy for your shares by telephone until 11:59 p.m. Eastern Daylight Time on September 9, 2019, by callingcard. Whether or not you plan to attend the toll-free telephone number on the enclosed proxy card, 1-800- 652-VOTE (8683). Telephone proxy submission is available 24 hours a day. Easy-to-follow voice prompts allow2021 Annual Meeting, we urge you to submit avote by proxy forto ensure your shares and confirm that your instructionsvote is counted. You may still attend the 2021 Annual Meeting even if you have been properly recorded. Our telephone proxy submission procedures are designed to authenticate stockholdersalready voted by using individual control numbers. 

·Submitting a Proxy via the Internet:  You can submit a proxy for your shares via the Internet until 11:59 p.m. Eastern Daylight Time on September 9, 2019, by accessing the website listed on the enclosed proxy card, www.envisionreports.com/SLS, and following the instructions you will find on the website. Internet proxy submission is available 24 hours a day. As with telephone proxy submission, you will be given the opportunity to confirm that your instructions have been properly recorded. 

·Submitting a Proxy by Mail:proxy. If you choose to submit avoted by proxy for your shares by mail, simply mark the enclosed proxy card, date and sign it, and return it in the postage paid envelope provided.

By casting your vote in any of the three ways listed above, you are authorizing the individuals listed on the proxydecide to vote, or change your sharesproxy, while in attendance at the 2021 Annual Meeting, you must first revoke your proxy at the 2021 Annual Meeting and then vote in accordance with your instructions. You may also attend the Special Meeting andinstructions provided at the 2021 Annual Meeting.

Beneficial Owner: Shares Registered in person.the Name of Broker, Bank or Other Nominee

If you are thea beneficial owner of shares registered in the name of your broker, bank, or other nominee, you should followhave received a voting instruction form with these proxy materials from that organization rather than from us. Simply complete and mail the instructionsvoting instruction form to ensure that your vote is counted. Alternatively, you may vote by telephone or over the Internet as instructed by your broker, bank or other nominee.

What am I voting on?

This Proxy Statement describes the proposals on which we would like you, as a stockholder, to vote at the 2021 Annual Meeting. This Proxy Statement provides you with information on the proposals, as well as other information about us, so that you can make an informed decision as to whether and how to vote your stock.

At the 2021 Annual Meeting, stockholders will act upon the following three proposals:

How Does our Board of Directors Recommend That I Vote on the Proposals?

Our Board of Directors recommends that you vote as follows:

How many votes do I have?

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

What happens if I do not vote?

Stockholder of Record: Shares Registered in the materialsYour Name

If you received with this proxy statement from the holderare a stockholder of record forand do not vote, your shares towill not be voted.

The availabilityBeneficial Owner: Shares Registered in the Name of telephonicBroker or Internet voting will depend on the bank's or broker's voting process. Please check with your bank or broker and follow the voting procedures your bank or broker provides to vote your shares. Also, please note that if the holder of record of your shares is a bank, broker or other nominee and you wish to vote in person at the Special Meeting, you must request a legal proxy from your bank, broker or other nominee that holds your shares and present that proxy and a photo ID at the Special Meeting; otherwise, you will not be able to vote in person at the Special Meeting.

If I am the beneficial owner of shares held in "street name" by my broker, will my broker automatically vote my shares for me?Bank

If you are a beneficial owner of shares registered in the name of your broker, bank, or other nominee (sometimes referred to as shares held in “street name”) and you do not provide instructions how to vote your shares, your broker, bank or other nominee may still be able to vote your shares in its discretion. A broker or other nominee may generally vote in their discretion on “routine”routine matters. In this regard, Proposals 1, 3 and 34 are considered to be “routine”“non-routine”, meaning that if your broker does not receive instructions from you on how to vote your shares on such routinenon-routine matter, the broker will have discretion to vote your shares. Proposal 2 is considered to be a “non-routine” matter meaning that if you do not return voting instructions to your broker by its deadline, the broker will not have the authority to vote on the matter with respect to your shares. This is generally referred to as a “broker non-vote.” Therefore, broker non-votes may exist in connection with Proposals 1, 3 and 4. However, Proposal 2 is considered to be a “routine” matter, meaning that if you do not return voting instructions to your broker by its deadline, your shares may be voted by your broker in its discretion on Proposal 2.

How will my shares be votedWhat if I give myreturn a proxy card or otherwise vote but do not specify how my shares should be voted?make specific choices?

If you provide specificreturn a signed and dated proxy card or otherwise vote without marking voting instructions,selections, your shares will be voted, as applicable:

If any other matter is properly presented at the Special2021 Annual Meeting, in accordance with your instructions. If you are a stockholder of record and sign and return a proxy card without giving specific voting instructions,proxyholder will vote your shares will be voted "FOR" the Reverse Stock Split proposal, "FOR" the 2019 Equity Plan proposal and "FOR" the adjournment proposal.using their best judgment.

What voteWho is the required to pass each proposal?paying for this proxy solicitation?

We will pay for the entire cost of soliciting proxies. In addition to these proxy materials, our directors and employees may also solicit proxies in person, by telephone, or by other means of communication. Directors and employees will not be paid any additional compensation for soliciting proxies. We may also reimburse brokerage firms, banks and other nominees for the cost of forwarding proxy materials to beneficial owners. We have engaged The affirmative voteProxy Advisory Group, LLC to assist in the solicitation of the holders ofproxies and provide related advice and information support, for a majority of the outstanding shares of our common stock as of the record date is required to approve the Reverse Stock Split proposalservices fee and the affirmativereimbursement of customary disbursements, which are not expected to exceed $15,000 in total.

Can I change my vote after submitting my proxy?

Stockholder of a majority ofRecord: Shares Registered in Your Name

Yes. You can revoke your proxy at any time before the votes cast by stockholders present, in person or by proxy, and entitled tofinal vote at the Special Meeting, is required to approve the 2019 Equity Plan proposal and the adjournment proposal.

Can I vote in person at the Special Meeting?

Yes. If you hold shares in your own name as a stockholder of record, you may come to the Special Meeting and cast your vote at the meeting by properly completing and submitting a ballot.2021 Annual Meeting. If you are the beneficial ownerrecord holder of your shares, heldyou may revoke your proxy in any one of the following ways:

Your most current proxy card or telephone or Internet proxy is the one that is counted.

Beneficial Owner: Shares Registered in the nameName of Broker or Bank

If your shares are held by your broker, bank or other nominee, you must first obtain a legal proxy fromshould follow the instructions provided by your broker, bank or other nominee giving you the right to vote those shares and submit that proxy along with a properly completed ballot at the meeting; otherwise, you will not be able to vote in person at the Special Meeting.

How can I change my vote?nominee.

You may revoke your proxy at any time before it is exercised by:

Any written notice of revocation, or later dated proxy, should be delivered to:When are stockholder proposals and director nominations due for next year’s annual meeting?

SELLAS Life Sciences Group, Inc.

15 West 38th Street, 10th Floor

Proposals of stockholders intended to be presented at our 2022 annual meeting of stockholders pursuant to Rule 14a-8 promulgated under the Exchange Act must be received by us at our principal offices, Times Square Tower, 7 Times Square, Suite 2503, New York, New York 10018

10036, Attention: Barbara A. Wood, Corporate Secretary,

Alternatively, you may hand deliver a written revocation notice, or a no later dated proxy,than December 24, 2021, the date that is 120 days prior to the Secretary atfirst anniversary of the Special Meeting before we begin voting.date of this proxy statement, in order to be included in the proxy statement and proxy card relating to that meeting.

If your sharesa stockholder wishes to present a proposal at our 2022 annual meeting, but does not wish to have the proposal considered for inclusion in our proxy statement and proxy card, pursuant to the advance notice provision in our bylaws, such stockholder must give written notice to our Corporate Secretary at our principal executive offices at the address noted above. The Corporate Secretary must receive such notice no earlier than February 8, 2022, and no later than March 10, 2022, provided that if the date of the Company common stock are2022 annual meeting of stockholders is held by a bank, broker or other nominee, youbefore June 8, 2022, such notice must follow the instructions providedinstead be received by the bank, broker or other nominee if you wishCorporate Secretary no earlier than the 120th day prior to change your vote.the 2022 annual meeting of stockholders and not later than the close of business on the 90th day prior to the 2022 annual meeting of stockholders in order for such notice to be timely.

WhatHow are the quorum requirements for the proposals?votes counted?

In orderVotes will be counted by the inspector of election appointed for the 2021 Annual Meeting, who will separately count, with respect to take action on(i) the proposals,proposal to elect directors, votes “For,” “Withhold” and broker non-votes; and (ii) Proposals 2, 3 and 4, votes “For” and “Against,” abstentions and, if applicable, broker non-votes.

What are “broker non-votes”?

As discussed above, when a quorum, consisting of the holders of 105,046,344 shares (a majority of the aggregate numberbeneficial owner of shares ofheld in “street name” does not give instructions to his or her broker, bank or nominee holding the Company’s common stock issued and outstanding and entitledshares as to how to vote as ofon matters deemed to be “non-routine” under NYSE rules, the record date forbroker, bank or nominee cannot vote the Special Meeting), must be present in person or by proxy. This is referred to as a "quorum." Proxies marked "Abstain" and broker non-votes (as further discussed below) will be treated asshares. These unvoted shares that are present for purposes of determining the presence of a quorum.

What happens if a quorum is not present at the Special Meeting?

If the shares present in person or represented by proxy at the Special Meeting are not sufficient to constitute a quorum, the stockholders by a vote of the holders of a majority of votes present in person or represented by proxy (which may be voted by the proxyholders) may, without further notice to any stockholder (unless a new record date is set), adjourn the meeting to a different time and place to permit further solicitations of proxies sufficient to constitute a quorum.

What is an "abstention" and how would it affect the vote?

An "abstention" occurs when a stockholder sends in a proxy with explicit instructions to decline to vote regarding a particular matter. Abstentions are counted as present for purposes of determining a quorum. Abstentions with respect to the Reverse Stock Split proposal will have the same effect as a vote "Against" the proposals. Abstentions“broker non-votes.” Proposals 1, 3 and 4 are not considered to be votes cast“non-routine” under NYSE rules and we, therefore, will have no impact on the 2019 Equity Plan proposal and the adjournment proposal.expect broker non-votes to exist in connection with those proposals.

What isAs a “broker non-vote and how would it affect the vote?

Brokers, banks or other nominees that are member firms of the New York Stock Exchange and who hold shares in street name for customers have the discretion to vote those shares with respect to certain matters if they have not received instructions from the beneficial owners. If a broker that is a record holder of common stock does return a signed proxy, but is not authorized to vote on one or more matters (with respect to each such matter, a "broker non-vote"), the shares of common stock represented by such proxy will be considered present at the Special Meeting for purposes of determining the presence of a quorum. A broker that is a member of the New York Stock Exchange is prohibited, unless the stockholder provides the broker with written instructions, from giving a proxy on nonroutine matters. Consequently, your brokerage firm or other nominee will have discretionary authority to vote your shares with respect to routine matters but may not vote your shares with respect to non-routine matters.

We believe that each of the Reverse Stock Split proposal and the adjournment proposal are deemed to be a "routine" matter. Therefore,reminder, if you are a beneficial owner of shares registeredheld in “street name,” in order to ensure your shares are voted in the name of your broker or other nominee andway you fail to provide instructions to your broker or nominee as to how to vote your shares on the Reverse Stock Split proposal or the adjournment proposal, your broker or nominee will have the discretion to vote your shares however they see fit. Accordingly, ifwould prefer, you fail tomust provide voting instructions to your broker or nominee holding the shares by the deadline provided in the materials you receive from your broker or nominee can vote your shares on the Reverse Stock Split proposal or the adjournment proposal in a manner that is contrary to what you intend. In addition, while we do not expect any broker non-votes on the Reverse Stock Split proposal or the adjournment proposal, if you do not provide voting instructions and your broker or nominee fails to vote your shares, this will have the same effect as a vote "Against" the Reverse Stock Split proposal. If you are a beneficial owner of shares registered in the name of your broker or other nominee, we strongly encourage you to provide voting instructions to the broker or nominee that holds your shares to ensure that your shares are voted in the manner in which you want them to be voted.nominee.

Brokers will not have this discretionary authority with respectHow many votes are needed to the approval of the 2019 Equity Plan and because approval of the 2019 Equity Plan requires the affirmative vote of theapprove each proposal?

The holders of a majority of the shares of stock that are present in person or by proxy and entitled to vote at the Special Meeting, broker non-votes will have no effect.   

Can other matters be decided at the Special Meeting?

Other than the Reverse Stock Split proposal, the 2019 Equity Plan proposal and the adjournment proposal, no other matters will be presented for action by the stockholders at the Special Meeting.

Who will conduct the proxy solicitation and how much will it cost?

We are soliciting proxies from stockholders on behalf of the Board and will pay for all costs incurred by it in connection with the solicitation. In addition to solicitation by mail, the directors, officers and associates of the Company and its subsidiaries may solicit proxies from stockholders of the Company in person or by telephone, facsimile or email without additional compensation other than reimbursement for their actual expenses.

We have retained The Proxy Advisory Group, LLC, a proxy solicitation firm, to assist in the solicitation of proxies and to provide related advice and informational support for a service fee, plus customary disbursements, which are not expected to exceed $25,000in the aggregate. Arrangements also will be made with brokerage firms and other custodians, nominees and fiduciaries for the forwarding of solicitation material to the beneficial owners of stock held of record by such persons, and we will reimburse such custodians, nominees and fiduciaries for their reasonable out-of-pocket expenses in connection with the forwarding of solicitation materials to the beneficial owners of our stock.

If you have any questions or need assistance voting your shares of the Company common stock, please contact The Proxy Advisory Group, LLC, the Company's proxy solicitor, by calling (212) 616-2180.

PROPOSAL NO. 1

THE REVERSE STOCK SPLIT PROPOSAL

General 

The Company is asking stockholders to adopt and approve the proposal that the Company’s Amended and Restated Certificate of Incorporation be amended, by way of a Certificate of Amendment, to effect the Reverse Stock Split. The proposed amendment, if effected, will effect a Reverse Stock Split of the outstanding shares of the Company's common stock at a Reverse Stock Split ratio of not less than 1-for-20 and not greater than 1-for-60, with the exact ratio and effective time of the Reverse Stock Split to be determined by the Board at any time within one year of the date of the Special Meeting. The foregoing description of the proposed amendment is a summary and is subject to the full text of the proposed amendment, which is attached to this proxy statement as Annex A.

If approved by the stockholders, the Reverse Stock Split, if any, would become effective at a time, and at a ratio, to be designated by the Board of Directors. The Board of Directors may effect only one Reverse Stock Split as a result of this authorization. The Board of Directors also may determine in its discretion not to effect the Reverse Stock Split and not to file the Certificate of Amendment. No further action on the part of stockholders will be required to either implement or abandon the Reverse Stock Split. The determination of the ratio of the Reverse Stock Split will be based on a number of factors, described further below under the heading “—Criteria to be Used for Determining Whether to Implement Reverse Stock Split.” The Reverse Stock Split, if approved by stockholders and if deemed by the Board of Directors to be in the best interests of us and our stockholders, will be effected, if at all, at a time that is not later than the date that is within one year from the date of the Special Meeting.

As of the July 12, 2019 record date 210,092,687 shares of our common stock were issued and outstanding. Based on such number of shares of our common stock issued and outstanding, immediately following the effectiveness of the Reverse Stock Split (and without giving any effect to the payment of cash in lieu of fractional shares), we will have, depending on the Reverse Stock Split ratio selected by our Board of Directors, issued and outstanding shares of stock as illustrated in the table under the caption “—Effects of the Reverse Stock Split—Effect on Shares of Common Stock.”

The Reverse Stock Split will be realized simultaneously for all outstanding common stock, options to purchase shares of our common stock (including shares available for future grants under the 2017 Equity Incentive Plan and the 2019 Equity Plan if approved by our stockholders pursuant to Proposal 2) and warrants to purchase shares of our common stock. The Reverse Stock Split will affect all holders of common stock uniformly and each stockholder will hold the same percentage of common stock outstanding immediately following the Reverse Stock Split as that stockholder held immediately prior to the Reverse Stock Split, except for immaterial adjustments that may result from the treatment of fractional shares as described below. The Reverse Stock Split will not change the par value of our common stock and will not reduce the number of authorized shares of common stock (see "—Effects of the Reverse Stock Split").

No fractional shares of common stock will be issued as a result of the Reverse Stock Split. Instead, any stockholder who would have been entitled to receive a fractional share as a result of the Reverse Stock Split will receive cash payments in lieu of such fractional shares.

Reasons for the Reverse Stock Split

Nasdaq Compliance. Our common stock is publicly traded and listed on the Nasdaq Capital Market (“Nasdaq”) under the symbol "SLS." Our Board of Directors authorized the reverse split of our common stock with the primary intent of increasing the per share trading price of our common stock in order to ensure that we continue to satisfy the requirements for the continued listing of our common stock on Nasdaq which we believe helps support and maintain stock liquidity and Company recognition for our stockholders. Accordingly, we believe that effecting the Reverse Stock Split is in the Company's and our stockholders' best interests.

Companies listed on the Nasdaq are subject to various rules and requirements imposed by Nasdaq which must be satisfied in order to continue having their stock listed on the exchange (these are called the Nasdaq’s continued listing standards). One of these standards is the “minimum bid price” requirement set forth in Marketplace Rule 5450(a)(1), which requires that the bid price of the stock of listed companies be at least $1.00 per share. A listed company risks being delisted and removed from the Nasdaq if the closing bid price of its stock remains below $1.00 per share for an extended period of time. The closing bid price of our common stock has been below $1.00 per share since April 16, 2019.

On May 31, 2019, we received a letter from Nasdaq indicating that, based upon the closing bid price of our common stock for the last 30 consecutive business days, we did not meet the minimum bid price of $1.00 per share required for continued listing on the Nasdaq Capital Market pursuant to Minimum Bid Price Rule. We have been provided an initial period of 180 calendar days, or until November 27, 2019, to regain compliance with the Minimum Bid Price Rule. The letter also indicated that if at any time before November 27, 2019 the closing bid price for our common stock is at least $1.00 for a minimum of ten consecutive business days, Nasdaq will provide written notification to the company that it complies with the Minimum Bid Price Rule. If we do not regain compliance with the Minimum Bid Price Rule by November 27, 2019, we may be eligible for an additional compliance period of 180 calendar days; however, such extension is at the discretion of Nasdaq and there can be no assurance that Nasdaq will grant the extension. If we do not regain compliance with the Minimum Bid Price Rule by November 27, 2019 and Nasdaq does not grant us an additional compliance period at that time, Nasdaq will provide written notification to us that our common stock may be delisted. At that time, we may appeal Nasdaq’s delisting determination to a Nasdaq hearings panel. If we timely appeal, our common stock would remain listed pending the panel’s decision. There can be no assurance that, if we do appeal the delisting determination by Nasdaq to the panel, such appeal would be successful.

Additional Potential Investors. In addition to bringing the per share trading price of our common stock back above $1.00, we also believe that the Reverse Stock Split will make our common stock more attractive to a broader range of institutional and other investors, as we have been advised that the current per share trading price of our common stock may affect its acceptability to certain institutional investors, professional investors and other members of the investing public. Many brokerage houses and institutional investors have internal policies and practices that either prohibit them from investing in low-priced stocks or tend to discourage individual brokers from recommending low-priced stocks to their customers. In addition, some of those policies and practices may function to make the processing of trades in low-priced stocks economically unattractive to brokers.

Financial Planning Flexibility. The Board believes it is in the best interest of the Company to approve the Amendment to effect the Reverse Stock Split of the Company’s issued and outstanding common stock to give the Company greater flexibility in considering and planning for future potential business needs. The Reverse Stock Split will result in additional authorized and unissued shares becoming available for general corporate purposes as the Board may determine from time to time, including for use under its equity compensation plans.

Reducing the number of outstanding shares of our common stock through the Reverse Stock Split is intended, absent other factors, to increase the per share trading price of our common stock. However, other factors, such as our financial results, market conditions and the market perception of our business may adversely affect the per share trading price of our common stock. As a result, there can be no assurance that the Reverse Stock Split, if completed, will result in the intended benefits described above, that the per share trading price of our common stock will increase following the Reverse Stock Split or that the per share trading price of our common stock will not decrease in the future.

Criteria to be Used for Determining Whether to Implement Reverse Stock Split 

In determining whether to implement the Reverse Stock Split and which Reverse Stock Split ratio to implement, if any, following receipt of stockholder approval of the amendment to our Amended and Restated Certificate of Incorporation to effect the Reverse Stock Split, the Board of Directors may consider, among other things, various factors, such as:

Certain Risks and Potential Disadvantages Associated with the Reverse Stock Split 

We cannot assure you that the proposed Reverse Stock Split will increase our stock price.  We expect that the Reverse Stock Split will increase the per share trading price of our common stock. However, the effect of the Reverse Stock Split on the per share trading price of our common stock cannot be predicted with any certainty, and the history of reverse stock splits for other companies is varied, particularly since some investors may view a reverse stock split negatively. It is possible that the per share trading price of our common stock after the Reverse Stock Split will not increase in the same proportion as the reduction in the number of our outstanding shares of common stock following the Reverse Stock Split, and the Reverse Stock Split may not result in a per share trading price that would attract investors who do not trade in lower priced stocks. In addition, although we believe the Reverse Stock Split may enhance the marketability of our common stock to certain potential investors, we cannot assure you that, if implemented, our common stock will be more attractive to investors. Even if we implement the Reverse Stock Split, the per share trading price of our common stock may decrease due to factors unrelated to the Reverse Stock Split, including our future performance. If the Reverse Stock Split is consummated and the per share trading price of the common stock declines, the percentage decline as an absolute number and as a percentage of our overall market capitalization may be greater than would occur in the absence of the Reverse Stock Split.

The proposed Reverse Stock Split may decrease the liquidity of our common stock and result in higher transaction costs.  The liquidity of our common stock may be negatively impacted by the Reverse Stock Split, given the reduced number of shares that would be outstanding after the Reverse Stock Split, particularly if the per share trading price does not increase as a result of the Reverse Stock Split. In addition, if the Reverse Stock Split is implemented, it will increase the number of our stockholders who own "odd lots" of fewer than 100 shares of common stock. Brokerage commission and other costs of transactions in odd lots are generally higher than the costs of transactions of more than 100 shares of common stock. Accordingly, the Reverse Stock Split may not achieve the desired results of increasing marketability of our common stock as described above.

Dilution to existing stockholders if the Company issues new shares of Common Stock. Although the Reverse Stock Split will not in itself cause dilution to our existing stockholders, the number of shares the Company will be authorized to issue will not be decreased proportionally. Thus, should the Company decide to issue new shares of common stock in the future to raise capital, existing stockholders’ ownership will be diluted.

Procedure for Effecting Reverse Stock Split and Exchange of Stock Certificates

If the Certificate of Amendment is approved by our stockholders, and if at such time the Board of Directors still believes that the Reverse Stock Split is in the best interests of the Company and its stockholders, the Board of Directors will determine the ratio of the Reverse Stock Split to be implemented. We will file the Certificate of Amendment with the Secretary of State of the State of Delaware at such time as the Board of Directors has determined the appropriate effective time for the Reverse Stock Split (the “Effective Time”). The Board of Directors may delay effecting the Reverse Stock Split, if at all, until a time that is not later than one year from the date of the Special Meeting, without re-soliciting stockholder approval. The Reverse Stock Split will become effective on the date of filing of the Certificate of Amendment with the Secretary of State of the State of Delaware. Beginning on the effective date of the Reverse Stock Split, each certificate representing pre-Reverse Stock Split shares will be deemed for all corporate purposes to evidence ownership of post-Reverse Stock Split shares.

If, at any time prior to the filing of the Certificate of Amendment with the Delaware Secretary of State, notwithstanding stockholder approval, and without further action by the stockholders, the Board of Directors, in its sole discretion, determines that it is in the Company's best interests and the best interests of the Company's stockholders to delay the filing of the Certificate of Amendment or abandon the Reverse Stock Split, the Reverse Stock Split may be delayed or abandoned.

Fractional Shares 

Stockholders will not receive fractional shares of common stock in connection with the Reverse Stock Split. Instead, the transfer agent will aggregate all fractional shares and sell them as soon as practicable after the Effective Time at the then-prevailing prices on the open market, on behalf of those stockholders who would otherwise be entitled to receive a fractional share as a result of the Reverse Stock Split. We expect that the transfer agent will conduct the sale in an orderly fashion at a reasonable pace and that it may take several days to sell all of the aggregated fractional shares of our common stock. After the transfer agent's completion of such sale, stockholders who would have been entitled to a fractional share will instead receive a cash payment from the transfer agent in an amount equal to their respective pro rata shares of the total proceeds of that sale net of any brokerage costs incurred by the transfer agent to sell such stock.

Stockholders will not be entitled to receive interest for the period of time between the Effective Time and the date payment is made for their fractional share interest. You should also be aware that, under the escheat laws of certain jurisdictions, sums due for fractional interests that are not timely claimed after the funds are made available may be required to be paid to the designated agent for each such jurisdiction. Thereafter, stockholders otherwise entitled to receive such funds may have to obtain the funds directly from the state to which they were paid.

If you believe that you may not hold sufficient shares of the Company's common stock at the Effective Time to receive at least one share in the Reverse Stock Split and you want to continue to hold the Company's common stock after the Reverse Stock Split, you may do so by either:

in each case, so that you hold a number of shares of our common stock in your account prior to the Reverse Stock Split that would entitle you to receive at least one share of common stock in the Reverse Stock Split. Shares of our common stock held in registered form and shares of our common stock held in "street name" (that is, through a broker, bank or other holder of record) for the same stockholder will be considered held in separate accounts and will not be aggregated when effecting the Reverse Stock Split.

Effects of the Reverse Stock Split

General 

After the effective date of the Reverse Stock Split, if implemented by the Board of Directors, each stockholder will own a reduced number of shares of common stock. The principal effect of the Reverse Stock Split will be to proportionately decrease the number of outstanding shares of our common stock based on the Reverse Stock Split ratio selected by our Board of Directors. As a matter of Delaware law, the implementation of the Reverse Stock Split does not require a reduction in the total number of authorized shares of our common stock.

Voting rights and other rights of the holders of our common stock will not be affected by the Reverse Stock Split, other than as a result of the treatment of fractional shares as described above. For example, a holder of 2% of the voting power of the outstanding shares of our common stock immediately prior to the effectiveness of the Reverse Stock Split will generally continue to hold 2% (assuming there is no impact as a result of the payment of cash in lieu of issuing fractional shares) of the voting power of the outstanding shares of our common stock after the Reverse Stock Split. The number of stockholders of record will not be affected by the Reverse Stock Split (except to the extent any are cashed out as a result of holding fractional shares). If approved and implemented, the Reverse Stock Split may result in some stockholders owning "odd lots" of less than 100 shares of our common stock. Odd lot shares may be more difficult to sell, and brokerage commissions and other costs of transactions in odd lots are generally somewhat higher than the costs of transactions in "round lots" of even multiples of 100 shares. Our Board of Directors believes, however, that these potential effects are outweighed by the benefits of the Reverse Stock Split.

Effect on Shares of Common Stock 

The following table contains approximate information, based on share information as of July 17, 2019, relating to our outstanding common stock assuming Reverse Stock Split ratios of 1-for-20, 1-for-40 and 1-for-60, which reflect the low end, middle and high end of the range that our stockholders are being asked to approve. In addition, the following table sets forth (i) the number of shares of our common stock that would be issued and outstanding, (ii) the number of shares of our common stock that would be reserved for issuance pursuant to outstanding warrants and options and (iii) the weighted-average exercise price of outstanding options and warrants, each giving effect to the Reverse Stock Split and based on securities outstanding as of July 17, 2019.

If this Reverse Stock Split Proposal is approved and our Board of Directors elects to effect the Reverse Stock Split, the number of outstanding shares of common stock will be reduced in proportion to the ratio of the split chosen by our Board of Directors and we would communicate to the public, prior to the effective date of the stock split, additional details regarding the Reverse Stock Split, including the specific ratio selected by our Board of Directors.       

After the effective date of the Reverse Stock Split that our Board of Directors elects to implement, our common stock would have a new committee on uniform securities identification procedures, or CUSIP number, a number used to identify our common stock.

Our common stock is currently registered under Section 12(b) of the Securities Exchange Act of 1934, or the Exchange Act, and we are subject to the periodic reporting and other requirements of the Exchange Act. The Reverse Stock Split will not affect the registration of our common stock under the Exchange Act or the listing of our common stock on Nasdaq. Following the Reverse Stock Split, our common stock will continue to be listed on Nasdaq under the symbol "SLS," although it will be considered a new listing with a new CUSIP number.

Effect on Preferred Stock 

Pursuant to our Amended and Restated Certificate of Incorporation, our authorized capital stock includes 5,000,000 shares of Preferred Stock, par value $0.0001 per share. The proposed amendment to our Amended and Restated Certificate of Incorporation to effect the Reverse Stock Split would not impact the total authorized number of shares of preferred stock or the par value of the preferred stock.

Effect on Par Value 

The proposed amendments to our Amended and Restated Certificate of Incorporation will not affect the par value of our common stock, which will remain at $0.0001.

Reduction in Stated Capital

As a result of the Reverse Stock Split, upon the Effective Time, the stated capital on our balance sheet attributable to our common stock, which consists of the par value per share of our common stock multiplied by the aggregate number of shares of our common stock issued and outstanding, will be reduced in proportion to the size of the Reverse Stock Split, subject to a minor adjustment in respect of the treatment of fractional shares, and the additional paid-in capital account will be credited with the amount by which the stated capital is reduced. Our stockholders' equity, in the aggregate, will remain unchanged.

Effect on Authorized Shares of Common Stock

Currently, we are authorized to issue up to a total of 350,000,000 shares of common stock. On the Record Date, there were 210,082,687 shares of our common stock issued and outstanding, warrants to purchase 32,781,849 shares of our common stock issued and outstanding (with a weighted average exercise price of $2.07) and options to purchase 1,210,234 shares of our common stock issued and outstanding under our equity compensation plans (with a weighted average exercise price of $2.32). This leaves only 105,151,046 shares of our authorized common stock available for future issuance, both for equity financings and equity compensation.

Effecting the Reverse Stock Split will not change the total authorized number of shares of common stock. However, the reduction in the issued and outstanding shares, and the corresponding adjustment of shares issuable pursuant to warrants and options, which would be decreased by a factor of between 20 and 60, would provide more authorized shares available for future issuance. Because holders of our common stock have no preemptive rights to purchase or subscribe for any unissued stock of the Company, the issuance of additional shares in the future of authorized common stock that will become newly available as a result of the implementation of the Reverse Stock Split will reduce the current stockholders’ percentage ownership interest in the total outstanding shares of common stock.

We may issue additional equity capital in the future to support our planned clinical research and general operations. The additional available shares that the proposed Reverse Stock Split will provide will allow us to pursue any such financing. However, with the exception of the reservation of shares for issuance upon exercise of the our outstanding warrants and the reservation of shares underlying the 2017 Incentive Plan and 2019 Equity Plan, if it is approved by our stockholders at the Special Meeting, we currently do not have any specific plans, arrangements or understandings to issue any of the shares of common stock that will be newly available as a result of the implementation of the Reverse Stock Split.

No Going Private Transaction 

Notwithstanding the decrease in the number of outstanding shares following the proposed Reverse Stock Split, our Board of Directors does not intend for this transaction to be the first step in a "going private transaction" within the meaning of Rule 13e-3 of the Exchange Act.

Shares Held in Book-Entry and Through a Broker, Bank or Other Holder of Record 

If you hold registered shares of our common stock in a book-entry form, you do not need to take any action to receive your post-Reverse Stock Split shares of our common stock in registered book-entry form or your cash payment in lieu of fractional shares, if applicable. If you are entitled to post-Reverse Stock Split shares of our common stock, a transaction statement will automatically be sent to your address of record as soon as practicable after the Effective Time indicating the number of shares of our common stock you hold. In addition, if you are entitled to a payment of cash in lieu of fractional shares, a check will be mailed to you at your registered address as soon as practicable after the Effective Time. By signing and cashing this check, you will warrant that you owned the shares of the Company's common stock for which you received a cash payment.

At the Effective Time, we intend to treat stockholders holding shares of our common stock in "street name" (that is, through a broker, bank or other holder of record) in the same manner as registered stockholders. Brokers, banks or other holders of record will be instructed to effect the Reverse Stock Split for their beneficial holders holding shares of our common stock in "street name"; however, these brokers, banks or other holders of record may apply their own specific procedures for processing the Reverse Stock Split. If you hold your shares of our common stock with a broker, bank or other holder of record, and you have any questions in this regard, we encourage you to contact your holder of record.

Shares Held in Certificated Form 

If you hold any of your shares of our common stock in certificated form (the "Old Certificate(s)"), you will receive a transmittal letter from our transfer agent as soon as practicable after the Effective Time. The transmittal letter will be accompanied by instructions specifying how you can deliver your Old Certificate(s) so that you are in a position to freely trade your post-Reverse Stock Split shares of our common stock, which will be in a book-entry form, evidenced by a transaction statement that will be sent to your address of record as soon as practicable after your delivery of a letter of transmittal and your Old Certificate, together with any payment of cash in lieu of fractional shares to which you are entitled. Until surrendered as contemplated herein, a stockholder's Old Certificate(s) shall be deemed at and after the Effective Time to represent the number of full shares of our common stock resulting from the Reverse Stock Split.

YOU SHOULD NOT SEND YOUR OLD CERTIFICATES NOW. YOU SHOULD SEND THEM ONLY AFTER YOU RECEIVE THE LETTER OF TRANSMITTAL FROM OUR TRANSFER AGENT.

Vote Required 

Under Delaware law, the affirmative vote of a majority of the shares of common stock issued and outstanding and entitled to vote at the Special2021 Annual Meeting is required to adopt and approvewill constitute a quorum for the amendment to our Amended and Restated Certificatetransaction of Incorporation to effect the Reverse Stock Split. Because adoption and approval of the amendment to our Amended and Restated Certificate of Incorporation to effect the Reverse Stock Split requires a majority of the outstanding shares, an abstention with respect to the Reverse Stock Split proposal will have the same effect as a vote "Against" the proposal.

The Company’s Board of Directors recommends that you vote "FOR" the Reverse Stock Split proposal.

No Appraisal Rights 

Under the Delaware General Corporation Law, our stockholders are not entitled to dissenter's rights or appraisal rights with respect to the Reverse Stock Split described in this proposal and we will not independently provide our stockholders with any such rights.

Interest of Certain Persons in Matters to be Acted Upon 

No officer or director has any substantial interest, direct or indirect, by security holdings or otherwise, in the Reverse Stock Split that is not shared by all of our other stockholders.

Certain U.S. Federal Income Tax Consequences of the Reverse Stock Split 

The following discussion is a general summary of certain U.S. federal income tax consequences of the Reverse Stock Split that may be relevant to holders of our common stock that hold such stock as a capital asset for U.S. federal income tax purposes (generally, property held for investment). This summary is based upon the provisions of the Internal Revenue Code of 1986, as amended (the "Code"), Treasury regulations promulgated thereunder, administrative rulings and judicial decisions as of the date hereof, all of which may change, possibly with retroactive effect, resulting in U.S. federal income tax consequences that may differ from those discussed below.

This discussion applies only to holders that are U.S. Holders (as defined below) and does not address all aspects of federal income taxation that may be relevant to such holders in light of their particular circumstances or to holders that may be subject to special tax rules, including: (i) holders subject to the alternative minimum tax; (ii) banks, insurance companies, or other financial institutions; (iii) tax-exempt organizations; (iv) dealers in securities or commodities; (v) regulated investment companies or real estate investment trusts; (vi) partnerships (or other flow-through entities for U.S. federal income tax purposes and their partners or members); (vii) traders in securities that elect to use a mark-to-market method of accounting for their securities holdings; (viii) U.S. Holders (as defined below) whose "functional currency" is not the U.S. dollar; (ix) persons holding our common stock as a position in a hedging transaction, "straddle," "conversion transaction" or other risk reduction transaction; (x) persons who acquire shares of our common stock in connection with employment or other performance of services; or (xi) U.S. expatriates. If a partnership (including any entity or arrangement treated as a partnership for U.S. federal income tax purposes) holds shares of our common stock, the tax treatment of a holder that is a partner in the partnership generally will depend upon the status of the partner and the activities of the partnership.

We have not sought, and will not seek, an opinion of counsel or a ruling from the Internal Revenue Service ("IRS") regarding the U.S. federal income tax consequences of the Reverse Stock Split and there can be no assurance that the IRS will not challenge the statements and conclusions set forth below or a court would not sustain any such challenge. The following summary does not address any U.S. state or local or any foreign tax consequences, any estate, gift or other non-U.S. federal income tax consequences, or the Medicare tax on net investment income.

EACH HOLDER OF COMMON STOCK SHOULD CONSULT SUCH HOLDER'S TAX ADVISOR WITH RESPECT TO THE PARTICULAR TAX CONSEQUENCES OF THE REVERSE STOCK SPLIT TO SUCH HOLDER.

For purposes of the discussion below, a "U.S. Holder" is a beneficial owner of shares of our common stock that for U.S. federal income tax purposes is: (1) an individual citizen or resident of the United States; (2) a corporation (including any entity taxable as a corporation for U.S. federal income tax purposes) created or organized in or under the laws of the United States, any state or political subdivision thereof; (3) an estate the income of which is subject to U.S. federal income taxation regardless of its source; or (4) a trust, if (i) a court within the United States is able to exercise primary supervision over the administration of the trust and one or more U.S. persons have the authority to control all substantial decisions of the trust, or (ii) the trust has a valid election in effect to be treated as a U.S. person.

The Reverse Stock Split is intended to be treated as a "recapitalization" for U.S. federal income tax purposes. As a result, a U.S. Holder generally should not recognize gain or loss upon the Reverse Stock Split, except with respect to cash received in lieu of a fractional share of our common stock, as discussed below. A U.S. Holder's aggregate tax basis in the shares of our common stock received pursuant to the Reverse Stock Split should equal the aggregate tax basis of the shares of our common stock surrendered (excluding any portion of such basis that is allocated to any fractional share of our common stock), and such U.S. Holder's holding period in the shares of our common stock received should include the holding period in the shares of our common stock surrendered. Treasury regulations promulgated under the Code provide detailed rules for allocating the tax basis and holding period of the shares of our common stock surrendered to the shares of our common stock received pursuant to the Reverse Stock Split. Holders of shares of our common stock acquired on different dates and at different prices should consult their tax advisors regarding the allocation of the tax basis and holding period of such shares.

A U.S. Holder that receives cash in lieu of a fractional share of our common stock pursuant to the Reverse Stock Split should recognize capital gain or loss in an amount equal to the difference between the amount of cash received and the U.S. Holder's tax basis in the shares of our common stock surrendered that is allocated to such fractional share. Such capital gain or loss should be long term capital gain or loss if the U.S. Holder's holding period for our common stock surrendered exceeded one yearbusiness at the Effective Time.

THE BOARD OF DIRECTORS UNANIMOUSLY RECOMMEND A VOTE "FOR" PROPOSAL NO. 1 RELATING TO THE AMENDMENT OF OUR AMENDED AND RESTATED CERTIFICATE OF INCORPORATION TO EFFECT A REVERSE STOCK SPLIT.

PROPOSAL 2: APPROVAL OF THE COMPANY’S 2019 EQUITY INCENTIVE PLAN

We are requesting that you vote to approve the adoption of the SELLAS Life Sciences Group, Inc. 2019 Equity Incentive Plan (the “2019 Equity Plan”), which was approved by our Board of Directors on July 26, 2019 effective upon stockholder approval at the Special2021 Annual Meeting. If this proposal is approved:

The 2019 Equity Plan includes the following provisions:

Why We Are Requesting Stockholder Approval of the 2019 Equity Plan

We believe that our future success depends, in large part, upon our ability to maintain a competitive position in attracting, retaining and motivating persons who are expected to make important contributions to the Company by providing such persons with equity ownership opportunities and performance-based incentives. The life sciences industry is highly competitive, and our results are largely attributable to the talents, expertise, efforts and dedication of our employees. Our compensation program, including the granting of equity compensation, is the primary means by which we attract and recruit new employees, as well as retain our most experienced and skilled employees.

Equity compensation is also fundamental to our compensation philosophy and core objectives of paying for performance and aligning the interests of employees with those of stockholders. A significant portion of our employees’ compensation is provided in the form of equity. We believe that equity awards, and the potential they hold for appreciation through an increase in our stock price, support our pay-for-performance philosophy, provide further incentive to our employees to focus on creating long-term stockholder value and create an ownership culture that links employees’ interests with those of our stockholders and our long-term results, performance, and financial condition.

As of July 17, 2019, 100% of our outstanding stock options were underwater, with a weighted-average exercise price for 1,210,234 options outstanding under the 2017 Plan of $2.32 per share and individual option exercise prices ranging up to $5.50 per share, and with a weighted-average exercise price for 10,171 options outstanding under a prior Company equity award plan of $1,240.55 per share and individual option exercise prices ranging up to $2,328.00 per share as compared to the $0.14 per share closing price of our common stock on Nasdaq on July 17, 2019. Accordingly, we believe that our employees currently have a very limited opportunity to participate in any future appreciation in the value of our common stock. For example, if the value of our common stock tripled from its closing price on Nasdaq of $0.14 on July 17, 2019 to $0.42 per share, our employees would be entitled to realize none of the increased equity value of the Company on a fully diluted basis assuming full acceleration of all vesting provisions. We believe that such a limited opportunity to participate in appreciation in the value of our common stock results in such outstanding options holding insufficient retention value for our employees, puts us at risk of not being able to retain our most experienced and skilled employees and provides for insufficient alignment of our employees’ interests with those of our stockholders.

As of July 17, 2019 we had 476,124 shares available for grant under the 2017 Plan, representing less than 1% of the sum of (i) the total number of our shares of common stock outstanding, plus (ii) the total number ofrepresented in person or by proxy (including shares of common stock issuable under outstanding equity incentive awards, plus (iii) the total number of shares available for grant under the 2017 Plan. As of July 17, 2019, we had 12,758 restricted stock units outstanding outside the 2017 Plan. During the years ended December 31, 2017 and 2018 and the six months ended June 30, 2019, we granted equity awardswhich abstain or do not vote with respect to 0, 482,500 and 940,000 shares, respectively, to employees, non-employee directors and consultants. The following table sets forth a summary of outstanding stock options granted under our 2017 Plan, our shares available for grant under our 2017 Plan, and related information for employees and nonemployees as of July 17, 2019:

Without the 2019 Equity Plan, we believe that we would not have sufficient shares available for grant under the 2017 Plan to make meaningful equity incentive grants to any potential new employees and we would not be able to adequately complete our anticipated annual Company-wide equity award grants for fiscal year 2020. Without the 2019 Equity Plan, we believe that we would be forced to rely on providing cash-settled awards for a portion of our incentive-based compensation in order to retain our most experienced and skilled employees, which we believe would put us at a competitive disadvantage in our industry and would not be in our stockholders’ best interests as it would remove incentives aligning the interests of our employees and our senior leaders with those of our stockholders to drive company-wide performance and create long-term stockholder value.

In determining the terms of the 2019 Equity Plan, we considered several factors, including the number of shares needed for annual employee option grants over the next two to three years, which we estimated at 4% to 8% of our outstanding stock at the time of such grants, the number of option shares needed for new hires over the next two to three years, including anticipated executive level hires in senior commercial, financial and clinical positions, and potential performance grants to employees to align employee interests with specified program, strategic and financial priorities.

The 2019 Equity Plan is being submitted to you for approval at the Special Meeting in order to ensure favorable federal income tax treatment for grants of incentive stock options under Section 422 of the Internal Revenue Code of 1986, as amended (the “Code”). Approval by our stockholders of the 2019 Equity Plan is also required by the listing rules of Nasdaq.

In the event the Reverse Stock Split proposal included in this Proxy Statement is approved by the stockholders of the Company and the amendment to the Certificate of Incorporation is filed with the Secretary of State of the State of Delaware, the shares under the 2019 Equity Plan will be accordingly adjusted pursuant to the terms of the 2019 Equity Plan, as will the shares issuable under any other existing plan described above.

The following is a brief summary of the 2019 Equity Plan. This summary is qualified in its entirety by reference to the text of the 2019 Equity Plan, a copy of which is attached as Annex B to this Proxy Statement.

Summary of Material Features of the 2019 Equity Plan

Eligibility. The 2019 Equity Plan allows us, under the direction of our Board of Directors or an authorized committee, to make grants of stock options, restricted and unrestricted stock awards and other stock-based awards to employees, consultants and directors who, in the opinion of the Compensation Committee, are in a position to make a significant contribution to our long-term success. All employees, directors and consultants of the Company and its affiliates are eligible to participate in the 2019 Equity Plan. As of July 17, 2019, there were approximately 10 individuals eligible to participate in the 2019 Equity Plan. The amounts of future grants under the 2019 Equity Plan are not determinable, as awards under the 2019 Equity Plan will be granted at the sole discretion of the Board of Directors or an authorized committee, and we cannot determine at this time either the persons who will receive awards under the 2019 Equity Plan or the amount or types of any such awards.

Shares Available for Issuance. The 2019 Equity Plan provides for the issuance of up to 10,000,000 shares of our common stock plus a number of additional shares to be issued if awards outstanding under our 2017 Plan are cancelled or expire on or after the date of the Special Meeting of stockholders. Generally, shares of common stock reserved for awards under the 2019 Equity Plan that lapse or are canceled (other than by exercise) will be added back to the share reserve available for future awards. However, shares of common stock tendered in payment for an award or shares of common stock withheld for taxes are not available again for future awards. In addition, shares repurchased by the Company with the proceeds of the option exercise price may not be reissued under the 2019 Equity Plan. No more than 80,000,000 shares shall be issued as incentive stock options under the 2019 Equity Plan. The number of shares to be granted to any non-employee director in any calendar year is limited such that the aggregate grant date fair value of the equity grant taken together with any cash fees paid by the Company to such non-employee director for services on the Board will not exceed $400,000, except with respect to the calendar year in which a non-employee director is first appointed or elected to the Board of Directors.

The 2019 Equity Plan provides that on the first day of the Company’s fiscal years 2020, 2021, 2022, and 2023, the number of Shares that may be issued from time to time pursuant to the 2019 Equity Plan, shall be increased by an amount equal to the lesser of (i) 5% of the number of outstanding shares of Common Stock as of the end of the prior fiscal year; and (ii) an amount determined by the Board of Directors or an authorized committee.

Maximum term. Stock options granted under the 2019 Equity Plan will terminate not more than ten years from the date of the grant or at such earlier time as the option agreement may provide.

Stock Options. Stock options granted under the 2019 Equity Plan may either be incentive stock options, which are intended to satisfy the requirements of Section 422 of the Code, or non-qualified stock options, which are not intended to meet those requirements. Incentive Stock Options may be granted to employees of the Company and its affiliates. Non-qualified options may be granted to employees, directors and consultants of the Company and its affiliates and the term of the option may not be longer than ten years. The exercise price of a stock option may not be less than 100% of the fair market value of our common stock on the date of grant. If an incentive stock option is granted to an individual who owns more than 10% of the combined voting power of all classes of our capital stock, the exercise price may not be less than 110% of the fair market value of our common stock on the date of grant and the term of the option may not be longer than five years.

Award agreements for stock options include rules for exercise of the stock options after termination of service. Options may not be exercised unless they are vested, and no option may be exercised after the end of the term set forth in the award agreement. Generally, stock options will be exercisable for three months after termination of service for any reason other than death or total and permanent disability, and for 12 months after termination of service on account of death or total and permanent disability but will not be exercisable if the termination of service was due to cause.

Restricted Stock. Restricted stock is common stock that is subject to restrictions, including a prohibition against transfer and a substantial risk of forfeiture, until the end of a “restricted period” during which the grantee must satisfy certain time or performance-based vesting conditions. If the grantee does not satisfy the vesting conditions by the end of the restricted period, the restricted stock is forfeited.

During the restricted period, the holder of restricted stock has the rights and privileges of a regular stockholder, except that the holder of such restricted stock is not entitled to receive dividends during the restricted period and the restrictions set forth in the applicable award agreement apply. For example, the holder of restricted stock may vote the restricted shares; but he or she may not sell the shares until the restrictions are lifted.

Other Stock-Based Awards. The 2019 Equity Plan also authorizes the grant of other types of stock-based compensation including, but not limited to stock appreciation rights, phantom stock awards, and stock unit awards. Our Board of Directors or an authorized committee may award such stock-based awards subject to such conditions and restrictions as it may determine. These conditions and restrictions may include continued employment with us through a specified restricted period or achievement of one or more performance goals.

Restricted Stock Units.Restricted stock units are phantom shares that vest in accordance with terms and conditions established by the Board of Directors or an authorized committee and when the applicable restrictions lapse, the grantee shall be entitled to receive a payout in cash, shares or a combination thereof based on the number of restricted stock units as specified in the award agreement. Dividend equivalents may accrue but shall not be paid prior to and only to the extent that, the restricted stock unit award vests.

Plan Administration. In accordance with the terms of the 2019 Equity Plan, our Board of Directors has authorized our Compensation Committee to administer the 2019 Equity Plan. The Compensation Committee may delegate part of its authority and powers under the 2019 Equity Plan to one or more of our directors and/or officers, but only the Compensation Committee can make awards to participants whomatters presented for stockholder approval) will be counted for purposes of determining whether a quorum is present at the 2021 Annual Meeting. The following votes are subject to the reporting and other requirements of Section 16required for approval of the Securities Exchange Act of 1934. In accordance withproposals being presented at the provisions of the 2019 Equity Plan, our Compensation Committee determines the terms of awards, including:

In addition, our Compensation Committee may, in its discretion, amend any term or condition of an outstanding award provided (i) such term or condition as amended is permitted by our 2019 Equity Plan, and (ii) any such amendment shall be made only with the consent of the participant to whom such award was made, if the amendment is adverse to the participant unless such amendment is required by applicable law or necessary to preserve the economic value of such award; and provided, further, that, without the prior approval of our stockholders, when the exercise price or strike price exceeds the fair market value of a share, options and stock appreciation rights will not be repriced, replaced or regranted through cancellation or by lowering the exercise price of a previously granted award.2021 Annual Meeting:

Stock Dividends and Stock Splits.Proposal 1: To Elect One Class II Director. If our common stock shall be subdivided or combined intoDirectors are elected by a greater or smaller number of shares or if we issue any shares of common stock as a stock dividend, the number of shares of our common stock deliverable upon exercise of an option issued or upon issuance of an award shall be appropriately increased or decreased proportionately, and appropriate adjustments shall be made in the exercise price per share of stock options or purchase price, if any, and performance goals applicable to performance-based awards, if any, to reflect such subdivision, combination or stock dividend.

Corporate Transactions. Upon a merger or other reorganization event, our Board of Directors, may, in its sole discretion, take any one or more of the following actions pursuant to the 2019 Equity Plan, as to some or all outstanding awards:

In the event that the transaction also constitutes a change of control (as defined in the 2019 Equity Plan):

Amendment and Termination.The 2019 Equity Plan may be amended by our stockholders. It may also be amended by our Board of Directors or an authorized committee, provided that any amendment approved by our Board of Directors or an authorized committee which is of a scope that requires stockholder approval as required by (i) the rules of Nasdaq, (ii) in order to ensure favorable federal income tax treatment for any incentive stock options under Code Section 422 or (iii) for any other reason, is subject to obtaining such stockholder approval.

In addition, other than in connection with stock dividends, stock splits, recapitalizations or reorganizations, the Board of Directors or an authorized committee may not when the exercise price exceeds the fair market value of a share, without stockholder approval reduce the exercise price or cancel any outstanding option in exchange for a replacement option having a lower exercise price, or for any other equity award or for cash. In addition, the Board of Directors or an authorized committee may not take any other action that is considered a direct or indirect “repricing” for purposes of the stockholder approval rules of the applicable securities exchange or inter-dealer quotation system on which the shares are listed, including any other action that is treated as a repricing under generally accepted accounting principles. However, no such action may adversely affect any rights under any outstanding award without the holder’s consent unless such amendment is required by applicable law or necessary to preserve the economic value of such award.

Duration of Plan. The 2019 Equity Plan will expire by its terms on July 26, 2029.

Federal Income Tax Considerations

The material federal income tax consequences of the issuance and exercise of stock options and other awards under the 2019 Equity Plan, based on the current provisions of the Code and regulations, are as follows. Changes to these laws could alter the tax consequences described below. This summary assumes that all awards granted under the 2019 Equity Plan are exempt from or comply with, the rules under Section 409A of the Code related to nonqualified deferred compensation.

Incentive Stock Options.Incentive stock options are intended to qualify for treatment under Section 422 of the Code. An incentive stock option does not result in taxable income to the optionee or deduction to us at the time it is granted or exercised, provided that no disposition is made by the optionee of the shares acquired pursuant to the option within two years after the date of grant of the option nor within one year after the date of issuance of shares to the optionee (referred to as the “ISO holding period”). However, the difference between the fair market value of the shares on the date of exercise and the option price will be an item of tax preference includible in “alternative minimum taxable income” of the optionee. Upon disposition of the shares after the expiration of the ISO holding period, the optionee will generally recognize long term capital gain or loss based on the difference between the disposition proceeds and the option price paid for the shares. If the shares are disposed of prior to the expiration of the ISO holding period, the optionee generally will recognize taxable compensation, and we will have a corresponding deduction, in the year of the disposition, equal to the excess of the fair market value of the shares on the date of exercise of the option over the option price. Any additional gain realized on the disposition will normally constitute capital gain. If the amount realized upon such a disqualifying disposition is less than fair market value of the shares on the date of exercise, the amount of compensation income will be limited to the excess of the amount realized over the optionee’s adjusted basis in the shares.

Non-Qualified Options.Options otherwise qualifying as incentive stock options, to the extent the aggregate fair market value of shares with respect to which such options are first exercisable by an individual in any calendar year exceeds $100,000, and options designated as non-qualified options will be treated as options that are not incentive stock options.

A non-qualified option ordinarily will not result in income to the optionee or deduction to us at the time of grant. The optionee will recognize compensation income at the time of exercise of such non-qualified option in an amount equal to the excess of the then value of the shares over the option price per share. Such compensation income of optionees may be subject to withholding taxes, and a deduction may then be allowable to us in an amount equal to the optionee’s compensation income.

An optionee’s initial basis in shares so acquired will be the amount paid on exercise of the non-qualified option plus the amount of any corresponding compensation income. Any gain or loss as a result of a subsequent disposition of the shares so acquired will be capital gain or loss.

Stock Grants.With respect to stock grants under the 2019 Equity Plan that result in the issuance of shares that are either not restricted as to transferability or not subject to a substantial risk of forfeiture, the grantee must generally recognize ordinary income equal to the fair market value of shares received. Thus, deferral of the time of issuance will generally result in the deferral of the time the grantee will be liable for income taxes with respect to such issuance. We generally will be entitled to a deduction in an amount equal to the ordinary income recognized by the grantee.

With respect to stock grants involving the issuance of shares that are restricted as to transferability and subject to a substantial risk of forfeiture, the grantee must generally recognize ordinary income equal to the fair market value of the shares received at the first time the shares become transferable or are not subject to a substantial risk of forfeiture, whichever occurs earlier. A grantee may elect to be taxed at the time of receipt of shares rather than upon lapse of restrictions on transferability or substantial risk of forfeiture, but if the grantee subsequently forfeits such shares, the grantee would not be entitled to any tax deduction, including as a capital loss, for the value of the shares on which he previously paid tax. The grantee must file such election with the Internal Revenue Service within 30 days of the receipt of the shares. We generally will be entitled to a deduction in an amount equal to the ordinary income recognized by the grantee.

Stock Units. The grantee recognizes no income until the issuance of the shares. At that time, the grantee must generally recognize ordinary income equal to the fair market value of the shares received. We generally will be entitled to a deduction in an amount equal to the ordinary income recognized by the grantee.

Vote Required.

The affirmative vote of a majorityplurality of the votes cast by proxy or in person at the Special Meeting is required to approve the adoption of the 2019 Equity Plan.

Recommendation

THE BOARD OF DIRECTORS RECOMMENDS APPROVAL OF THE ADOPTION OF THE 2019 EQUITY PLAN, AND PROXIES SOLICITED BY THE BOARD OF DIRECTORS WILL BE VOTED IN FAVOR OF THE ADOPTION OF THE 2019 EQUITY PLAN UNLESS A STOCKHOLDER HAS INDICATED OTHERWISE ON THE PROXY.

PROPOSAL NO. 3

THE ADJOURNMENT PROPOSAL

General 

The Company is asking stockholders to approve, if necessary, adjournmentholders of the Special Meeting to solicit additional proxies in favor of Proposal 1 and Proposal 2. Any adjournment of the Special Meeting for the purpose of soliciting additional proxies will allow stockholders who have already sent in their proxies to revoke them at any time prior to the time that the proxies are used.

Vote Required 

Under Delaware law, the affirmative vote of a majority of the votes cast by stockholdersshares present in person or represented by proxy and entitled to vote on the election of directors. Accordingly, the nominee receiving the highest number of affirmative votes will be elected. The only nominee for Class II director to be considered at the Special2021 Annual Meeting is David A. Scheinberg. Shares represented by executed proxies will be voted, if authority to do so is not withheld, for the election of the foregoing Class II Director.

Proposal 2: To Ratify the Appointment by the Audit Committee of Moss Adams LLP as our Independent Registered Public Accounting Firm for the Fiscal Year Ending December 31, 2021. The affirmative vote of the holders of shares of common stock representing a majority of the votes cast on the matter is required for the ratification of the appointment of Moss Adams LLP as our independent registered public accounting firm for the current fiscal year.

Proposal 3: To approve, on a non-binding advisory basis, the compensation of our Named Executive Officers. This proposal calls for a non-binding, advisory vote, and accordingly there is no “required vote” that would constitute approval. However, our Board of Directors, including our compensation committee, values the opinions of our stockholders and we will consider our stockholders’ concerns to the extent there are a substantial number of votes cast against the executive officer compensation as disclosed in this proxy statement and evaluate what actions may be appropriate to address those concerns.

Proposal 4: To approve the adjournment proposal. Abstentions2021 Employee Stock Purchase Plan. The affirmative vote of the holders of shares of common stock representing a majority of the votes cast on the matter is required for the approval of the 2021 Employee Stock Purchase Plan.

Shares that abstain from voting as to a particular matter and broker non-votesshares held in “street name” by brokerage firms who indicate on their proxies that they do not have discretionary authority to vote such shares as to a particular matter will not be counted as votes in favor of such matter, and will also not be counted as shares voting on such matter. Accordingly, abstentions and “broker non-votes” will have no effect on the outcome of this proposal.voting on the proposals referenced above.

THE BOARD OF DIRECTORS RECOMMENDS THAT YOU VOTE "FOR" THE ADJOURNMENT PROPOSAL.What is the quorum requirement?

A quorum of stockholders is necessary to hold a valid meeting. A quorum will be present if stockholders holding at least a majority of our then outstanding shares of the common stock entitled to vote are present at the 2021 Annual Meeting in person or represented by proxy. On the Record Date, there were 15,084,754 shares issued and outstanding and entitled to vote.

Your shares will be counted towards the quorum only if you submit a valid proxy (or one is submitted on your behalf by your broker, bank or other nominee) or if you cast your vote online. If there is no quorum, the holders of a majority of shares present at the 2021 Annual Meeting or represented by proxy may adjourn the 2021 Annual Meeting to another date.

How can I find out the 2021 Annual Meeting voting results?

Preliminary voting results will be announced at the 2021 Annual Meeting. In addition, final voting results will be published in a current report on Form 8-K that we expect to file within four business days after the 2021 Annual Meeting. If final voting results are not available to us in time to file a current report on Form 8-K within four business days after the 2021 Annual Meeting, we intend to file a current report on Form 8-K to publish preliminary results and, within four business days after the final results are known to us, file an additional current report on Form 8-K to publish the final results.

What proxy materials are available on the Internet?

This proxy statement and the annual report to stockholders are available at http://www.envisionreports.com/SLS.

What if I Receive More Than One Notice or Proxy Card?

You may receive more than one Notice or proxy card if you hold shares of our common stock in more than one account, which may be in registered form or held in street name. Please vote in the manner described above under “How Do I Vote?” for each account to ensure that all of your shares are voted.

How may I obtain an additional copy of the proxy materials if I share an address with another stockholder?

Some brokers or other nominee record holders may be sending you a single Notice or, if applicable, a single set of our proxy materials if multiple stockholders of the Company live in your household. This practice, which has been approved by the SEC, is called “householding.” Once you receive notice from your broker or other nominee record holder that it will be “householding” the Notice or if, applicable, our proxy materials, the practice will continue until you are otherwise notified or until you notify them that you no longer want to participate in the practice. Stockholders who participate in householding will continue to have access to and utilize separate proxy voting instructions.

We will promptly deliver a separate copy of our Notice or if applicable, our proxy materials to you if you write to our Corporate Secretary at: SELLAS Life Sciences Group, Inc., Times Square Tower, 7 Times Square, Suite 2503, New York, NY 10036, (646) 200-5278. If you want to receive your own Notice or, if applicable, set of our proxy materials in the future or, if you share an address with another stockholder and together both of you would like to receive only a single Notice or, if applicable, set of proxy materials, you should contact your broker or other nominee record holder directly or you may contact us at the above address and phone number.

SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT OF THE COMPANY

The following table sets forth as of July 17, 2019 (except as otherwise noted), certain information concerningwith respect to the beneficial ownership of (a) each director, (b)our common stock as of April 13, 2021 for (i) the named executive officers named in the Summary Compensation Table on page 14 of this proxy statement, (ii) each of our "Named Executive Officers" (as such term is defined in Item 402(a)(3)directors and director nominees, (iii) all of Regulation S-K under the Exchange Act), (c)our current directors and named executive officers as a group and (iv) each holderstockholder known toby us to own beneficially own more than 5% of our common stock and (d) all directors and executive officers as a group (based on 225,992,587 shares of common stock outstanding as of July 17, 2019). Eachstock. Beneficial ownership is determined in accordance with the rules of the persons named below has soleSEC and includes voting power and soleor investment power with respect to the securities. We deem shares set forth opposite hisof common stock that may be acquired by an individual or her name, exceptgroup within 60 days of April 13, 2021 pursuant to the exercise of options or warrants or the vesting of restricted stock units to be outstanding for the purpose of computing the percentage ownership of such individual or group, but those shares are not deemed to be outstanding for the purpose of computing the percentage ownership of any other person shown in the table. Except as otherwise noted.indicated in footnotes to this table, we believe that the stockholders named in this table have sole voting and investment power with respect to all shares of common stock shown to be beneficially owned by them based on information provided to us by these stockholders. Percentage of ownership is based on 15,084,754 shares of common stock outstanding on April 13, 2021.

* Represents beneficial ownership of less than one percent (1%) of the outstanding common stock.

EXECUTIVE OFFICERMANAGEMENT AND DIRECTOR COMPENSATIONCORPORATE GOVERNANCE

Summary Compensation TableBoard of Directors

The following table showsOur Bylaws provide that our business shall be managed by or under the compensation paiddirection of our Board of Directors. Our Board of Directors is divided into three classes for purposes of election. One class is elected at each annual meeting of stockholders to serve for a three-year term. Our Board of Directors has set the current size of the Board at five members, classified into three classes as follows: (i) Jane Wasman and Robert Van Nostrand are members of Class I with a term ending at the 2023 annual meeting; (ii) David A. Scheinberg is a member of Class II with a term ending at the 2021 Annual Meeting; and (iii) Angelos M. Stergiou and John Varian are members of Class III with a term ending at the 2022 annual meeting.

Our Board of Directors, upon the recommendation of the Nominating and Corporate Governance Committee, has nominated David Scheinberg for election at the 2021 Annual Meeting as a Class II director for a term of three years to serve until the 2024 annual meeting of stockholders, and until his successor has been elected and qualified.

Set forth below are the names of (i) the persons nominated for election as directors, and (ii) those directors whose terms do not expire this year, their ages, their offices in the Company, if any, their principal occupations or accruedemployment for at least the past five years, the length of their tenure as directors and the names of other public companies in which such persons hold or have held directorships during the last two fiscalpast five years endedas of April 27, 2021. Additionally, information about the specific experience, qualifications, attributes or skills that led to our Board of Directors’ conclusion at the time of filing of this proxy statement that each person listed below should serve as a director is set forth below:

*Denotes Chair of Committee

Jane Wasman. Ms. Wasman has been a director of the Company, Chair of the Board and Chair of the Nominating and Corporate Governance Committee of the Board since December 31,2017. Ms. Wasman became a member of the Compensation Committee in 2017 and 2018the Audit Committee in 2019. Ms. Wasman was President, International & General Counsel and Corporate Secretary of Acorda Therapeutics, Inc., or Acorda, a publicly traded biopharmaceutical company, from October 2012 until December 2019, managing its international, legal, quality, IP and compliance functions. From January 2012 until October 2012, she was Acorda’s Chief, Strategic Development, General Counsel and Corporate Secretary, and from May 2004 until January 2012, she was Acorda’s Executive Vice President, General Counsel and Corporate Secretary. Before joining Acorda, Ms. Wasman was with Schering-Plough Corporation, a global pharmaceutical company, for over eight years, holding various U.S. and international leadership positions, including Staff Vice President and Associate General Counsel. Ms. Wasman earned a J.D. from Harvard Law School and her undergraduate degree magna cum laude from Princeton University. Ms. Wasman is also a member of the board of directors of Rigel Pharmaceuticals, Inc. and Athersys, Inc., publicly traded biopharmaceutical companies, and Cytovia Therapeutics, a private biopharma company, and has been a member of the board of directors and of the executive committee of the board of NewYorkBIO since 2007. The Company believes Ms. Wasman’s significant executive and management experience at publicly traded biopharmaceutical companies qualifies her to serve on our named executive officers, or NEOs, for 2018. The NEOs areBoard.

Angelos M. Stergiou, M.D., Sc.D. h.c. Dr. Stergiou has served as our President and Chief Executive Officer, and a director, since December 2012. In 2012, Dr. Stergiou founded our predecessor entity, or Private SELLAS, that completed a business combination with Galena Biopharma on December 29, 2017, and served as the President and Chief Executive Officer and a director of Private SELLAS since that time, and as Chairman from 2012 to July 2016, and as Vice Chairman from July 2016 to December 2017. In connection therewith, Dr. Stergiou led the negotiation of an exclusive license agreement with Memorial Sloan Kettering Cancer Center, or MSK, to develop and commercialize MSK’s WT1 peptide vaccine technology, which was satisfied in part by the transfer to MSK of certain of Dr. Stergiou’s shares in Private SELLAS. Dr. Stergiou also co-founded Genesis Life Sciences, Ltd. (now Genesis Research), a boutique health economics and pricing-reimbursement and health access company where he served as President and Chief Operating Officer from 2009 to 2011. From 2004 to 2008 Dr. Stergiou served as Vice President and Head of Drug Development at Accentia Biopharmaceuticals, Inc and also served in the same capacity as well as Chief Medical Officer at its subsidiary Biovest International, Inc. during the same time. While at Biovest International, Inc., Dr. Stergiou led the Phase 3 development of a therapeutic cancer vaccine, BiovaxID, which was presented at the American Society of Clinical Oncology plenary session in 2009. Dr. Stergiou started his biotechnology career in 2002 at PAION AG where he served as its U.S. program lead of desmoteplase (DEDAS) and served on the joint steering and oversight committee of PAION AG with Forest Laboratories, Inc. in 2003-2004. Dr. Stergiou holds an M.D. from the U.S. American Institute of Medicine and a Sc.D. h.c. from Kentucky Wesleyan College and received his undergraduate degree in pre-medicine, biology and chemistry from Kentucky Wesleyan College. Dr. Stergiou is a member of the Board of Trustees at Kentucky Wesleyan College, a Fellow of the Royal Society of Medicine, an active member of the World Medical Association, and a member of the American Academy of Physicians in Clinical Research and the Association of Clinical Research Professionals. The Company believes that Dr. Stergiou’s experience as the founder of Private SELLAS and as President, Chief Executive Officer and Director of the Company, as well as his extensive experience in the biopharmaceutical industry and his significant management experience, qualifies him to serve on our Board.

David A. Scheinberg, M.D., Ph.D. Dr. Scheinberg has been a director of the Company since December 2017. Dr. Scheinberg is currently the Vincent Astor Chair and Chairman of Molecular Pharmacology, Sloan Kettering Institute. He also founded and chairs the Center for Experimental Therapeutics at MSK, where he spearheaded the discovery and early clinical development of galinpepimut-S and founded and was chair of the Nanotechnology Center from 2010 to 2014. Additionally, Dr. Scheinberg is a Professor of Medicine and Pharmacology and co-chair of the Pharmacology graduate program at the Weill-Cornell University Medical College and Professor in the Gerstner-Sloan Kettering Graduate School at MSK. Dr. Scheinberg is also an attending physician in the Department of Medicine, Leukemia Service and Hematology Laboratory Service/Department of Clinical Laboratories at Memorial Hospital. Dr. Scheinberg is an advisor to charitable foundations and cancer centers and sat on the board of directors of Progenics Pharmaceuticals, Inc. (NASDAQ: PGNX), a biotechnology company, from 1996 to 2019, and currently sits on the board of directors of Sapience Therapeutics, Inc., a privately held, preclinical stage biotechnology company. Dr. Scheinberg also served on Private SELLAS’ Scientific Advisory Board from 2015 to 2017. From 2010 through 2016 he served on the board of directors of Contrafect Corporation, a publicly traded clinical-stage biotechnology company. Dr. Scheinberg holds an M.D. and a Ph.D. in Pharmacology and Experimental Therapeutics from the Johns Hopkins University School of Medicine. Dr. Scheinberg earned his undergraduate degree in Biology from Cornell University. The Company believes Dr. Scheinberg’s experience on Private SELLAS’s Scientific Advisory Board and other public board experience, as well as his expertise as a leading academic oncologist at MSK, including broad knowledge of and contacts in the highest levels of medical research, qualifies him to serve on our Board.

Robert L. Van Nostrand. Mr. Van Nostrand has been a director of the Company and Chair of the Compensation Committee since December 2017. He was a member of the board of directors of Achillion Pharmaceuticals, Inc. (NASDAQ: ACHN), a biotechnology company, until it was acquired in January 2020. He is a member of the board of directors of Intra-Cellular Therapies, Inc. (NASDAQ: ITCI), a biopharmaceutical company, Yield10 Bioscience, Inc. (NASDAQ: YTEN), formerly Metabolix, Inc., a bio-agricultural company, Likeminds, Inc., a private biotech company, and the Biomedical Research Alliance of New York, a private company providing clinical trial services. Mr. Van Nostrand was Executive Vice President and Chief Financial Officer of Aureon Laboratories, Inc., a pathology life science company, from January 2010 to July 2010. Prior to joining Aureon Laboratories, Mr. Van Nostrand served as Executive Vice President and Chief Financial Officer of AGI Dermatics, a private biotechnology company, from July 2007 to September 2008, when the company was acquired. Between 1986 and 2007, Mr. Van Nostrand held various executive and other management positions, including Chief Compliance Officer and Chief Financial Officer, at OSI Pharmaceuticals, Inc., or OSI. Prior to joining OSI, Mr. Van Nostrand served in a managerial position with the accounting firm, Touche Ross & Co., currently Deloitte. Mr. Van Nostrand is a member of the board of NewYorkBIO where he previously served as Chairman. Mr. Van Nostrand holds a B.S. in Accounting from Long Island University, New York and completed advanced management studies at the Wharton School of the University of Pennsylvania. He is a Certified Public Accountant. The Company believes Mr. Van Nostrand’s vast board and industry experience in life sciences, his qualification as a financial expert, as well as his experience in transaction structuring and risk management qualifies him to serve on our Board.

John Varian. Mr. Varian has been a director of the Company and Chair of the Audit Committee since December 2017. Mr. Varian served as Chief Executive Officer of XOMA Corporation, or XOMA, from August 2011 through December 2016 and served as a member of the board of directors of XOMA from December 2008 through May 2017. Mr. Varian served as a member of the board of directors of Versartis, Inc. (NASDAQ: VSAR) from March 2014 through October 2018, when it acquired Aravive, and the board of directors of Egalet Corporation (NASDAQ: EGLT) from June 2018 through February 2019, when it acquired the assets of Iroko. Mr. Varian previously served as Chief Operating Officer of ARYx Therapeutics, Inc. from December 2003 through August 2011. Beginning in May 2000, Mr. Varian was Chief Financial Officer of Genset S.A. in France, where he was a key member of the team negotiating Genset’s sale to Serono S.A. in 2002. From 1998 to 2000, Mr. Varian served as Senior Vice President, Finance and Administration of Elan Pharmaceuticals, Inc., joining the company as part of its acquisition of Neurex Corporation. Prior to the acquisition, he served as Neurex Corporation’s Chief Financial Officer from 1997 until 1998. From 1991 until 1997, Mr. Varian served as the VP Finance and Chief Financial Officer of Anergen Inc. Mr. Varian was an Audit Principal/Senior Manager at Ernst & Young LLP from 1987 until 1991, where he focused on life sciences. Mr. Varian was also a founding committee member of Bay Bio and a former chairman of the Association of Bioscience Financial Officers International Conference. Mr. Varian is also a member of the board of directors of AmMax Bio, Inc., a private biopharmaceutical company. Mr. Varian holds a B.B.A. from Western Michigan University. He is a Certified Public Accountant. The Company believes Mr. Varian’s significant experience working with biopharmaceutical companies, including developing and implementing strategy, with a focus on financing, corporate financial management and related matters, qualifies him to serve on our Board.

Independence of the Board of Directors

As required under Nasdaq listing standards, a majority of the members of a listed company’s board of directors must qualify as “independent,” as affirmatively determined by the board of directors of such listed company. Our Board consults with our internal and outside counsel to ensure that its determinations are consistent with relevant securities and other laws and regulations regarding the definition of “independent,” including those set forth in pertinent listing standards of Nasdaq, as in effect from time to time.

Consistent with these considerations, after review of all relevant identified transactions or relationships between each director, or any of his or her family members, and us, our senior management and our independent auditors, our Board has affirmatively determined that the following directors are independent directors within the meaning of the applicable Nasdaq listing standards: Jane Wasman, Robert L. Van Nostrand, each Class I directors, and John Varian, a Class III director. In making this determination, our Board found that none of these directors had a material or other disqualifying relationship with the Company. David A. Scheinberg, M.D., Ph.D., our Class II director, because of payments made by Private SELLAS between 2015 and 2018 to MSK pursuant to a Sponsored Research Agreement which provided financial support for research conducted by Dr. Scheinberg, and Angelos M. Stergiou, M.D. ScD. h.c., Sc.D. h.c.our President and Chief Executive Officer and a Class III director, are not presently considered “independent” pursuant to the applicable Nasdaq standards.

Board Leadership Structure

Our Board has an independent Chair, Jane Wasman, who has authority, among other things, to preside over Board meetings and stockholder meetings, as well as such powers and duties as may from time to time be assigned by the Board. Accordingly, the Chair has substantial ability to shape the work of the Board. We believe that separation of the positions of Chair and Chief Executive Officer reinforces the independence of the Board in its oversight of our business and affairs. In addition, we believe that having an independent Chair creates an environment that is more conducive to objective evaluation and oversight of management’s performance, increasing management accountability and improving the ability of our Board to monitor whether management’s actions are in our best interests and those of our stockholders. As a result, we believe that having an independent Chair can enhance the effectiveness of our Board as a whole.

Role of the Board in Risk Oversight

One of the Board’s key functions is informed oversight of our risk management process. Our Board does not have a standing risk management committee, but rather administers this oversight function directly through the Board as a whole, as well as through the standing committees that address risks inherent in their respective areas of oversight. In particular, our Board is responsible for monitoring and assessing strategic risk exposure, including a determination of the nature and level of risk appropriate for us. Our Audit Committee has the responsibility to consider and discuss our major financial risk exposures and the other two most highly compensatedsteps management has taken to monitor and control these exposures, including guidelines and policies to govern the process by which risk assessment and management is undertaken. Our Audit Committee also monitors compliance with certain legal and regulatory requirements, including requirements related to privacy and data protection, and oversees the performance of the internal audit function. Our Nominating and Corporate Governance Committee monitors the effectiveness of our corporate governance guidelines, including whether they are successful in preventing illegal or improper liability-creating conduct. Our Compensation Committee assesses and monitors whether any of our compensation policies and programs has the potential to encourage excessive risk-taking.

Management periodically reports to the Board or relevant committee, which provides guidance on risk assessment and mitigation. Each committee charged with risk oversight reports to the Board on risk matters.

Corporate Governance Guidelines

We have adopted Corporate Governance Guidelines to assure that the Board has the necessary authority and practices in place to review and evaluate our business operations as needed and to make decisions that are independent of our management. The guidelines are also intended to align the interests of directors and management with those of our stockholders. The Corporate Governance Guidelines set forth the practices the Board follows with respect to board composition and selection, board meetings and involvement of senior management, Chief Executive Officer performance evaluation and succession planning, and board committees and compensation. The Corporate Governance Guidelines, as well as the charters for each committee of the Board, may be viewed at https://www.sellaslifesciences.com/investors/corporate-governance/default.aspx#section=documents.

Clawback Policy

In March 2021, our Board of Directors adopted a clawback policy. The clawback policy applies to all incentive-based compensation granted after the policy’s adoption, including cash and equity incentive awards. The policy provides that if both (1) an accounting restatement is required due to our material noncompliance with any financial reporting requirement under the U.S. federal securities laws and (2) our Board of Directors (or a committee thereof), in its sole discretion, determines that an act or omission of a current or former executive officers earning more than $100,000officer contributed to the circumstances requiring the restatement and that such act or omission involved fraud or intentional misconduct, then we will use reasonable efforts to recover from such person up to 100% of any incentive-based compensation awarded during the three-year period preceding the date on which we are required to prepare such accounting restatement.

Committees of the Board of Directors and Meeting Attendance

Board of Directors. During the fiscal year ended December 31, 2018,2020 there were 19 meetings of our Board of Directors. No director attended fewer than 75% of the total number of meetings of our Board of Directors and of committees of our Board of Directors on which such director served during 2020. Our Board of Directors makes every effort to but is not required to attend each identified below under the heading “Summary Compensation Table.”annual meeting of our stockholders. All directors attended our annual meeting of stockholders held in 2020.

Committees of the Board of Directors. Our Board has three standing committees: an Audit Committee, a Compensation Committee and a Nominating and Corporate Governance Committee. Each of the committees has authority to engage legal counsel or other experts or consultants, as it deems appropriate to carry out its responsibilities. Our Board has determined that each member of our committees meets the applicable Nasdaq rules and regulations regarding “independence” and each member is free of any relationship that would impair his or her individual exercise of independent judgment with regard to the Company. Our Board also has a Science Committee (formerly known as the Research & Development Committee), which meets from time to time to review the Company’s clinical programs.

Audit Committee

The Audit Committee is currently comprised of three directors: Messrs. Varian and Van Nostrand, and Ms. Wasman. The Audit Committee met four times in 2020. Our Board has adopted a written Audit Committee charter that is available to stockholders in the corporate governance section of our website at https://www.sellaslifesciences.com/investors/corporate-governance/default.aspx#section=documents.

The Audit Committee was established by our Board in accordance with Section 3(a)(58)(A) of the Securities Exchange Act of 1934, as amended, or the Exchange Act, to oversee our corporate accounting and financial reporting processes and audits of our financial statements. The Audit Committee’s responsibilities include, among other things:

Our Board reviews the Nasdaq listing standards’ definition of “independence” for Audit Committee members on an annual basis and has determined that all members of our Audit Committee are independent (as currently defined in Rule 5605(c)(2)(A)(i) and (ii) of the Nasdaq listing standards and under Rule 10A-3 under the Exchange Act).

Our Board has also determined that Messrs. Varian and Van Nostrand each qualify as an “audit committee financial expert,” as defined in applicable SEC rules. Our Board made a qualitative assessment of the level of knowledge and experience of both Mr. Varian and Mr. Van Nostrand based on a number of factors, including the formal education and experience of each of Messrs. Van Nostrand and Varian as former chief financial officers for public reporting companies, and the status of Messrs. Van Nostrand and Varian as Certified Public Accountants.

Report of the Audit Committee of the Board of Directors

The Audit Committee of our Board of Directors, which consists entirely of directors who meet the independence and experience requirements of the Nasdaq Capital Market, has furnished the following report:

The Audit Committee assists our Board of Directors in overseeing and monitoring the integrity of our financial reporting process, compliance with legal and regulatory requirements and the quality of internal and external audit processes. This committee’s role and responsibilities are set forth in our charter adopted by our Board of Directors, which is available on our website at https://www.sellaslifesciences.com/investors/corporate-governance/default.aspx#section=documents. This committee reviews and reassesses our charter annually and recommends any changes to our Board of Directors for approval. The Audit Committee is responsible for overseeing our overall financial reporting process, and for the appointment, compensation, retention, and oversight of the work of Moss Adams LLP. In fulfilling its responsibilities for the financial statements for fiscal year December 31, 2020, the Audit Committee took the following actions:

Members of the Company’s Audit Committee:

Narrative Disclosure To Summary Compensation TableCommittee

The Compensation Committee typicallyis currently comprised of two directors: Ms. Wasman and Mr. Van Nostrand. Each of Ms. Wasman and Mr. Van Nostrand is independent (as independence is currently defined in Rule 5605(d)(2) of the Nasdaq listing standards). The Compensation Committee met three times in 2020. Our Board has adopted a written Compensation Committee charter that is available to stockholders in the corporate governance section of our website at https://www.sellaslifesciences.com/investors/corporate-governance/default.aspx#section=documents.

The Compensation Committee acts on behalf of the Board to review, recommend for adoption and oversee our compensation strategy, policies, plans and programs, including:

Each year, our Compensation Committee reviews with management our executive compensation tables and accompanying narrative disclosure and considers whether to recommend that it be included in proxy statements and other filings.

Compensation Committee Processes and Procedures

Typically, the Compensation Committee meets at least quarterlytwice a year and with greater frequency if necessary. The agenda for each meeting is usually developed by the Chairman of the Compensation Committee, in consultation with the Chief Executive Officer. The Compensation Committee meets regularly in executive session. However, from time to time, various members of management and other employees as well as outside advisors or consultants may be invited by the Compensation Committee to make presentations, to provide financial or other background information or advice or to otherwise participate in Compensation Committee meetings. The Chief Executive Officer may not participate in, or be present during, any deliberations or determinations of our Compensation Committee regarding his compensation or individual performance objectives. The charter of the Compensation Committee grants the Compensation Committee full access to all books, records, facilities and personnel of the Company. In addition, under the charter, the Compensation Committee has the authority to obtain, at the expense of the Company, advice and assistance from compensation consultants and internal and external legal, accounting or other advisors and other external resources that the Compensation Committee considers necessary or appropriate in the performance of its duties. The Compensation Committee has direct responsibility for the oversight of the work of any consultants or advisers engaged for the purpose of advising our Compensation Committee. In particular, the Compensation Committee has the sole authority to retain, in its sole discretion, compensation consultants to assist in its evaluation of executive and director compensation, including the authority to approve the consultant’s reasonable fees and other retention terms.fees. Under the charter, the Compensation Committee may select, or receive advice from, a compensation consultant, legal counsel or other adviser to the Compensation Committee, other than in-house legal counsel and certain other types of advisers, only after taking into consideration six factors, prescribed by the SEC and Nasdaq, that bear upon the adviser’s independence; however, there is no requirement that any adviser be independent.

DuringThe Compensation Committee has engaged Radford, a division of Aon Hewitt, which is a subsidiary of Aon plc, or Radford, as its compensation consultant, to evaluate long and short-term executive compensation, director compensation and executive severance plans. The Compensation Committee has assessed the independence of Radford pursuant to SEC rules and has concluded that Radford’s work for the Compensation Committee does not raise any conflict of interest. On an annual basis, Radford reviews our executive officer and director compensation relative to a peer group and against survey data available to Radford. Working with Radford, the Compensation Committee reviews and adjusts our peer group in the latter part of each year for upcoming end-of-year compensation decisions. Decisions regarding 2020 salaries and short term non-equity incentive plan compensation were made by our Compensation Committee in early 2020 by reference to the peer group determined by our Compensation Committee at the end of 2019. In late 2019, the Compensation Committee and Radford, using industry standard parameters for establishing a peer group, sought to identify companies that fit the following criteria:

Based on these criteria, the Compensation Committee identified the following companies for our 2020 peer group: Actinium Pharmaceuticals, Inc., Aldeyra Therapeutics, Inc., Altimmune, Inc., AVEO Pharmaceuticals, Inc., Cidara Therapeutics, Inc., ContraFect Corporation, Cyclacel Pharmaceuticals, Inc., Evelo Biosciences, Inc., GlycoMimetics, Inc., Innovate Biopharmaceuticals, Inc., Jounce Therapeutics, Inc., Kezar Life Sciences, Inc., Merrimack Pharmaceuticals, Inc., NewLink Genetics Corporation, Onconova Therapeutics, Inc., Oncternal Therapeutics, Inc., resTORbio, Inc., Selecta Biosciences Inc., Sophiris Bio Inc., Stemline Therapeutics, Inc., Sunesis Pharmaceuticals Inc., Tocagen, Inc., Tyme Technologies Inc., and Verastem, Inc.

Radford ultimately developed compensation recommendations that were presented to the Compensation Committee for its consideration. Based on these recommendations, we determined our current compensation levels for our executive officers, including base salary and target bonus payments.

Nominating and Corporate Governance Committee

The Nominating and Corporate Governance Committee is responsible for identifying, reviewing and evaluating candidates to serve as directors of the Company (consistent with criteria approved by the Board), reviewing and evaluating incumbent directors, selecting candidates for election to our Board, making recommendations to our Board regarding the membership of the committees of the Board, and assessing the performance of management and our Board.

The Nominating and Corporate Governance Committee is comprised of three directors: Ms. Wasman and Messrs. Van Nostrand and Varian. All members of our Nominating and Corporate Governance Committee are independent (as independence is currently defined in Rule 5605(a)(2) of the Nasdaq listing standards). The Nominating and Corporate Governance Committee met two times in 2020. Our Board has adopted a written Nominating and Corporate Governance Committee charter that is available to stockholders in the corporate governance section of our website at https://www.sellaslifesciences.com/investors/corporate-governance/default.aspx#section=documents.

Generally, our Nominating and Corporate Governance Committee will consider candidates recommended from several sources, such as other directors or officers, stockholders, third party search firms or other appropriate sources. Once identified, the Nominating and Corporate Governance Committee will evaluate a candidate’s qualifications. The Nominating and Corporate Governance Committee believes that candidates for director should have certain qualifications, including the ability to read and understand basic financial statements and the possession of the highest personal integrity and ethics. Candidates for director should also be over 21 years of age. Our Nominating and Corporate Governance Committee also intends to consider such factors as possessing relevant expertise enabling the candidate to offer advice and guidance to management, having sufficient time to devote to the affairs of the Company, demonstrated excellence in his or her field, having the ability to exercise sound business judgment and having the commitment to rigorously represent the long-term interests of our stockholders. However, our Nominating and Corporate Governance Committee retains the right to modify these qualifications from time to time. Candidates for director nominees are reviewed in the context of the current composition of the Board, the operating requirements of the Company and the long-term interests of stockholders. In conducting this assessment, our Nominating and Corporate Governance Committee typically considers diversity, age, skills and such other factors as it deems appropriate, given our current needs and the needs of our Board, to maintain a balance of knowledge, experience and capability. The Nominating and Corporate Governance Committee considers issues of diversity among its members in identifying and considering nominees for director and strives where appropriate to achieve a diverse balance of backgrounds, perspectives, experience, age, gender, ethnicity and country of citizenship on our Board of Directors and its committees.

In the case of incumbent directors whose terms of office are set to expire, our Nominating and Corporate Governance Committee reviews these directors’ overall service to the Company during their terms, including the number of meetings attended, level of participation, quality of performance and any other relationships and transactions that might impair the directors’ independence. The Committee also takes into account the results of the Board’s self-evaluation, conducted annually on a group and individual basis. In the case of new director candidates, our Nominating and Corporate Governance Committee also determines whether the nominee is independent for Nasdaq purposes, which determination is based upon applicable Nasdaq listing standards, applicable SEC rules and regulations and the advice of counsel, if necessary. The Nominating and Corporate Governance Committee then uses its network of contacts to compile a list of potential candidates, but may also engage, if it deems appropriate, a professional search firm. The Nominating and Corporate Governance Committee conducts any appropriate and necessary inquiries into the backgrounds and qualifications of possible candidates after considering the function and needs of the Board.

Our Nominating and Corporate Governance Committee believes that it is in the best position to identify, review, evaluate and select qualified candidates for Board membership, based on the comprehensive criteria for Board membership approved by the Board. The Nominating and Corporate Governance Committee meets to discuss and consider the candidates’ qualifications and then selects a nominee for recommendation to the Board by majority vote. Although the Nominating and Corporate Governance Committee does not have a formal policy with regard to the consideration of director candidates recommended by stockholders, it has the power and authority to consider recommendations for Board nominees and proposals submitted by the Company’s stockholders.

If a stockholder wishes to propose a candidate for consideration as a nominee for election to our Board of Directors, that stockholder must follow the procedures described in our Bylaws. Any such recommendation should be made in writing on a timely basis as set forth in our Bylaws to our Corporate Secretary at our principal office and should be accompanied by the following information concerning the proposed nominee:

The Company may require any proposed nominee to furnish such other information as it may reasonably require to determine the eligibility of such proposed nominee to serve as an independent director of the Company or that could be material to a reasonable stockholder’s understanding of the independence, or lack thereof, of such proposed nominee.

Science Committee

The Board has a Science Committee (formerly known as the Research & Development Committee) that meets from time to time to review the Company’s clinical programs and is comprised of Dr. David A. Scheinberg, as Chair, and Dr. Angelos M. Stergiou and Mr. John Varian, as members. The Science Committee met seven times in 2020.

Stockholder Communications with the Board of Directors

The Board expects that the views of our stockholders will be heard by the Board, its committees or individual directors, as applicable, and that appropriate responses be provided to stockholders on a timely basis. Stockholders wishing to formally communicate with the Board, any committee of the Board, the independent directors as a group or any individual director may send communications directly to us at SELLAS Life Sciences Group, Inc., Times Square Tower, 7 Times Square, Suite 2503, New York, New York 10036, Attention: Corporate Secretary. All clearly marked written communications, other than unsolicited advertising or promotional materials, are logged and copied, and forwarded to the director(s) to whom the communication was addressed. Undirected communications will be distributed to our entire Board, or to any individual director or directors as appropriate, depending on the facts and circumstances outlined in the communications. Please note that the foregoing communication procedure does not apply to (i) stockholder proposals pursuant to Exchange Act Rule 14a-8 and communications made in connection with such proposals or (ii) service of process or any other notice in a legal proceeding.

Code of Ethics

We have adopted a Code of Business Conduct and Ethics, or the Code, which, along with our Amended and Restated Certificate of Incorporation, Amended and Restated Bylaws and the charters of our Board committees, provides a framework for the governance of our company. The Board’s Corporate Governance and Nominating Committee is responsible for periodically reviewing our governance practices and principles. The Code applies to all of our directors, officers and employees.

The Code reflects current best practices and enhances our personnel’s understanding of our standards of ethical business practices, promotes awareness of ethical issues that may be encountered in carrying out an employee’s or director’s responsibilities, and provides clarity as to how to address ethical issues that may arise.

The foregoing description of the Code does not purport to be complete and is qualified in its entirety by reference to the full text of the Code, a copy of which is posted on our website at https://www.sellaslifesciences.com/investors/corporate-governance/default.aspx#section=documents, and a printed copy may also be obtained by any stockholder upon request directed to SELLAS Life Sciences Group, Inc., Times Square Tower, 7 Times Square, Suite 2503, New York, NY 10036, Attention: Corporate Secretary. We also anticipate filing any future amendment or waiver of the Code on our website within four business days of the date of such amendment or waiver. The contents of our website are not incorporated by reference in this report or made a part hereof for any purpose.

Executive Officers

The names and ages of our current executive officers and their positions are as follows:

Biographical Information Regarding Executive Officers

Set forth below is a biographical description of each executive officer based on information supplied by such executive officer:

Angelos M. Stergiou, M.D., Sc.D. h.c., see “Board of Directors.”

Barbara A. Wood, Esq. Ms. Wood has served as the Company’s Executive Vice President, General Counsel and Corporate Secretary since March 2018. Prior to joining the Company, Ms. Wood served as Senior Vice President, General Counsel and Corporate Secretary at IVERIC bio, Inc. (formerly known as Ophthotech Corporation) from November 2013 to February 2018. From January 2011 to November 2013, Ms. Wood practiced law at Wood Legal. From April 2001 to December 2010 Ms. Wood served in varying roles at OSI Pharmaceuticals, Inc., most recently as Senior Vice President, General Counsel and Corporate Secretary. Before joining OSI, Ms. Wood was a partner at the New York law firm of Squadron, Ellenoff, Plesent & Sheinfeld (now part of Hogan Lovells), focusing on mergers and acquisitions, biotechnology, licensing, securities and venture capital matters. Ms. Wood received her B.A. in Economics and Classics, magna cum laude, from Connecticut College and her J.D. from Columbia Law School where she was a Harlan Fiske Stone Scholar.

Dragan Cicic, M.D. Dr. Cicic has served as Senior Vice President, Clinical Development of the Company since February 2020. Dr. Cicic has 21 years of experience in the biopharmaceutical industry.  Before joining the Company, he was a Senior Vice President, Clinical Lead, at Klus Pharma, a wholly owned U.S. subsidiary of Kelun, a major China-based multinational pharmaceutical company with about 30,000 employees worldwide.  At Klus Pharma, Dr. Cicic led the global clinical development of targeted solid cancer biologicals and was involved in the development of novel checkpoint inhibitors as well as other innovative biological and small molecule drug candidates. Prior to Klus Pharma, Dr. Cicic held senior management positions at Actinium Pharmaceuticals where he launched key clinical trials, both early and late stage, in hematologic malignancies, primarily in acute myeloid leukemia.  Dr. Cicic also worked with QED Technologies, a consulting company focused on life sciences.  He received his medical degree from the University of Belgrade, and an MBA from the Wharton School of the University of Pennsylvania. Dr. Cicic also did a Fellowship at Harvard University. Dr. Cicic has published extensively in the fields of hematologic malignancies and solid cancers. He is a member of the American Society of Hematology.

John T. Burns Mr. Burns has served as the Company’s Vice President, Finance, and Corporate Controller since December 2017 and as Vice President, Finance, and Corporate Controller and Chief Accounting Officer since January 2021. Mr. Burns has over 10 years’ experience in finance and accounting. Mr. Burns joined the Company in May 2013 and has held various positions of increasing responsibility during his tenure. Prior to joining the Company, Mr. Burns was a Securities and Exchange Reporting Manager at Pixelworks, Inc. (NASDAQ: PXLW), and began his career in public accounting at Moss Adams LLP. Mr. Burns received a B.S.M. in Finance and Master of Accounting degree from Tulane University. He is an active Certified Public Accountant.

EXECUTIVE OFFICER AND DIRECTOR COMPENSATION

Summary Compensation Table

The following table shows the compensation paid or accrued during the last two fiscal years ended December 31, 2020 and 2019 to our named executive officers, or NEOs, for 2020. The NEOs are (i) our President and Chief Executive Officer, Angelos M. Stergiou, M.D., Sc.D. h.c. and (ii) our other two most highly compensated executive officers earning more than $100,000 who were serving as executive officers at the end of the year ended December 31, 2018,2020, each identified below under the heading “Summary Compensation Table.”

Narrative Disclosure To Summary Compensation Table

Non-Equity Incentive Plan Short Term Compensation

Annual bonuses for our executive officers are based on the achievement of corporate goals typically comprised of a mix of clinical, financial and business development performance objectives. The corporate goals are approved by the Board of Directors on an annual basis at the start of each year. Dr. Stergiou’s bonus is based 100% on the level of achievement of the corporate goals, while the bonuses of the other executive officers are computed based on a combination of achievement of corporate goals and individual performance.

Equity Grants

In March 2020, the Compensation Committee recommended, and our Board approved, the grant of 95,000, 70,000 and 50,00025,000 options to Dr. Stergiou Dr. Sarlis and Ms. Wood, respectively, at an exercise price of $5.24$1.89 per share.share, which was the fair market value on the grant date. One quarter of the shares subject to these options vested in March 20192021 and the remaining shares subject to the options will vest and become exercisable in equal monthly installments for 36 months thereafter. In March 2020, the Compensation Committee also granted to Dr. Cicic, pursuant to his employment offer letter described below, 35,000 options at an exercise price of $1.89 per share, which was the fair market value on the grant date. One quarter of the shares subject to these options vested in March 2021 and the remaining shares subject to the options will vest and become exercisable in equal monthly installments for 36 months thereafter. In addition, in March 2020, the Compensation Committee recommended, and our Board approved, the grant of 95,000, 35,000 and 25,000 performance-based restricted stock units to Dr. Stergiou, Ms. Wood and Dr. Cicic, respectively (the “March 2020 RSUs”). The March 2020 RSUs will vest as follows: (i) 50% on meeting the primary endpoint in the Company’s Phase 3 REGAL study for its lead clinical candidate, galinpepimut-S (“GPS”) and (ii) 50% upon approval by the U.S. Food and Drug Administration (“FDA”) of a biologics license application (“BLA”) for GPS.

We have entered into employment agreements with each of the named executive officers described below, which include standard confidential information and/or inventions assignment agreements, and under which each of the named executive officers has agreed not to disclose our confidential information. The named executive officers are each eligible to participate in, subject to applicable eligibility requirements, all of our employee retirement and welfare benefit plans and programs made available to senior level executives. All severance benefits payable to the named executive officers under their employment agreements are subject to their signing, not revoking and complying with a release of claims in favor of us and are subject to applicable taxes and withholding.

Angelos M. Stergiou, M.D., Sc.D. h.c.

In September 2016, Private SELLAS entered into an employment agreement, or 2016 Stergiou Agreement, with Dr. Stergiou, President and Chief Executive Officer. The 2016 Stergiou Agreement was replaced and superseded in March 2019 by a new employment agreement, or the 2019 Stergiou Agreement, with Dr. Stergiou. Under 2016 Stergiou Agreement, which was governed by Bermuda law, Dr. Stergiou iswas entitled to an annual base salary of $400,000, net of all legally required applicable taxes, withholdings and deductions (subject to review and adjustment in the discretion of the Board or the compensation committee) and a discretionary annual cash bonus, with a target amount no less than 30% of Dr. Stergiou’s then effective base salary (subject to continued employment and the achievement of certain performance objectives established by the Board of Directors or compensation committee). The 2016 Stergiou Agreement also providesprovided that Dr. Stergiou willwould receive a monthly housing allowance of $10,000, net of all legally required applicable taxes, withholdings and deductions, and maywould be eligible to receive an additional discretionary bonus as determined by the Company in its sole discretion.

The 2016 Stergiou Agreement doesdid not have a specified term and either party maycould terminate such agreement by providing written notice at any time, with or without cause. We must provide Dr. Stergiou with six months’ notice prior to a termination without cause and may elect to place Dr. Stergiou on garden leave (with base salary and other benefits) during such period. Dr. Stergiou must provide written notice of a termination for good reason within 90 days of the event constituting good reason. We have a period of 30 days to correct the act or failure to act that constitutes good reason. If we fail to cure, Dr. Stergiou must provide a second notice of termination at least 30 and no more than 90 days after the first notice.

In March 2019, we entered into a new employment agreement, orThe 2019 Stergiou Agreement with Dr. Stergiou which became effective as of July 1, 2019, at which time it replaced and superseded the 2016 Stergiou Agreement. The 2019 Stergiou Agreement has aan initial two-year term unless terminated prior thereto (i) by us with cause (at any time) or without cause (upon at least 30 days’ prior written notice), or (ii) by Dr. Stergiou for good reason (upon at least 90 days prior written notice of the reason with a cure period of 30 days for us to correct the act or failure to act that constitutes good reason), or without good reason (upon at least 90 days prior written notice) or (iii) due to Dr. Stergiou’s death or disability. The 2019 Stergiou Agreement shall continue until terminated in accordance with its terms.

Pursuant to the terms of the 2019 Stergiou Agreement, Dr. Stergiou is entitled to an annual base salary of $525,000 (subject to review and adjustment in the sole discretion of the Board or the compensation committee thereof) and a discretionary annual cash bonus, with a target amount no less than 50% of Dr. Stergiou’s then effective base salary (subject to continued employment and the achievement of certain performance objectives established by the Board of Directors or compensation committee of the Board). The agreement also provides that to the extent that any benefit distributable pursuant to the terms of the agreement would be subject to the excise tax imposed under Section 4999 of the Internal Revenue Code of 1986, as amended, or the IRC, then the total payments payable to Dr. Stergiou will be reduced as set forth in the agreement (but not below zero) so that the maximum amount of such payments (after the reduction) shall be one dollar ($1.00) less than the amount which would cause such payments to be subject to the excise tax.

In addition, Dr. Stergiou is eligible to receive equity awards in the sole discretion of the Board or the compensation committee thereof.

Nicholas J. Sarlis, M.D., Ph.D., FACP

In September 2016, Private SELLAS entered into an employment agreement with Dr. Sarlis, or the Sarlis Employment Agreement, which was in effect during the years ended December 31, 2017 and 2018. The Sarlis Employment Agreement provided for a four-year term with an annual base salary of $345,000. Pursuant to the terms of such agreement, Dr. Sarlis was eligible to receive a discretionary annual cash bonus of up to 25% of his base salary (subject to continued employment and the achievement of certain performance objectives established by the Board of Directors or compensation committee). Dr. Sarlis was also eligible to receive an additional discretionary bonus.

In January 2019, we entered into a new agreement with Dr. Sarlis, or the Transition Agreement, which supersedes the Sarlis Employment Agreement. Pursuant to the Transition Agreement, Dr. Sarlis resigned from his position as Chief Medical Officer and became a consultant effective May 15, 2019. Pursuant to the terms of the Transition Agreement, Dr. Sarlis continued to receive his base salary of $380,000 per annum, and continued to participate in our benefit plans and programs through May 14, 2019. Dr. Sarlis is currently providing consulting services to us for not less than 25 hours per week for a monthly fee of $23,500 and is being reimbursed for COBRA coverage for health benefits until December 31, 2019. Dr. Sarlis will receive a lump sum payment, payable on or before December 31, 2019, consisting of his pro-rata incentive bonus for 2019, in an amount determined by the board based upon our achievement of the approved corporate goals for 2019, with a target percentage of 40% prorated for the actual number of days in the transition employment period.Compensation Committee.

Barbara A. Wood, Esq.

Effective March 14, 2018, we entered into an employment letter agreement with Ms. Wood. Under this agreement, Ms. Wood is entitled to an annual base salary of $365,000 (subject to review and adjustment in the discretion of the Board of Directors or the compensation committee)Compensation Committee) and a discretionary annual cash bonus, with a target amount of up to 40% of Ms. Wood’s then-effective base salary (subject to continued employment and the achievement of certain performance objectives established by our Board or compensation committee)Compensation Committee).

In connection with Ms. Wood entering into her employment letter agreement, and pursuant to the terms thereof, we granted to Ms. Wood incentive stock options to purchase up to 50,0001,000 shares of our common stock. The option has an exercise price equal to the market price of our common stock upon the date of grant and vests as to one quarter after one year from grant and with the remainder over 36 equal monthly installments thereafter, so that the option will be fully vested and exercisable four years from the date of grant.

Ms. Wood’s employment letter agreement does not have a specified term and either party may terminate Ms. Wood’s employment agreement by providing written notice at any time, with or without cause. In December 2018, we entered into a severance agreement with Ms. Wood, or the Wood Severance Agreement, pursuant to which Ms. Wood may receive additional compensation in the event that Ms. Wood'sWood’s employment was terminated under certain conditions. See the discussion below under “Potential Payments Upon Termination or Change of Control.” In addition to the payment of severance amounts, the Wood Severance Agreement also provides that to the extent that any benefit distributable pursuant to the terms of the Wood Severance Agreement would be subject to the excise tax imposed under Section 4999 of the IRC, then the total payments payable to Ms. Wood shall be reduced as set forth in the Wood Severance Agreement (but not below zero) so that the maximum amount of such payments (after the reduction) shall be one dollar ($1.00) less than the amount which would cause such payments to be subject to the excise tax.

Dragan Cicic, M.D.

Effective January 2, 2020, we entered into an employment letter agreement with Mr. Cicic. Under this agreement, Mr. Cicic is entitled to an annual base salary of $330,000 (subject to review and adjustment in the discretion of the Board of Directors or the Compensation Committee) and a discretionary annual cash bonus, with a target amount of up to 30% of Mr. Cicic’s then-effective base salary (subject to continued employment and the achievement of certain performance objectives established by our Board or Compensation Committee). In January 2021, the target amount was increased to 35%. Mr. Cicic’s employment letter agreement does not have a specified term and either party may terminate Mr. Cicic’s employment agreement by providing written notice at any time, with or without cause.

In connection with Mr. Cicic’s hiring, we granted to Mr. Cicic incentive stock options to purchase up to 35,000 shares of our common stock. The option has an exercise price equal to the market price of our common stock upon the date of grant and vests as to one quarter after one year from grant and with the remainder over 36 equal monthly installments thereafter, so that the option will be fully vested and exercisable four years from the date of grant.

Outstanding Equity Awards At 2020 Fiscal Year-End

The following table discloses certain information regarding all outstanding equity awards at fiscal year-end for each of the officers named in the Summary Compensation Table.

Potential Payments Upon Termination or Change of Control

Angelos M. Stergiou

Potential Payments Made Upon Termination with Cause or Without Good Reason. Reason. The 2019 Stergiou Agreement provides that if Dr. Stergiou’sStergiou employment is terminated with cause by us, or by Dr. Stergiou without good reason, we will pay Dr. Stergiou all his accrued benefits, and all other rights and benefits of Dr. Stergiou will terminate upon such termination, except for any right to the continuation of benefits otherwise provided by law.

Potential Payments Made Upon Termination Without Cause or for Good Reason.The 2019 Stergiou Agreement provides that if we terminate Dr. Stergiou’s employment without cause or Dr. Stergiou resigns for good reason, we will pay Dr. Stergiou the following amounts in equal installments over a defined twelve12 month period: (i) an amount equal to 18 months of his then-current base salary, less standard employment-related withholdings and deductions and (ii) an amount equal to a pro-rated portion of his annual short-term incentive compensation for the year in which his employment terminates, without regard to whether the performance goals with respect to such bonus have been established or met and less standard employment-related withholdings and deductions. In addition, Dr. Stergiou will be entitled, if he so elects, to receive reimbursement for Consolidated Omnibus Budget Reconciliation Act of 1986 (“COBRA”) monthly premiums for a specified period of time.

Payments Made Upon Death or Disability. The 2019 Stergiou Agreement providesthat upon Dr. Stergiou’s death or permanent disability, we will pay Dr. Stergiou or his estate, as the case may be, (i) any base salary that has fully accrued but not been paid as of the effective date of such termination, any annual and discretionary bonuses that have been earned pursuant to the terms of his agreement but not paid as of the date of such termination, as well as any vested and accrued employment benefits subject to the terms of any applicable employment benefit arrangements and applicable law; and (ii) a prorated bonus for the year in which his death or permanent disability occurs; and (iii) all other payments and benefits to which he may be entitled under the terms of any other applicable compensation arrangement or benefit, equity or perquisite plan or program, including, but not limited to, any applicable insurance benefits. All other rights and benefits will terminate upon such termination, except for any right to the continuation of benefits otherwise provided by law.

Potential Payments Upon Termination Related to Change in Control.The 2019 Stergiou Agreement provides that if we terminate Dr. Stergiou’s employment without cause or he resigns for good reason within a one month period prior to or one year following a change in control we will pay him the following amounts in equal installments over a 12 month period: (i) an amount equal to 24 months of his then-current Base Salary, less standard employment-related withholdings and deductions; and (ii) an amount equal to one and one-half times his target bonus for the year in which his employment terminates, without regard to whether the performance goals with respect to such target bonus have been established or met and less standard employment-related with holdings and deductions. In addition, Dr. Stergiou will be entitled, if he so elects, to receive reimbursement for COBRA monthly premiums for a specified period of time. Furthermore, the vesting of all of his equity awards will immediately vest in full and become exercisable as of the date of termination.

Barbara A. Wood

Potential Payments Made Upon Termination Without Cause or for Good Reason. Pursuant to the terms of the Wood Severance Agreement, in the event that Ms. Wood'sWood’s employment is terminated by us without cause or by Ms. Wood for good reason, we will pay Ms. Wood the following amounts in equal installments over a 12- month period: (i) an amount equal to 12 months of the then-current base salary, less standard employment-related withholdings and deductions, and (ii) an amount equal to a pro-rated portion of Ms. Wood annual short-term incentive compensation for the year in which the employment terminates, without regard to whether the performance goals with respect to such bonus have been have been established or met and less standard employment-related withholdings and deductions. In addition, Ms. Wood will be entitled, if she so elects, to receive reimbursement for COBRA monthly premiums for a specified period of time.

Potential Payments Upon Termination Related to Change in Control. The Wood Severance Agreement provides that if we terminate Ms. Wood'sWood’s employment without cause or she resigns for good reason within one year following a change in control we will pay her the following amounts in equal installments over a 18 month period: (i) an amount equal to 18 months of her then-current Base Salary, less standard employment-related withholdings and deductions; and (ii) an amount equal to her target bonus for the year in which her employment terminates, without regard to whether the performance goals with respect to such target bonus have been established or met and less standard employment-related with holdings and deductions. In addition, Ms. Wood will be entitled, if she so elects, to receive reimbursement for COBRA monthly premiums for a specified period of time.

Director Compensation

The following table shows the total compensation paid or accrued during the fiscal year ended December 31, 20182020 to each of our non-employee directors. Directors who are employed by us are not compensated for their service on our Board of Directors.

Director Compensation Policy

Our Board and its compensation committeethe Compensation Committee have adopted the following compensation for our directors:

* $25,000 during fiscal 2018.

Securities Authorized for Issuance Under Equity Compensation Plans

The following table provides certain aggregate information with respect to all of the Company’s equity compensation plans in effect as of December 31, 2018.2020.

Equity Compensation Plan Information as of December 31, 20182020

Related Person Transactions Policy and Procedures

We have adopted a written Related Person Transactions and SEC Compliance Policy that sets forth our policies and procedures regarding the identification, review, consideration and approval or ratification of “related persons transactions.” For purposes of our policy only, a “related person transaction” is a transaction, arrangement or relationship (or any series of similar transactions, arrangements or relationships) in which we and any “related person” are participants involving an amount that exceeds $120,000. Transactions involving compensation for services provided to us as an employee, director, consultant or similar capacity by a related person are not covered by this policy. A related person is any executive officer, director, or more than 5% stockholder, including any of their immediate family members, and any entity owned or controlled by such persons.

Under the policy, where a transaction has been identified as a related person transaction, management must present information regarding the proposed related person transaction to our Audit Committee (or, where Audit Committee approval would be inappropriate, to another independent body of our Board) for consideration and approval or ratification. The presentation must include a description of, among other things, the material facts, the interests, direct and indirect, of the related persons, the benefits of the transaction to us and whether any alternative transactions were available. To identify related person transactions in advance, we rely on information supplied by our executive officers, directors and certain significant stockholders. In considering related person transactions, our Audit Committee takes into account the relevant available facts and circumstances including, but not limited to (a) the risks, costs and benefits to us, (b) the impact on a director’s independence in the event the related person is a director, immediate family member of a director or an entity with which a director is affiliated, (c) the terms of the transaction, (d) the availability of other sources for comparable services or products and (e) the terms available to or from, as the case may be, unrelated third parties or to or from employees generally. In the event a director has an interest in the proposed transaction, the director must recuse himself or herself fromform the deliberations and approval. The policy requires that, in determining whether to approve, ratify or reject a related person transaction, our Audit Committee consider, in light of known circumstances, whether the transaction is in, or is not inconsistent with, our best interests and those of our stockholders, as our Audit Committee determines in the good faith exercise of its discretion.

DELINQUENT SECTION 16(a) REPORTS

Our records reflect that all reports which were required to be filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, as amended, were filed on a timely basis.

CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTSPROPOSAL 1

StatementsELECTION OF DIRECTORS

Our Board of Directors currently consists of five members, classified into three classes as follows: (1) Jane Wasman and Robert Van Nostrand are members of Class I with a term ending at the 2023 annual meeting; (2) David A. Scheinberg is a member of Class II with a term ending at the 2021 Annual Meeting; and (3) Angelos M. Stergiou and John Varian are members of Class III with a term ending at the 2022 annual meeting. At each annual meeting of stockholders, directors are elected for a full term of three years to succeed those directors whose terms are expiring. Our Board of Directors is nominating David A. Scheinberg for election at the 2021 Annual Meeting as a Class II director to serve for a term of three years until his death, resignation or removal pursuant to our Bylaws.

Unless authority to vote for this nominee is withheld, the shares represented by proxies solicited by the Board will be voted “FOR” the election of the foregoing Class II director. In the event that the foregoing nominee becomes unable or unwilling to serve, the shares represented by proxies solicited by the Board will be voted for the election of such other person as our Board of Directors may recommend in that nominee’s place. We have no reason to believe that the foregoing nominee will be unable or unwilling to serve as a director.

THE board of directors UNANIMOUSLY Recommends The Election Of DAVID A. SCHEINBERG As A CLASS II Director, And Proxies Solicited By Our board of directors Will Be Voted In Favor Thereof Unless A Stockholder Has Indicated Otherwise On The Proxy.

PROPOSAL 2

RATIFICATION OF APPOINTMENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

The Audit Committee of our Board has appointed Moss Adams LLP, or Moss Adams, as our independent registered public accounting firm for the fiscal year ended December 31, 2021 and has further directed that management submit the appointment of its independent registered public accounting firm for ratification by the stockholders at the 2021 Annual Meeting.

Moss Adams currently serves as our independent registered public accounting firm and audited our financial statements for the year ended December 31, 2020. Moss Adams has served as our auditors since 2018. Moss Adams does not have and has not had any financial interest, direct or indirect, in our Company, and does not have and has not had any connection with our company except in its professional capacity as our independent auditors.

Our Audit Committee and our Board believe that the continued retention of Moss Adams to serve as our independent registered public accounting firm is in the best interests of the Company and its stockholders. As a matter of good corporate governance, we are asking stockholders to ratify such appointment. If this appointment is not ratified at the 2021 Annual Meeting, the Audit Committee intends to reconsider its selection of Moss Adams. Even if the appointment is ratified, the Audit Committee in its sole discretion may direct the appointment of a different independent registered public accounting firm at any time during the fiscal year if the Audit Committee determines that such a change would be in the best interests of our company and its stockholders.

Audit and non-audit services to be provided by Moss Adams are subject to the prior approval of the Audit Committee. In general, the Audit Committee’s policy is to grant such approval where it determines that the non-audit services are not incompatible with maintaining the independent registered public accounting firm’s independence and there are costs or other efficiencies in obtaining such services from the independent registered public accounting firm as compared to other possible providers. Representatives of Moss Adams are expected to be present at the 2021 Annual Meeting, will have an opportunity to make a statement if they desire to do so, and will be available to respond to questions.

Our Audit Committee is directly responsible for appointing, compensating and providing oversight of the performance of our independent registered public accounting firm for the purpose of issuing audit reports and related work regarding our financial statements and the effectiveness of our internal control over financial reporting. The Audit Committee is also responsible for approving the audit and non-audit fees of our independent registered public accounting firm. In order to assure continuing auditor independence, the Audit Committee periodically considers whether there should be a regular rotation of the independent registered public accounting firm.

“FOR” votes from holders of a majority of the shares present in person or represented by proxy and entitled to vote on the matter at the 2021 Annual Meeting that cast votes is required to ratify the appointment of Moss Adams. Abstentions and broker non-votes will count towards a quorum but will have no effect on the outcome of this Proposal 2.

Principal Accountant Fees and Services

The following table represents aggregate fees billed to us for the years ended December 31, 2020 and 2019, by Moss Adams, our principal accountant.

At our 2019 annual meeting of stockholders, the stockholders indicated their preference that we solicit a non-binding advisory vote on the compensation of our named executive officers, commonly referred to as a “say-on-pay vote,” every year. The Board of Directors adopted a policy that is consistent with that preference. In accordance with that policy, this year, we are again asking the stockholders to approve, on an advisory basis, the compensation of our named executive officers as disclosed in this proxy statement that are not historical, are forward-looking statements made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. Such statements include, but are not limited to, statements regarding the Company's intent to solicit approval of the proposal to effect a Reverse Stock Split, the timing of the Reverse Stock Split, the potential benefits of a Reverse Stock Split, including but not limited to increased investor interest, continued listing on Nasdaq, the potential for a higher stock price, the timing and effects of the proposed amendments to our Amended and Restated Certificate of Incorporation, and any assumptions underlying any of the foregoing. Words such as "anticipate," "believe," "continue," "could," "estimate," "expect," "intend," "may," "plan," "predict," "project," "should," and "will" and variations of such words and similar expressions are intended to identify such forward-looking statements.in accordance with SEC rules.

These forward-looking statements are not guarantees of future performance and involve risks, assumptions and uncertainties. These and other risks, assumptions and uncertainties are more fully described in Item 1A (Risk Factors) of our most recent Annual Report on Form 10-K, the section entitled “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” in our most recent Form 10-Q and in other documents that we file or furnish with the SEC, which you are encouraged to read. Should one or more of these risks or uncertainties materialize, or should underlying assumptions prove incorrect, actual results may vary materially from those indicated or anticipated by such forward-looking statements. Accordingly, you are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date they are made. The Company expressly disclaims any current intention to update publicly any forward-looking statement after the distribution of this proxy statement, whether as a result of new information, future events, changes in assumptions or otherwise.

STOCKHOLDER PROPOSALS FOR THE 2020 ANNUAL MEETING OF STOCKHOLDERS

Proposals of stockholders intended to be presented atAt our 2020 annual meeting of stockholders, pursuantwe sought an advisory “say-on-pay” vote on our Company’s executive compensation program.  The 2020 say-on-pay proposal was approved by approximately 58% of the votes cast. The votes cast against the 2020 say-on-pay proposal represented approximately 5% of the Company’s total outstanding shares and our research has indicated that the great majority of these votes against the 2020 say-on-pay proposal came from individual stockholders who submitted their votes anonymously. We have been unable to Rule 14a-8 promulgated underidentify any votes against the Exchange Act must be received2020 say-on-pay proposal submitted by us atinstitutional stockholders or other accredited investors. We take very seriously the views of our principal offices, 15 West 38th Street, 10th Floor, New York, New York 10018, Attention: Corporate Secretary, no later than January 31,stockholders regarding our executive compensation and we consider a 58% vote in favor of the 2020 in ordersay-on-pay proposal to be included inan unsatisfactory result. However, because of the proxy statement and proxy card relatingnature of the votes cast against the proposal, we have not been able to that meeting.engage more specifically with stockholders who submitted notable votes against the 2020 say-on-pay proposal.

If Our Compensation Committee and Management are committed to considering and being responsive to stockholder views on executive compensation. We continue to re-evaluate our pay practices and compensation programs with guidance from our independent compensation consultant, Radford. Additionally, during the last twelve months, Dr. Stergiou, together with other members of management, has periodically held meetings with stockholders and participated in investor conferences which has provided him with the opportunity to understand stockholder views on the status of the Company’s clinical trial programs, financial performance, strategic business plans, corporate governance, executive compensation, and related subjects.

The summary compensation of our named executive officers subject to the vote is disclosed in the compensation tables and the related narrative disclosure contained in this Proxy Statement. Our Compensation Committee has adopted compensation policies and makes decisions which are focused on pay-for-performance principles, with the primary goal of strongly aligning the interests of our executives and employees with the interests of our stockholders. The structure of the compensation program for our named executive officers is designed to enable us to attract and retain talented and experienced executives to lead us successfully in a stockholder wishescompetitive environment.

Accordingly, our Board is asking the stockholders to presentindicate their support for the compensation of our named executive officers as described in this proxy statement by casting a non-binding advisory vote “FOR” the following resolution:

“RESOLVED, that the compensation paid to our named executive officers, as disclosed pursuant to Item 402 of Regulation S-K, including the compensation tables and narrative discussion is hereby APPROVED.”

Because the vote is advisory, it is not binding on the Board. Nevertheless, the views expressed by the stockholders, whether through this vote or otherwise, are important to management and the Board and, accordingly, our Board and our Compensation Committee intend to consider the results of this vote in making determinations in the future regarding executive compensation arrangements.

Advisory approval of this Proposal 3 requires that the proposal receive “FOR” votes from the holders of a majority of the shares voting online or represented by proxy and entitled to vote on the matter at the 2021 Annual Meeting that cast votes with respect to this Proposal 3. Abstentions and broker non-votes will count towards a quorum but will have no effect on the outcome of this Proposal 3. Unless the Board decides to modify its policy regarding the frequency of soliciting advisory votes on the compensation of our 2020named executive officers, the next scheduled say-on-pay vote will be at the 2022 annual meeting of stockholders, but does not wish to have the proposal considered for inclusion in our proxy statement and proxy card, pursuant to the advance notice provision in our bylaws, such stockholder must give written notice to our Corporate Secretary at our principal executive offices at the address noted above. The Corporate Secretary must receive such notice no earlier than March 14, 2020, and no later than April 13, 2020, provided that if the date of the 2020 annual meeting of stockholders is held before July 12, 2020, such notice must instead be received by the Corporate Secretary no earlier than the 120th day prior to the 2020 annual meeting of stockholders and not later than the close of business on the 90th day prior to the 2020 annual meeting of stockholders in order for such notice to be timely.stockholders.

THE BOARD OF DIRECTORS UNANIMOUSLY RECOMMENDS A VOTE TO APPROVE THE COMPENSATION OF OUR NAMED EXECUTIVE OFFICERS, AND PROXIES SOLICITED BY OUR BOARD OF DIRECTORS WILL BE VOTED IN FAVOR OF SUCH APPROVAL UNLESS A STOCKHOLDER INDICATES OTHERWISE ON THE PROXY.