The Annual Meeting of Stockholders (the “Annual Meeting”) of Selecta Biosciences, Inc., a Delaware corporation (the “Company”), will be held at 9:00 a.m., Eastern timeTime, on Friday, June 16, 2017,19, 2020, by virtual meeting online at www.virtualshareholdermeeting.com/SELB,SELB2020, for the following purposes:

Holders of record of our Common Stock as of the close of business on April 21, 201723, 2020 are entitled to notice of and to vote at the Annual Meeting, or any continuation, postponement or adjournment of the Annual Meeting. A complete list of these stockholders will be open to the examination of any stockholder at our principal executive offices at 480 Arsenal Way, Watertown, MA, 02472 for a period of ten days prior to the Annual Meeting for a purpose germane to the meeting by sending an email to ShareholderRequests@selectabio.com, stating the purpose of the request and providing proof of ownership of Company stock. The list of these stockholders will also be available on the daybottom panel of your screen during the Annual Meeting.meeting at www.virtualshareholdermeeting.com/SELB2020 after entering the 16-digit control number included on the Notice of Internet Availability of Proxy Materials or any proxy card that you received, or on the materials provided by your bank or broker. The Annual Meeting may be continued or adjourned from time to time without notice other than by announcement at the Annual Meeting.

If any other matter properly comes before the stockholders for a vote at the Annual Meeting, the proxy holders named on the Company’s proxy card will vote your shares in accordance with their best judgment.

If you are currently a stockholder sharing an address with another stockholder and received more than one copy of the Internet Notice,proxy materials, but wish to receive only one copy of future Internet Notices or proxy materials for your household, please contact Broadridge at the above phone number or address.

The Record Date for the Annual Meeting is April 21, 2017.23, 2020. You are entitled to vote at the Annual Meeting only if you were a stockholder of record at the close of business on that date, or if you hold a valid proxy for the Annual Meeting. Each outstanding share of Common Stock is entitled to one vote for all matters before the Annual Meeting. At the close of business on the Record Date, there were 18,581,20287,489,681 shares of Common Stock outstanding and entitled to vote at the Annual Meeting.

A record holder holds shares in his or her name. Shares held in “street name” means shares that are held in the name of a bank or broker on a person’s behalf.

Yes. If your shares are held by a bank or a brokerage firm, you are considered the “beneficial owner” of those shares held in “street name.” If your shares are held in street name, these proxy materials are being provided to you by your bank or brokerage firm, along with a voting instruction card if you received printed copies of our proxy materials. As the beneficial owner, you have the right to direct your bank or brokerage firm how to vote your shares, and the bank or brokerage firm is required to vote your shares in accordance with your instructions. If your shares are held in street name, you may not vote your shares electronically atplease refer to the online Annual Meeting, unless you obtain a legal proxyinformation from your bank, broker or brokerage firm.other nominee on how to submit your voting instructions.

A quorum must be present at the Annual Meeting for any business to be conducted. The presence at the Annual Meeting, onlinein person, or by remove communication, or represented by proxy, of the holders of a majority in voting power of the Common Stock issued and outstanding and entitled to vote on the Record Date will constitute a quorum.

To participate in the Annual Meeting, you will need the 16-digit control number included in your Internet Notice, on your proxy card or on the instructions that accompanied your proxy materials. The meeting webcast will begin promptly at 9:00 a.m., Eastern Time. We encourage you to access the meeting prior to the start time. Online check-in will begin at 8:55 a.m., Eastern Time, and you should allow ample time for the check-in procedures. If your shares are held in street name and you did not receive a 16-digit control number, you may gain access to and vote at the Annual Meeting by logging into your bank or brokerage firm's website and selecting the shareholder communications mailbox to access the meeting. The control number will automatically populate. Instructions should also be provided on the voting instruction card provided by your bank or brokerage firm. If you lose your 16-digit control number, you may join the Annual Meeting as a "Guest," but you will not be able to vote, ask questions, or access the list of stockholders as of the Record Date.

We will have technicians ready to assist you with any technical difficulties you may have accessing the virtual meeting website. If you encounter any difficulties accessing the virtual meeting website during the check-in or meeting time, please call:

It means that your shares are held in more than one account at the transfer agent and/or with banks or brokers. Please vote all of your shares. To ensure that all of your shares are voted, for each Internet Notice or set of proxy materials, please submit your proxy by phone, via the Internet, or, if you received printed copies of the proxy materials, by signing, dating and returning the enclosed proxy card in the enclosed envelope.

Yes.

If you are a registered stockholder, you may revoke your proxy and change your vote:

Your most recent proxy card or telephone or Internet proxy is the one that is counted. Your participatingparticipation in the online Annual Meeting by itself will not revoke your proxy unless you give written notice of revocation to the Corporate Secretary before your proxy is voted or you vote electronically at the online Annual Meeting.

If your shares are held in street name, you may change or revoke your voting instructions by following the specific directions provided to you by your bank or broker, or you may vote electronically at the online Annual Meeting by obtaining a legal proxy from your bank or broker and submittingfollowing the legal proxy along with your online vote.instructions above.

A representative of Broadridge Financial Solutions, Inc., our inspector of election, will tabulate and certify the votes.

A “vote withheld,” in the case of the proposal regarding the election of directors, or an “abstention,” in the case of the proposal regarding the ratification of the appointment of Ernst & Young LLP as our independent registered public accounting firm, represents a stockholder’s affirmative choice to decline to vote on a proposal. Votes withheld and abstentions are counted as present and entitled to vote for purposes of determining a quorum. Votes withheld have no effect on the election of directors and abstentions have no effect on the ratification of the appointment of Ernst & Young LLP.

Generally, broker non-votes occur when shares held by a broker in “street name” for a beneficial owner are not voted with respect to a particular proposal because the broker (1) has not received voting instructions from the

We plan to announce preliminary voting results at the Annual Meeting and we will report the final results in a Current Report on Form 8-K, which we intend to file with the SEC within four business days of the Annual Meeting.

We currently have nine (9)eight (8) directors on our Board, including three (3) Class I Directors. Our current Class I Directors are Carl Gordon, Ph.D.,Scott D. Myers, who has servedwas appointed to serve on our Board since 2010, Edwin Kania, Jr., who has served on our Board since 2013, andof Directors in June 2019, Timothy A. Springer, Ph.D., who has served on our Board of Directors since June 2016. Neither Dr. Gordon nor Mr. Kania2016, and Patrick Zenner, who has served on our Board of Directors since June 2017. All three members have been nominated for re-electionelection as a Class I Director at the Annual Meeting following the end of his current term. The Board has nominated two director candidates for election as Class I Directors at the Annual Meeting: Timothy Springer, Ph.D. and Patrick Zenner. Proxies cannot be voted for a greater number of persons than the number of nominees named in this proposal.Meeting.

The proposal regarding the election of directors requires the approval of a plurality of the votes cast. This means that the twothree nominees receiving the highest number of affirmative “FOR” votes will be elected as Class I Directors. Votes withheld and broker non-votes are not considered to be votes cast and, accordingly, will have no effect on the outcome of the vote on this proposal.

Our Restated Certificate of Incorporation and Amended and Restated Bylaws provide that the authorized number of directors may be changed only by resolution of the Board of Directors. Any additional directorships resulting from an increase in the number of directors will be distributed among the three classes so that, as nearly as possible, each class will consist of one-third of the directors. The division of our Board of Directors into three classes with staggered three-year terms may delay or prevent a change of our management or a change in control of our Company. Our directors may be removed only for cause by the affirmative vote of the holders of at least two thirds of our outstanding voting stock entitled to vote in the election of directors.

There are no family relationships among any of our executive officers or directors.

The proposal regarding the election of directors requires the approval of a plurality of the votes cast. This means that the twothree nominees receiving the highest number of affirmative “FOR” votes will be elected as Class I Directors. Votes withheld and broker non-votes are not considered to be votes cast and, accordingly, will have no effect on the outcome of the vote on this proposal.

The nominees for election to the Board of Directors as Class I Directors are as follows:

The principal occupations and business experience, for at least the past five years, of each Class I nominee for election at the 2017 Annual Meeting are as follows:

Timothy A. Springer, Ph.D., has served as a member of our boardBoard of directorsDirectors since June 2016 and as a scientific advisor to us since December 2008. Since 1989, Dr. Springer has served as the Latham Family Professor at Harvard Medical School. He has also served as Senior Investigator in the Program in Cellular and Molecular Medicine at Boston Children’s Hospital since 2012, and as Professor of Biological Chemistry and Molecular Pharmacology at Harvard Medical School and Professor of Medicine at Boston Children’s Hospital since 2011. Dr. Springer was the Founder of LeukoSite, a biotechnology company acquired by Millennium Pharmaceuticals in 1999. Additionally, he is a founder, investor and board member of Scholar Rock and Morphic Therapeutic. Dr. Springer is a member of the National Academy of Sciences and his honors include the Crafoord Prize, the American Association of Immunologists Meritorious Career Award, the Stratton Medal from the American Society of

Hematology, and the Basic Research Prize from the American Heart Association. Dr. Springer received a B.A. from the University of California, Berkeley, and a Ph.D. from Harvard University. Dr. Springer’s extensive knowledge of our business and the nanomedicine field contributed to our boardBoard of directors’Directors’ conclusion that he should serve as a director of our company.

The current members of the Board of Directors who are Class II Directors are as follows:

The principal occupations and business experience, for at least the past five years, of each Class II Director are as follows:

The current members of the Board of Directors who are Class III Directors are as follows:

The principal occupations and business experience, for at least the past five years, of each Class III Director are as follows:

Our Audit Committee has appointed Ernst & Young LLP as our independent registered public accounting firm for the fiscal year ending December 31, 2017.2020. Our Board has directed that this appointment be submitted to our stockholders for ratification. Although ratification of our appointment of Ernst & Young LLP is not required, we value the opinions of our stockholders and believe that stockholder ratification of our appointment is a good corporate governance practice.

Ernst & Young LLP also served as our independent registered public accounting firm for the fiscal year ended December 31, 2016.2019. Neither the accounting firm nor any of its members has any direct or indirect financial interest in or any connection with us in any capacity other than as our auditors, providing audit and non-audit relatedother services. A representative of Ernst & Young LLP is expected to attend the Annual Meeting and to have an opportunity to make a statement and be available to respond to appropriate questions from stockholders.

In the event that the appointment of Ernst & Young LLP is not ratified by the stockholders, the Audit Committee will consider this fact when it appoints the independent auditors for the fiscal year ending December 31, 2018.2021. Even if the appointment of Ernst & Young LLP is ratified, the Audit Committee retains the discretion to appoint a different independent auditor at any time if it determines that such a change is in the interestsinterest of the Company.

This proposal requires the affirmative vote of the holders of a majority in voting power of the votes cast affirmatively or negatively. Abstentions are not considered to be votes cast and, accordingly, will have no effect on the outcome of the vote on this proposal. Because brokers have discretionary authority to vote on the ratification of the appointment of Ernst & Young LLP, we do not expect any broker non-votes in connection with this proposal.

The Audit Committee has reviewed the Company’s audited financial statements for the fiscal year ended December 31, 20162019 and has discussed these financial statements with management and the Company’s independent registered public accounting firm. The Audit Committee has also received from, and discussed with, the Company’s independent registered public accounting firm various communications that such independent registered public accounting firm is required to provide to the Audit Committee, including the matters required to be discussed by statement on Auditing Standards No. 1301, as adopted by the Public Company Accounting Oversight Board (“PCAOB”).

Based on its discussions with management and the independent registered public accounting firm, and its review of the representations and information provided by management and the independent registered public accounting firm, the Audit Committee recommended to the Board of Directors that the audited financial statements be included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2016.2019.

The following table summarizes the fees of Ernst & Young LLP, our independent registered public accounting firm, billed to usthe Company for each of the last two fiscal years for audit services and billed to us in each of the last two fiscal years for other services:

Audit fees consist of fees billed for the audit of our annual consolidated financial statements, the review of the interim consolidated financial statements, and related services that are normally provided in connection with registration statements, including the registration statement for our initial public offering. There are $562,500 of fees included in the 2015statements. For 2019, audit fees in connection with our initial public offering in June 2016. Included in the 2016 audit fees is $508,421 of fees billed in connection with our initial public offering in June 2016. 

The Audit Committee has adopted a policy (the “Pre-Approval Policy”) which sets forth the procedures and conditions pursuant to which audit and non-audit services proposed to be performed by the independent auditor may be pre-approved. The Pre-Approval Policy generally provides that we will not engage Ernst & Young LLP to render any audit, audit-related, tax or permissible non-audit service unless the service is either (i) explicitly approved by the Audit Committee (“specific pre-approval”) or (ii) entered into pursuant to the pre-approval policies and procedures described in the Pre-Approval Policy (“general pre-approval”). Unless a type of service to be provided by Ernst & Young LLP has received general pre-approval under the Pre-Approval Policy, it requires specific pre-approval by the Audit Committee or by a designated member of the Audit Committee to whom the committee has delegated the authority to grant pre-approvals. Any proposed services exceeding pre-approved cost levels or budgeted amounts will also require specific pre-approval. For both types of pre-approval, the Audit Committee will consider whether such services are consistent with the SEC’s rules on auditor independence. The

biotechnology company and serves as the Chairperson of the Compensation Committee, and a member of the Audit Committee. Ms. Kogan is a graduate of the SCALE program at Durect Corporation, a small-cap specialty pharmaceutical company. From February 2004 to August 2006, he was Senior Patent Counsel for ALZA Corporation, or ALZA, a Johnson & Johnson company. Prior to working at Durect and ALZA, Mr. Abraham was employed by the law firms of Wilson Sonsini Goodrich and Rosati, and Finnegan Henderson Farabow Garrett and Dunner. Mr. Abraham also was a Patent Examiner at the USPTO. Mr. Abraham received his B.S. in Chemical Engineering from theSouthwestern University of Rochester and his J.D. from the George Washington School of Law. Ms. Kogan graduated cum laude from Columbia University, Barnard College, with a B.A. in economics.

None of our executive officers is related to any other executive officer or to any of our directors.

All of our directors and Class I director nominees, other than Werner Cautreels,Carsten Brunn, Ph.D. and Omid Farokhzad, M.D., qualify as “independent” in accordance with the listing requirements of The NASDAQNasdaq Global Select Market (“NASDAQ”Nasdaq”)., and Amir Nashat, Ph.D. qualified as "independent" while he served on our Board of Directors. The NASDAQNasdaq independence definition includes a series of objective tests, including that the director is not, and has not been for at least three years, one of our employees and that neither the director nor any of his family members has engaged in various types of business dealings with us. In addition, as required by NASDAQNasdaq rules, our Board of Directors has made a subjective determination as to each independent director that no relationships exist, which, in the opinion of our Board of Directors, would interfere with the exercise of independent judgment in carrying out the responsibilities of a director. In making these determinations, our Board of Directors reviewed and discussed information provided by the directors and us with regard to each director’s business and personal activities and relationships as they may relate to us and our management.management, including that each of Dr. CautreelsSpringer and Mr. Sallin are affiliated with certain of our significant stockholders. Dr. Brunn is not independent because he is the President and Chief Executive Officer of Selecta. Dr. Farokhzad is not independent because he receives consulting fees under the terms of a consulting agreement with Selecta. There are no family relationships among any of our directors or executive officers.

The Nominating and Corporate Governance Committee is primarily responsible for searching for qualified director candidates for election to the Board and filling vacancies on the Board. To facilitate the search process, the Nominating and Corporate Governance Committee may solicit current directors and executives of the Company for the names of potentially qualified candidates or ask directors and executives to pursue their own business contacts for the names of potentially qualified candidates. The Nominating and Corporate Governance Committee may also consult with outside advisors or retain search firms to assist in the search for qualified candidates, or consider

In evaluating the suitability of individual candidates (both new candidates and current Board members), the Nominating and Corporate Governance Committee, in recommending candidates for election, and the Board, in approving (and, in the case of vacancies, appointing) such candidates, may take into account many factors, including: personal and professional integrity, ethics and values; experience in corporate management, such as serving as an officer or former officer of a publicly heldpublic company; strong finance experience; experience relevant to the Company’s industry; experience as a board member or executive officer of another publicly heldpublic company; relevant academic expertise or other proficiency in an area of the Company’s operations; diversity of expertise and experience in substantive matters pertaining to the Company’s business relative to other board members; diversity of background and perspective, including, but not limited to, with respect to age, gender, race, place of residence and specialized experience; practical and mature business judgment, including, but not limited to, the ability to make independent analytical inquiries; and any other relevant qualifications, attributes or skills.skills as may be determined by the Nominating and Corporate Governance Committee from time to time. The Board evaluates each individual in the context of the Board as a whole, with the objective of assembling a group that can best perpetuate the success of the business and represent stockholder interests through the exercise of sound judgment using its diversity of experience in these various areas. In determining whether to recommend a director for re-election, the Nominating and Corporate Governance Committee may also consider the director’s past attendance at meetings and participation in and contributions to the activities of the Board. Scott D. Myers, one of our Class I Director nominees, was identified as a potential candidate to serve on our Board of Directors by Carsten Brunn, Ph.D., our President and Chief Executive Officer, and was recommended by the Nominating and Corporate Governance Committee.

Stockholders may recommend individuals to the Nominating and Corporate Governance Committee for consideration as potential director candidates by submitting the names of the recommended individuals, together with appropriate biographical information and background materials, to the Nominating and Corporate Governance Committee, c/o Corporate Secretary, Selecta Biosciences, Inc., 480 Arsenal Way,65 Grove Street, Watertown, MAMassachusetts 02472. In the event there is a vacancy, and assuming that appropriate biographical and background material has been provided on a timely basis, the Committee will evaluate stockholder-recommended candidates by following substantially the same process, and applying substantially the same criteria, as it follows for candidates submitted by others.

The Board will give appropriate attention to written communications that are submitted by stockholders to the Company, and will respond if and as appropriate. Our Corporate Secretary is primarily responsible for monitoring communications from stockholders and for providing copies or summaries to the directors as he or she considers appropriate.

Our Amended and Restated Bylaws and Corporate Governance Guidelines provide our Board of Directors with flexibility to combine or separate the positions of Chairman of the Board and Chief Executive Officer in accordance with its determination that utilizing one or the other structure would be in the best interests of ourthe Company. AtCurrently, the current time, Werner Cautreels, Ph.D., our President androle of Chairman of the Board is separate from the role of Chief Executive Officer, serveswith Carrie S. Cox serving as Chairman of the Board. Our Board of Directors has determined that combiningand Dr. Brunn serving as Chief Executive Officer. The Board evaluates whether the rolespositions of Chairman of the Board and Chief Executive Officer is bestshould be combined or separated on an ongoing basis based on factors such as the experience of the applicable individuals and the current business environment of the Company. After considering these factors, the Board determined that continuing to separate the positions of Chairman and Chief Executive Officer was appropriate for our company and its shareholdersthe Company at this time because it promotes unified leadership by Dr. Cautreels and allows for a single, clear focus for management to executetime.

If, in the Company’s strategy and business plans. Iffuture, the Chairman of the Board is a member of management or does not otherwise qualify as independent, our Corporate Governance Guidelines provide for the appointment by the independent directors of a Lead Director. Since our Chairman of the Board is a member of management, the independent directors elected Amir Nashat, Ph.D., as the Lead Director. The Lead Director’s responsibilities would include, but arewould not be limited to, presiding over all

Risk assessment and oversight are an integral part of our governance and management processes. Our Board of Directors encourages management to promote a culture that incorporates risk management into our corporate strategy and day-to-day business operations. Management discusses strategic and operational risks at regular management meetings and conducts specific strategic planning and review sessions during the year that include a focused discussion and analysis of the risks facing us.the Company. Throughout the year, senior management reviews these risks with the Board of Directors at regular board meetings as part of management presentations that focus on particular business functions, operations or strategies, and presents the steps taken by management to mitigate or eliminate such risks. Our Board of Directors does not have a standing risk management committee, but rather administers this oversight function directly through the Board of Directors as a whole, as well as through various standing committees of the Board of Directors that address risks inherent in their respective areas of oversight. In particular, our Board of Directors is responsible for monitoring and assessing strategic risk exposure, including business continuity risks, such as risks relating to the COVID-19 pandemic, and our Audit Committee is responsible for overseeing our major financial risk exposures and the steps our management has taken to monitor and control these exposures. The Audit Committee also monitors compliance with legal and regulatory requirements and considers and approves or disapproves any related person transactions. Our Nominating and Corporate Governance Committee monitors the effectiveness of the Corporate Governance Guidelines. Our Compensation Committee assesses and monitors whether any of our compensation policies and programs has the potential to encourage excessive risk-taking. The Board does not believe that its role in the oversight of our risks affects the Board’s leadership structure.

Our Corporate Governance Guidelines require the Nominating and Corporate Governance Committee to periodically oversee an annual assessment of the Board and its committees.

We have a written Code of Business Conduct and Ethics that applies to our directors, officers and employees, including our principal executive officer, principal financial officer, principal accounting officer or controller, or persons performing similar functions. We have posted aA current copy of the code is posted on our website, www.selectabiosciences.com.www.selectabio.com. In addition, we intend to post on our website all disclosures that are required by law or the rules of NASDAQNasdaq concerning any amendments to, or waivers from, any provision of the code.

There were eightnine meetings of the Board of Directors during the fiscal year ended December 31, 2016.2019. Our independent directors also had regularly scheduled executive sessions. During the fiscal year ended December 31, 2016,2019, each director attended at least 75% of the aggregate of (i) all meetings of the Board of Directors and (ii) all meetings of the committees on which the Directordirector served during the period in which he served as a director.

The members of each of the Board committees and committee Chairs are set forth in the following chart.

Our Audit Committee’s responsibilities include:

The Audit Committee charter is available on our website at www.selectabio.com. The members of the Audit Committee are Timothy C. Barabe, Carl Gordon, Ph.D., Edwin Kania, Jr.Carrie S. Cox and Amir Nashat, Ph.D.Patrick Zenner. Mr. KaniaBarabe serves as the Chairperson of the committee. Our Board has affirmatively determined that each of Mr. Barabe, Ms. Cox and Mr. Zenner is independent for purposes of serving on an audit committee under Rule 10A-3 promulgated under the Securities Exchange Act of 1934, as amended (the "Exchange Act") and the Nasdaq rules. The members of our Audit Committee meet the

TheIn 2019, the Audit Committee met twice in 2016.seven times.

Our Compensation Committee is responsible for assisting the Board in the discharge of its responsibilities relating to the compensation of our executive officers. In fulfilling its purpose, our Compensation Committee has the following principal duties:

The Compensation Committee has the authority to retain or obtain the advice of compensation consultants, legal counsel and other advisors to assist it in carrying out its responsibilities.

The Compensation Committee may delegate its authority under its charter to one or more subcommittees as it deems appropriate from time to time as further described in its charter, which is available on our website at www.selectabiosciences.com.www.selectabio.com. The Compensation Committee may also delegate to an officer the authority to grant equity awards to certain employees, as further described in its charter and subject to the terms of our equity plans.

In 2016,2019, the Compensation Committee engaged Radford (“Radford”), aSurvey and Consulting, an Aon Hewitt company and compensation consulting firm (“Radford”), to assess and make recommendations with respect to the amount and types of compensation to provide our executives and directors. Radford reported directly to the Compensation Committee; however, our Chief Executive Officer consulted with Radford with respect to its assessments of the compensation of executive officers other than the Chief Executive Officer. The Compensation Committee reviewed compensation assessments provided by Radford comparing our compensation to that of a group of peer companies within our industry and met with Radford to discuss compensation of our executive officers and our Board, including the Chief Executive Officer, and to receive input and advice. The Compensation Committee has considered the adviser independence factors required under SEC rules as they relate to Radford and does not believe Radford’s work in 20162019 raised a conflict of interest.

The Compensation Committee uses competitive compensation data from an annual total compensation study of peer companies performed by Radford to inform the Compensation Committee's decisions about overall compensation opportunities and specific compensation elements. Additionally, the Compensation Committee uses multiple reference points when establishing targeted compensation levels. The Compensation Committee does not benchmark specific compensation elements or total compensation to any specific percentile relative to the peer companies or the broader United States market. Instead, the Compensation Committee applies judgment and discretion in establishing targeted pay levels, taking into account not only competitive market data, but also factors such as Company, business and individual performance, scope of responsibility, critical needs and skill sets, leadership potential and succession planning.

The Compensation Committee charter is available on our website at www.selectabio.com. The members of our Compensation Committee are Peter Barton Hutt, Edwin Kania, Jr.Scott D. Myers, Göran Ando, M.D., Carrie S. Cox and Aymeric Sallin, M.S. Peter Barton HuttSallin. Scott D. Myers serves as Chairperson of the committee. Our boardBoard of directorsDirectors has determined that each of Mr. Hutt, Mr. KaniaMyers, Dr. Ando, Ms. Cox and Mr. Sallin is independent under the applicable SEC and NASDAQNasdaq rules, including the heightened standard for independence specific to members of a compensation committee, and is a “non‑employee director” as defined in Rule 16b‑3 promulgated under the Exchange Act.

TheIn 2019, the Compensation Committee met twice during 2016.five times.

Our Nominating and Corporate Governance Committee’s responsibilities include:

The Nominating and Corporate Governance Committee charter is available on our website at www.selectabio.com. The members of our Nominating and Corporate Governance Committee are Omid Farokhzad, M.D., Amir Nashat, Ph.D.Patrick Zenner, Scott D. Myers and Timothy A. Springer, Ph.D. Dr. NashatMr. Zenner serves as the Chairperson of the committee. Our boardBoard of directorsDirectors has determined that Dr. Nashat andMr. Myers, Dr. Springer and Mr. Zenner are independent under the applicable NASDAQNasdaq rules. Under the applicable NASDAQ rules, we are permitted to phase-in our compliance with the independent nominating and corporate governance committee requirements of NASDAQ as follows: (1) one independent member at the time of listing, (2) a majority of independent members within 90 days of listing and (3) all independent members within one year of listing. Within one year of our listing on The NASDAQ Global Market, we expect that Dr. Farokhzad will have resigned from our Nominating and Corporate Governance Committee and that any new director added to

In 2019, the Nominating and Corporate Governance Committee will bemet four times.

Timothy A. Springer, Ph.D. is the sole member of our Science Committee and also serves as the Chairperson of the committee. Our Board of Directors has determined that Dr. Springer is independent under the applicable NASDAQNasdaq rules.

This section discusses the material components of the executive compensation program offered to our named executive officers identified below. For 2016,2019, our named executive officers and their positions as of December 31, 2019 were:

The primary elements of compensation for our named executive officers are base salary, annual performance bonuses and equity-based compensation awards. The named executive officers also participate in employee benefit plans and programs that we offer to our other full-time employees on the same basis.

We pay our named executive officers a base salary to compensate them for the satisfactory performance of services rendered to our company.the Company. The base salary payable to each named executive officer is intended to provide

In early 2016, our board of directors approved increasesDr. Brunn did not receive a base salary increase for 2019. Ms. Kogan joined the Company in theMarch 2019 with an annual base salariessalary of our named executive officers. Dr. Cautreels’ base salary was increased from $400,000 to $425,000, Dr. Sands’ base salary was increased from $280,000 to $300,000 and Mr. Keller’s base salary was increased from $275,000 to $290,000.

Our named executive officers have the opportunity to earn annual performance bonuses based on the achievement of short-term We offer our named executive officers the opportunity to earn annual cash bonuses to compensate them for attaining short-term company and individual performance goals. Each named executive officer has an annual target bonus that that is expressed as a percentage of his or her annual base salary. In May 2016, our board of director approved increases to each named executive officer’sThe 2019 target bonus amount effective upon the closing of our initial public offering. The 2016 target bonus percentage for Dr. CautreelsBrunn was increased from 25% to 45%50% of his base salary, for Ms. Kogan was 40% of her base salary and for our other named executive officers, from 25%Mr. Smolinski was 40% of his base salary. Pursuant to 35% of their respective base salaries.Ms. Kogan's employment agreement, her 2019 bonus was guaranteed to be at least $119,934.

Our Compensation Committee, based upon the recommendation of our chief executive officer,Chief Executive Officer, establishes companyCompany performance goals each year and, at the completion of the year, generally determines actual bonus payouts after assessing companyCompany performance against these goals and each named executive officer’s individual performance and contributions to the company’sCompany’s achievements. The 2016 company performance goalsFor 2019, bonuses were entirely determined based on completing our Initial Public Offering, completing the Phase 1 a/bCompany performance in meeting clinical, trial for SEL-212, initiating our Phase 2 clinical trial of SEL-212business development and executing a significant business deal.financial goals.

The actual cash bonuses earned by our named executive officersDr. Brunn, Ms. Kogan and Mr. Smolinski for 2016 and 20152019 are reported under the “Non-equity incentive award” column of the 2016 and 2015 Summary Compensation Table above.plan compensation” column.

We grant stock optionsoption awards to our named executive officers as thea long-term incentive component of their compensation. We have historically granted stock optionsoption awards to named executive officers when they commenced employment with us and have from time to time thereafter made additional grants as, and when, our boardBoard of directorsDirectors determined appropriate to reward,recruit, retain or encouragereward particular named executive officers.

In connection with our initial public offering, we adopted and our stockholders approved athe 2016 Incentive Award Plan (the “2016 Plan”) to facilitate the grant of cash and equity incentives to our directors, employees (including our named executive officers) and consultants and to enable our companythe Company to obtain and retain the services of these individuals, which we believe isare essential to our long-term success. Following the effective date of our 2016 Plan, we stopped making grants under our 2008 Stock Incentive Plan (the “2008 Plan”). However, the 2008 Plan continues to govern the terms and conditions of the outstanding awards granted under it.the 2008 Plan.

Our stock optionsoption awards have an exercise price at least equal to the fair market value of our common stock on the date of grant as determined by our board of directors, and typically vest as to 25% of the underlying shares on the first anniversary of the date of grant and in equal monthly installments over the following 36 months, subject to the holder’s continued employment with us and potential accelerated vesting in certain circumstances, including as described below for our named executive officers in the section titled “Potential payments upon a change in control.” From time to time, our boardBoard of directorsDirectors may also construct alternate vesting schedules as it determines are appropriate to motivate particular employees. Our stock optionsoption awards may be intended to qualify as incentive stock options under the Code. The 2008 Plan, generally permits “early exercise”

Our named executive officers are eligible to participate in our employee benefit plans and programs, including medical and dental benefits, flexible spending accounts, long-term care benefits, and short- and long-term disability and life insurance, to the same extent as our other full-time employees, subject to the terms and eligibility requirements of those plans.

The following table sets forth information regarding outstanding stock options held byIn 2019, we also provided certain travel and relocation benefits to Dr. Brunn and Mr. Smolinski pursuant to their employment agreements. Dr. Brunn was entitled to receive a stipend of $6,000 per month through June 2019 to offset the costs of travel and commuting expenses incurred in performing his duties for the Company and direct payment of, or reimbursement for, up to $75,000 in moving expenses incurred in connection with his relocation to the greater Boston, Massachusetts area. Pursuant to his employment agreement, Mr. Smolinski was entitled to reimbursement of expenses incurred for travel between his primary residence in New Jersey and our named executive officers asoffices in Massachusetts, up to a maximum amount of December 31, 2016.$6,100 monthly. We also provided Dr. Brunn and Mr. Smolinski with a tax gross-up to offset the tax liability incurred for such travel and relocation benefits.

In connection with our initial public offering, weWe have entered into new employment agreements with each of our named executive officers, effective June 6, 2016.

IfThe employment agreements provide that if we terminate Dr. Cautreels, Dr. Sands or Mr. Kellerthe named executive officer without "cause" or hethe named executive officer resigns for "good reason," subject to histhe named executive officer's timely executing a release of claims in our favor and continued compliance with a separate restrictive covenant agreement, hethe named executive officer is entitled to receive (i) base salary continuation for a period of 12 months, (ii) a prorated portion of the annual bonus hethe named executive officer would otherwise have earned for the year of termination, based on actual performance for the full year, (or based on his target bonusor, if suchthe termination occurs during the first quarter of the calendar year),year, based on the named executive officer's target bonus and (iii) direct payment of or reimbursement for continued medical, dental or vision coverage pursuant to COBRA for up to 12 months. If such termination occurs within the 12 months following or the 60 days preceding a change in control, each named executive officer would be entitled to receive, in addition to the foregoing payments and benefits, accelerated vesting of such named executive officer's outstanding unvested companyCompany equity awards that vest solely based on the passage of time. The companyCompany must provide a

named executive officer 30 days' notice, or pay in lieu of notice, in the event we terminate such named executive officer for any reason other than "cause"."cause."

For purposes of the new employment agreements, "cause" generally means, subject to applicable cure rights, the named executive officer's (i) commission of, or indictment or conviction of, any felony or any crime involving dishonesty; (ii) participation in any fraud against the company;Company; (iii) intentional damage to any companyCompany property; (iv) misconduct which materially and adversely reflects upon the business, operations, or reputation of the company; orCompany; (v) breach of any material provision of the employment agreement or any other written agreement with the company.Company; or (vi) for Ms. Kogan and Mr. Smolinski, a material or substantial failure to perform, or material or substantial negligence of, the executive's duties and responsibilities to the Company. "Good reason" generally means, subject to the company'sCompany's cure rights, the occurrence of any of the following, without the named executive officer's written consent (i) a material reduction in his or her base salary or target bonus opportunity; (ii) a material diminution in his or her authority, title, duties or areas of responsibility; (iii) the requirement that he or she report to someone other than the boardBoard of directorsDirectors with respect to Dr. Cautreelsour Chief Executive Officer or the chief executive officerChief Executive Officer with respect to Dr. Sands and Mr. Keller;our other named executive officers; (iv) the relocation of his or her primary office to a location more than 40 miles from the Boston metropolitan area; or (v) a material breach by the companyCompany of the employment agreement or any other written agreement with the named executive officer.

Director fees are paid in arrears in four equal quarterly installments not later than the fifteenth day following the final day of each calendar quarter, provided that the amount of each payment is prorated for any portion of a quarter that a director is not serving on our board.Board. Each member of our boardBoard of directorsDirectors is entitled to be reimbursed for reasonable travel and other expenses incurred in connection with attending meetings of the boardBoard of directorsDirectors and any committee of the boardBoard of directorsDirectors on which he or she serves.

The following table sets forth the compensation earned to our non-employee directors for their service on our boardBoard of directorsDirectors during 2016.

The table below shows the aggregate number of option awards (exercisable and unexercisable) held by each non-employee director as of December 31, 2016.2019. None of our non-employee directors held unvested stock awards in our companythe Company as of that date.