SEC Form PRE 14A filed by CytomX Therapeutics Inc.

You are cordially invited to attend the 2026 Annual Meeting of Stockholders of CytomX Therapeutics, Inc., a Delaware corporation (the “Company” or “CytomX”). The 2026 Annual Meeting of Stockholders will be held on June 17, 2026, at 1:30 p.m., Pacific Time. The 2026 Annual Meeting of Stockholders will be convened and held entirely online to support and facilitate stockholder participation. You will be able to attend and participate online in the 2026 Annual Meeting of Stockholders by visiting www.virtualshareholdermeeting.com/CTMX2026, where you will be able to listen to the meeting live, submit questions, and vote.

The 2026 Annual Meeting of Stockholders is being convened to conduct the following business:

These items of business are more fully described in the Proxy Statement accompanying this Notice of Annual Meeting of Stockholders. The record date for the 2026 Annual Meeting of Stockholders is April 20, 2026. Only stockholders of record at the close of business on that date are entitled to notice of, and to vote at, the 2026 Annual Meeting of Stockholders or any adjournment thereof.

The Board of Directors recommends that you vote as follows on the matters to be presented to stockholders at the 2026 Annual Meeting of Stockholders:

Your vote is very important. Whether or not you attend the 2026 Annual Meeting of Stockholders (by logging into www.virtualshareholdermeeting.com/CTMX2026), it is important that your shares be represented. We encourage you to read the accompanying Proxy Statement and our Annual Report on Form 10-K for the year ended December 31, 2025, and submit your proxy on the Internet, by phone or by mail in accordance with the instructions in the Notice of Internet Availability of Proxy Materials. Please review the instructions on the proxy card or the information forwarded by your bank, broker or other holder of record regarding each of these voting options. If you receive more than one set of proxy materials or notice of internet availability because your shares are registered in different names or addresses, each proxy should be signed and submitted to ensure that all of your shares will be voted. Instructions on how to attend the meeting webcast, ask questions or vote your shares online will also be included with the Notice of Internet Availability of Proxy Materials, and are provided in the Proxy Statement accompanying this Notice of Annual Meeting of Stockholders.

On behalf of the Board of Directors, thank you for your participation in this important annual process.

We sent you a Notice of Internet Availability of Proxy Materials because the board of directors of CytomX Therapeutics, Inc. (the “Board”) is soliciting your proxy to vote at our 2026 Annual Meeting of Stockholders to be held on June 17, 2026 at 1:30 p.m., Pacific Time. The meeting will be held virtually, via a live webcast at www.virtualshareholdermeeting.com/CTMX2026. To attend the live webcast, you will need your unique 16-digit control number provided on the Notice of Internet Availability of Proxy Materials.

We invite you to attend the annual meeting to vote on the proposals described in this Proxy Statement. However, you do not need to attend the meeting to vote your shares. Instead, you may vote by proxy over the Internet or by phone by following the instructions provided in the notice or, if you request printed copies of the proxy materials by mail, you may vote by mail.

Pursuant to the rules adopted by the Securities and Exchange Commission (the “SEC”), we have elected to provide access to our Annual Meeting materials, which include this Proxy Statement and our Annual Report on Form 10-K for the year ended December 31, 2025 (the “Form 10-K”), over the internet in lieu of mailing printed copies. We will begin mailing the Notice of Internet Availability to our stockholders of record as of April 20, 2026 (the “Record Date”) for the first time on or about April 28, 2026. The Notice of Internet Availability will contain instructions on how to access and review the 2026 Annual Meeting materials, how to access the live webcast of the 2026 Annual Meeting of Stockholders, and will also contain instructions on how to request a printed copy of the 2026 Annual Meeting materials. In addition, we have provided brokers, dealers, banks, voting trustees and their nominees, at our expense, with additional copies of our proxy materials and the Form 10-K so that our record-holders can supply these materials to the beneficial owners of shares of our common stock as of the Record Date. The Form 10-K is also available in the “Financial & Filings” section of our website at http://ir.cytomx.com/financial-information/annual-reports.

As used in this Proxy Statement, “CytomX,” the “Company,” “we” or “us” refer to CytomX Therapeutics, Inc., a Delaware corporation.

Only stockholders of record at the close of business on April 20, 2026 will be entitled to vote at the annual meeting. On this Record Date, there were      shares of common stock outstanding and entitled to vote.

If, on April 20, 2026, your shares were registered directly in your name with our transfer agent, Computershare Trust Company, N.A., then you are a stockholder of record. The notice will be sent to you by mail and via the Internet directly by us. As a stockholder of record, you may vote online during the live webcast of the meeting at www.virtualshareholdermeeting.com/CTMX2026, or vote by proxy. Whether or not you plan to attend the annual meeting online, we urge you to vote on the Internet or by phone as instructed in the notice or by proxy by mail by requesting a paper copy of the proxy materials as instructed in the notice to ensure your vote is counted.

If, on April 20, 2026, your shares were held in an account at a brokerage firm, bank or other agent, then you are the beneficial owner of shares held in “street name” and the notice is being forwarded to you by that organization.

The organization holding your account is considered the stockholder of record for purposes of voting at the annual meeting. As a beneficial owner, you have the right to direct your broker, bank or other agent on how to vote the shares in your account. Your brokerage firm, bank or other agent will not be able to vote in the election of directors, the amendment to our Amended and Restated 2015 Equity Incentive Plan, the amendment to our Amended and Restated Employee Stock Purchase Plan, the non-binding advisory vote to approve the compensation of our named executive officers and the non-binding advisory vote on the frequency of future advisory votes to approve executive compensation unless they have your voting instructions, so it is very important that you indicate your voting instructions to the institution holding your shares. You are also invited to attend the annual meeting online, as instructed in this Proxy Statement. However, since you are not the stockholder of record, you may not vote your shares online during the annual meeting unless you request and obtain a valid proxy from your broker, bank or other agent.

There are seven matters scheduled for a vote:

Under rules adopted by the SEC, we are sending the notice to our stockholders of record and beneficial owners as of April 20, 2026. Stockholders will have the ability to access the proxy materials, including this Proxy Statement and our Annual Report on Form 10-K for the fiscal year ended December 31, 2025, on the Internet at www.proxyvote.com or to request a printed or electronic set of the proxy materials at no charge. Instructions on how to access the proxy materials over the Internet and how to request a printed copy may be found on the notice.

In addition, any stockholder may request to receive proxy materials in printed form by mail or electronically by email on an ongoing basis. Choosing to receive future proxy materials by email will save us the cost of printing and mailing documents to stockholders and will reduce the impact of annual meetings on the environment. A stockholder who chooses to receive future proxy materials by email will receive an email prior to next year’s annual meeting with instructions containing a link to those materials and a link to the proxy voting website. A stockholder’s election to receive proxy materials by email will remain in effect until the stockholder terminates it.

Please note that by casting your vote by proxy you are authorizing the individuals listed on the Proxy Card to vote your shares in accordance with your instructions and in their discretion with respect to any other matter that properly comes before the annual meeting or any adjournments or postponements thereof.

The procedures for voting are:

If you are a stockholder of record as of April 20, 2026, you may vote by attending the annual meeting online at www.virtualshareholdermeeting.com/CTMX2026 and following the instructions posted on the webcast portal. You may also vote by proxy over the Internet or by phone by following the instructions provided in the Notice of Internet Availability of Proxy Materials or, if you request printed copies of the proxy materials by mail, you may vote by mail. If your proxy is properly executed in time to be voted at the annual meeting, the shares represented by the proxy will be voted in accordance with the instructions you provide. Whether or not you plan to attend the annual meeting online, we urge you to vote by proxy to ensure your vote is counted. You may still attend the annual meeting online and vote online at www.virtualshareholdermeeting.com/CTMX2026 if you have already voted by proxy, so long as you do so before voting closes.

If you are a beneficial owner of shares registered in the name of your broker, bank or other agent, you should have received a notice and voting instructions from that organization rather than from us. Simply follow the instructions to ensure that your vote is counted. To vote online at the annual meeting, you must obtain a valid proxy from your broker, bank or other agent. Follow the instructions from your broker, bank or other agent included with the notice, or contact your broker, bank or other agent to request a proxy form.

We provide Internet proxy voting to allow you to vote your shares online, with procedures designed to ensure the authenticity and correctness of your proxy vote instructions. However, please be aware that you must bear any costs associated with your Internet access, such as usage charges from Internet access providers and telephone companies.

On each matter to be voted upon, you have one vote for each share of common stock you owned as of April 20, 2026.

A quorum of stockholders is necessary to take any action at the meeting, other than to adjourn the meeting. The presence, online or by proxy duly authorized, of the holders of a majority of the outstanding shares of stock entitled to vote will constitute a quorum. On April 20, 2026, there were     shares of common stock outstanding and entitled to vote.

Your shares will be counted toward the quorum only if you submit a valid proxy or vote online at the annual meeting. Abstentions and broker non-votes will be counted toward the quorum requirement. If there is no quorum, the chairman of the annual meeting or the holders of a majority of the shares casting votes at the annual meeting may adjourn the annual meeting to another date.

If you are a stockholder of record and you return a proxy card without marking any voting selections, your shares will be voted as follows:

If any other matter is properly presented at the meeting, your proxy (one of the individuals named on your proxy card) will vote your shares using their best judgment.

If you are a beneficial owner of shares registered in the name of your broker, bank or other agent, your shares are held by your broker, bank or other agent as your nominee, or in “street name,” and you will need to obtain a proxy form from the organization that holds your shares and follow the instructions included on that form regarding how to instruct the organization to vote your shares. If you do not give instructions to your broker, bank or other agent, they can vote your shares with respect to “discretionary” items but not with respect to “non-discretionary” items. Discretionary items are proposals considered routine under the rules of various national securities exchanges, and, in the absence of your voting instructions, your broker, bank or other agent may vote your shares held in street name on such proposals. Non-discretionary items are proposals considered non-routine under the rules of various national securities exchanges, and, in the absence of your voting instructions, your broker, bank or other agent may not vote your shares held in street name on such proposals and the shares will be treated as broker non-votes.

Proposal 1 (the election of directors), Proposal 4 (amendment to our Amended and Restated 2015 Equity Incentive Plan), Proposal 5 (amendment to our Amended and Restated Employee Stock Purchase Plan), Proposal 6 (non-binding advisory vote to approve the compensation of our named executive officers) and Proposal 7 (non-binding advisory vote on the frequency of future advisory votes to approve executive compensation) are considered non-routine under applicable rules. A broker or other nominee cannot vote without instructions on non-routine matters, and therefore there may be broker non-votes on Proposals 1, 4, 5, 6 and 7.

Proposal 2 (the ratification of the selection of Ernst & Young LLP as our independent registered public accounting firm for the year ending December 31, 2026) and Proposal 3 (amendment of our Amended and Restated Certificate of Incorporation) are considered routine under applicable rules. A broker or other nominee may generally vote on routine matters, and therefore no broker non-votes are expected to exist in connection with Proposals 2 and 3.

Votes will be counted by the inspector of election appointed for the annual meeting, who will count:

Farooq Nomani, our Senior Director and Corporate Counsel, will serve as the inspector of elections.

We will pay for the entire cost of soliciting proxies. We have retained Georgeson LLC to assist in the solicitation of proxies for a fee of approximately $15,000 plus associated costs and expenses. In addition to the notice and the proxy materials, our directors and employees may also solicit proxies online, by telephone or by other means of communication. We will not pay our directors and employees any additional compensation for soliciting proxies. We may also reimburse brokerage firms, banks and other agents for the cost of forwarding the notice and any other proxy materials to beneficial owners.

If you receive more than one notice, your shares are registered in more than one name or are registered in different accounts. Please vote by proxy according to each notice to ensure that all of your shares are voted.

Yes, you can revoke your proxy at any time before the final vote at the annual meeting. If you are a stockholder of record, you may revoke your proxy in any one of three ways:

If you are a beneficial owner, you may revoke your proxy by submitting new instructions to your broker, bank or other agent, or if you have received a proxy from your broker, bank or other agent giving you the right to vote your shares at the annual meeting, by attending our virtual annual meeting by visiting www.virtualshareholdermeeting.com/CTMX2026 with your 16-digit control number (available in your notice and proxy card) and following the instructions to vote online.

This year’s annual meeting will be held entirely online to support and facilitate stockholder participation. Stockholders of record as of April 20, 2026, will be able to attend and participate in the annual meeting online by accessing www.virtualshareholdermeeting.com/CTMX2026. To join the annual meeting, you will need to have your 16-digit control number, which is included on your Notice of Internet Availability of Proxy Materials and your proxy card.

Even if you plan to attend the annual meeting online, we recommend that you also vote by proxy as described herein so that your vote will be counted if you decide not to attend the annual meeting.

Access to the audio webcast of the annual meeting. The live audio webcast of the annual meeting will begin promptly at 1:30 p.m., Pacific Time on June 17, 2026. Online access to the audio webcast will open approximately thirty minutes prior to the start of the annual meeting to allow time for you to log in and test the computer audio system. We encourage our stockholders to access the annual meeting prior to the start time.

Log in Instructions. To attend the online annual meeting, log in at www.virtualshareholdermeeting.com/CTMX2026. Stockholders will need their unique 16-digit control number, which appears on the Notice of Internet Availability of Proxy Materials and the instructions that accompanied the proxy materials. In the event that you do not have a control number, please contact your broker, bank, or other nominee as soon as possible and no later than May 30, 2026, so that you can be provided with a control number and gain access to the annual meeting.

Submitting questions at the virtual annual meeting. As part of the annual meeting, we will hold a live question and answer session, during which we intend to answer questions submitted during the meeting in accordance with the annual meeting’s rules of conduct that are pertinent to the Company and the meeting matters, as time permits. Questions and answers will be grouped by topic and substantially similar questions will be grouped and answered once. The annual meeting’s rules of conduct will be posted on the Company website approximately 2 weeks prior to the date of the annual meeting.

Technical Assistance. Beginning 30 minutes prior to the start of and during the virtual annual meeting, we will have a support team ready to assist stockholders with any technical difficulties they may have accessing or hearing the virtual meeting.

If you encounter any difficulties accessing the virtual meeting during the check-in or meeting time, you may call our support team at the numbers available on www.virtualshareholdermeeting.com/CTMX2026.

Availability of live webcast to team members and other constituents. The live audio webcast will be available to not only our stockholders but also our team members and other constituents.

Pursuant to Rule 14a-8 under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), some stockholder proposals may be eligible for inclusion in our proxy statement for our 2027 Annual Meeting of Stockholders. Any such proposal must be submitted in writing by December 29, 2026, to our Secretary, care of CytomX Therapeutics, Inc., at 151 Oyster Point Boulevard, Suite 400, South San Francisco, CA 94080, the address of our principal executive offices. If we change the date of our 2027 Annual Meeting of Stockholders by more than 30 days from the date of the 2026 Annual Meeting of Stockholders, the deadline shall be a reasonable time before we begin to print and send our proxy materials. Stockholders interested in submitting such a proposal are advised to contact knowledgeable counsel with regard to the detailed requirements of the applicable securities laws and our bylaws. The submission of a stockholder proposal does not guarantee that it will be included in our proxy statement.

Our bylaws also establish an advance notice procedure for stockholders who wish to present a proposal before an annual meeting of stockholders but do not intend for the proposal to be included in our proxy statement. Our bylaws provide that if you wish to submit a proposal that is not to be included in next year’s proxy statement or nominate a director, a timely written notice of a stockholder proposal must be delivered to, or mailed and received by, our Secretary, care of CytomX Therapeutics, Inc., at 151 Oyster Point Boulevard, Suite 400, South San Francisco, CA 94080, no earlier than February 17, 2027 and no later than the close of business on March 19, 2027, which notice must contain the information specified in our bylaws. If we change the date of our 2027 Annual Meeting of Stockholders by more than 30 days before, or more than 60 days after, the one-year anniversary of the 2026 Annual Meeting of Stockholders, then the written notice of a stockholder proposal that is not intended to be included in our proxy statement must be delivered, or mailed and received, not later than the 90^th day prior to our 2027 Annual Meeting of Stockholders or, if later, the 10^th day following the day on which certain public disclosure as described in our bylaws of the meeting date is made.

In addition to satisfying the foregoing requirements under our current bylaws, stockholders who intend to solicit proxies in support of director nominees other than the Company’s nominees for our annual meeting to be held in 2027 must provide notice that sets forth the information required by Rule 14a-19 under the Exchange Act no later than 5:00 p.m., Eastern Time, on April 18, 2027, including providing a statement that such stockholder intends to solicit the holders of shares representing at least 67% of the voting power of the Company’s shares entitled to vote on the election of directors in support of director nominees other than the Company’s nominees. If our 2027 annual meeting is changed by more than 30 calendar days from the first anniversary of our 2026 annual meeting, stockholders must comply with the additional requirements of Rule 14a-19(b) under the Exchange Act no later than the later of 60 calendar days prior to the date of the 2027 annual meeting or the 10^th calendar day following the day on which public announcement of the date of the 2027 annual meeting is first made.

We intend to file a proxy statement and WHITE proxy card with the SEC in connection with our solicitation of proxies for our 2027 Annual Meeting of Stockholders. Stockholders may obtain our proxy statement (and any amendments and supplements thereto) and other documents for our 2027 Annual Meeting of Stockholders as and when filed by us with the SEC without charge from the SEC’s website at: www.sec.gov.

We have adopted a procedure approved by the SEC called “householding.” Under this procedure, stockholders who have the same address may receive only one copy of our annual report, proxy statement or Notice of Internet Availability of Proxy Materials, unless one or more of these stockholders notifies us that they wish to receive individual copies of such documents. This process potentially means extra convenience for stockholders and cost savings for companies.

If you are a beneficial owner of our common stock, once you receive notice from your broker, bank or other agent that they will be householding communications to your address, householding will continue until you are notified otherwise or until you revoke your consent. If, at any time, you no longer wish to participate in householding and would prefer to receive separate copies of our annual report, proxy statement or Notice of Internet Availability of Proxy Materials, please notify your broker, bank or other agent, and direct your written request to CytomX Therapeutics, Inc., Secretary, at 151 Oyster Point Boulevard, Suite 400, South San Francisco, CA 94080 or contact our Secretary at (650) 515-3185. Upon written or oral request to us, we will promptly deliver a separate copy of the annual report to security holders, proxy statement, or Notice of Internet Availability of Proxy Materials, as applicable, to a security

holder at a shared address to which a single copy of the documents was delivered. Stockholders who currently receive multiple copies of our annual report, proxy statement or Notice of Internet Availability of Proxy Materials at their address and would like to request householding of their communications should contact their broker, bank or other agent.

Preliminary voting results will be announced during the live webcast of the annual meeting. Final voting results will be published in a Current Report on Form 8-K filed with the SEC within four business days following the annual meeting.

Our Board currently consists of eight directors and is divided into three classes, designated as Class I, Class II and Class III. Under our Amended and Restated Certificate of Incorporation, our Board is authorized to assign its members in office to each class and each class has a term of three years. There are currently two directors in Class II, Matthew P. Young, and Elaine V. Jones Ph.D., whose terms of office are scheduled to expire at the 2026 Annual Meeting of Stockholders. Both, Mr. Young and Dr. Jones have been nominated for election at the 2026 Annual Meeting of Stockholders.

Any vacancies on our Board resulting from death, resignation, disqualification, removal or other causes, and any newly created directorships resulting from any increase in the number of directors, shall be filled by the affirmative vote of a majority of the directors then in office, even though less than a quorum of the Board. Any director elected to fill a vacancy shall hold office for the remainder of the unexpired term in which the vacancy occurred or newly created directorship was created and until such director’s successor shall have been elected and qualified.

Directors are elected by a majority of the votes cast at the annual meeting and entitled to vote on the election of directors. A majority of votes cast shall mean that the number of shares voted “For” a director’s election exceeds 50% of the number of votes cast with respect to that director’s election, with votes cast including votes “Against” in each case and excluding abstentions and broker non-votes with respect to that director’s election. Shares represented by executed proxies will be voted for the election of the nominees named below, unless the “Against” or “Abstain” voting selection has been marked on the proxy card.

If either of Mr. Young or Dr. Jones become unavailable for election as a result of an unexpected occurrence, shares that would otherwise be voted for such director will be voted for the election of a substitute nominee proposed by the Nominating and Corporate Governance Committee and nominated by the Board. Mr. Young and Dr. Jones have agreed to serve if elected. Our management has no reason to believe that either Mr. Young or Dr. Jones will be unable to serve. If elected at the annual meeting, both Mr. Young and Dr. Jones will serve until the earliest of the 2029 Annual Meeting of Stockholders, or their respective successor is elected and qualified, or until their respective death, resignation or removal.

The following are brief biographies of Mr. Young and Dr. Jones, the nominees for director, and a discussion of their specific experience, qualifications, attributes or skills that led the Nominating and Corporate Governance Committee of the Board to recommend each of them for director, as of the date of this proxy statement.

Mr. Matthew P. Young has served as a member of our Board since September 2015. Mr. Young currently serves as a Managing Director at Longitude Capital, a position he has held since August 2022. Before that, Mr. Young was serving as Chief Operating Officer and Chief Financial Officer of GRAIL from October 2019 to December 2021. Prior to joining GRAIL, Mr. Young had served as Executive Vice President and Chief Financial Officer of Jazz Pharmaceuticals (“Jazz”), a role he held since February 2015. He previously had served as Senior Vice President and Chief Financial Officer of Jazz since March 2014 and as Senior Vice President, Corporate Development of Jazz since April 2013. Prior to joining Jazz, Mr. Young worked in investment banking for approximately 20 years. From February 2009 to April 2013, he served as a Managing Director in global healthcare of Barclays Capital Inc., an investment banking firm, where his role included acting as the co-head of life sciences at Barclays Capital. From 2007 to 2008, Mr. Young served as a Managing Director of Citigroup Global Markets Inc., an investment banking firm, and, from 2003 to 2007, as a Managing Director of Lehman Brothers Inc., an investment banking firm. In 2015, he joined the board of directors of PRA Health Sciences Inc., a contract research company, a position he held until July 2021. Mr. Young currently serves on the board of directors of the privately-held biopharmaceutical companies OrsoBio, Inc., Alpha-9 Oncology, Inc. and AllIn Bio. Mr. Young received a B.S. in economics and a M.B.A. from the Wharton School of the University of Pennsylvania. We believe that Mr. Young is qualified to serve on our Board due to his extensive management experience, significant experience in the life sciences industry and financial expertise.

Elaine V. Jones, Ph.D., has served as a member of our Board since May 2019. Dr. Jones retired in April 2019 from her role as Vice President, Worldwide Business Development and Senior Partner at Pfizer Ventures, the venture capital arm of Pfizer Inc. After joining Pfizer Ventures as Executive Director in 2008, Dr. Jones was responsible for making and managing venture investments for Pfizer as well as serving in board roles for several therapeutic companies. Prior to

this, Dr. Jones held the position of General Partner at EuclidSR Partners, a venture firm specializing in private investment in private and public equity within the health sciences, healthcare, biopharmaceutical sectors, until 2008. Dr. Jones began her investment career at S.R. One, the corporate investment fund of GlaxoSmithKline, which she joined in 1999. Prior to this, Dr. Jones served as Director of Scientific Licensing at SmithKline Beecham and as a research scientist in the research and development division of SmithKline Beecham Pharmaceutical. During her venture career, Dr. Jones has served on the boards of more than 20 early to mid-stage biotechnology, therapeutic and pharmaceutical companies. She has served on the board of HBM Healthcare Investments AG, a publicly-traded Swiss Investment Company since June 2018. She has also served on the board of NextCure, Inc., a publicly-traded biopharmaceutical company, since December 2015. Dr. Jones also currently serves on the boards of privately held biopharmaceutical companies and has served on the board of the Novartis Venture Fund since 2020. Dr. Jones previously served as a member of the board of directors of Gritstone Oncology, a publicly-traded biopharmaceutical company, from September 2019 to April 2025. Dr. Jones holds a B.S. in biology from Juniata College and a Ph.D. in microbiology from the University of Pittsburgh. We believe that Dr. Jones is qualified to serve on our Board due to her broad knowledge of the life sciences industry and significant experience in pharmaceutical drug discovery and business development.

THE BOARD OF DIRECTORS RECOMMENDS A VOTE “FOR” THE ELECTION OF EACH OF THE NAMED NOMINEES.

The Audit Committee of our Board has selected Ernst & Young LLP as our independent registered public accounting firm for the fiscal year ending December 31, 2026, and has further directed that management submit the selection of our independent registered public accounting firm for ratification by the stockholders at the annual meeting. Ernst & Young LLP has audited our financial statements for each of our fiscal years since the fiscal year ended December 31, 2017. Representatives of Ernst & Young LLP are expected to be present at the virtual annual meeting. During the webcast, they will have an opportunity to make a statement if they so desire and will be available to respond to appropriate questions submitted online.

Neither our bylaws nor other governing documents or law require stockholder ratification of the selection of Ernst & Young LLP as our independent registered public accounting firm. However, the Audit Committee is submitting the selection of Ernst & Young LLP to the stockholders for ratification as a matter of good corporate practice. If the stockholders fail to ratify the selection, the Audit Committee will reconsider whether or not to retain Ernst & Young LLP. Even if the selection is ratified, the Audit Committee, in its discretion, may direct the appointment of a different independent registered public accounting firm at any time during the year if the Audit Committee determines that such a change would be in our best interests and our stockholders’ best interest.

The affirmative vote of the holders of a majority of the votes cast either online or by proxy at the annual meeting and that are entitled to vote on this proposal will be required to ratify the selection of Ernst & Young LLP for our fiscal year ending December 31, 2026, with votes cast including votes “Against” and excluding abstentions. Abstentions will not be counted as votes cast and will have no effect on the outcome of this proposal. This is a routine proposal and therefore no broker non-votes are expected to exist in connection with this proposal.

The following table provides information regarding the approximate fees billed by Ernst & Young LLP during the years ended December 31, 2025 and 2024. The Audit Committee approved all of the fees described below.

The Audit Committee has adopted policies and procedures for the pre-approval of audit and non-audit services provided by our independent registered public accounting firm, Ernst & Young LLP. The policy generally requires pre-approval for specified services in the defined categories of audit services, audit-related services and tax services up to specified amounts. Pre-approval may also be given as part of the Audit Committee’s approval of the scope of the engagement of the independent registered public accounting firm or on an individual explicit case-by-case basis before the independent registered public accounting firm is engaged to provide each service. The pre-approval of services may be delegated to one or more of the Audit Committee’s members, but the decision must be reported to the full Audit Committee at its next scheduled meeting.

The Audit Committee will review both audit and non-audit services performed by Ernst & Young LLP and the fees charged for such services on at least an annual basis. Among other things, the Audit Committee will review non-audit services proposed to be provided by Ernst & Young LLP and pre-approve such services only if they are compatible with maintaining Ernst & Young LLP’s status as an independent registered public accounting firm. All services provided by Ernst & Young LLP in 2025 and 2024 were pre-approved by our Board or the Audit Committee after review of each of the services proposed for approval.

THE BOARD OF DIRECTORS RECOMMENDS A VOTE “FOR” THE RATIFICATION OF THE SELECTION OF ERNST & YOUNG LLP AS OUR INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM FOR THE FISCAL YEAR ENDING DECEMBER 31, 2026.

We are asking our stockholders to approve an amendment to Article Four, Section A of our Amended and Restated Certificate of Incorporation to increase the total number of authorized shares of common stock, par value $0.00001 per share, from 300,000,000 shares to 600,000,000 shares (the “Charter Amendment”). The Charter Amendment will not change the number of authorized shares of preferred stock, which will remain at 10,000,000 shares. If approved, the total number of shares of all classes of capital stock that the Company is authorized to issue will increase from 310,000,000 shares to 610,000,000 shares.

The following table sets forth, as of March 31, 2026, information regarding our authorized, issued and outstanding, reserved, and available shares of common stock:

As of March 31, 2026, 82,306,122 shares of authorized common stock remained available for future issuance. The Charter Amendment will not change the number of authorized shares of preferred stock. As of March 31, 2026, 10,000,000 shares of preferred stock, par value $0.00001 per share, were authorized, and no shares of preferred stock were issued and outstanding.

In April 2026, the Board determined that the Charter Amendment was advisable and in the best interests of the Company and its stockholders and unanimously approved the Charter Amendment, subject to stockholder approval.

The Board believes that additional authorized shares of common stock are necessary to provide the Company with the flexibility to respond to future opportunities and needs. In particular, the Board considered the following factors in recommending the Charter Amendment:

The Board currently has no specific plans, arrangements, or agreements to issue any of the proposed additional authorized shares of common stock, other than shares that may be issued under the Company’s existing equity compensation plans in the ordinary course. As a general matter, the Board would be able to issue the additional authorized shares at its discretion from time to time without further action or approval of the Company’s stockholders, except as may be required by applicable law or the rules and listing requirements of the Nasdaq Stock Market or any other applicable securities exchange. For example, the Nasdaq Stock Market listing rules generally require stockholder approval for issuances of common stock in connection with certain acquisitions, private placements, or equity compensation arrangements that exceed specified thresholds.

If the Charter Amendment is approved, the additional 300,000,000 authorized shares of common stock will be identical in all respects to the shares of common stock currently authorized and outstanding. Holders of our common stock do not currently have, and will not have as a result of the Charter Amendment, preemptive, subscription, redemption, or conversion rights. The Charter Amendment will not change the number of shares of common stock or preferred stock currently outstanding, nor will it have any immediate dilutive effect or change the rights of current holders of our common stock.

However, to the extent that the additional authorized shares of common stock are issued in the future, they may decrease existing stockholders’ percentage equity ownership and, depending on the price at which they are issued, could be dilutive to the voting power of existing stockholders and may dilute earnings and book value on a per share basis. Because our stockholders do not have preemptive rights, current stockholders would not have a prior right to purchase any new issuance of capital stock in order to maintain their proportionate ownership of our common stock.

The availability of additional shares of common stock for issuance could, under certain circumstances, discourage or make any efforts to obtain control of the Company more difficult. For example, the Board could, without further stockholder approval, issue shares of common stock in a public or private offering, including to persons allied with the Board, which could dilute the stock ownership or voting power of parties seeking to obtain control of the Company. The increase in authorized shares of common stock could also have the effect of rendering more difficult or discouraging a merger, tender offer, or proxy contest, the assumption of control by a holder of a large block of our stock, or the removal of incumbent management. The Board is not aware of any actual or contemplated attempt to acquire control of the Company, and the Charter Amendment is not being presented with the intent that it be used to prevent or discourage any acquisition attempt. However, nothing would prevent the Board from taking any actions that it deems consistent with its fiduciary duties.

Stockholders will not have any appraisal or dissenters’ rights under the Delaware General Corporation Law in connection with the Charter Amendment.

If the Charter Amendment is approved by our stockholders, Article Four, Section A of our Amended and Restated Certificate of Incorporation would be amended and restated in its entirety to read as follows:

“A. The Company is authorized to issue two classes of stock to be designated, respectively, Common Stock and Preferred Stock. The total number of shares that the Company is authorized to issue is 610,000,000 shares, 600,000,000 shares of which shall be Common Stock (the “Common Stock”), and 10,000,000 shares of which shall be Preferred Stock (the “Preferred Stock”). The Common Stock shall have a par value of $0.00001 per share and the Preferred Stock shall have a par value of $0.00001 per share.”

The full text of the proposed Certificate of Amendment is attached to this Proxy Statement as Appendix A.

If the Charter Amendment is approved by our stockholders, the amendment will become effective immediately upon the filing of a Certificate of Amendment to our Amended and Restated Certificate of Incorporation with the Secretary of State of the State of Delaware, which we expect to file promptly after the annual meeting. Notwithstanding stockholder approval of the Charter Amendment, at any time prior to the effectiveness of the filing of the Certificate of Amendment with the Secretary of State of the State of Delaware, the Board may abandon the Charter Amendment without further action by the stockholders. If the Charter Amendment is not approved by our stockholders, the number of authorized shares of common stock will remain unchanged at 300,000,000.

If our stockholders do not approve the Charter Amendment, our authorized shares of common stock will remain at 300,000,000 shares, of which only 82,306,122 shares remained available for future issuance as of March 31, 2026. The Company’s long-term growth strategy may require the issuance of additional shares beyond those currently available. Without sufficient authorized shares, the Company could face the following risks:

The affirmative vote of a majority of the votes cast either online or by proxy at the annual meeting and that are entitled to vote on the proposal will be required to approve the Charter Amendment, with votes cast including votes “Against” and excluding abstentions. This is a routine proposal and therefore we do not expect any broker non-votes.

THE BOARD OF DIRECTORS RECOMMENDS THAT STOCKHOLDERS VOTE “FOR” THE RESOLUTION TO AMEND OUR AMENDED AND RESTATED CERTIFICATE OF INCORPORATION TO INCREASE THE NUMBER OF SHARES OF AUTHORIZED COMMON STOCK FROM 300,000,000 SHARES TO 600,000,000 SHARES.

We are asking our stockholders to approve an amendment to our Amended and Restated 2015 Equity Incentive Plan (the “Amended and Restated 2015 Plan”) to increase the number of shares authorized for issuance thereunder by 6,500,000 million shares, thereby increasing the available share reserve from 1,711,325 shares to 8,211,325 shares. Our Board, upon recommendation of our Compensation Committee, approved the amendment in March 2026, subject to stockholder approval.

If this Proposal No. 4 is approved by our stockholders, the increase in the number of shares available for issuance under our Amended and Restated 2015 Plan will become effective as of the date of the Annual Meeting.

The full text of the proposed amendment is attached to this Proxy Statement as Appendix B.

As of March 31, 2025, we had 1,711,325 shares available for issuance under our Amended and Restated 2015 Plan. Our Compensation Committee has determined that these reserves would be insufficient to meet our operational needs over the next 1-2 year period and we are therefore requesting 6,500,000 additional shares to be approved for issuance under our Amended and Restated 2015 Plan. The increase in our share reserve allows us more flexibility in our equity grant practices and ensures that we retain an important compensation tool for all service providers, not just newly hired employees.

Our Board believes that the issuance of equity awards is a key element underlying our ability to attract, retain and motivate key personnel, non-employee directors, employees, consultants, and advisors because of the competition for highly trained and experienced individuals among biotechnology and pharmaceutical companies, especially in the greater San Francisco Bay Area. Therefore, the Board believes that the increase in shares under our Amended and Restated 2015 Plan is in the best interests of our business and our stockholders and recommends a vote in favor of this Proposal No. 4.

Approval of this Proposal No. 4 by our stockholders will allow us to grant equity awards under the Amended and Restated 2015 Plan at levels we determine to be appropriate, competitive and aligned with industry standards to attract, motivate and retain talent. The Amended and Restated 2015 Plan allows us to utilize equity awards as long-term incentives to secure and retain the services of our employees, non-employee directors, consultants and advisors, consistent with our compensation philosophy and common compensation practice for our industry in the greater San Francisco Bay Area. To date, equity awards have been a key aspect of our program to attract and retain key employees and non-employee directors. We believe the use of equity awards strongly aligns the interests of our employees with those of our stockholders by placing a considerable proportion of our employees’ total compensation “at risk” because it is contingent on the appreciation in value of our common stock. In addition, we believe equity awards encourage employee ownership of our common stock and promote retention through the reward of long-term Company performance.

Our compensation philosophy reflects broad-based eligibility for equity awards, and we generally grant equity awards to all of our employees and non-employee directors and certain consultants and advisors. However, we recognize that equity awards dilute existing stockholders, and, therefore, we are mindful about responsibly managing the growth of our equity compensation program. We are committed to effectively monitoring our equity compensation share reserve, including our “burn rate,” to ensure that we maximize stockholders’ value by granting the appropriate number of equity awards necessary to attract, reward, and retain employees and non-employee directors. The tables below show certain historical overhang and burn rate percentages.

In its determination to approve the amendment to the Amended and Restated 2015 Plan, our Compensation Committee reviewed an analysis prepared by Aon, its compensation consultant, which included an analysis of our historic and estimated prospective share usage needs and the potential dilutive impact of the Amended and Restated 2015 Plan.

Specifically, our Compensation Committee considered:

The following table provides certain additional information regarding our equity incentive program and reflects all outstanding equity awards as of March 31, 2026. The Amended and Restated 2015 Plan is the only equity incentive plan we currently have in place under which we can grant awards (other than the shares available for purchase under the ESPP).

In its determination to approve the increase in shares under our Amended and Restated 2015 Plan, the Board was primarily motivated by a desire to ensure the Company has an available pool of shares from which to grant long-term equity-based incentive awards, which the Board believes is a primary incentive and retention mechanism for our employees, consultants, and directors. The Board considered key factors in making its determination including our historical grant rates, the shares remaining available for issuance under the Amended and Restated 2015 Plan and the potential dilution associated with the amendment to the Amended and Restated 2015 Plan.

This review included a consideration of the following key metrics, factors, and philosophies:

The following table provides detailed information regarding the activity under our equity incentive plans for fiscal years 2023-2025:

Subject to adjustment for certain changes in our capitalization, if this Proposal No. 4 is approved by our stockholders, then under the Amended and Restated 2015 Plan, as amended, we will have a total of approximately 8,211,325 shares available for grant after our Annual Meeting (based on 6,500,000 million newly registered shares and the 1,711,325 shares that were available as of March 31, 2026).

We believe that our request for 6,500,000 million new shares under the Amended and Restated 2015 Plan is necessary for us to remain competitive in the greater San Francisco Bay Area marketplace and support our equity grant practices to align the interests of our employees, consultants and non-employee directors with our stockholders. We anticipate the available pool of shares in the Amended and Restated 2015 Plan, as amended, will be sufficient for our equity awards for approximately the next 1-2 year period after considering our present average share usage rate, and that such pool of shares is necessary to provide a predictable amount of available equity awards for attracting, retaining, and motivating employees, non-employee directors, consultants and advisors.

The material features of the Amended and Restated 2015 Plan, as amended, are described below. The following description of the Amended and Restated 2015 Plan, as amended, is a summary only and is qualified in its entirety by reference to the complete text of the Amended and Restated 2015 Plan, as amended. Shareholders are urged to read the actual text of the Amended and Restated 2015 Plan, as amended, in its entirety, which is appended as Appendix B to the copy of this Proxy Statement filed with the SEC, which may be accessed from the SEC’s website at www.sec.gov.

The Amended and Restated 2015 Plan is designed to align the interests of our employees, directors and consultants with those of the Company’s stockholders by increasing their proprietary interests in the Company’s growth and

success, to advance the interests of the Company by attracting and retaining employees, directors, officers, and other service providers, and to motivate such persons to act in the long-term best interests of the Company and its stockholders.

The terms of the Amended and Restated 2015 Plan provide for the grant of incentive stock options, non-statutory stock options, share awards in the form of bonus shares, restricted shares, or restricted share unit awards, share appreciation rights, and performance units that may be settled in cash, stock, or a combination thereof.

Subject to adjustment for certain changes in our capitalization, if this Proposal 4 is approved, the aggregate number of shares of our common stock that may be issued pursuant to awards granted under the Amended and Restated 2015 Plan (the “Share Reserve”), will be increased by 6,500,000 million shares.

To the extent shares of common stock underlying an award (whether granted under the Amended and Restated 2015 Plan or our 2019 Employment Inducement Incentive Plan), are not issued or delivered by reason of (i) the expiration, termination, cancellation or forfeiture of such award (excluding shares subject to an option cancelled upon settlement in shares of a related tandem SAR or shares subject to a tandem SAR cancelled upon exercise of a related option) or (ii) the settlement of such award in cash, then such shares shall again be available under the Amended and Restated 2015 Plan, other than grants of incentive stock options under the Amended and Restated 2015 Plan.

Shares subject to an award under the Amended and Restated 2015 Plan or the 2019 Plan may not be made available for issuance under the Amended and Restated 2015 Plan if such shares are: (i) shares that were subject to a share-settled SAR and were not issued upon the net settlement or net exercise of such SAR, (ii) shares used to pay the exercise price of an option, (iii) shares delivered or withheld by us to pay withholding taxes related to an award under the Amended and Restated 2015 Plan or the 2019 Plan, or (iv) shares repurchased on the open market with the proceeds of an option exercise.

The Share Reserve shall not be reduced by (i) the number of shares subject to substitute awards (defined as an award granted under this Amended and Restated 2015 Plan upon the assumption of, or in substitution for, outstanding equity awards previously granted by a company or other entity in connection with a corporate transaction), or (ii) available shares under a stockholder approved plan of the company or other entity which was a party to a corporate transaction with the Company (as appropriately adjusted to reflect such corporate transaction) which become subject to awards granted under the Amended and Restated 2015 Plan (subject to applicable stock exchange requirements).

All of our officers, employees, non-employee directors, consultants, agents, and independent contractors are eligible to participate in the Amended and Restated 2015 Plan and may receive all types of awards other than incentive stock options. Incentive stock options may be granted under the Amended and Restated 2015 Plan only to our employees (including officers) and employees of our subsidiaries. As of March 31, 2026, 5 officers, 64 employees, 7 non-employee directors, 0 consultants, 0 agents and 85 independent contractors were eligible for awards under the Amended and Restated 2015 Plan.

The Amended and Restated 2015 Plan is administered by a committee (the “Committee”) designated by the Board or a subcommittee thereof, consisting of two or more members of the Board, each of whom is intended to be (i) “Non-Employee Director” within the meaning of Rule 16b-3 under the Exchange Act, and (ii) “independent” within the meaning of the rules of the Nasdaq Stock Exchange of any other stock exchange on which shares are then traded. The Committee may delegate some or all of its power and authority hereunder to the Board or, subject to applicable law, to the Chief Executive Officer and President or such other executive officer as the Committee deems appropriate.

The Committee may determine the recipients, the form, amount and timing of each award to such recipients, the number of shares, exercise price or base price associated with the award, the time and conditions of exercise or settlement of the award and all other terms and conditions of the award, including, without limitation, the form of agreement evidencing the award. The Committee may, in its sole discretion and for any reason at any time, take action such that (i) any or all outstanding options and SARs shall become exercisable in part or in full, (ii) all or a portion of

the restriction period applicable to any outstanding restricted shares or restricted share units shall lapse, (iii) all or a portion of the performance period applicable to any outstanding award shall lapse and (iv) the performance measures (if any) applicable to any outstanding award shall be deemed to be satisfied at the target or any other level.

Under the Amended and Restated 2015 Plan, the Committee may not amend or replace any previously granted stock option or share appreciation right in a transaction that constitutes a repricing within the meaning of the rules of the Nasdaq Stock Exchange or any other stock exchange on which the shares are then traded, without the prior approval of the Company’s stockholders.

The Amended and Restated 2015 Plan provides that dividends or dividend equivalents may be paid or credited with respect to any shares of our common stock subject to an award (other than a stock option or share appreciation right), as determined by the Board and contained in the applicable award agreement; provided, however, that (i) no dividends or dividend equivalents may be paid with respect to any such shares before the date such shares have vested, (ii) any dividends or dividend equivalents that are credited with respect to any such shares will be subject to all of the terms and conditions applicable to such shares under the terms of the applicable award agreement (including any vesting conditions), and (iii) any dividends or dividend equivalents that are credited with respect to any such shares will be forfeited to us on the date such shares are forfeited to or repurchased by us due to a failure to vest.

Stock options may be granted under the Amended and Restated 2015 Plan pursuant to stock option agreements. The Amended and Restated 2015 Plan permits the grant of stock options that are intended to qualify as incentive stock options, or ISOs, and non-statutory stock options, or NSOs.

The exercise price of NSOs may not be less than 100% of the fair market value of the common stock subject to the stock option on the date of grant. The exercise price of ISOs may not be less than 100% of the fair market value of the common stock subject to the stock option on the date of grant and, in some cases (see “Limitations on Incentive Stock Options” below), may not be less than 110% of such fair market value.

Stock options granted under the Amended and Restated 2015 Plan may not be exercised later than ten years after the grant date and, in some cases (see “Limitations on Incentive Stock Options” below), may not exceed five years. All terms relating to the exercise, cancellation, or other disposition of an option or share appreciation right (i) upon a termination of employment with or service to the Company of the holder of such option or share appreciation right, whether by reason of disability, retirement, death, or any other reason, or (ii) during a paid or unpaid leave of absence, shall be determined by the Committee and set forth in the applicable award agreement.

Acceptable forms of consideration for the purchase of our common stock pursuant to the exercise of a stock option under the Amended and Restated 2015 Plan may include (i) cash, (ii) delivery (either actual delivery or by attestation procedures established by the Company) of shares having a fair market value, determined as of the date of exercise, equal to the aggregate purchase price payable by reason of such exercise, (iii) authorizing the Company to withhold whole shares which would otherwise be delivered having an aggregate fair market value, determined as of the date of exercise, equal to the amount necessary to satisfy such obligation, (iv) in cash by a broker-dealer acceptable to the company to whom the optionee has submitted an irrevocable notice of exercise, or (v) a combination of (i) through (iii).

Stock options granted under the Amended and Restated 2015 Plan may become exercisable in cumulative increments, or “vest,” as determined by the Committee at the rate specified in the stock option agreement. Shares covered by different stock options granted under the Amended and Restated 2015 Plan may be subject to different vesting schedules as the Committee may determine. The Committee also has flexibility to provide for accelerated vesting of stock options in certain events.

Generally, an optionee may not transfer a stock option other than by will or the laws of descent and distribution or pursuant to beneficiary designation procedures approved by the Company or, to the extent expressly permitted in the option agreement, to a family member or a trust or entity established by the holder for estate planning purposes or a charitable organization designated by the holder, in each case, without consideration.

The aggregate fair market value, determined at the time of grant, of shares of our common stock with respect to ISOs that are exercisable for the first time by an optionee during any calendar year may not exceed $100,000. The stock options or portions of stock options that exceed this limit or otherwise fail to qualify as ISOs are treated as NSOs. No ISO may be granted to any person who, at the time of grant, owns or is deemed to own stock possessing more than 10% of our total combined voting power or that of any affiliate unless the following conditions are satisfied:

Subject to adjustment for certain changes in our capitalization, the aggregate maximum number of shares of our common stock that may be issued pursuant to the exercise of ISOs granted under the Amended and Restated 2015 Plan is 25,000,000 shares.

Restricted share awards may be granted under the Amended and Restated 2015 Plan pursuant to restricted share award agreements. Shares of our common stock acquired under a restricted share award may be subject to forfeiture to or repurchase by us in accordance with a vesting schedule, which may include performance measures, to be determined by the Committee. Rights to acquire shares of our common stock under a restricted share award may be transferred only upon such terms and conditions as are set forth in the restricted share award agreement. Any dividends paid on restricted shares will be subject to the same vesting conditions as apply to the shares subject to the restricted share award.

Restricted share unit awards may be granted under the Amended and Restated 2015 Plan pursuant to restricted share unit award agreements. A restricted share unit award may be settled by the delivery of shares of our common stock, in cash, in a combination thereof. Restricted share unit awards may be subject to vesting in accordance with a vesting schedule, subject to the holder’s continuous employment or service with the Company during a specified period, or the satisfaction of specified performance measures during a performance period. The award agreement shall specify whether the holder is entitled to receive, on a current or deferred basis, dividend equivalents, provided that any additional shares credited by reason of such dividend equivalents will be subject to all of the same terms and conditions of the underlying restricted share unit award.

Share appreciation rights may be granted under the Amended and Restated 2015 Plan pursuant to share appreciation right agreements. Each share appreciation right is denominated in common stock share equivalents. The strike price of each share appreciation right will be determined by the Committee, but will in no event be less than 100% of the fair market value of the common stock subject to the share appreciation right on the date of grant (unless in the award is a “Substitute Award”). The Committee may also impose restrictions or conditions upon the vesting of share appreciation rights that it deems appropriate.

The Amended and Restated 2015 Plan allows us to grant performance unit awards. Performance unit awards may be granted, vest or be exercised based upon the attainment during a specified period of time of specified performance goals. The length of any performance period, the performance goals to be achieved during the performance period, and the measure of whether and to what degree such performance goals have been attained will be determined by the Committee.

In granting a performance award, the Committee will set a period of time, or a performance period, over which the performance measures should be attained. The criteria or objectives that comprise the performance measures may be expressed on an absolute or relative basis and may include comparisons based on current internal targets, the past performance of the Company (including the performance of one or more subsidiaries, divisions, or operating units) or the past or current performance of other companies (or a combination of such past and current performance). In addition to the ratios specifically enumerated above, performance goals may include comparisons relating to capital (including,

but not limited to, the cost of capital), shareholders’ equity, shares outstanding, assets or net assets, sales, or any combination thereof. The applicable performance measures may be applied on a pre-or post-tax basis. The performance goals may consist of any objective or subjective corporate-wide or subsidiary, division, operating unit or individual measures, whether or not listed in this Proposal No. 4. Performance goals shall be subject to such other special rules and conditions as the Committee may establish at any time.

The Committee has the discretion to grant Bonus Share Awards, which shall not be subject to any vesting conditions or performance measures. Upon the grant of a Bonus Share Award, subject to the Company’s right to require payment of any taxes in accordance with Section 5.5 of the Amended and Restated 2015 Plan, a certificate or certificates evidencing ownership of the requisite number of shares shall be delivered to the holder of such award.

Stock awards granted under the Amended and Restated 2015 Plan will be subject to recoupment in accordance with the Company’s current clawback policy, as well as any clawback policy we adopt pursuant to applicable law and listing requirements. In addition, our Board may impose such other clawback, recovery or recoupment provisions in any stock award agreement as it determines necessary or appropriate.

In the event of any equity restructuring that causes the per share value of the shares to change after the effectiveness of an initial public offering, such as a stock dividend, stock split, spinoff, rights offering or recapitalization through an extraordinary dividend, the number and class of securities available under the Amended and Restated 2015 Plan, the terms of each outstanding option and share appreciation right, the terms of each outstanding restricted share award and restricted share unit award, and the terms of each performance unit award shall be appropriately adjusted by the Committee, such adjustments to be made in the case of outstanding options and share appreciation rights without an increase in the aggregate purchase price or base price and in accordance with Section 409A of the Code.

In the event of a change in control (as defined in the Amended and Restated 2015 Plan and described below), our Board will have the discretion to take one or more of the following actions with respect to outstanding stock awards:

For purposes of the Amended and Restated 2015 Plan, a “change in control” generally means any one of the following events:

In no event shall a change in control include the initial public offering or any bona fide primary or secondary public offering following the occurrence of the initial public offering.

Our Board will have the authority to amend or terminate the Amended and Restated 2015 Plan at any time. However, except as otherwise provided in the Amended and Restated 2015 Plan, no amendment or termination of the Amended and Restated 2015 Plan may materially impair any rights under awards already granted to a participant unless agreed to by the affected participant. We will obtain shareholder approval of any amendment to the Amended and Restated 2015 Plan as required by applicable law and listing requirements. No ISOs may be granted under the Amended and Restated 2015 Plan after the tenth anniversary of the earlier of (i) the date the Amended and Restated 2015 Plan was adopted by our Board of Directors or (ii) the date that the Amended and Restated 2015 Plan is approved by our shareholders.

The information set forth below is a summary only and does not purport to be complete. The information is based upon current federal income tax rules and therefore is subject to change when those rules change. Because the tax consequences to any recipient may depend on his or her particular situation, each recipient should consult the recipient’s tax adviser regarding the federal, state, local, and other tax consequences of the grant or exercise of an award or the disposition of stock acquired as a result of an award. The Amended and Restated 2015 Plan is not qualified under the

provisions of Section 401(a) of the Code and is not subject to any of the provisions of the Employee Retirement Income Security Act of 1974. Our ability to realize the benefit of any tax deductions described below depends on our generation of taxable income as well as the requirement of reasonableness, the provisions of Section 162(m) of the Code, and the satisfaction of our tax reporting obligations.

Generally, there is no taxation upon the grant of an NSO if the stock option is granted with an exercise price equal to the fair market value of the underlying stock on the grant date. On exercise, an optionee will recognize ordinary income equal to the excess, if any, of the fair market value on the date of exercise of the stock over the exercise price. If the optionee is employed by us or one of our affiliates, that income will be subject to withholding taxes. The optionee’s tax basis in those shares will be equal to their fair market value on the date of exercise of the stock option, and the optionee’s capital gain holding period for those shares will begin on that date.

Subject to the requirement of reasonableness, the provisions of Section 162(m) of the Code, and the satisfaction of a tax reporting obligation, we will generally be entitled to a tax deduction equal to the taxable ordinary income realized by the optionee.

The Amended and Restated 2015 Plan provides for the grant of stock options that qualify as “incentive stock options,” as defined in Section 422 of the Code. Under the Code, an optionee generally is not subject to ordinary income tax upon the grant or exercise of an ISO. If the optionee holds a share received on exercise of an ISO for more than two years from the date the stock option was granted and more than one year from the date the stock option was exercised, which is referred to as the required holding period, the difference, if any, between the amount realized on a sale or other taxable disposition of that share and the holder’s tax basis in that share will be long-term capital gain or loss.

If, however, an optionee disposes of a share acquired on exercise of an ISO before the end of the required holding period, which is referred to as a disqualifying disposition, the optionee generally will recognize ordinary income in the year of the disqualifying disposition equal to the excess, if any, of the fair market value of the share on the date the ISO was exercised over the exercise price. However, if the sales proceeds are less than the fair market value of the share on the date of exercise of the stock option, the amount of ordinary income recognized by the optionee will not exceed the gain, if any, realized on the sale. If the amount realized on a disqualifying disposition exceeds the fair market value of the share on the date of exercise of the stock option, that excess will be short-term or long-term capital gain, depending on whether the holding period for the share exceeds one year.

For purposes of the alternative minimum tax, the amount by which the fair market value of a share of stock acquired on exercise of an ISO exceeds the exercise price of that stock option generally will be an adjustment included in the optionee’s alternative minimum taxable income for the year in which the stock option is exercised. If, however, there is a disqualifying disposition of the share in the year in which the stock option is exercised, there will be no adjustment for alternative minimum tax purposes with respect to that share. In computing alternative minimum taxable income, the tax basis of a share acquired on exercise of an ISO is increased by the amount of the adjustment taken into account with respect to that share for alternative minimum tax purposes in the year the stock option is exercised.

We are not allowed an income tax deduction with respect to the grant or exercise of an ISO or the disposition of a share acquired on exercise of an ISO after the required holding period. If there is a disqualifying disposition of a share, however, we are allowed a deduction in an amount equal to the ordinary income includible in income by the optionee, subject to Section 162(m) of the Code and provided that amount constitutes an ordinary and necessary business expense for us and is reasonable in amount, and either the employee includes that amount in income or we timely satisfy our reporting requirements with respect to that amount.

Generally, the recipient of a restricted share award will recognize ordinary income at the time the stock is received equal to the excess, if any, of the fair market value of the stock received over any amount paid by the recipient in exchange for the stock. If, however, the stock is not vested when it is received (for example, if the employee is required to work for a period of time in order to have the right to sell the stock), the recipient generally will not recognize income until the stock becomes vested, at which time the recipient will recognize ordinary income equal to the excess, if any, of the fair market value of the stock on the date it becomes vested over any amount paid by the recipient in exchange for

the stock. A recipient may, however, file an election with the Internal Revenue Service, within 30 days following his or her receipt of the stock award, to recognize ordinary income, as of the date the recipient receives the award, equal to the excess, if any, of the fair market value of the stock on the date the award is granted over any amount paid by the recipient for the stock.

The recipient’s basis for the determination of gain or loss upon the subsequent disposition of shares acquired from stock awards will be the amount paid for such shares plus any ordinary income recognized either when the stock is received or when the stock becomes vested.

Subject to the requirement of reasonableness, the provisions of Section 162(m) of the Code, and the satisfaction of a tax reporting obligation, we will generally be entitled to a tax deduction equal to the taxable ordinary income realized by the recipient of the stock award.

Generally, the recipient of a stock unit structured to conform to the requirements of Section 409A of the Code or an exception to Section 409A of the Code will recognize ordinary income at the time the stock is delivered equal to the excess, if any, of the fair market value of the shares of our common stock received over any amount paid by the recipient in exchange for the shares of our common stock. To conform to the requirements of Section 409A of the Code, the shares of our common stock subject to a stock unit award may generally only be delivered upon one of the following events: a fixed calendar date (or dates), separation from service, death, disability or a change in control. If delivery occurs on another date, unless the stock units otherwise comply with or qualify for an exception to the requirements of Section 409A of the Code, in addition to the tax treatment described above, the recipient will owe an additional 20% federal tax and interest on any taxes owed.

The recipient’s basis for the determination of gain or loss upon the subsequent disposition of shares acquired from stock units will be the amount paid for such shares plus any ordinary income recognized when the stock is delivered. Subject to the requirement of reasonableness, the provisions of Section 162(m) of the Code, and the satisfaction of a tax reporting obligation, we will generally be entitled to a tax deduction equal to the taxable ordinary income realized by the recipient of the stock award.

We may grant under the Amended and Restated 2015 Plan share appreciation rights separate from any other award or in tandem with other awards under the Amended and Restated 2015 Plan.

Where the share appreciation rights are granted with a strike price equal to the fair market value of the underlying stock on the grant date, the recipient will recognize ordinary income equal to the fair market value of the stock or cash received upon such exercise. Subject to the requirement of reasonableness, the provisions of Section 162(m) of the Code, and the satisfaction of a tax reporting obligation, we will generally be entitled to a tax deduction equal to the taxable ordinary income realized by the recipient of the share appreciation right.

Compensation of persons who are “covered employees” of the Company is subject to the tax deduction limits of Section 162(m) of the Code. The exemption from Section 162(m)’s deduction limit for performance-based compensation has been repealed, effective for taxable years beginning after December 31, 2017, such that compensation paid to our covered employees in excess of $1 million will not be deductible unless it qualifies for transition relief applicable to certain arrangements in place as of November 2, 2017 and which is not modified in any material respect on or after such date.

Except as described in this paragraph with respect to our non-employee directors, the Company cannot currently determine the benefits or number of shares subject to awards that may be granted in the future to executive officers, directors, and employees under the Amended and Restated 2015 Plan. We do not presently have any current plans, proposals or arrangements, written or otherwise, to issue any of the newly available authorized shares under the Amended and Restated 2015 Plan. Our non-employee directors are, however, entitled to receive automatic annual awards of 38,000 stock options each under our director compensation program, as described below under “Director Compensation.” As a result, we

anticipate an aggregate of 266,000 stock options will be granted on the date of the Annual Meeting to our non-employee directors pursuant to the fiscal year 2026 non-employee director compensation program will be granted under the Amended and Restated 2015 Plan, assuming approval of this Proposal No. 4.

The following table sets forth, for each of the individuals and various groups indicated, the total number of shares of our common stock subject to equity awards that have been granted under the Amended and Restated 2015 Plan since its inception through March 31, 2026.

Approval of Proposal No. 4: The affirmative vote of a majority of the votes cast either online or by proxy at the annual meeting and that are entitled to vote on the proposal will be required to approve the amendment to our Amended and Restated Plan, with votes cast including votes “Against” and excluding abstentions and broker non-votes. Brokers are not authorized to vote on this proposal without instruction from the beneficial owners. Abstentions and broker non-votes will have no effect on this proposal. If this Proposal 4 is approved by our shareholders, the amendment to increase shares under our Amended and Restated 2015 Plan will become effective as of the date of the Annual Meeting.

THE BOARD OF DIRECTORS RECOMMENDS THAT STOCKHOLDERS VOTE “FOR” THE RESOLUTION TO APPROVE THE AMENDMENT TO OUR AMENDED AND RESTATED 2015 EQUITY INCENTIVE PLAN.

We are asking our stockholders to approve an amendment to our Amended and Restated Employee Stock Purchase Plan (the “ESPP”) to increase the number of shares authorized for issuance thereunder by 1,000,000 shares, thereby increasing the aggregate number of shares reserved for issuance under the ESPP from 2,370,046 shares to 3,370,546 shares. Our Board, upon recommendation of our Compensation Committee, approved the amendment in March 2026, subject to stockholder approval.

As of March 31, 2026, 348,824 shares of our common stock remained available for issuance under the ESPP. The proposed increase in the number of shares available for issuance under the ESPP by 1,000,000 shares represents approximately 0.46% of our outstanding common stock as of March 31, 2026. The ESPP serves as an important component of our employee compensation program, as it helps to attract and retain employees by providing eligible employees with the opportunity to become Company stockholders at favorable prices and participate in the Company’s success, aligning the interests of participating employees with those of stockholders. The Board believes the continuation of a robust ESPP program positively impacts our ability to attract and retain talent and promote stock ownership by employees.

If this Proposal No. 5 is approved by our stockholders, the increase in the number of shares available for issuance under our ESPP will become effective as of the date of the Annual Meeting. If this Proposal No. 5 is not approved by our stockholders, the amendment will not become effective and the ESPP will continue in effect without the increase in the number of shares available for issuance.

The full text of the proposed amendment is attached to this Proxy Statement as Appendix C.

In determining the number of shares of common stock to request for approval to reserve for issuance under the amended ESPP, a number of factors were considered, including the following:

In light of the factors described above, and the fact that the ability to continue to offer an employee stock purchase plan is vital in our view to our ability to continue to attract and retain employees in the extremely competitive labor markets in which we compete, our Board has determined that the size of the share reserve under the ESPP is reasonable and appropriate at this time.

The ESPP was initially adopted by the Board on September 17, 2015, and approved by our stockholders on October 2, 2015. The Board approved an amendment and restatement of the ESPP on June 11, 2025 and most recently approved the amendment to the ESPP on March 18, 2026.

The following summary describes the material terms of the ESPP, as amended. This summary of the ESPP is not a complete description of all provisions of the ESPP and is qualified in its entirety by reference to the ESPP, as amended, which is attached hereto as Appendix C. Stockholders are encouraged to read the ESPP in its entirety.

The ESPP is intended to provide eligible employees of the Company and its participating subsidiaries with an opportunity to acquire shares of our common stock at a price below their market value and to pay for the purchases

through payroll deductions, thereby enabling the Company to attract, retain and motivate valued employees. The ESPP is intended to qualify for favorable tax treatment as an “employee stock purchase plan” under Section 423 of the Internal Revenue Code.

If this Proposal No. 5 is approved by our stockholders, subject to adjustment upon changes in capitalization of the Company, the maximum aggregate number of shares reserved for issuance under the ESPP will be increased by 1,000,000 shares to an aggregate of be 3,370,546 shares.

The Compensation Committee serves as the primary administrator of the ESPP (the “ESPP Administrator”).

The ESPP Administrator will have the discretionary authority to determine the time and frequency of granting options under the ESPP, as well as the terms and conditions and the number of shares subject to each option, and to do everything necessary and appropriate to administer the ESPP, including, without limitation, interpreting the provisions of the ESPP (but any such interpretation shall not be inconsistent with provisions of Section 423 of the Code). All determinations and decisions by the ESPP Administrator regarding the ESPP will be final and binding on all participants. The ESPP shall be administered so as to ensure that all participants in the ESPP have the same rights and privileges. The ESPP Administrator may adopt rules or procedures relating to the operation and administration of the ESPP to accommodate the specific requirements of local laws and procedures.

All full and part-time employees of the Company and its participating subsidiaries are eligible to participate in the ESPP. However, no employee is eligible to participate in the ESPP if, immediately after electing to participate, the employee would own stock of the Company (including stock such employee may purchase under outstanding options) representing 5% or more of the total combined voting power or value of all classes of stock of the Company. In addition, no employee is permitted to continue to participate under the ESPP, in any calendar year if their purchase rights would exceed $25,000 of the fair market value of such stock (determined at the time the right is granted) for that calendar year. The ESPP Administrator may, for offering periods that have not yet commenced, establish additional eligibility requirements, provided that they are consistent with Section 423 of the Internal Revenue Code.

Under the ESPP, each calendar year is divided into two six-month offering periods” commencing January 1 and July 1 of each year (or such other period designated by the ESPP Administrator, provided that in no event shall an offering period exceed twenty-seven (27) months). At the end of each such period, the Company will apply the amount contributed by the participant during that period to purchase shares of common stock for him or her. The purchase price will be equal to 85% of the lower of (a) the market price of common stock on the first business day of the applicable offering period or (b) the market price of common stock on the last business day of the offering period. No participant may purchase more than 6,000 shares in any one purchase period.

As of March 31, 2026, approximately 69 employees will be eligible to participate in the ESPP and the closing price for our common stock was $4.7.

Eligible employees become participants in the ESPP by completing an election form authorizing payroll deductions and filing it with our stock administrator before the first day of the applicable offering period. The payroll deductions made for each participant may not be less than 1% and not more than 15% of the participant’s cash compensation (which shall mean solely the participant’s base pay), and may not exceed such percentage of the participant’s cash compensation as the participant designates. Payroll deductions commence with the first paycheck issued during the offering period and are deducted from subsequent paychecks throughout the offering period unless terminated as provided in the ESPP.

During the offering period, payroll deduction authorizations may not be increased or decreased, although a participant may change his or her payroll deduction for any subsequent offering period by properly completing and submitting an election change form in accordance with the procedures prescribed by the ESPP Administrator and a participant’s payroll contributions may be decreased to zero percent (0%) at any time during an offering period, to the extent necessary to comply with Section 3(b) of the ESPP (as described above) and Section 423(b)(8) of the Code.

On the first day of each offering period, each participant automatically will be granted an option to acquire on the next following exercise date a number of full shares of common stock of the Company, determined by dividing the participant’s payroll deductions accumulated prior to such exercise date divided by the applicable purchase price. However, a participant cannot accrue rights to purchase more than $25,000 (or any other maximum that may be prescribed by the Code) in fair market value of stock for each calendar year in which an option is outstanding. All participants granted options under the ESPP will have the same rights and privileges consistent with the requirements set forth in Section 423 of the Code.

The purchase price of shares of our common stock acquired pursuant to enrolment in the ESPP will be 85% of the lower closing stock price on either the first or last business day (defined as the day on which the NASDAQ is open for trading) of the offering period.

On the applicable exercise date, each participant will be deemed to have exercised his or her option and the accumulated payroll deductions in the participant’s account will be applied to purchase the greatest number of whole shares of our common stock (rounded down to the nearest whole share) that can be purchased with such account balance at the applicable purchase price, which will be placed, in book-entry form, into a record keeping account in the name of the participant. However, no more than 6,000 shares of common stock may be purchased by a participant on any exercise date, or such lesser number as the ESPP Administrator may prescribe in accordance with Section 423 of the Code.

Any payroll deductions accumulated in a participant’s account that are not sufficient to purchase a full share will be retained in the participant’s account for the subsequent option period (subject to earlier withdrawal in accordance with the terms of the ESPP). Any other amounts of payroll deductions in a participant’s account that are not used for the purchase of shares of stock, whether because of the participant’s withdrawal, because the amount would enable the participant to purchase more than the 6,000 share maximum or for any other reason, will be returned to the participant, without interest, as soon as administratively practicable after such withdrawal, exercise date or other event, as applicable.

Participants may withdraw from the ESPP by properly completing and submitting to the Company a withdrawal form in accordance with the procedures prescribed by the ESPP Administrator, which must be submitted before the last date of the applicable offering period. As soon as practicable after withdrawal, payroll deductions cease and all amounts credited to the participant’s account are refunded in cash, without interest. A participant who has withdrawn from the ESPP cannot be a participant in future offering periods unless he or she re-enrolls pursuant to the ESPP’s guidelines.

On the date that a participant’s employment terminates or the participant ceases to provide services to the Company or any participating subsidiary (which does not include any period following that date which the participant may be eligible for or in receipt of other payments from the Company including in lieu of notice or termination or severance pay or as wrongful dismissal damages) for any reason prior to an exercise date, the payroll deductions in the participant’s purchase account will be returned to him or her (or his or her beneficiary, in the case of the participant’s death) and his or her option will be automatically terminated. A participant may designate in writing a beneficiary who is to receive shares and cash in the event of the participant’s death subsequent to the purchase of shares, but prior to delivery. A participant may also designate a beneficiary to receive cash in his or her account in the event of such participant’s death prior to the last day of the offering period. Any other attempted assignment, except by will, and the laws of descent and distribution, may be treated as a withdrawal.

In the event of any change in our outstanding common stock by reason of a stock dividend, split-up, recapitalization, merger, consolidation, reorganization, or other capital change, the aggregate number and type of shares of stock available under the ESPP, the number and type of shares of stock granted under any outstanding options, the maximum number and type of shares of stock purchasable under any outstanding option, and the purchase price per

share of stock under any outstanding option will be appropriately adjusted, provided that the ESPP Administrator is satisfied that such adjustment will not constitute a modification of the rights granted under the ESPP or otherwise disqualify the ESPP as an employee stock purchase plan under the provisions of Section 423 of the Code.

In the event of a proposed sale of all or substantially all of the assets of the Company, or the merger of the Company with or into another corporation, the successor corporation will be deemed to assume the ESPP, or provide an equivalent substitute, unless the Board determines, in the exercise of its sole discretion, that in lieu of such assumption or substitution to either terminate the ESPP and return to each participant the payroll deductions credited to such participant or to provide for the applicable offering period in progress to end on a date prior to the consummation of such sale or merger.

The Board or ESPP Administrator may at any time and for any reason amend, modify, suspend, discontinue, or terminate the ESPP to any extent and in any manner it may deem advisable, subject to applicable laws, and provided, that no participant’s existing rights are adversely affected thereby. Stockholder approval shall be obtained, to the extent necessary to comply with Section 423 of the Code (or any other applicable law, regulation or stock exchange rule).

The number of shares that may be purchased under the ESPP will depend on each employee’s voluntary election to participate, the rate of contributions by such employees and the purchase price of the shares issuable under the ESPP at future dates. Accordingly, it is not possible to determine the value of the future benefits which may be received by participants under the ESPP.

Pursuant to SEC rules, the following table sets forth, with respect to the groups named below, the number of shares of our common stock that were purchased under ESPP from its inception through March 31, 2026.

The following is a brief description of the federal income tax treatment that will generally apply to the grant and exercise of rights under the ESPP, based on federal income tax laws currently in effect. The exact federal income tax treatment of options will depend on the specific nature of any such option and the individual tax attributes of the participant. The following summary is not intended to be exhaustive and, among other considerations, does not describe gift, estate, social security, state, local or international tax consequences.

The ESPP is intended to qualify as an “employee stock purchase plan” under Section 423 of the Internal Revenue Code for participants who are subject to U.S. income taxation. If the applicable holding period requirements are met, a participant does not recognize any taxable income at the time shares are purchased under the ESPP. Instead, taxable income is recognized by the participant when the shares purchased under the ESPP are sold or otherwise disposed of. Upon a sale or other disposition of the shares, the participant generally will be subject to tax in an amount that depends on how long the participant held the shares. If the shares are sold or otherwise disposed of at least 2 years from the first day of the applicable offering period and 1 year from the date of purchase, the participant will recognize ordinary income equal to the lesser of the excess of the fair market value of the shares at the time of such sale or disposition over the purchase price of the shares, or 15% of the fair market value of the shares on the first day of the offering period. Any additional gain will be treated as long-term capital gain. If the shares are sold or otherwise disposed of before the expiration of either of these holding periods, the participant will recognize ordinary income equal to the excess of the fair market value of the shares on the date the shares are purchased over the purchase price. Any additional gain or loss on such sale or disposition will be long-term or short-term capital gain or loss, depending on how long the shares have been held from the date of purchase.

The Company generally is not entitled to a deduction for amounts taxed as ordinary income or capital gain to a participant, except to the extent of ordinary income recognized by the participant upon a sale or disposition of shares prior to the expiration of the holding periods described above.

Approval of Proposal No. 5: The affirmative vote of a majority of the votes cast either online or by proxy at the annual meeting and that are entitled to vote on the proposal will be required to approve the amendment to our Amended and Restated Employee Stock Purchase Plan, with votes cast including votes “Against” and excluding abstentions and broker non-votes. Thus, the number of votes “FOR” must exceed the number of votes “AGAINST” for this proposal to pass. Brokers are not authorized to vote on this proposal without instruction from the beneficial owners. Abstentions and broker non-votes will have no effect on this proposal. If this Proposal 5 is approved by our shareholders, the amendment increasing the shares reserved for issuance under our Amended and Restated Employee Stock Purchase Plan will become effective as of the date of the Annual Meeting.

THE BOARD OF DIRECTORS RECOMMENDS THAT STOCKHOLDERS VOTE “FOR” THE RESOLUTION TO AMEND OUR AMENDED AND RESTATED EMPLOYEE STOCK PURCHASE PLAN.

The Dodd-Frank Wall Street Reform and Consumer Protection Act of 2010 (the “Dodd-Frank Act”) enables our stockholders to vote to approve, on an advisory, non-binding basis, the compensation of our named executive officers as disclosed in this Proxy Statement in accordance with the SEC’s rules, commonly known as a “Say-on-Pay” vote. Accordingly, we are seeking a non-binding, advisory vote to approve the compensation of our named executive officers as described in the “Executive Compensation” section of this Proxy Statement and the compensation tables and accompanying narrative disclosures that follow. At our 2025 annual meeting of stockholders, approximately 80% of the votes cast approved, on an advisory basis, the compensation of our named executive officers.

Our Compensation Committee and the Board believe that the information provided in the “Executive Compensation” section of this Proxy Statement, compensation tables and accompanying narrative disclosures demonstrates that our executive compensation program is designed appropriately, emphasizes pay for performance and aligns management’s interests with our stockholders’ interests to support long-term value creation.

Accordingly, our Board recommends that stockholders vote “FOR” the following resolution:

While the vote on this resolution is advisory and not binding on us, the Compensation Committee, or our Board, the Compensation Committee and our Board values thoughtful input from stockholders and will consider the outcome of the vote on this resolution when considering future executive compensation decisions. Our Board has adopted a policy of providing for annual advisory votes from stockholders on executive compensation. Unless our Board modifies its policy on the frequency of future Say-on-Pay advisory votes, the next Say-on-Pay advisory vote will be held at the 2027 annual meeting of stockholders.

THE BOARD OF DIRECTORS RECOMMENDS THAT STOCKHOLDERS VOTE, ON A NON-BINDING ADVISORY BASIS, “FOR” THE RESOLUTION TO APPROVE THE COMPENSATION OF OUR NAMED EXECUTIVE OFFICERS.

The Dodd-Frank Act enables our stockholders to indicate how frequently they believe we should seek a non-binding advisory vote from stockholders to approve the compensation of our named executive officers. We are providing our stockholders with the choice of selecting a frequency of 1 year, 2 years or 3 years or abstaining from this advisory vote. The Board is also seeking an advisory “Say-on-Pay” vote from stockholders at the 2026 annual meeting of stockholders and expects to seek such vote every year. We believe that this frequency is appropriate because it will enable our stockholders to vote, on an advisory basis, on the most recent executive compensation information that is presented in each of our proxy statements, leading to a more meaningful and coherent communication between the Company and our stockholders on the compensation of our named executive officers. The Board’s current plan is further based on the premise that this recommendation could be modified if it becomes apparent that an annual frequency vote is not meaningful, is burdensome or is more frequent than indicated by best corporate governance practices.

Based on these factors, the Board recommends that future advisory votes by stockholders on named executive officer compensation occur every year, until the next advisory vote on the frequency of future “Say-on-Pay” votes.

Stockholders are not being asked to approve or disapprove the Board’s recommendation, but rather to indicate their choice among the following frequency options: one year, two years or three years, or to abstain from voting on this item. If none of the frequency alternatives - one year, two years or three years - receives a majority of the votes cast, we will consider the highest number of votes cast by stockholders to be the frequency that has been selected by stockholders.

Accordingly, we are asking stockholders to approve the following non-binding advisory resolution at the annual meeting:

The vote on this resolution is advisory, and therefore not binding on the Company, the Board or its Compensation Committee. The Board may decide that it is in the best interests of the Company and its stockholders to hold future advisory “Say-on-Pay” votes more or less frequently than the frequency indicated by stockholders in voting on this proposal.

THE BOARD OF DIRECTORS RECOMMENDS THAT STOCKHOLDERS APPROVE, IN A NON-BINDING ADVISORY VOTE, THAT FUTURE ADVISORY VOTES BY STOCKHOLDERS TO APPROVE THE COMPENSATION OF OUR NAMED EXECUTIVE OFFICERS BE REQUESTED EVERY “1 YEAR”.

The following table sets forth certain information regarding the ownership of our common stock as of March 31, 2026, by: (i) each of our directors; (ii) each of our named executive officers; (iii) all of our executive officers and directors as a group; and (iv) all those known by us to be beneficial owners of more than 5% of our common stock. On March 31, 2026, there were 217,693,878 shares of common stock outstanding and entitled to vote. Unless otherwise indicated below, the address for each beneficial owner listed is c/o CytomX Therapeutics, Inc., at 151 Oyster Point Boulevard, Suite 400, South San Francisco, California.

Section 16(a) of the Exchange Act requires that our Section 16 officers and directors, and persons who own more than 10% of a registered class of our equity securities, file reports of ownership and changes in ownership (Forms 3, 4, and 5) with the SEC. Such officers, directors, and greater-than-10% beneficial owners are required to furnish us with copies of all of these forms that they file.

Based solely on our review of the Section 16(a) reports that have been filed by or on behalf of our officers, directors, and persons who own more than 10% of a registered class of our equity securities, and on written representations from our officers and directors, we believe that all such persons complied on a timely basis with all Section 16(a) filing requirements during the year ended December 31, 2025, except Ms. Lester’s due to administrative delay.

We have adopted a written related party transactions policy, which sets forth the policies and procedures for the review and approval or ratification of related party transactions. The policy covers, with certain exceptions set forth in Item 404 of Regulation S-K promulgated under the Exchange Act, any transaction, arrangement or relationship, or any series of similar transactions, arrangements or relationships, in which we were or are to be a participant, where the amount involved exceeds the lesser of $120,000 or one percent of the average of our total assets at year-end for the last two completed years, and a related party had, has or will have a direct or indirect material interest, including indebtedness, guarantees of indebtedness and employment by us of a related party.

A related party transaction reviewed under the policy will be considered approved or ratified if it is authorized by the Audit Committee of our Board or the chairperson of the Audit Committee in accordance with the standards set forth in the policy after full disclosure of the related party’s interests in the transaction. As appropriate for the circumstances, the Audit Committee or the chairperson of the Audit Committee, as applicable, shall review and consider:

Since January 1, 2024, we have followed all policies and procedures in reviewing, approving and ratifying related person transactions.

We describe below transactions and series of similar transactions since January 1, 2025, to which we were a party or will be a party, in which (i) the amounts involved exceeded or will exceed $120,000 and (ii) any of our directors, executive officers, holders of more than 5% of our capital stock or any member of their immediate family had or will have a direct or indirect material interest, other than compensation arrangements with directors and executive officers, which are described where required in the sections titled “Director Compensation” and “Executive Compensation,” respectively, in this Proxy Statement.

We have entered employment-related agreements with our executive officers. See section titled “Executive Compensation,” in this Proxy Statement for more information regarding each of these agreements and compensation of our directors and executive officers.

We have entered into indemnification agreements with each of our directors and executive officers. These agreements, among other things, require us or will require us to indemnify each director and executive officer to the fullest extent permitted by Delaware law, including indemnification of expenses such as attorneys’ fees, judgments, fines and settlement amounts incurred by the director or executive officer in any action or proceeding, including any action or proceeding by or in right of us, arising out of the person’s services as a director or executive officer.

The following sets forth information about our directors as of March 31, 2026.

The following are brief biographies of our current directors whose current term of office continues through the 2026 Annual Meeting of Stockholders. Biographies of our two current directors who are being nominated to a new term of office at the 2026 Annual Meeting of Stockholders are included above under “Proposal No. 1 Election of Directors.”

Dr. McCarthy joined CytomX in December 2010 as our Chief Business Officer and became a member of our Board, President and Chief Executive Officer in August 2011. In January 2019, Dr. McCarthy became Chairman of our Board of directors and currently serves as Chief Executive Officer and Chairman of our Board. Dr. McCarthy has more than twenty years of experience in the biotechnology industry encompassing roles in R&D, business development, financing and general management. Following completion of his post-doctoral training at the Schering Plough DNAX Research Institute, Dr. McCarthy held research leadership and program management roles at Millennium Pharmaceuticals where he managed biologics discovery programs. After Millennium, Dr. McCarthy joined SGX Pharmaceuticals, where he spearheaded a wide range of large pharma partnerships as vice president business development and helped drive a strategic reorientation of the company from a platform business model to product-focused oncology company, leading to completion of an initial public offering in 2006. Immediately prior to joining CytomX, Dr. McCarthy was a transactional partner at Pappas Ventures from April 2006 to December 2010, where he was responsible for investments in therapeutic, medical device and molecular diagnostic companies. Dr. McCarthy is an author on multiple peer reviewed scientific publications, issued patents and filed patent applications. He received a B.Sc. in biochemistry and pharmacology at King’s College, University of London; an MBA from the Rady School of Management at the University of California San Diego; and a D.Phil. in cancer biology from St. John’s College, University of Oxford. Dr. McCarthy currently serves as a member of the Dean’s Advisory Council at the UCSD Rady School of Management and was previously a member of the board of directors of OncoResponse. We believe Dr. McCarthy is qualified to serve on our Board based on his management experience in the life sciences sector, including at CytomX, his deep knowledge of the industry, and his strategic and business development expertise.

Dr. Mohindru has served as a member of our Board since December 2020. Since January 2026, Dr. Mohindru has served as the Chief Executive Officer of Cardiff Oncology, a publicly-traded clinical-stage oncology-focused biopharmaceutical company, where she has also served as a member of the board of directors since June 2021. Prior to that, Dr. Mohindru served as Chief Executive Officer and member of the board of directors at Novasenta, a privately-held drug discovery company that focuses on immunotherapy treatment for novel cancer targets, a position she held from April 2021 to March 2024. Previously, she served as the CEO of CereXis, Inc., a biopharmaceutical company focused on rare tumor indications, from December 2019 to October 2020. Prior to that, she served as chief financial officer and chief strategy officer at Cara Therapeutics, Inc., a publicly-traded biotechnology company, from August 2017 to December 2019. Between June 2013 and August 2017, she held various roles at Curis, Inc., a publicly-traded biopharmaceutical company, including as Vice President of Corporate Strategy & Investor Strategy and Chief Strategy Officer. Dr. Mohindru is also a member of the board of directors of Roshon Therapeutics, a privately-

held biopharmaceutical company, a position she has held since October 2024. She also previously served as a member of the board of directors of SAB Biotherapeutics, a publicly-traded clinical stage biopharmaceutical company. Prior to her leadership roles in the biotechnology industry, Dr. Mohindru spent many years as an equity research analyst covering the biotechnology sector at UBS, Credit Suisse and ThinkEquity. She also cofounded a privately-held biotechnology company and was a healthcare industry consultant. Dr. Mohindru received her Ph.D. in neurosciences from Northwestern University and her Masters in biotechnology and BS in human biology (Hons) from the All India Institute of Medical Sciences, New Delhi, India. We believe Dr. Mohindru is qualified to serve on our Board based on her substantial management experience in the life sciences industry and her background in biotechnology finance and corporate strategy.

Dr. Su joined our Board of Directors in March 2024. Currently, Dr. Su serves as the Chief Executive Officer of Marengo Therapeutics (“Marengo”) and member of its board of directors, having held both positions since July 2021. Prior to joining Marengo, Dr. Su served as Senior Vice President and Global Head of the Oncology Business Franchise for Merck KGaA (“Merck”) from March 2019 to July 2021 and concurrently as Merck’s US Head of its Oncology Business Unit between July 2020 and July 2021. Dr. Su served as Chief Medical Officer of EMD Serono, part of the larger Merck group, from October 2017 to May 2019. Dr. Su currently serves as a member of the board of directors at Karyopharm Therapeutics Inc., a publicly-traded biopharmaceutical company, a position he has held since August 2023. He previously served as a member of the board of directors at Galvanize Therapeutics, Inc., a privately held biopharmaceutical company, a position he held from July 2024 to July 2025. Before his career in the life sciences industry, Dr. Su served on the faculty of Duke University Medical School between 2001 and 2006, where he led early oncology clinical studies focusing on mRNA-based and cell-based immunotherapy, and then, between 2006 and 2009, served as the director of the Cell and Gene Therapy program at the University of Florida. Dr. Su received his Doctor of Medicine from Technical University of Dresden in Germany and his MBA from the University of Toronto in Canada. We believe Dr. Su is qualified to serve on our Board based on his substantial drug development and corporate strategy experience in the biotechnology industry complemented by his academic background in life sciences.

Biographical information included above under “Proposal No. 1 Election of Directors”

Biographical information included above under “Proposal No. 1 Election of Directors”

Mr. James R. Meyers has served as a member of our Board since December 2018. Currently, Mr. Meyers serves as the President and CEO of IntraBio, a privately-held biopharmaceutical company with a late-stage drug pipeline that develops treatments for genetic and neurodegenerative diseases, having been appointed to that position in November 2020. Mr. Meyers has served on the board of Sangamo Therapeutics, Inc., a publicly-traded biotechnology company, since December 2019, and previously served on the board of Arbutus Biopharma Corporation, also a publicly-traded biotechnology company, from October 2018 to February 2025. Prior to that, Mr. Meyers had served as a senior advisor to Gilead Sciences from February 2018 to December 2021. Prior to his advisory role, Mr. Meyers most recently served as Gilead’s Executive Vice President of worldwide commercial operations where he was responsible for all commercial activities including pricing and market access in North America, Europe, Middle East, Australia and Japan. Over his 22-year career at Gilead, Mr. Meyers led some of the most important and successful product launches in the history of the biopharmaceutical industry, most notably in the therapeutic areas of HCV and HIV. Prior to joining Gilead, Mr. Meyers held positions of increasing responsibility in sales, training, marketing and management with Zeneca Pharmaceuticals and Astra USA. In addition to the above, Mr. Meyers has also served on the board of directors of IntegriChain Corporation, a privately-held biopharmaceutical company, since March 2024, and Pulmocide, Ltd., a

privately-held biopharmaceutical company based in the United Kingdom, since September 2021. Mr. Meyers holds a B.S. in Economics from Boston College. We believe that Mr. Meyers is qualified to serve on our Board due to his worldwide commercial leadership experience within the biotechnology industry.

Ms. Halley Gilbert has served as a member of our Board since April 2020. Currently, Ms. Gilbert serves as the Chief Legal Officer and Chief Operating Officer of Tubulis GmbH, a biopharmaceutical company headquartered in Germany with offices in Cambridge Massachusetts, a position she has held since July 2025. Previously, Ms. Gilbert had served as Chief Legal Officer at CARGO Therapeutics, a publicly-traded biopharmaceutical company, a position she held from September 2023 to July 2025. Ms. Gilbert had previously served as the Chief Legal Officer of NeoGenomics Laboratories, a position she held from August 2021 to April 2022. Prior to her role at NeoGenomics Laboratories, Ms. Gilbert held the position of Chief Operating Officer of Adagio Therapeutics, Inc., from June 2020 to August 2021. Until February 2020, Ms. Gilbert held the position of Senior Vice President, Corporate Development and Chief Administrative Officer at Ironwood Pharmaceuticals, Inc. having joined the company in 2008 as Vice President and General Counsel. Prior to this, Ms. Gilbert served in several roles at Cubist Pharmaceuticals, Inc. (acquired by Merck), including as Vice President, Deputy General Counsel, Assistant Secretary and Assistant General Counsel from 2002 to 2007. From 1999 to 2002, Ms. Gilbert held the position of Corporate Counsel at Genzyme Corporation. Ms. Gilbert began her career at the law firm of Skadden, Arps, Slate, Meagher & Flom LLP, where, serving as a corporate associate from 1995 to 1998, she specialized in mergers and acquisitions and securities law. Ms. Gilbert has served on the board of Arcutis Biotherapeutics, Inc., a publicly-traded biopharmaceutical company, since April 2020, and on the board of Vaxcyte, Inc., a publicly-traded vaccine innovation company, since April 2020. Ms. Gilbert formerly served on the board of directors of Dermira, Inc. (acquired by Eli Lilly and Company) and Achaogen, Inc. Ms. Gilbert received a J.D. from Northwestern University School of Law and a B.A. from Tufts University. We believe that Ms. Gilbert is qualified to serve on our Board due to her broad knowledge of the life sciences industry and significant experience in business development, corporate strategy, law and compliance.

Dr. Alan Ashworth has served as a member of our Board since September 2021. He currently serves as the President of the Helen Diller Family Comprehensive Cancer Center at the University of California, San Francisco (UCSF), a position he has held since 2015. He also serves as the Senior Vice President for Cancer Services and a Professor of Medicine in Division of Hematology/Oncology, Department of Medicine at UCSF Health, position(s) he has held since 2015. Prior to joining UCSF, Dr. Ashworth was Chief Executive Officer of the Institute of Cancer Research, a position he held from 2011 to 2014, as well as serving as their Director of the Breakthrough Breast Cancer Center from 1999 to 2011 and Professor of Molecular Biology from 1997 to 2014. Since January 2025, Dr. Ashworth has served as a co-founder and member of the board of directors of Tiller Therapeutics, a privately-held biopharmaceutical corporation. He is an elected member of European Molecular Biology Organization, the Academy of Medical Sciences, and a Fellow of the Royal Society. Dr. Ashworth received his Ph.D. in biochemistry from University College London, U.K., and his B.Sc. in chemistry and biochemistry from Imperial College of Science and Technology, University of London, U.K. We believe that Dr. Ashworth is qualified to serve on our Board due to his deep medical experience and service on the boards of directors of several cancer centers.

The Board met 7 times during the fiscal year ended December 31, 2025. The Audit Committee of the Board met 4 times, the Compensation Committee of the Board met 5 times and the Nominating and Corporate Governance Committee of the Board met 2 times. Each member of the Board attended at least 75% of the aggregate number of meetings of our Board and of the committees on which they served, that were held during the period of the last fiscal year and during which they served on the Board or such committees.

Our Board has a policy of encouraging director attendance at our annual meetings of stockholders, but attendance is not mandatory. Our Board and management team encourage all of our directors to attend the virtual 2026 Annual Meeting of Stockholders. The majority of our directors attended the virtual 2025 Annual Meeting of Stockholders.

The Board has documented our governance practices in our corporate governance guidelines to assure that the Board will have 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 certain practices the Board will follow with respect to Board composition, Board committees, Board nomination, director qualifications and evaluation of the Board and committees. The corporate governance guidelines and the charter for each committee of the Board may be viewed at www.cytomx.com.

Our bylaws and corporate governance guidelines provide our Board with flexibility to combine or separate the positions of chairman of the Board and chief executive officer and/or the implementation of a lead director in accordance with its determination that utilizing one or the other structure would be in the best interests of the Company. The position of chief executive officer and chairman of the Board is currently held by Sean A. McCarthy, D. Phil. The Board also appointed Matthew P. Young to serve as Lead Independent Director of the Board. In that role, Mr. Young presides over the executive sessions of the Board in which Dr. McCarthy does not participate, serves as a liaison to Dr. McCarthy and management on behalf of the Board and performs such other duties and exercises such other powers as may from time to time be assigned by the bylaws or the Board.

Our Board has concluded that our current leadership structure is appropriate at this time. However, our Board will continue to periodically review our leadership structure and may make such changes in the future as it deems appropriate.

The Board monitors and assesses key business risks directly through deliberations of the Board and also by way of delegation of certain risk oversight functions to be performed by committees of the Board. The Board regularly reviews and assesses, among other matters, the following important areas that present both opportunities and risk to the Company’s business:

The discussion above of risk oversight matters reviewed by the Board is intended to be illustrative only and not a complete list of all important matters reviewed and considered by the Board in providing oversight and direction for the Company’s senior management and business.

The risk oversight function of the Board is also administered through various Board committees. The Audit Committee oversees the management of financial, accounting, internal controls, disclosure controls, the engagement and regular oversight of the independent auditors and other financial compliance risks. The Audit Committee also

periodically reviews the Company’s investment policy for its cash reserves and fraud monitoring practices and procedures, including the maintenance and monitoring of a whistleblower hotline.

The Compensation Committee is responsible for the design and oversight of the Company’s compensation programs. The Compensation Committee also regularly reviews and reports to the Board on succession planning for the chief executive officer and certain other select senior management positions.

The Nominating and Corporate Governance Committee periodically reviews the Company’s corporate governance practices, including certain risks that those practices are intended to address and certain corporate compliance risks. The Nominating and Corporate Governance Committee periodically reviews the composition of the Board to help ensure that a diversity of skills and experiences is represented by the members of the Board taking into account the stage of growth of the Company and its strategic direction, as well as identifies, evaluates and nominates qualified candidates.

In carrying out their risk oversight functions, the Board and its committees routinely request and review management updates, reports from the independent auditors and legal and regulatory advice from outside experts, as appropriate, to assist in discerning and managing important risks that may be faced by the Company. The Board is committed to continuing to ensure and evolve its risk oversight practices as appropriate given the stage of the Company’s evolution as a drug development Company and the fast-paced changes in the biopharmaceutical industry.

Under the rules of The Nasdaq Stock Market LLC (“Nasdaq”), independent directors must comprise a majority of a listed company’s board of directors within twelve months from the date of listing. In addition, Nasdaq rules require that, subject to specified exceptions, each member of a listed company’s audit, compensation and nominating and corporate governance committees be independent. Audit committee members must also satisfy additional independence criteria set forth in Rule 10A-3 under the Exchange Act, and in Nasdaq Rule 5605(c)(2)(A). Under Nasdaq rules, a director will only qualify as an “independent director” if, in the opinion of that company’s board of directors, that person does not have a relationship that would interfere with the exercise of independent judgment in carrying out the responsibilities of a director.

To be considered independent for purposes of Rule 10A-3, a member of an audit committee of a listed company may not, other than in their capacity as a member of the audit committee, the board of directors or any other board committee, accept, directly or indirectly, any consulting, advisory or other compensatory fee from the listed company or any of its subsidiaries or be an affiliated person of the listed company or any of its subsidiaries.

Our Board has undertaken a review of its composition, the composition of its committees and the independence of each director. Based upon information requested from and provided by each director concerning their background, employment and affiliations, including family relationships, our Board determined that none of our directors, other than Dr. McCarthy, has a relationship that would interfere with the exercise of independent judgment in carrying out the responsibilities of a director and that each of these directors is “independent” as that term is defined under the Nasdaq rules. Dr. McCarthy is not considered independent because he is an employee of the Company. Our Board determined that Matthew P. Young, a member of our Audit Committee, James R. Meyers, a member of our Compensation Committee, Elaine V. Jones, Ph.D., a member of our Compensation Committee and Nominating and Corporate Governance Committee, Halley Gilbert, a member of our Audit Committee and Nominating and Corporate Governance Committee, Mani Mohindru, Ph.D., a member of our Audit Committee, Alan Ashworth, Ph.D., a member of our Nominating and Corporate Governance Committee, and Zhen Su, M.D., M.B.A., a member of our Compensation Committee, satisfy the independence standards for such committees established by applicable SEC and the Nasdaq rules, including, with respect to Ms. Gilbert, Dr. Mohindru and Mr. Young, the heightened independence criteria applicable to the Audit Committee, as set forth in Rule 10A-3 and Nasdaq Rule 5605. In making these determinations, our Board considered the relationships that each non-employee director has with us and all other facts and circumstances our Board deemed relevant in determining their independence, including the beneficial ownership of our capital stock by each non-employee director.

Our Board has three regularly constituted committees: an Audit Committee, a Compensation Committee and a Nominating and Corporate Governance Committee. The following table provides current membership information for each of the Board committees:

Below is a description of each committee of our Board.

The Audit Committee of the Board oversees our corporate accounting and financial reporting process. For this purpose, the Audit Committee performs several functions and its responsibilities include, among other things:

The Audit Committee has the power to investigate any matter brought to its attention within the scope of its duties and will have the authority to retain counsel and advisors to fulfill its responsibilities and duties.

The Audit Committee has the authority to retain special legal, accounting or other consultants to advise the committee as it deems necessary, at the Company’s expense, to carry out its duties and to determine the compensation of any such advisors.

The members of the Audit Committee are Matthew P. Young, Mani Mohindru, Ph.D. and Halley Gilbert. Mr. Young serves as the chairperson of the committee. Our Board has determined that each of Mr. Young, Dr. Mohindru and Ms. Gilbert are “independent” for Audit Committee purposes as that term is defined in the applicable rules of the SEC and The Nasdaq Global Select Market. Our Board has designated Mr. Young as an “audit committee financial expert” as defined under the applicable rules of the SEC and has determined that Mr. Young has the requisite financial sophistication as defined under the applicable rules and regulations of Nasdaq. The Audit Committee has adopted a written Audit Committee charter that satisfies the applicable standards of the SEC and Nasdaq, and which is available on our corporate website at www.cytomx.com.

The Compensation Committee of the Board, in consultation with independent compensation consultants, reviews the type and level of compensation for directors, officers, employees and recommends compensation actions to the Board and administers the variable compensation programs to be adopted by the Company. The responsibilities of the Compensation Committee include, among other things:

The Compensation Committee has the power to investigate any matter brought to its attention within the scope of its duties and will have the authority to retain counsel and advisors to fulfill its responsibilities and duties.

The Compensation Committee has the sole authority to retain or replace, at the Company’s expense, any independent counsel, compensation and benefits consultants and other outside experts or advisors as the committee believes to be necessary or appropriate. The committee may also utilize the services of the Company’s regular legal counsel or other advisors to the Company. The Compensation Committee has engaged Aon’s Human Capital Solutions practice, a division of Aon plc since 2015 as a compensation consultant to evaluate non-employee director compensation and compensation in comparison to industry peers.

The members of the Compensation Committee are James Meyers, Elaine V. Jones, Ph.D. and Zhen Su, M.D., M.B.A. Mr. Meyers serves as the chairperson of the committee. Our Board has determined that each member of the Compensation Committee is an independent director for Compensation Committee purposes as that term is defined in the applicable Nasdaq rules, and is a “non-employee director” within the meaning of Rule 16b-3(d)(3) promulgated under the Exchange Act. The Compensation Committee has adopted a written Compensation Committee charter that satisfies the applicable standards of the SEC and Nasdaq, and which is available on our corporate website at www.cytomx.com.

In 2025, none of our named executive officers (a) served on the compensation committee of another entity that had an executive officer who served on our Compensation Committee; (b) served as director of another entity that had an executive officer who served on our Compensation Committee; or (c) served on the compensation committee of another entity that had an executive officer who served as one of our directors.

The responsibilities of the Nominating and Corporate Governance Committee include, among other things:

The Nominating and Corporate Governance Committee has the power to investigate any matter brought to its attention within the scope of its duties and will have the authority to retain counsel and advisors to fulfill its responsibilities and duties.

The Nominating and Corporate Governance Committee may retain, at the Company’s expense, any independent counsel, experts or advisors that the committee believes to be desirable and appropriate. The committee may also use the services of the Company’s regular legal counsel or other advisors to the Company.

The Nominating and Corporate Governance Committee is comprised of Halley Gilbert, Elaine V. Jones, Ph.D., and Alan Ashworth, Ph.D. Ms. Gilbert serves as the chairperson of the committee. Our Board has determined that Ms. Gilbert, Dr. Jones and Dr. Ashworth are independent directors for Nominating and Corporate Governance Committee purposes as that term is defined in the applicable rules of The Nasdaq Global Select Market. The Nominating and Corporate Governance Committee has adopted a written committee charter that satisfies the applicable standards of the SEC and Nasdaq, and which is available on our corporate website at www.cytomx.com.

The Nominating and Corporate Governance Committee reviews candidates for director nominees in the context of the current composition of the Board, our operating requirements and the long-term interests of stockholders. In conducting this assessment, the Nominating and Corporate Governance Committee values diversity of abilities, experience, perspective, education, gender, background, race and national origin, and such other factors as it deems appropriate given our current needs and those of our Board to maintain a balance of knowledge, experience and capability. Additionally, in evaluating and identifying potential nominees, the Nominating and Corporate Governance Committee evaluates skills and backgrounds which may complement those already serving, or provide additional expertise or perspective not already present on our Board.

Although the Company has not adopted specific targets, the Nominating and Corporate Governance Committee considers the level of representation of women and other diverse candidates on our Board when making recommendations for nominees to our Board.

The Nominating and Corporate Governance Committee also periodically reviews the overall effectiveness of the Board, including Board attendance, level of participation, quality of performance, self-assessment reviews and any relationships or transactions that might impair director independence. In the case of new director candidates, the committee will also determine whether the nominee must be 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 committee may also use its network of contacts to compile a list of potential candidates and engage, if it deems appropriate, a professional search firm. The committee conducts any appropriate and necessary inquiries into the backgrounds and qualifications of possible candidates after considering the function and needs of the Board. The committee meets to discuss and consider such candidates’ qualifications and then selects a nominee for recommendation to the Board by majority vote.

The Nominating and Corporate Governance Committee will consider for nomination any qualified director candidates recommended by our stockholders. Any stockholder who wishes to recommend a director candidate is directed to submit in writing the candidate’s name, biographical information, relevant qualifications and other information required by our bylaws to our Secretary at our principal executive offices before the deadline set forth in our bylaws. All written submissions received from our stockholders will be reviewed by the Nominating and Corporate

Governance Committee at the next appropriate meeting. The Nominating and Corporate Governance Committee will evaluate any suggested director candidates received from our stockholders in the same manner as recommendations received from management, committee members or members of our Board.

Any holder of our securities may contact the Board or a specified individual director by writing to the attention of the Board or a specified individual director and sending such communication to our Corporate Secretary at our executive offices as identified in this Proxy Statement. Each communication from a security holder should include the following information in order to permit security holder status to be confirmed and to provide an address to forward a response if deemed appropriate:

Our Corporate Secretary will forward all appropriate communications to the Board or individual members of the Board as specified in the communication. Our Corporate Secretary may (but is not required to) review all correspondence addressed to the Board, or any individual member of the Board of Directors, for any inappropriate correspondence more suitably directed to management. The Board, a committee of the Board, or individual directors, as appropriate, will consider and review carefully any communications from stockholders forwarded by our Corporate Secretary.

During 2025, we engaged in an effort to contact certain of our institutional stockholders to listen to their views on corporate issues, including environmental, social and governance matters. We engaged in valuable dialogue on matters of interest to those stockholders and to the Company. We intend to continue to conduct activities directed at stockholder engagement in the future and value input from our stockholders on these matters.

There were no material changes to the procedures by which stockholders may recommend nominees to our Board in 2025.

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

We have adopted a code of business conduct and ethics that applies to all employees, including our principal executive officer, principal financial officer, principal accounting officer or controller, or persons performing similar functions. The code of business conduct and ethics is available on our website at www.cytomx.com. Amendments to, and waivers from, the code of business conduct and ethics that apply to any director, executive officer or persons performing similar functions will be disclosed at the website address provided above and, to the extent required by applicable regulations, on a Current Report on Form 8-K filed with the SEC.

The Company does not permit our employees or directors to engage in hedging transactions with respect to Company equity securities. We have adopted an insider trading policy (the “Corporate Securities Trading Policy”) governing the purchase, sale and other dispositions of our securities by our directors, officers and employees that we believe is reasonably designed to promote compliance with insider trading laws, rules and regulations, and any applicable listing standards. A copy of our Corporate Securities Trading Policy is filed as Exhibit 19.1 to our Annual Report on Form 10-K for the year ended December 31, 2023.

The following table presents information regarding the compensation paid to members of our Board, except for Sean A. McCarthy, D. Phil., who is also our Chief Executive Officer and Chairman of the Board. The compensation paid to Mr. McCarthy is set forth in the section titled “Executive Compensation Summary” in this Proxy Statement. Dr. McCarthy was not entitled to receive additional compensation for his service as a director or chairman.

During 2025, our Board members were compensated pursuant to our non-employee director compensation program, which provides for cash and equity-based compensation for service on the Board and its committees. Under the program, our non-employee directors receive the following cash compensation for their service on the Board and its committees:

In 2025, the annual non-employee director cash compensation was paid quarterly in arrears. Under the program, non-employee directors also receive reimbursement for out-of-pocket expenses incurred in connection with attendance at meetings of our Board.

Under our non-employee director stock option program, new non-employee members of the Board are automatically granted an initial option to purchase 76,000 shares of our common stock on the date such person first becomes a non-employee director. The initial grant will vest with respect to 1/36^th of the shares subject to the option on each monthly anniversary measured from the grant date, such that 100% of the shares subject to the option will be fully vested and exercisable on the third anniversary of the grant date, subject to the director’s continued service to us through the applicable vesting date.

On the date of each annual meeting of our stockholders, each non-employee director (other than any director receiving an initial grant on the date of such annual meeting) who is then serving as a non-employee director and who will continue as a non-employee director following the date of such annual meeting will automatically be granted an option to purchase 38,000 shares of our common stock. This annual grant will vest in full on the earlier of: (i) the date of the next annual meeting of our stockholders or (ii) the first anniversary of the date of grant, subject to the director’s continuous service to us through the applicable date.

The exercise price of all stock option grants is equal to the closing price of CytomX common stock as reported by the Nasdaq on the date of grant. In addition, upon a change in control, the vesting of all equity awards held by our non-employee directors will accelerate in full.

The following sets forth information about our executive officers as of March 31, 2026.

The following is biographical information as of March 31, 2026 for our executive officers. For Dr. McCarthy’s biographical information, see ‘Board of Directors and Corporate Governance’ above.

Mr. Ogden joined CytomX in August 2021 as Vice President, Finance and Accounting. In June 2024, Mr. Ogden was promoted to Senior Vice President and Chief Financial Officer of the Company. Prior to this, Mr. Ogden served as the Chief Financial Officer of the Lilly Diabetes division at Eli Lilly and Company (“Eli Lilly”) from May 2021 to August 2021. While at Eli Lilly, Mr. Ogden also held the positions of Senior Director, Chief Financial Officer and Treasurer of Lilly del Caribe, from April 2018 to May 2021, the Director of Investor Relations from June 2016 to April 2018, and the Financial Director of the U.S. Diabetes division, from January 2014 to May 2016. Mr. Ogden received his B.A. in economics from Wabash College and his M.B.A. from Harvard Business School.

Dr. Belvin joined CytomX in April 2018 as our Vice President of Research Oncology and currently serves as our Senior Vice President and Chief Scientific Officer, a position she has held since April 2022. Dr. Belvin has also served as our Head of Research since April 2020. Prior to her time at CytomX, Dr. Belvin held roles of increasing responsibility at Genentech, a publicly-traded biopharmaceutical company, where, from 2004 to 2018, she led multiple preclinical pipeline teams and oversaw programs in cancer signaling, cancer metabolism, and cancer immunology. Dr. Belvin began her career at Exelixis, a publicly-traded biopharmaceutical company, where she served as Senior Scientist from 1999 to 2004 and managed teams responsible for preclinical pipeline discovery within the oncology and inflammation portfolios. Dr. Belvin received her B.A. degree from Harvard University and her Ph.D. from the University of California, Berkeley. Dr. Belvin also trained at the Dana-Farber Cancer Institute and Cold Spring Harbor Laboratory.

Dr. Chu joined CytomX in July 2023 as Senior Vice President, Chief Medical Officer. Prior to joining CytomX, Dr. Chu held various leadership positions in the clinical development group at Fate Therapeutics (“Fate”), a publicly-traded biopharmaceutical company, between April 2019 and February 2022, and was promoted to Chief Medical Officer of Fate in February 2022, a position he held up to July 2023. Prior to his tenure at Fate, Dr. Chu held various positions at Genentech, a publicly-traded biopharmaceutical company, with his last position served being Associate Group Medical Director for Product Development Oncology, from December 2017 to April 2019. Dr. Chu received his B.A. in Molecular Biology from Princeton University and his M.D. from the University of Rochester School of Medicine and Dentistry.

Ms. Lester joined CytomX in October 2025 as Senior Vice President, Chief Business Officer. Prior to joining CytomX, Ms. Lester was Chief Business Officer at Replicate Bioscience, a biopharmaceutical corporation, from July 2023 to August 2025. Prior to joining Replicate, Ms. Lester worked at Harpoon Therapeutics, a T cell engager platform company that was later acquired by Merck, where she served as VP of Corporate Development from September 2017 to July 2021 and then SVP of Business Development and Corporate Strategy from July 2021 to July 2023. Previously, Ms. Lester held senior roles in corporate strategy, portfolio management, and commercialization at Bruin Biometrics from September 2014 to September 2017 and Onyx Pharmaceuticals, now an Amgen subsidiary, from June 2012 to August 2014. Earlier in her career, she worked in Deloitte and Booz Allen Hamilton’s life sciences consulting practices, where she advised on multi-billion-dollar M&A transactions, new product planning and strategic growth initiatives. Ms. Lester received her M.B.A. from the Kellogg School of Management at Northwestern University and her B.A. in Biological Basis of Behavior from University of Pennsylvania.

This section discusses the material components of the executive compensation program for our executive officers who are named in the “Summary Compensation Table” below.

As a “smaller reporting company” as defined in Item 10(f), we are not required to include a Compensation Discussion and Analysis section and have elected to comply with the scaled disclosure requirements applicable to smaller reporting companies.

Our named executive officers (“NEOs” or “Named Executive Officers”) for 2025 are as follows:

The Compensation Committee’s objective is to have compensation programs and practices that are competitive with our peers and industry through a mix of cash (base salary and annual, performance-based cash incentive bonuses) and long-term incentives (equity awards).

The Compensation Committee reviewed our NEOs’ base salaries referencing relevant compensation survey data from Aon (including peer company data), as well as taking into account our Chief Executive Officer’s assessment of individual executive performance (except with respect to his own salary). For 2025, Dr. McCarthy’s, Mr. Ogden’s and Ms. Lester’s annual base salary was $675,290, $478,650 and $445,000, respectively.

Our annual cash incentive program is designed to reward all employees, including our NEOs, for the achievement of the Company’s annual corporate goals, as well as individual performance against annual individual goals. We believe that annual incentives hold executives accountable, reward executives based on actual business results and help create a “pay for performance” culture. There are no minimum or guaranteed bonus payments for employees, including the NEOs.

Under our cash incentive program, every employee, including each NEO, has an established annual performance-based incentive target, which is equal to a percentage of the employee’s base salary. This percentage increases as levels of responsibility increase.

For 2025, Dr. McCarthy, Mr. Ogden and Ms. Lester had a target bonus opportunity of 60%, 40% and 40% of annual base salary, respectively. Each NEO’s target bonus opportunity could be earned based on the achievement of certain corporate and individual performance goals, as approved by our Board or Compensation Committee. Our Board and Compensation Committee retain the discretion to modify performance goals or to increase or reduce amounts payable upon achievement of performance goals. In December 2025, our Compensation Committee determined that corporate goals had been achieved at 135% of target and awarded bonuses to Dr. McCarthy, Mr. Ogden and Ms. Lester at 135%, 152% and 125% (Ms. Lester’s bonus payout was prorated on account of her October 20, 2025 start date) respectively, of the NEO’s target bonus opportunity.

Furthermore, in May 2025, our Compensation Committee approved the achievement of certain milestone awards that had been granted to Dr. McCarthy and Mr. Ogden in January 2025 that entitled them to earn a one-time bonus payment in the amount of $202,587 and $95,730, respectively.

In 2025, equity awards to executives (as well as non-executive employees) were comprised of stock option grants, restricted share units, or RSUs, and performance stock units, or PSUs, under our Amended and Restated 2015 Plan.

CytomX’s standard vesting schedule for the first stock option grant awarded to newly hired employees, including executive officers, provides that 25% of the shares granted will vest on the first anniversary of the commencement of employment, with the balance vesting in equal monthly installments over the subsequent thirty-six (36) months, until option shares are fully vested, subject to the individual’s continued service to us through the applicable vesting date. For RSUs that are granted to a newly hired employee, the grant of RSUs occurs when the new employee starts his or her employment and 25% of the shares will vest 12 months from the first June 15 or October 15 following the new employee’s start date, with the balance of the shares (75%) to vest an annual basis over the subsequent three years of their employment, subject to the individual’s continued service to us through each applicable vesting date.

Additional annual option grants made after an employee, including an executive officer, has provided services to the Company generally vest monthly from the date of grant over four years, subject to the individual’s continued service to us through the applicable vesting date. Additional annual RSU grants to employees will generally vest 33.3% on an annual basis over the next three years of their employment, subject to the individual’s continued service to us through the applicable vesting date. The vesting schedule for the PSUs awarded to executives provide that PSUs granted will vest upon achievement of certain specific Company objectives, which may include development, research or financial objectives, subject to continued service through the applicable vesting date.

We granted our NEOs the following equity awards in 2025.

In accordance with our equity grant practices, the exercise price for these stock option grants was equal to the closing price of our common stock as reported by the Nasdaq Global Select Market on the date of grant and the vesting schedule is as described above for new-hire and subsequent grants.

Our NEOs are entitled to certain severance and change in control benefits under the terms of their severance and change of control agreements, as may have been amended and restated, and our equity plans.

Dr. McCarthy’s severance and change of control agreement provides for: (i) 18 months of salary, pro-rated annual target bonus and 18 months of COBRA premiums in the event of a termination of employment by us without cause or by Dr. McCarthy for good reason outside of the 60 days prior to or 12 months following a change in control and (ii) 24 months of salary, 24 months of annual target bonus, 24 months of COBRA premiums and full acceleration of outstanding equity awards in the event of a termination of employment by us without cause or by Dr. McCarthy for good reason within 60 days prior to or 12 months following a change in control.

For other NEOs, the severance and change of control agreements provide for: (i) 12 months of base salary, prorated annual target bonus and 12 months of COBRA premiums in the event of a termination of employment by us without cause or by the NEO for good reason outside of the 60 days prior to or 12 months following a change in control and (ii) 12 months of base salary, annual target bonus, and 12 months of COBRA premiums and full acceleration of outstanding equity awards in the event of a termination of employment by us without cause or by the NEO for good reason within 60 days prior to or 12 months following a change in control.

We offer a comprehensive array of benefits to our employees, including our NEOs, who are eligible to participate on the same terms as other employees. Benefit programs include a variety of health insurance plans, 401(k) plan with Company matching contributions at Board-approved levels, employee stock purchase plan and term life insurance. These benefits are offered to all employees, including executive officers, in order to attract and retain employees. We do not offer defined benefit pension or other supplementary retirement benefits to employees.

The following table provides a summary of compensation paid to our named executive officers for the years ended December 31, 2025 and 2024.

The following table presents information regarding the outstanding stock options, PSUs and RSUs held by each of the named executive officers as of December 31, 2025.