Zymeworks Inc.

Discussion of Executive Compensation Practices

This section describes our executive compensation philosophy and how we implemented it through our 2025 compensation program for our named executive officers. The named executive officers for 2025 are:

•Kenneth Galbraith, our Chief Executive Officer, President, Chair of the Board of Directors and interim Chief Financial Officer;

•Paul A. Moore, Ph.D., our Chief Scientific Officer; and

•Jeffrey Smith, M.D., our former Executive Vice President and Chief Medical Officer.

This discussion contains forward-looking statements that are based on our current plans, considerations, expectations and projections regarding future compensation programs. Actual compensation programs adopted in the future may differ materially from the various planned programs summarized in this discussion.

In the paragraphs that follow, we provide an overview and analysis of our compensation program and policies, the material compensation decisions we have made under those programs and policies, and the material factors that we considered in making those decisions.

2025 Advisory Vote on Executive Compensation

At our 2025 annual general meeting, we conducted an advisory vote on named executive officer compensation. At that meeting, 94.06% of the votes cast on the advisory vote proposal were supportive of our named executive officer compensation program as disclosed in our 2025 proxy statement. Our next advisory vote on named executive officer compensation will be held at our 2026 annual general meeting.

The compensation committee reviewed the advisory vote results in the context of our overall compensation philosophy and programs, and based on the level of support, determined that no significant changes to our compensation policies and programs were necessary to address the results of the stockholder advisory vote. The compensation committee will continue to consider the results from future stockholder advisory votes on named executive officer compensation and other relevant market developments affecting named executive officer compensation to determine whether any subsequent changes to our named executive officer compensation programs and policies would be warranted to reflect any stockholder concerns reflected in those advisory votes or to address market developments. We frequently engage in stockholder outreach and discuss a wide range of topics, including discussions regarding compensation-related matters. We take our say-on-pay vote results seriously and will continue to consider the feedback we receive from stockholders and use such feedback to inform the compensation committee’s deliberations and decisions with respect to our executive compensation practices.

Overview of Compensation Program

Compensation Philosophy

The goal of our compensation program is to attract, retain and motivate our employees and executives, including our named executive officers. The compensation committee is responsible for setting our executive compensation and reviewing and approving, or recommending to the board of directors for approval, the Company’s annual corporate performance objectives applicable to executive and other Company bonus programs. In considering executive compensation, the compensation committee strives to ensure that our total compensation is competitive within the industry in which we operate and supports our overall strategy and corporate objectives. The combination of base salary, annual incentives and long-term incentives that we provide our executives is designed to accomplish this.

Compensation Objectives

The objectives of our executive compensation program are to:

•attract and retain highly qualified executive officers who have a history of proven success;

•align the interests of executive officers with our stockholders’ interests and with the execution of our business strategy;

•motivate and reward our executive officers through competitive pay practices and an appropriate mix of short- and long-term incentives;

•evaluate and reward executive performance on the basis of achievement of corporate goals and key financial measurements which we believe closely correlate to long-term stockholder value; and

•tie compensation awards directly to corporate goals and key financial measurements with evaluations based on achieving and overachieving predetermined objectives.

Role of the Compensation Committee

During 2025, the compensation committee’s work included the following:

•Competitive Compensation Review – The compensation committee reviewed compensation practices and policies with respect to our executives against Zymeworks’ peer group of companies (as further described below), in order to allow us to place our compensation practices for these positions in a market context. This reference exercise included a review of base salary, total cash compensation and total direct compensation.

•Executive Compensation – The compensation committee reviewed the corporate goals and objectives applicable to the compensation of the Company’s executives and evaluated the executives’ performance in light of those goals and objectives. Based on this review and evaluation, the compensation committee approved the 2025 compensation for the Company’s executives, including each of the named executive officers.

•Short- and Long-Term Incentive Plans – The compensation committee administers the Company’s incentive compensation plans and equity-based plans with respect to the Company’s executives, including the named executive officers.

•Succession Planning – The compensation committee reviewed the succession plan for the Chief Executive Officer and other executive officers.

In reaching its decisions, the compensation committee may consider input from management and other factors that the compensation committee considers appropriate. Decisions made by the compensation committee are the responsibility of the compensation committee and may reflect factors and considerations other than the information and/or recommendations provided by management.

Independent Compensation Consultant

In 2025, the compensation committee retained the Talent Solutions practice at Aon plc, as an independent consultant to the compensation committee to conduct competitive reviews and assessments of Zymeworks’ executive compensation program and recommend go-forward strategies. The compensation committee made the decision to retain Aon in its sole discretion and was directly responsible for the appointment, compensation and oversight of Aon’s work. The compensation committee is involved in and approves the adoption of the following procedures during Aon’s assessments:

•establishing the public company peer group used in the executive compensation assessment;

•reviewing the detailed assessment of Zymeworks’ executive compensation program versus the market;

•reviewing and approving executive pay mix;

•reviewing the assessment of Zymeworks’ board of directors compensation program versus the market; and

•reviewing and approving the non-executive equity compensation program.

The compensation committee utilizes these strategies when contemplating future executive compensation matters.

In 2025, Aon was retained to review the salaries, bonuses and equity plan levels and participation of executive employees, as well as equity plan levels and participation of employees below the executive level. Zymeworks’ management did not make or recommend such engagements and all such other services were approved by the compensation committee. Except as discussed below, Aon did not perform other services to the Company other than as a compensation consultant. The compensation committee determined Aon to be independent after evaluating the factors required under the applicable listing standard.

In addition to Aon’s services related to determining or recommending the amount or form of executive and non-employee director compensation, management has engaged Aon to perform unrelated broad-based compensation services and risk brokerage services (which included global risk in Canada and the United States). In 2025, fees paid to Aon for these unrelated broad-based compensation and risk brokerage services did not exceed $120,000 in the aggregate. The compensation committee was informed about these services.

Peer Companies and Use of Market Data

We compare our executive compensation program to those of a group of peer companies (North American biotechnology companies of a similar size and stage of development). The first step in the process is that the compensation committee, with the support of Aon and management, reviews trends in biotechnology compensation practices and reviews and approves the list of peer companies used for benchmarking. As part of its analysis in 2024 related to 2025 compensation, Aon collected and analyzed compensation information from a comparative group of biotechnology companies, or peer group, approved by the compensation committee. The compensation committee evaluates the criteria used in establishing the peer group at least annually. The compensation committee seeks input from management in addition to Aon to ensure the peer group is consistent with our current business objectives and strategy.

The list of peer companies is approved based on various factors including industry classification, market capitalization, headcount and stage of development. In September 2024, with assistance from Aon, the compensation committee approved a peer group consisting of publicly traded, pre-commercial biopharmaceutical companies:

•with an emphasis on developmental stage companies with Phase 3 clinical trials and companies with pending new drug applications (“NDAs”) or BLAs;

•with market capitalizations generally between $200 million and $2.0 billion (based on the Company’s then-current 30-day average market capitalization of approximately $744 million);

•with generally between 100 and 800 employees; and

•that are located in Canada and the United States, with a focus on companies headquartered in biotechnology hub markets.

Based on these criteria, in September 2024, the compensation committee approved the following peer group set forth below and used this peer group to inform compensation decisions for 2025:

(1) Added to the peer group in September 2024. The following companies were deleted from the peer group approved in September 2024: Adaptimmune Therapeutics plc, Atara Biotherapeutics, Inc., Gossamer Bio, Inc., Mersana Therapeutics, Inc., NGM Biopharmaceuticals, Inc. and Repare Therapeutics Inc.

Our compensation committee uses comparative data from our peer group as a reference when setting and adjusting executive compensation, but it does not target our overall program or any particular element of compensation to be at a particular percentile compared to our peers. Rather, our compensation committee uses a range of peer group data for each executive position for which data is available, along with an assessment of each executive’s performance, criticality and tenure, to ensure that our executive compensation program and its constituent elements are and remain competitive in relation to our peers.

Components of Compensation Package

In 2025, our executive compensation program consisted of three major components:

•base salary;

•annual cash bonuses based on a comparison of corporate performance to pre-set goals and objectives; and

•long-term incentives, which in 2025, consisted of grants of stock options and time-based restricted stock units.

In making 2025 compensation decisions, our compensation committee believed that each component of executive compensation must be evaluated and determined with reference to competitive market data, individual and Company-wide performance, our recruiting and retention goals, internal equity and consistency, and other information it deems relevant. As it evaluated executive compensation in 2025, the compensation committee believed that in the biopharmaceutical/biotechnology industry, long-term incentives such as stock options and restricted stock units are a primary motivator in attracting and retaining executives, in addition to salary and cash incentive bonuses.

The primary components of our 2025 executive compensation program are described in more detail below.

Base Salary

Annual base salary is designed to provide a competitive fixed rate of pay recognizing different levels of responsibility and performance within Zymeworks. This compensation component helps us to attract and retain highly qualified executives who have a history of proven success. In determining whether to increase the base salary for a particular executive, our compensation committee in discussions with our Chief Executive Officer (for executives other than the Chief Executive Officer) considers a variety of factors, including performance, length of service and criticality of role. The determination of base salary affects the amount of an executive’s cash bonus. The table below shows the base salaries of our named executive officers for 2025:

(1) Mr. Galbraith has also served as our interim Chief Financial Officer, principal financial officer and principal accounting officer since January 2026.

(2) Dr. Smith retired from his position as our Executive Vice President and Chief Medical Officer effective January 31, 2026.

Cash Bonus

The cash bonus component is designed to provide our named executive officers with annual cash incentive awards based on achievement of certain goals and objectives. The awards represent pay at risk – they result in payment only if and to the extent certain goals and objectives are met – and do not affect decisions regarding other components of compensation. This compensation component motivates and rewards our named executive officers for outstanding performance. In addition, we occasionally provide sign-on bonuses to newly hired executives in order to induce them to join the Company.

Annual cash incentive compensation for our named executive officers is paid pursuant to the Company’s Executive Incentive Compensation Plan, which provides the compensation committee discretion to make changes to performance targets and bonus targets, to decrease, increase or eliminate bonuses and to change other terms and conditions related to annual incentive compensation, in each case as the compensation committee deems appropriate to meet the overarching retention and incentive goals associated with our executive bonus program.

Named executive officers are eligible to receive an amount targeted at a pre-determined percentage of their base salary established at the beginning of each year. The compensation committee set annual target bonuses for each of Mr. Galbraith, Dr. Moore and Dr. Smith in January 2025 as follows:

(1) Mr. Galbraith has also served as our interim Chief Financial Officer since January 2026.

(2) Dr. Smith retired from his position as our Executive Vice President and Chief Medical Officer effective January 31, 2026.

At the beginning of each year, the compensation committee approves, or recommends that the board of directors approve, performance targets that are tied to the level of achievement of corporate and/or individual goals, and the compensation committee approves the weighting assigned to each goal. For 2025, the corporate and individual weighting was 100% corporate and 0% individual for all named executive officers. Achievement of corporate goals was a precondition for payment of bonuses with respect to 2025. Our compensation committee believed that this mix was appropriate in order to incentivize our management team to achieve our key corporate objectives.

After the end of the year, the compensation committee determines the performance bonus payable to each named executive officer based on the results achieved as compared to the performance targets established for a particular year. Depending on level of achievement, named executive officers may earn up to 150% of their respective target bonuses. There is no minimum bonus payable.

2025 Company Corporate Goals and Achievement

In December 2024, the board of directors (with input from members of the compensation committee) approved, and in January 2025, the members of the compensation committee updated, corporate goals for 2025 that were grouped into five main categories: (i) Ziihera, (ii) Finance and Partnerships, (iii) Clinical Development, (iv) Pre-Clinical Development and (v) Talent.

In January 2026, the compensation committee reviewed our performance against the corporate goals under the 2025 bonus plan, and determined that these goals were achieved at the 87.75% level. Additional detail on these goals and the assessed achievement is set forth in the table below:

The Company performed well against its 2025 corporate goals with respect to Ziihera, Clinical Development and Pre-Clinical Development. The Company did not fully achieve its 2025 corporate goals with respect to Finance and Partnerships, given various factors, including changes in the competitive landscape and financial markets impacting the timing of potential partnerships and financing opportunities. While the Company performed well in its Talent retention goals, we did not fully meet our Talent goals related to maintaining and enhancing our corporate culture and this will be a continued focus for us in the future. Given the Company’s strong overall performance against its 2025 corporate goals, the compensation committee determined that these goals were achieved at the 87.75% level and approved 2025 bonuses for our named executive officers as follows:

(1) Bonus amounts for all named executive officers are determined in U.S. dollars, and the table above reflects this determination in U.S. dollars. However, the bonus amount for Mr. Galbraith was paid in British pounds, the bonus amount for Dr. Moore was paid in Canadian dollars and the bonus amount for Dr. Smith was paid in Euros. The U.S. dollar figures reported in the Summary Compensation Table under the column header titled “Non-Equity Incentive Plan Compensation” vary from the figures in the table above due to the impact of foreign currency conversions. For additional information on foreign currency conversion rates, see “–Summary Compensation Table.”

Long-Term Incentives

Our Amended and Restated Stock Option and Equity Compensation Plan (the “Equity Compensation Plan”) authorizes us to make grants to eligible recipients of stock options, restricted stock, restricted stock units and other share-based awards, to attract, retain, motivate and reward qualified directors and employees and to enable and encourage such directors and employees to acquire shares of common stock as long-term investments.

The Company granted a mix of stock options and time-based restricted stock units to Mr. Galbraith, Dr. Moore and Dr. Smith in January 2025. The compensation committee believes this approach aligns the interests of our executives (including those of our named executive officers) with our stockholders’ interests by rewarding for improvements in stock price over a period of time. The Company issues stock options and restricted stock units to reward for future performance and appreciation. Because stock options only have value if our stock price increases relative to the stock option’s exercise price, we consider them to be an important performance-based tool that encourages our named executive officers to focus on driving increases to stockholder value. Time-based restricted stock units play an important role in our executive compensation program because they provide some value even during periods of stock price or market volatilities, provide retention incentives during the vesting period, and reinforce a culture of ownership. By granting restricted stock units, the Company can also reduce the dilutive effect of the equity incentive awards in the form of stock options, which benefits our stockholders over time. In addition, the vesting feature of our stock awards contributes to executive retention by providing an incentive to our executives to remain employed by us during the vesting period. For 2025, we determined that annual grants to Mr. Galbraith, Dr. Moore, and Dr. Smith based on an approximately 50/50 value mix of stock options and time-based restricted stock units was most appropriate to reflect the continued change in the market and the evolution of our compensation program away from an options-only approach. The compensation committee evaluates the long-term incentive programs for each year, and the appropriate mix of equity awards to grant to our executive officers for the applicable year. In future years or for particular executives, the compensation committee may approve a different mix of equity awards if it determines necessary or appropriate to achieve our compensation objectives.

For the stock options, the option exercise price may not be less than the closing price of our common stock on the date of grant. For the 2025 stock option grants to our named executive officers, 25% of the granted options is scheduled to vest on the first anniversary of grant date (subject to continued service and any applicable acceleration of vesting provisions in their employment agreements, as described below). On the last day of each month thereafter, a further 1/36 th of the total number of remaining granted options is scheduled to vest. These options are subject to any applicable acceleration provisions in the Equity Compensation Plan or in the named executive officer’s employment agreement.

Each restricted stock unit represents the right to receive one share of our common stock upon vesting of that unit, without the payment of an exercise price or other cash consideration for the issued shares of common stock. For the 2025 restricted stock unit grants to Mr. Galbraith, Dr. Moore and Dr. Smith, 1/3 rd of the restricted stock units are scheduled to vest on each anniversary of the grant date (subject to the named executive officer’s continued service and subject to any applicable acceleration provisions in the Equity Compensation Plan or in the named executive officer’s employment agreement).

The following table shows information regarding stock option and restricted stock unit grants to each of our named executive officers made during the year ended December 31, 2025:

(1) Restricted stock units vest in three equal annual installments beginning on January 10, 2026, subject to the recipient’s continued service through each vesting date and any applicable acceleration of vesting provisions described under the section below entitled “Executive Employment Arrangements and Potential Payments upon Termination or Change in Control.”

(2) Options vest and become exercisable with respect to (i) 25% of the underlying shares one year after the grant date and (ii) the remainder of the underlying shares in 36 equal monthly installments following the first anniversary of the date of grant, subject to the optionee’s continued service through each vesting date and any applicable acceleration of vesting provisions described under the section below entitled “Executive Employment Arrangements and Potential Payments upon Termination or Change in Control.”

(3) The exercise price of the stock options is the closing price of the Company’s stock on the Nasdaq on the grant date.

(4) The amounts set forth in this column reflect the grant date fair value for restricted stock unit awards and stock option awards computed in accordance with Financial Accounting Standards Board Accounting Standards Codification Topic 718, Compensation – Stock Compensation. See Note 2 - “Notes to Consolidated Financial Statements – Summary of Significant Accounting Policies – Stock-Based Compensation”and Note 10(e) - “Notes to Consolidated Financial Statements – Stockholders’ Equity – Stock-Based Compensation” included in this Annual Report on Form 10-K for our year ended December 31, 2025.

Previous grants are taken into account when considering new option and restricted stock unit grants, as well as other factors such as market data, retention and incentive considerations, internal equity, Company performance and prior and expected future individual contributions. Decisions regarding long-term incentives do not affect decisions regarding other components of compensation.

In January 2026, the compensation committee recommended, and our board of directors approved, certain changes to our equity compensation mix to further enhance the direct alignment of executive compensation with stockholders’ interests. These changes included adding performance RSUs to the continuing named executive officers’ compensation to focus executives on long-term value creation through the achievement of stock price performance. The vesting of the performance-based RSU is based upon achievement of performance conditions tied to certain cumulative total stockholder return goals, and certain total stockholder return goals relative to companies in the Nasdaq Biotech Index over a three-year performance period, and which generally require the executive officer’s continued service to us through the three-year period. In addition, we revised the vesting schedule of 2026 time-based RSU grants to a four-year schedule, with 25% of the RSUs vesting on each anniversary of the grant date, which strengthens the retention power of our equity program.

Benefits and Perquisites

Other compensation to our named executive officers primarily consists of participation in our broad-based employee benefit plans. Named executive officers are eligible to participate in all our employee benefit plans, in each case on the same basis as other employees in the entity in which they are employed, including a retirement savings plan for those employed in Canada, a 401(k) plan for those employed in the United States, and pension plans for those employed in Ireland and the UK. Our named executive officers also are eligible to participate in our employee stock purchase plan on the same terms as our other eligible employees.

Currently, we do not view perquisites or other personal benefits as a material component of our executive compensation program. However, we do provide certain perquisites to our named executive officers in situations where we believe it is appropriate to assist an individual in the performance of his or her duties, to make them more efficient and effective, and for recruitment and retention purposes.

In addition, consistent with our philosophy regarding personal benefits, and as further described in “Executive Compensation –Executive Employment Arrangements and Potential Payments upon Termination or Change in Control,” to encourage and facilitate Dr. Moore’s relocation to Canada, we provide him with tax equalization payments to neutralize any increase in his taxes as a result of his relocation, and tax preparation assistance for two years following his relocation. The compensation committee believes these benefits were appropriate to enable a smooth relocation for Dr. Moore and to allow him to keep his focus on the business rather than on the costs and burdens of the relocation.

We also provide certain personal benefits to Mr. Galbraith, which were negotiated as part of Mr. Galbraith’s initial January 2022 employment agreement and subsequent amendments, including the most recent amendment in January 2024. These benefits were provided in order to induce him to initially join and later to remain with the Company and to increase his ability to work efficiently. These benefits include certain housing, travel, relocation, and certain tax equalization and gross-up benefits, as described in “Executive Compensation – Executive Employment Arrangements and Potential Payments upon Termination or Change in Control.” In late 2022 and again in January 2024, we amended Mr. Galbraith’s employment agreement to extend the time period for certain benefits, as described in “Executive Compensation – Executive Employment Arrangements and Potential Payments upon Termination or Change in Control.” The compensation committee approved the extension of these benefits as it believed that doing so would assist Mr. Galbraith in the continued performance of his duties and continue to aid in his efficiency.

In the future, we may continue to provide perquisites or other personal benefits in circumstances where we believe it is appropriate to assist an individual named executive officer in the performance of his or her duties, to make him or her more efficient and effective, and for recruitment, motivation or retention purposes.

Anti-Hedging Policy

Under the terms of our Insider Trading Policy, all directors, officers, employees, as well as any other personnel that we determine should be subject to our Insider Trading Policy (such as certain contractors and consultants), any person or entity an insider controls, exercises substantial influence over, serves as a trustee or in a similar fiduciary capacity of or is otherwise involved with, in connection with securities trading or investment decisions and an insider’s spouse, partner, parents, children, dependents and other family members or roommates, are prohibited from purchasing financial instruments (including, for greater certainty, prepaid variable forward contracts, equity swaps, collars, or units of exchange funds) designed to hedge or offset a decrease in the market value of our securities. Any person covered by our Insider Trading Policy is prohibited from pledging Zymeworks securities as collateral for any loan, in margin accounts or as part of pledging transactions, regardless of whether such person is in possession of non-public material information. A copy of our insider trading policy is filed as Exhibit 19.1 to this Annual Report on Form 10-K.

Potential Payments upon Termination or Change in Control

Certain of our executives, including each of our named executive officers, are parties to employment agreements with us which set forth conditions of employment and the payments that will be made upon termination of their employment. Additional discussion of the employment agreements with our named executive officers is set forth below under “Executive Compensation – Executive Employment Arrangements and Potential Payments upon Termination or Change in Control.” We believe that these protections are necessary to provide our valuable named executive officers with incentives to forgo other employment opportunities and to maintain continued focus and dedication to their responsibilities to maximize stockholder value, including if there is a potential transaction that could involve a change in control, without undue concern that the officer will be terminated and lose his or her income and benefits. We believe the level of severance and change in control benefits provided is appropriate and is necessary to attract and retain key employees.

Summary Compensation Table

The following table presents the compensation awarded to, earned by or paid to each of our named executive officers for the years ended December 31, 2025 and December 31, 2024. We do not have non-qualified deferred compensation.

(1) Salary, bonus, non-equity incentive plan compensation (cash bonus with respect to corporate goal achievement) and amounts in the “All Other Compensation” column for all named executive officers are determined in U.S. dollars. However, cash compensation amounts for Mr. Galbraith were paid in British pounds and have been converted to U.S. dollars for the purposes of the table. For 2025 and 2024 the U.S. dollar per British pound exchange rates used for such conversions were 1.3180 and 1.2780, based on the average annual Bank of Canada exchange rates for U.S. dollar and British pound for 2025 and 2024, respectively. Cash compensation amounts for Dr. Moore were paid in Canadian dollars and have been converted to U.S. dollars for the purposes of the table. For 2025 and 2024, respectively, the U.S. dollar per Canadian dollar exchange rates used for such conversions were 0.7155 and 0.7301, which were the average annual Bank of Canada exchange rates for 2025 and 2024, respectively. Cash compensation amounts for Dr. Smith were paid in Euros and have been converted to U.S. dollars for the purposes of the table. For 2025, the U.S. dollar per Euro exchange rate used for the conversions was 1.1292, based on the average annual Bank of Canada exchange rates for U.S. dollar and Euro for 2025.

(2) The amounts set forth in these columns reflect the aggregate grant date fair value for restricted stock unit awards and option awards computed in accordance with Financial Accounting Standards Board Accounting Standards Codification Topic 718, Compensation – Stock Compensation. See Note 2 -“Notes to Consolidated Financial Statements – Summary of Significant Accounting Policies – Stock-Based Compensation” and Note 10(e) -“Notes to Consolidated Financial Statements – Shareholders’ Equity – Stock-Based Compensation” included in this Annual Report on Form 10-K for our year ended December 31, 2025.

(3) The amounts reflect the dollar value of incentive bonuses paid in 2026 and 2025 for performance during 2025 and 2024, respectively, as discussed further above under “Executive Compensation – Components of Compensation Package – Cash Bonus.”

(4) Mr. Galbraith has also served as our interim Chief Financial Officer since January 2026.

(5) Dr. Moore has served as our Chief Scientific Officer since July 2022.

(6) Dr. Smith retired from his position as our Executive Vice President and Chief Medical Officer effective January 31, 2026.

(7) Of the total amount for 2025, (i) $54,477 represents accommodation benefits, (ii) $6,590 represents Company contributions to a defined contribution pension plan, (iii) $789 represents life insurance premiums through our group extended benefit plan, (iv) $14,223 represents airfare for immediate family members in accordance with the terms of Mr. Galbraith’s employment agreement, (v) $621,582 represents an estimated tax gross-up in connection with taxation attributable to the performance of work outside the UK, and (vi) $12,960 represents reimbursement for tax prep aration services.

(8) Of the total amount for 2024, (i) $53,969 represents accommodation benefits, (ii) $6,390 represents Company contributions to a defined contribution pension plan, (iii) $14,516 represents private health insurance premiums, (iv) $701 represents life insurance premiums through our group extended benefit plan, (v) $30,853 represents airfare for immediate family members in accordance with the terms of Mr. Galbraith’s employment agreement, (vi) $268,541 represents an estimated tax gross-up in connection with taxation attributable to the performance of work outside the UK, and (vii) $3,030 represents reimbursement for tax preparation services.

(9) Of the total amount for 2025, (i) $307,079 represents a tax equalization payment(which includes $164,287 for estimated tax gross-up) for 2024 paid in 2025, and (ii) $876 represents life insurance premiums through our group extended benefit plan.

(10) Of the total amount for 2024, (i)$44,283 represents a tax equalization payment for 2023 paid in 2024, and (ii) $4,433 represents life insurance premiums through our group extended benefit plan.

(11) This represents pension contributions.

Clawback Policy

In November 2023, we adopted a compensation recovery policy (the “Clawback Policy”) in accordance with the SEC and Nasdaq requirements under the Dodd-Frank Wall Street Reform and Consumer Protection Act. This policy provides for the non-discretionary recovery of excess incentive-based compensation from current and former executive officers in the event of an accounting restatement, whether or not the executive officer was at fault for the restatement, in accordance with the SEC and Nasdaq requirements.

In addition, as a public company subject to Section 304 of the Sarbanes-Oxley Act of 2002, if we are required to prepare an accounting restatement due to our material noncompliance, as a result of misconduct, with any financial reporting requirement under the securities laws, our Chief Executive Officer and Chief Financial Officer may be legally required to reimburse us for any bonus or incentive-based or equity-based compensation they received from us during the 12-month period following the first public issuance or filing with the SEC of the financial document incorporating such financial reporting requirement, as well as profits realized from the sale of securities during that 12-month period.

Stock Ownership Guidelines

In September 2025, the board of directors adopted stock ownership guidelines for the Company’s non-management directors (other than those representing or affiliated with greater than ten percent stockholders) (the “Outside Director Stock Ownership Guidelines”). In December 2025, the board of directors adopted stock ownership guidelines for the Company’s executive officers (the “Executive Officer Stock Ownership Guidelines” and, together with the Outside Director Stock Ownership Guidelines, the “Stock Ownership Guidelines”). The purpose of the Stock Ownership Guidelines is to further align the interests of the Company’s leadership with the long-term interests of stockholders and further promote the Company’s commitment to sound corporate governance.

The Outside Director Stock Ownership Guidelines require covered directors in office at the time of its adoption to achieve beneficial ownership of at least 10,000 shares of common stock by September 2028 (the “Target Director Ownership”). The board of directors set the Target Director Ownership as a reasonable ownership position in light of the directors’ cash compensation and the then-current value of the Company’s common stock. The compensation committee will review the Target Director Ownership from time to time and, for directors who subsequently join the board of directors, set the applicable ownership target to be achieved within three years from their election or appointment. Mr. Cherry is the only director currently serving who was not on the board of directors at the time of adoption of the Outside Director Stock Ownership Guidelines. He is required to achieve beneficial ownership of at least 10,000 shares by January 2029.

The Executive Officer Stock Ownership Guidelines require the covered executives to achieve beneficial ownership of at least (i) for the CEO, 100,000 shares of common stock, and (ii) for all other executive officers, 25,000 shares of common stock, in each case, by December 2028 (the “Target Executive Officer Ownership”). The board of directors set the Target Executive Officer Ownership as a reasonable ownership position in light of the executives’ cash compensation and the then-current value of the Company’s common stock. The compensation committee will review the Target Executive Officer Ownership from time to time and, for new executives, confirm the applicable beneficial ownership target to be achieved within three years from the time of their appointment. Mr. Hollywood became an executive officer in January 2026 and Dr. Mekan became an executive officer in February 2026; they are required to achieve beneficial ownership of at least 25,000 shares by January 2029 and February 2029, respectively.

Directors and executive officers subject to the Stock Ownership Guidelines are expected to retain all shares received (net of shares withheld or sold to cover tax withholding obligations, if any) pursuant to their service as directors or executive officers, as applicable, until the Target Ownership is achieved. In determining beneficial ownership, the Stock Ownership Guidelines take into account the following: (i) shares owned outright, including shares owned jointly with a spouse/domestic partner or separately by a spouse/domestic partner and/or children that share such director’s or executive officer’s, as applicable, household; and (ii) shares owned through trusts or entities owned and controlled by, or for the benefit of, such director or executive officer, as applicable, or his or her spouse/domestic partner and/or children that share such director’s or executive officer’s, as applicable, household. Vested or unvested stock options and unvested restricted stock units, whether time-based or performance-based, will not be included in the determination of beneficial ownership.

The compensation committee has responsibility for the management and interpretation of the Stock Ownership Guidelines and for ensuring compliance with its terms. The compensation committee may also amend, defer or waive compliance for specific participants, or amend or terminate the Stock Ownership Guidelines as a whole.

Outstanding Equity Awards at 2025 Year End

The following table lists all outstanding equity awards granted in U.S. dollars under the Equity Compensation Plan and our Inducement Stock Option and Equity Compensation Plan (the “Inducement Plan”) held by our named executive officers as of December 31, 2025:

(1) Options vest and become exercisable with respect to (i) 25% of the underlying shares one year after the grant date and (ii) the remainder of the underlying shares in 36 equal monthly installments following the first anniversary of the date of grant, subject to the optionee’s continued service through each vesting date and any applicable acceleration of vesting provisions described under the section below entitled “Executive Employment Arrangements and Potential Payments upon Termination or Change in Control.”

(2) Restricted stock units vest in three equal annual installments on each of the first, second, and third anniversaries of the date of grant, subject to the holder’s continued service through each vesting date and any applicable acceleration of vesting provisions described under the section below entitled “Executive Employment Arrangements and Potential Payments upon Termination or Change in Control.”

(3) Market value of restricted stock units that have not vested is based on the closing price of the Company’s common stock on Nasdaq on December 31, 2025, which was $26.33 per share.

Pension Benefits

We do not have any qualified or non-qualified defined benefit pension plans.

Defined Contribution Plans

Registered Retirement Savings Plan

Our executive officers resident in Canada are eligible, along with all other employees resident in Canada, to participate in our registered retirement savings plan (“RRSP”) matching program. Under this program, we match the amount contributed by each employee into a group RRSP plan, up to a pre-determined percentage of annual salary. We match employee contributions to the group RRSP up to 6.0% of annual salary.

401(k) Plan

Our executive officers resident in the United States are eligible, along with all other U.S.-based employees, to participate in a 401(k) matching program. Under this program, we match the amount contributed by each employee into a 401(k) plan, up to a predetermined percentage of annual salary. We match employee contributions to a 401(k) plan up to 6.0% of annual salary, with company matching contributions not to exceed the annual personal and Age 50 Catch Up contribution limit (if applicable) set by the Internal Revenue Service, or the IRS, in any given year.

Group Personal Pension Plan

Our executive officers resident in the UK are eligible, along with all other employees resident in the UK, to participate in our group personal pension (“GPP”) plan matching program. Under this program, we match the amount contributed by each employee into a GPP plan, up to a pre-determined percentage of annual salary. We match employee contributions to a GPP plan up to 6.0% of annual salary.

Personal Retirement Savings Account

Our executive officers resident in Ireland are eligible, along with all other employees resident in Ireland, to participate in our Personal Retirement Savings Account (“PRSA”) matching program. Under this program, we match the amount contributed by each employee into a PRSA, up to a pre-determined percentage of annual salary. We match employee contributions to a PRSA up to 6.0% of annual salary.

Non-qualified Deferred Compensation

We do not have any non-qualified defined contribution plans or other deferred compensation plans.

Executive Employment Arrangements and Potential Payments upon Termination or Change in Control

Executive Employment Arrangements

Key provisions of the employment agreements that were in effect as of December 31, 2025, for our named executive officers are described below.

Kenneth Galbraith. In connection with Mr. Galbraith’s appointment as President and Chief Executive Officer in January 2022, Mr. Galbraith entered into an employment agreement with us (the “Original Agreement”), on December 30, 2022, Zymeworks BC and Zymeworks Management Inc., our subsidiaries, and Mr. Galbraith entered into an amendment to the Original Agreement (the “First Amendment”), and on January 3, 2024, Zymeworks BC and Mr. Galbraith entered into a second amendment (the “Second Amendment” and the Original Agreement, as amended by the First Amendment and the Second Amendment, the “Galbraith Employment Agreement”). The Galbraith Employment Agreement does not have a specific term. The Second Amendment established Mr. Galbraith’s principal place of employment as the UK, or another location as agreed upon between the parties, which removes the requirement for Mr. Galbraith to relocate to Vancouver, British Columbia or Seattle, Washington, and incorporated certain extensions of compensation and benefit provisions, as described below.

Pursuant to the Galbraith Employment Agreement, Mr. Galbraith is entitled to the following compensation and benefits:

•An annual base salary of $600,000, with eligibility to earn an annual discretionary bonus of up to 60% of his annual base salary, based upon the achievement of certain Company goals determined by the board of directors. Mr. Galbraith’s current annual base salary is $655,000 and his target annual discretionary bonus for 2026 is 75% of his annual base salary;

•Options, which were granted to Mr. Galbraith in 2022, to purchase 500,000 shares of our common stock at an exercise price per share equal to the fair market value on the date of grant (the “Inducement Options”). 25% of the Inducement Options vest and become exercisable on the one-year anniversary of the date of grant, and thereafter 1/36th of the remaining Inducement Options will vest on the last day of each month, until all of the Inducement Options have vested, subject to Mr. Galbraith’s continued service;

•Eligibility to participate in our employee benefit plans, policies and arrangements that, in the aggregate, are reasonably consistent with other executive officers generally, as well as reimbursement for certain fees and costs related to membership in certain professional associations and professional development;

•Enrollment in a qualifying pension scheme under the UK Pensions Act 2008;

•Prior to the Second Amendment, the Galbraith Employment Agreement provided for reimbursement of relocation expenses up to a maximum gross amount of $300,000, grossed up for the impact of any tax withholding, for reasonable moving expenses incurred by Mr. Galbraith and his immediate family during relocation from Mr. Galbraith’s primary residence to Vancouver, British Columbia or Seattle, Washington if he relocated on or before July 15, 2024 (under the Original Agreement, this related to a relocation within the first eighteen months of employment), with the total amount reimbursed under this provision required to be repaid if Mr. Galbraith’s employment had terminated within three years (two years under the Original Agreement) following the effective date of employment. The Second Amendment removed the requirement to relocate, and deleted this provision regarding relocation expenses;

•Temporary housing for Mr. Galbraith in Vancouver, British Columbia, grossed up for the impact of any tax withholding. The First Amendment had provided for this benefit through the earlier of Mr. Galbraith’s relocation or July 15, 2024, and under the Original Agreement, this was through the earlier of Mr. Galbraith’s relocation or the date that is 18 months following the effective date of employment;

•Reimbursement of reasonable travel and living expenses when traveling from his home to Vancouver, British Columbia or Seattle, Washington for his employment duties, as well as reimbursement or Company payment for reasonable airfare and lodging expenses for Mr. Galbraith and his immediate family for one trip per calendar year to Vancouver, British Columbia or Seattle, Washington, as applicable (under the Original Agreement, this related to trips that occurred prior to the end of 2023, and under the First Amendment, to trips that occurred prior to the end of 2024);

•A tax equalization payment if Mr. Galbraith is subject to income taxation or other taxation outside of the UK during the period of his employment, grossed up for the impact of any tax withholding, and tax preparation services;

•If we terminate Mr. Galbraith’s employment during his first three years of employment, then Mr. Galbraith will be eligible to receive twelve months of notice or the equivalent of twelve months of base salary as of the date notice is given, or any combination thereof that totals twelve months of combined notice and base salary. Commencing in the fourth year of his employment, if we terminate Mr. Galbraith’s employment, Mr. Galbraith will be eligible to receive an additional one month of notice or the equivalent of one month of base salary as of the date notice is given, or any combination thereof, for each additional completed year of service, up to a total maximum of eighteen months. Mr. Galbraith will also be eligible for continuation of group health and dental benefits through the applicable notice period to the extent permitted by any applicable benefit plan;

•In the event of termination on death or disability, as defined in our long-term disability plan or policy then in effect with respect to him, Mr. Galbraith, or his estate, will receive (x) a lump sum payment equal to the difference between (1) eighteen months of base salary plus target annual cash bonus as of the date of death or disability and (2) the amount that Mr. Galbraith or his estate will receive as a result of death or disability under our applicable insurance policies in effect as of the date of termination, (y) group extended health and dental benefits continuation for his surviving family members for eighteen months (or lump sum payment for the premium costs of such benefits in lieu thereof), and (z) full vesting acceleration of all unvested and outstanding stock options or other equity grants made to Mr. Galbraith as of the date of death or disability;

•If Mr. Galbraith’s employment is terminated by us without cause on or within twelve months following, or within three months prior to, a change of control (as defined in the Galbraith Employment Agreement), Mr. Galbraith will be eligible to receive (x) a lump sum payment of eighteen months of base salary and 100% of target annual cash bonus as of the date of termination, (y) group extended health and dental benefits continuation as of the date of termination for eighteen months (or lump sum payment for the premium costs of such benefit plans in lieu thereof) and (z) full vesting acceleration of all unvested and outstanding stock options or other equity grants as of the date of termination. Such payments will be subject to Mr. Galbraith entering into a valid settlement agreement with us; and

•In addition, the Galbraith Employment Agreement requires Mr. Galbraith, among other things, not to compete, either directly or indirectly, with us while employed by us and for up to six months following the termination of his employment with us. The Galbraith Employment Agreement also requires Mr. Galbraith not to solicit our employees or consultants to terminate their relationship with us while he is employed by us and for up to one year following the termination of his employment with us.

In January 2026, Ms. Leone Patterson ceased to serve in the positions of Executive Vice President, Chief Business Officer and Chief Financial Officer, including as principal financial officer and principal accounting officer. In connection with Ms. Patterson’s separation, Mr. Galbraith was appointed interim Chief Financial Officer and continued in his roles as Chair of the Board, President and Chief Executive Officer and assumed the duties of principal financial officer and principal accounting officer. The compensatory and other material terms of Mr. Galbraith’s employment with the Company were unchanged in connection with his appointment as interim Chief Financial Officer, principal financial officer and principal accounting officer.

Paul A. Moore. On July 18, 2022, the Company and our subsidiary ZBIentered into an employment agreement with Dr. Moore setting forth the terms and conditions of his employment as Chief Scientific Officer of the Company (the “Initial Employment Agreement”). In connection with Dr. Moore’s planned relocation from the United States to Canada, the Company and our subsidiary Zymeworks BC entered into an amended and restated employment agreement with Dr. Moore in July 2023 (the “Moore Employment Agreement”) that supersedes and replaces the Initial Employment Agreement. The Moore Employment Agreement does not have a stated term.

Pursuant to the Moore Employment Agreement, Dr. Moore is entitled to the following compensation and benefits:

•An annual base salary of $465,000, with eligibility to earn an annual discretionary bonus of up to 45% of his annual base salary, based upon the achievement of certain Company goals determined by the board of directors. Dr. Moore’s current annual base salary is $525,000 and his target annual discretionary bonus remains at 45% of his annual base salary;

•Eligibility to participate in our employee benefit plans, policies and arrangements, as well as reimbursement for certain fees and costs related to membership in certain professional associations and professional development;

•Reimbursement of relocation expenses up to a maximum of $200,000, grossed-up to offset the impact of any taxes on such payment, for reasonable and customary moving expenses that Dr. Moore incurs within eighteen months of his July 18, 2022 start date in connection with his relocation to the Vancouver, British Columbia metropolitan area, as contemplated in the Initial Employment Agreement.

•A tax equalization payment if Dr. Moore is subject to income taxation in Canada in a given year equal to the difference between (i) the sum of total Canadian taxes plus any U.S. federal, state and local income taxes, that Dr. Moore is or would be obligated to pay for an applicable tax year, and (ii) the amount of U.S. federal, state and local tax liability had Dr. Moore worked in the United States for the entire tax year. Any tax equalization payment will be grossed-up to offset the impact of taxes on such payment.

•Provision of tax preparation support or reimbursement of up to $5,000 per year for additional tax preparation expenses of Dr. Moore for a period of two years from his relocation to the Vancouver, British Columbia metropolitan area.

•If we terminate Dr. Moore’s employment without cause during his first three years of employment, then Dr. Moore will be eligible to receive twelve months of notice or the equivalent of twelve months of base salary as of the date notice is given, or any combination thereof that totals twelve months of combined notice and base salary. Commencing in the fourth year of his employment, if we terminate Dr. Moore’s employment without cause, Dr. Moore will be eligible to receive an additional one month of notice or the equivalent of one month of base salary as of the date notice is given, or any combination thereof, for each additional completed year of service, up to a total maximum of eighteen months. Dr. Moore will also be eligible for continuation of group health and dental benefits through the applicable notice period to the extent permitted by any applicable benefit plan. Such payments will be subject to Dr. Moore entering into a valid separation and release agreement with us;

•If Dr. Moore’s employment is terminated by us without cause on or within twelve months following a change of control (as defined in the Moore Employment Agreement), Dr. Moore will be eligible to receive as severance (x) eighteen months continued base salary following termination, (y) group extended health and dental benefits as of the date of termination for eighteen months, and (z) full vesting acceleration of all unvested and outstanding stock options or other equity grants as of the date of termination. Such payments will be subject to Dr. Moore entering into a valid separation and release agreement with us; and

•In addition, the Moore Employment Agreement requires Dr. Moore, among other things, not to compete, either directly or indirectly, with us while employed by us and for up to six months following the termination of his employment with us. The Moore Employment Agreement also requires Dr. Moore not to solicit our employees to terminate their relationship with us while he is employed by us and for up to one year following the termination of his employment with us.

In addition, if any of the payments or benefits provided for under the Moore Employment Agreement employment agreement or otherwise payable to Dr. Moore would constitute “parachute payments” within the meaning of Section 280G of the Code and would be subject to the related excise tax, he would be entitled to receive either full payment of such payments and benefits or such lesser amount that would result in no portion of the payments and benefits being subject to the excise tax, whichever results in the greater amount of after-tax benefits to him. The Moore Employment Agreement does not require us to provide any tax gross-up payments to him.

Jeffrey Smith. Prior to Dr. Smith’s retirement, Dr. Smith was subject to an employment agreement withour subsidiary Zymeworks Pharmaceuticals Limited dated January 3, 2023 (the “Smith Employment Agreement”). The Smith Employment Agreement set forth the terms and conditions of his employment as our then Senior Vice President, Early-Stage Development. Dr. Smith was subsequently promoted to Executive Vice President and Chief Medical Officer in January 2024. The Smith Employment Agreement did not have a stated term. Effective January 31, 2026, Dr. Smith retired from his position as Executive Vice President and Chief Medical Officer of the Company and his employment terminated effective January 31, 2026. In January 2026, Dr. Smith entered into a severance agreement (the “Smith Severance Agreement”) and a consultancy agreement (the “Smith Consultancy Agreement”), each described in greater detail below.

The Smith Employment Agreement provided for the following compensation and benefits to Dr. Smith:

•An annual base salary of $425,000, with eligibility to earn an annual discretionary bonus of up to 35% of his annual base salary, based upon the achievement of certain Company goals determined by the board of directors. With respect to 2025, Dr. Smith’s annual base salary was $485,000 and he was eligible to earn a discretionary bonus of up to 45% of his annual base salary;

•Eligibility to participate in Company employee benefit plans, policies and arrangements;

•An annual contribution of €2,500 towards Dr. Smith’s membership in a health insurance program;

•In the event of termination of Dr. Smith’s employment without cause during his first three years of employment, then Dr. Smith would be eligible to receive twelve months of notice or the equivalent of nine month’s base salary plus three months’ notice as of the date notice is given, or any combination thereof that totals twelve months of combined notice and base salary. Commencing in the fourth year of his employment, in the event of termination of Dr. Smith’s employment without cause, Dr. Smith would have been eligible to receive an additional one month of notice or the equivalent of one month of base salary as of the date notice is given, or any combination thereof, for each additional completed year of service, up to a total maximum of fifteen months plus three months’ notice. Any such payments would have been subject to Dr. Smith entering into a valid separation and release agreement with us; and

•In the event of termination of Dr. Smith’s employment by us without cause on or within twelve months following a change of control (as defined in the Smith Employment Agreement), Dr. Smith would be eligible to receive as severance (x) eighteen months continued base salary following termination, or the equivalent of fifteen months of base salary plus three months’ notice, and (y) full vesting acceleration of all unvested and outstanding stock options or other equity grants as of the date of termination. Any such payments would have been subject to Dr. Smith entering into a valid separation and release agreement with us.

On January 6, 2026, Zymeworks Pharmaceuticals Limited and Dr. Smith entered into the Smith Severance Agreement providing for a release of claims by Dr. Smith in exchange for certain benefits, including continued payment of Dr. Smith’s current base salary for twelve months following his termination date. On January 31, 2026, Zymeworks Pharmaceuticals Limited and Dr. Smith entered into the Smith Consultancy Agreement, providing for Dr. Smith’s receipt of a retainer fee equal to $10,000 per month (exclusive of any value added tax) in exchange for up to fifteen hours per month of services as an outside advisor on strategic planning and guidance. Dr. Smith will also be entitled to continued vesting of his equity awards during the term of the Consultancy Agreement per the pre-existing terms of such equity awards. The Smith Consultancy Agreement will terminate on January 31, 2027 unless earlier terminated pursuant to its terms.

Chief Financial Officer Employment Arrangements

Leone Patterson. Prior to Ms. Patterson’s separation from employment with us, Ms. Patterson was subject to an employment agreement withour subsidiary ZBI dated July 19, 2024 and effective September 1, 2024 (the “Patterson Employment Agreement”). The Patterson Employment Agreement set forth the terms and conditions of her employment as Executive Vice President, Chief Business Officer and Chief Financial Officer of the Company and did not have a stated term. In January 2026, Ms. Patterson was removed from her position as Executive Vice President, Chief Business Officer and Chief Financial Officer of the Company and her employment was terminated without cause effective January 31, 2026. Ms. Patterson and ZBI entered into a separation agreement and release (the “Patterson Separation Agreement”) on February 1, 2026 that contained a release of claims in favor of the Company and requires Ms. Patterson’s compliance with certain ongoing covenants, and which provides Ms. Patterson with the severance and payments described under the Patterson Employment Agreement that apply in connection with a termination without cause, as described in greater detail below.

The Patterson Employment Agreement provided for the following compensation and benefits for Ms. Patterson:

•An annual base salary of $485,000, with eligibility to earn an annual discretionary bonus of up to 45% of her annual base salary, based upon the achievement of certain Company goals determined by the board of directors;

•Eligibility to participate in Company employee benefit plans, policies and arrangements, as well as reimbursement for certain fees and costs related to membership in certain professional associations and professional development;

•Signing bonus of $50,000, which would have been repayable in full to ZBI within 30 days of Ms. Patterson’s employment termination date if her employment had been terminated for Cause (as defined in the Patterson Employment Agreement) or by Ms. Patterson for any reason, in either case, within one year of the effective date of the Patterson Employment Agreement;

•Options, which were granted to Ms. Patterson in 2024, to purchase 360,000 shares of our common stock at an exercise price per share equal to the fair market value on the date of grant. 25% of the Options vested and become exercisable on the one-year anniversary of the date of grant, and thereafter 1/36th of the remaining Options vested on the last day of each month, until Ms. Patterson’s separation;

•In the event of termination of Ms. Patterson’s employment without cause during her first three years of employment, then Ms. Patterson would be eligible to receive twelve months of notice or the equivalent of twelve months of base salary as of the date notice is given, or any combination thereof that totals twelve months of combined notice and base salary. Commencing in the fourth year of her employment, in the event of termination of Ms. Patterson’s employment without cause, Ms. Patterson would have been eligible to receive an additional one month of notice or the equivalent of one month of base salary as of the date notice is given, or any combination thereof, for each additional completed year of service, up to a total maximum of eighteen months. Ms. Patterson also became eligible for continuation of group health and dental benefits through the applicable notice period to the extent permitted by any applicable benefit plan. Any such payments would have been subject to Ms. Patterson entering into a valid separation and release agreement with us;

•In the event of termination of Ms. Patterson’s employment by us without cause on or within twelve months following a change of control (as defined in the Patterson Employment Agreement), Ms. Patterson would be eligible to receive as severance (x) eighteen months continued base salary following termination, (y) group extended health and dental benefits as of the date of termination for eighteen months, and (z) full vesting acceleration of all unvested and outstanding stock options or other equity grants as of the date of termination. Any such payments would have been subject to Ms. Patterson entering into a valid separation and release agreement with us.

In addition, if any of the payments or benefits provided for under the Patterson Employment Agreement or otherwise payable to Ms. Patterson would constitute “parachute payments” within the meaning of Section 280G of the Code and would be subject to the related excise tax, she would have been entitled to receive either full payment of such payments and benefits or such lesser amount that would result in no portion of the payments and benefits being subject to the excise tax, whichever results in the greater amount of after-tax benefits to her. The Patterson Employment Agreement did not require us to provide any tax gross-up payments to her.

On February 1, 2026, ZBI and Ms. Patterson entered into the Patterson Separation Agreement providing for severance payments and benefits consistent with the terms of the Patterson Employment Agreement, in exchange for a release of claims by Ms. Patterson and compliance with certain ongoing covenants, including:

•Continued payment of Ms. Patterson’s current base salary for twelve months following her separation date; and

•Reimbursement of premiums for continued group health coverage under COBRA for twelve months following the separation date, or until Ms. Patterson obtains health insurance coverage through another employer.

Equity Compensation Plan Information

Under our Original Plan, upon a transaction in which equity securities representing more than 66 2/3% of our common stock are sold (a “substantial sale”), if the purchaser offers to buy out options, the options must be sold to the purchaser at a purchase price equal to (x) the price per share in the transaction (calculated in accordance with the terms of the Original Plan) minus the exercise price per share, multiplied by (y) the number of shares then exercisable under the option. If the option holders do not sell their options to the purchaser, such options will terminate upon completion of the substantial sale.

Under our Equity Compensation Plan and our Inducement Plan, in connection with a change of control (as defined in the applicable plan), our board of directors or the committee to which our board of directors has delegated authority to administer the applicable plan (either, the “Administrator”) has the right to provide for the conversion or exchange of any outstanding awards into or for options, rights or other securities in any entity participating in or resulting from a change of control, cash or other property. If we enter into an agreement for a transaction that, if completed, would result in a change of control, or otherwise become aware of a pending change of control, we will give written notice to the award holders regarding the potential change of control and a description of the effect of the change of control on outstanding awards at least seven (7) days prior to the closing of change of control.

Under our Equity Compensation Plan and Inducement Plan, the Administrator may, in its discretion, accelerate the vesting and/or expiration date of any or all outstanding awards in connection with the change of control to provide that such designated awards shall be fully vested and any options not exercised within the specified period will be terminated after the completion of the change of control. If the change of control would also result in a capital reorganization, arrangement, amalgamation or reclassification of our share capital (and if the vesting and expiration of the awards has not been accelerated as contemplated by the prior sentence), upon completion of the change of control, the number and kind of shares subject to outstanding awards and, if applicable, the exercise price per share of options shall be appropriately adjusted (including by substituting the awards for awards with respect to securities in any successor entity to us) in such manner as the Administrator considers equitable to prevent substantial dilution or enlargement of the rights granted to Award holders. The Administrator also may make changes to the terms of the awards or the Equity Compensation Plan or Inducement Plan to the extent necessary or desirable to comply with any rules, regulations or policies of any stock exchange on which any of our securities may be listed, provided that the value of previously granted awards and the rights of award holders are not materially adversely affected by any such changes. In addition, in the event of a potential change of control, the Administrator may, in its sole discretion, modify the terms of the plan and/or the awards to assist the participants to tender into a take-over bid or other transaction leading to a change of control, including the authority to allow participants to conditionally exercise options.

The Company’s Policies and Practices Related to the Grant of Certain Equity Awards Close in Time to the Release of Material Nonpublic Information

During 2025, we granted stock options to employees, including our named executive officers. Wedo not take material nonpublic information into account in determining the timing of such awards. Further, we havenot timed the disclosure of material nonpublic information for the purpose of affecting the value of executive compensation. We typically grant annual equity awards (including stock options) to our executive officers and non-executive employees early in the first quarter of each year. For equity awards to executive officers in connection with their hire date, such grants are typically made on the date of the commencement of their employment. For equity awards to non-executive employees in connection with their hire date, such grants are typically made on a pre-determined date in the month following the commencement of their employment. We have never granted stock appreciation rights to any employees or other service providers.

Director Compensation Table

The following table presents the compensation awarded to, earned by or paid to our directors (other than Mr. Galbraith, whose compensation is provided in the Summary Compensation Table above) for the year ended December 31, 2025. Mr. Cherry is not included in the table as he did not become a director until January 2026. We do not currently have director compensation in the form of share-based awards (other than stock options and restricted stock units), non-equity incentive plan compensation or non-qualified deferred compensation.

(1) For directors Gregory A. Ciongoli and Robert E. Landry, the amounts set forth in this column reflect the aggregate grant date fair value for option awards computed in accordance with Financial Accounting Standards Board Accounting Standards Codification Topic 718, Compensation – Stock Compensation. See Note 2 - “Notes to Consolidated Financial Statements – Summary of Significant Accounting Policies – Stock-Based Compensation” and Note 10(e) - “Notes to Consolidated Financial Statements – Stockholders’ Equity Stock-Based Compensation” included in this Annual Report on Form 10-K for our year ended December 31, 2025.

(2) As of December 31, 2025, directors and former directors held the following number of options to purchase Company common shares: (i) Mr. Campoy, 118,000; (ii) Dr. Cesano, 105,000; (iii) Mr. Ciongoli, 62,000; (iv) Mr. Cox, 133,500; (v) Dr. Davidson, 105,000; (vi) Dr. Gallagher, nil; (vii) Mr. Landry, 62,000; (viii) Dr. Mahony, 141,000; (ix) Mr. Miller, nil; (x) Dr. Neu, 102,000; (xi) Mr. Nodelman, nil; and (xii) Mr. Platshon, 167,000. Mr. Platshon also holds 111,111 restricted stock units. Mr. Platshon’s options and restricted stock units were granted pursuant to the Platshon Employment Agreement described under Item 13, “Certain Relationships and Related Transactions and Director Independence – Certain Relationships and Related Transactions.”

(3) The Company made annual awards under the Company’s Amended and Restated Director Compensation Policy (discussed below) in January 2026. Due to the date in which they were made, these awards are not reported in this table and will be reported as compensation in 2026.

(4) Mr. Ciongoli joined the Company’s board of directors effective August 10, 2025.

(5) Mr. Cox resigned from the Company’s board of directors effective August 9, 2025.

(6) In November 2025, Dr. Nancy Davidson, Dr. Neil Gallagher, and Mr. Derek Miller submitted their resignations from their positions as members of our board of directors, including from any committee thereof, effective as of November 6, 2025. In recognition of their valuable service, the board of directors accelerated 28,778 option awards held by Dr. Davidson, 34,495 option awards held by Dr. Gallagher and 8,334 option awards held by Mr. Miller. Under ASC Topic 718, the acceleration was treated as a modification of the terms of outstanding option awards. The “Option Awards” column includes the incremental fair value of the modified award equal to $174,474, $227,743 and $49,129, for Dr. Davidson, Dr. Gallagher and Mr. Miller respectively, computed as of the modification date, compared with the fair value of the award immediately prior to the modification, computed in accordance with ASC Topic 718.

(7) Mr. Landry joined the Company’s board of directors effective August 10, 2025.

(8) Due to a clerical error, in 2024 Mr. Miller received $417 more than he was entitled to under the Company’s non-employee director compensation policy. This inadvertent overpayment was subsequently corrected by withholding such overpaid amounts from the amounts he was owed for service as a director in 2025.

(9) Dr. Neu joined the Company’s board of directors in March 2020. Dr. Neu was an employee of Baker Bros. Advisors LP until January 2021. Pursuant to the terms of Dr. Neu’s employment by Baker Brothers Advisors LP, the options granted to him in 2020 were, and will continue to be, beneficially owned by Baker Bros. Advisors LP.

(10) Mr. Nodelman joined the Company’s board of directors in February 2025. Mr. Nodelman waived his entitlement to cash and equity compensation otherwise payable to him pursuant to the Company’s non-employee director compensation policy.

(11) Mr. Platshon waived his entitlement to cash and equity compensation otherwise payable to him pursuant to the Company’s non-employee director compensation policy. Mr. Platshon resigned from the Company’s board of directors effective November 16, 2025. Following his resignation, Mr. Platshon was appointed Acting Chief Investment Officer of the Company. The terms of his employment are described under Item 13, “Certain Relationships and Related Transactions and Director Independence – Certain Relationships and Related Transactions.”

Director Compensation

The written charter of our compensation committee provides that the compensation committee will review compensation for members of our board of directors on at least an annual basis, taking into account their responsibilities and time commitment and information regarding the compensation paid at peer companies. The compensation committee will make recommendations to our board of directors with respect to changes to our approach to director compensation as it considers appropriate.

From time to time, the compensation committee works with Aon to update prior competitive assessments of our board of director compensation program.

Board Annual Assessment of Non-Employee Director Compensation

In December 2024, the board of directors, upon advice from its independent compensation consultants and recommendation from the compensation committee following its annual assessment of the board of directors’ compensation program, approved certain changes to the cash and equity compensation of non-employee directors, which changes adjust the board of directors’ compensation program to more closely align with the non-employee director compensation practices of the Company’s peer group as described below.

In September 2025, the board of directors adopted stock ownership guidelines for our non-management directors (other than those representing or affiliated with greater than ten percent stockholders). The Stock Ownership Guidelines are discussed above under “–Stock Ownership Guidelines.”

In January 2026, the board of directors, upon advice from its independent compensation consultants and recommendation from the compensation committee following its annual assessment of the board of directors’ compensation program, approved certain changes to the cash and equity compensation of non-employee directors, to adjust the board of directors’ compensation program to further align with the non-employee director compensation practices of the Company’s peer group at that time.

Cash Compensation for Directors

Beginning January 1, 2025, the annual cash retainer fee for service as a member of the research and development committee was increased from $6,000 to $7,500, with all other annual cash retainers for the board of directors and its committees remaining unchanged. Beginning January 1, 2026, the annual cash retainer fee for service on the board of directors increased from $40,000 to $45,000 and the additional annual cash retainer fee for service as Lead Independent Director increased from $25,000 to $30,000.

Specifically, in 2025, we provided, and for 2026, we provide the below annual cash retainer fees for service on our board of directors and committees. The fees for service on committees are in addition to the annual retainer fees for service on the board of directors.

(1) The research and development committee was dissolved in November 2025.

Equity Compensation for Directors

In 2025, new non-employee directors were granted an initial option grant to purchase 62,000 shares of common stock, (reduced from 2024 levels, which provided for options to purchase 74,000 shares) on or about the time such director joined the board of directors, with the same vesting schedule as in place for 2024 new non-employee director initial options, of 1/36th of the options vesting on each monthly anniversary of the grant date, subject to the optionee’s continued service through such date.

No annual option grants were made to non-employee directors during 2025. Prior to changes made in January 2026, non-employee directors were also entitled to receive an annual option grant to purchase 31,000 shares of common stock (reduced from 2024 levels, which provided for options to purchase 37,000 shares), to be granted at or about the time of the Company’s annual meeting of stockholders, with the same vesting schedule as in place for 2024 continuing non-employee director annual options, of 100% of the options vesting on the date of the next year’s annual meeting of stockholders, subject to the optionee’s continued service through such date. However, as the Company’s annual meeting of stockholders took place on December 30, 2025, the non-employee directors did not receive these grants and instead received annual grants in January 2026 pursuant to the revised formulation described below.

Pursuant to amendments approved by the board of directors in December 2024, upon cessation of a non-employee director’s continued service in 2025, each outstanding stock option held by such director was subject to (i) pro rata acceleration of vesting of options granted as annual equity awards in connection with the 2024 annual meeting of stockholders for directors departing after the 2024 annual meeting of stockholders, but at or before our 2025 annual meeting of stockholders, with the pro rata acceleration determined based on the number of full or partial months served as a non-employee director on and after the 2024 annual meeting of stockholders date.

In addition, the post-termination exercise period for vested options held by such departing directors was extended to three years following the director’s cessation of service (or, if earlier, upon the expiration of the option or pursuant to the change of control, liquidation, dissolution, merger or similar provisions of the equity plan under which the option was granted).

Further, in November 2025, in connection with the then-pending resignations from the board of directors by Drs. Davidson and Gallagher and Mr. Miller, the board of directors approved the acceleration of vesting of the remaining unvested portions of their initial option grants, which had been granted in December 2023, April 2024 and April 2023, respectively. The post-termination exercise period of these options was also extended to three years following the director’s cessation of service (or, if earlier, upon the expiration of the option or pursuant to the change of control, liquidation, dissolution, merger or similar provisions of the equity plan under which the option was granted).

Beginning January 2026, new non-employee directors will be granted, on or about the time such director joins the board of directors, an initial equity award consisting of (A) an option grant to purchase 23,000 shares of common stock, with a vesting schedule of 1/36th of the total shares of common stock underlying such option vesting on each monthly anniversary of the grant date, subject to the non-employee director’s continued service through the applicable vesting date, and (B) a grant of 15,400 restricted stock units with a vesting schedule of 1/3 of the restricted stock units vesting on each annual anniversary of the grant date, subject to the non-employee director’s continued service through the applicable vesting date. This represents a change from the approach in 2025, during which new non-employee directors were entitled to an initial option to purchase 62,000 shares of Company common stock, as described above.

In addition, in January 2026, non-employee directors were granted an annual equity award consisting of (A) an option grant to purchase 11,500 shares of common stock, with a vesting schedule of 100% of the total shares of common stock underlying such option vesting on the one-year anniversary of the grant date, subject to the non-employee director’s continued service through the applicable vesting date; and (B) a grant of 7,700 restricted stock units with a vesting schedule of 100% of the restricted stock units vesting on the one-year anniversary of the grant date, subject to the non-employee director’s continued service through the applicable vesting date. This represents a change from the approach in place for 2025, which had provided for an annual option to purchase 31,000 shares of Company common stock; as described above, non-employee directors did not receive any annual grants in 2025 and instead received equity awards in January 2026 as described in this paragraph.

In adopting the changes for non-employee director grants, beginning in January 2026, our compensation committee worked with its independent compensation consultant to assess the appropriate market data comparison, mix of equity award types, the number of shares underlying equity awards for both new and continuing non-employee directors, and the other terms and conditions applicable to such awards.

The post-termination exercise period for vested options held by departing directors is three years following the director’s cessation of service (or, if earlier, upon the expiration of the option).

Expense Reimbursement

Each member of our board of directors is also entitled to reimbursement for reasonable travel and other expenses incurred in connection with attending board meetings and meetings for any committee on which he or she serves. These amounts are not included in the table above.

Risk Management

As part of its normal practice, the compensation committee evaluates the risk-taking incentives created by our compensation programs, policies and practices and has concluded that such programs, policies and practices are not reasonably likely to have a material adverse effect on the Company.