ZYME · Zymeworks Inc.

The shares were acquired under the Issuer's Employee Stock Purchase Plan (the "ESPP") for the ESPP purchase period of January 1, 2026 to June 30, 2026.

The purchase price reflects a 15% discount to the closing price of the Issuer's Common Stock on June 30, 2026 pursuant to the provisions of the ESPP.

Stock options vest as follows: (i) 25% of underlying shares of common stock on first anniversary of grant date and (ii) remainder of underlying shares of common stock in 36 equal monthly installments on last day of month following first anniversary of grant date.

Each restricted stock unit ("RSU") represents the contingent right to receive, upon vesting of the RSU, one share of the Issuer's common stock.

RSUs vest in four equal annual installments beginning on first anniversary of grant date.

Each performance restricted stock unit ("PSU") represents a contingent right to receive one share of common stock. The amount reported is the maximum number of PSUs that may be earned upon achievement of certain cumulative total shareholder return ("TSR") goals over a three-year performance period ending on January 12, 2029 (or in some cases at earlier times). Between 50% and 200% of the target number of 38,000 PSUs ("Target Number") may be earned upon achievement of such TSR goals. 50% of the Target Number may be earned upon achievement of relative TSR goals if the Company's TSR for the performance period equals or exceeds a prespecified percentile for the Nasdaq Biotech Index.

(Continued from footnote 4) The PSUs will only vest at the end of the three-year performance period if the Reporting Person's service to the Company continues through such time that the board of directors of the Company certifies the achievement of TSR goals, except in certain limited cases (such as if service to the Company is terminated by the Company without cause or in case of a change of control).

Stock options vest as follows: (i) 25% of underlying shares of common stock on first anniversary of grant date and (ii) remainder of underlying shares of common stock in 36 equal monthly installments on last day of month following first anniversary of grant date.

Each restricted stock unit ("RSU") represents the contingent right to receive, upon vesting of the RSU, one share of the Issuer's common stock.

RSUs vest in four equal annual installments beginning on first anniversary of grant date.

Each performance restricted stock unit ("PSU") represents a contingent right to receive one share of common stock. The amount reported is the maximum number of PSUs that may be earned upon achievement of certain cumulative total shareholder return ("TSR") goals over a three-year performance period ending on January 12, 2029 (or in some cases at earlier times). Between 50% and 200% of the target number of 38,000 PSUs ("Target Number") may be earned upon achievement of such TSR goals. 50% of the Target Number may be earned upon achievement of relative TSR goals if the Company's TSR for the performance period equals or exceeds a prespecified percentile for the Nasdaq Biotech Index.

(Continued from footnote 1) The PSUs will only vest at the end of the three-year performance period if the Reporting Person's service to the Company continues through such time that the board of directors of the Company certifies the achievement of TSR goals, except in certain limited cases (such as if service to the Company is terminated by the Company without cause or in case of a change of control).

Each restricted stock unit ("RSU") represents the contingent right to receive, upon vesting of the RSU, one share of the Issuer's common stock.

RSUs vest in four equal annual installments beginning on first anniversary of grant date.

Stock options vest as follows: (i) 25% of underlying shares of common stock on first anniversary of grant date and (ii) remainder of underlying shares of common stock in 36 equal monthly installments on last day of month following first anniversary of grant date.

Each restricted stock unit ("RSU") represents the contingent right to receive, upon vesting of the RSU, one share of the Issuer's common stock.

RSUs vest in three equal annual installments beginning on first anniversary of grant date.

Stock options vest as follows: (i) 25% of underlying shares of common stock on first anniversary of grant date and (ii) remainder of underlying shares of common stock in 36 equal monthly installments on last day of month following first anniversary of grant date.

Each restricted stock unit ("RSU") represents the contingent right to receive, upon vesting of the RSU, one share of the Issuer's common stock.

RSUs vest in four equal annual installments beginning on first anniversary of grant date.

Stock options vest as follows: (i) 25% of underlying shares of common stock on first anniversary of grant date and (ii) remainder of underlying shares of common stock in 36 equal monthly installments on last day of month following first anniversary of grant date.

Each restricted stock unit ("RSU") represents the contingent right to receive, upon vesting of the RSU, one share of common stock.

RSUs vest on January 12, 2027.

Stock options vest on January 12, 2027.

Each performance restricted stock unit ("PSU") represents a contingent right to receive one share of common stock. The amount reported is the maximum number of PSUs that may be earned upon achievement of certain cumulative total shareholder return ("TSR") goals over a three-year performance period ending on January 12, 2029 (or in some cases at earlier times). Between 50% and 200% of the target number of 111,000 PSUs ("Target Number") may be earned upon achievement of such TSR goals. 50% of the Target Number may be earned upon achievement of relative TSR goals if the Company's TSR for the performance period equals or exceeds a prespecified percentile for the Nasdaq Biotech Index. The PSUs will only vest at the end of the three-year performance period if the reporting person's service to the Company continues through such time that the board of directors of the Company certifies the achievement of TSR goals,

(Continued from footnote 8) except in certain limited cases (such as if service to the Company is terminated by the Company without cause or in case of a change of control).

Represents shares of common stock issued upon vesting of one third of the restricted stock units ("RSUs") granted on January 10, 2025.

Each restricted stock unit ("RSU") represents the contingent right to receive, upon vesting of the RSU, one share of common stock.

RSUs vest in three equal annual installments beginning on first anniversary of grant date.

Each restricted stock unit ("RSU") represents the contingent right to receive, upon vesting of the RSU, one share of common stock.

RSUs vest on January 12, 2027.

Stock options vest as follows: (i) 25% of underlying shares of common stock on first anniversary of grant date and (ii) remainder of underlying shares of common stock in 36 equal monthly installments on last day of month following first anniversary of grant date.

Represents shares of common stock sold to cover tax withholding obligations and other applicable fees in connection with the vesting of RSUs pursuant to mandatory "sell to cover" provisions contained in the Reporting Person's applicable RSU grant agreement, and does not represent a discretionary sale by the Reporting Person. The Reporting Person did not sell or otherwise dispose of any of the shares reported on this Form 4 for any reason other than to cover required taxes and fees.

The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $22.49 to $23.05, inclusive. Upon request by the Commission staff, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.

Each restricted stock unit ("RSU") represents the contingent right to receive, upon vesting of the RSU, one share of common stock.

RSUs vest on January 12, 2027.

Represents shares of common stock issued upon vesting of one third of the restricted stock units ("RSUs") granted on January 10, 2025.

Each performance restricted stock unit ("PSU") represents a contingent right to receive one share of common stock. The amount reported is the maximum number of PSUs that may be earned upon achievement of certain cumulative total shareholder return ("TSR") goals over a three-year performance period ending on January 12, 2029 (or in some cases at earlier times). Between 50% and 200% of the target number of 33,000 PSUs ("Target Number") may be earned upon achievement of such TSR goals. 50% of the Target Number may be earned upon achievement of relative TSR goals if the Company's TSR for the performance period equals or exceeds a prespecified percentile for the Nasdaq Biotech Index. The PSUs will only vest at the end of the three-year performance period if the Reporting Person's service to the Company continues through such time that the board of directors of the Company certifies the achievement of TSR goals,

(Continued from footnote 8) except in certain limited cases (such as if service to the Company is terminated by the Company without cause or in case of a change of control).

Each RSU represents the contingent right to receive, upon vesting of the RSU, one share of common stock.

The RSUs were granted on January 10, 2025 and vest in three equal annual installments beginning on the first anniversary of grant date.

Each restricted stock unit ("RSU") represents the contingent right to receive, upon vesting of the RSU, one share of common stock.

RSUs vest on January 12, 2027.

Each RSU represents the contingent right to receive, upon vesting of the RSU, one share of the Issuer's common stock.

RSUs vest in four equal annual installments beginning on first anniversary of grant date.

Represents shares of common stock issued upon vesting of one third of the restricted stock units ("RSUs") granted on January 10, 2025.

Stock options vest on January 12, 2027.

Stock options vest on January 12, 2027.

Stock options vest on January 12, 2027.

Each restricted stock unit ("RSU") represents the contingent right to receive, upon vesting of the RSU, one share of common stock.

RSUs vest on January 12, 2027.

Each performance restricted stock unit ("PSU") represents a contingent right to receive one share of common stock. The amount reported is the maximum number of PSUs that may be earned upon achievement of certain cumulative total shareholder return ("TSR") goals over a three-year performance period ending on January 12, 2029 (or in some cases at earlier times). Between 50% and 200% of the target number of 33,000 PSUs ("Target Number") may be earned upon achievement of such TSR goals. 50% of the Target Number may be earned upon achievement of relative TSR goals if the Company's TSR for the performance period equals or exceeds a prespecified percentile for the Nasdaq Biotech Index.

(Continued from footnote 8) The PSUs will only vest at the end of the three-year performance period if the Reporting Person's service to the Company continues through such time that the board of directors of the Company certifies the achievement of TSR goals, except in certain limited cases (such as if service to the Company is terminated by the Company without cause or in case of a change of control).

Represents shares of common stock sold to cover tax withholding obligations and other applicable fees in connection with the vesting of RSUs pursuant to mandatory "sell to cover" provisions contained in the Reporting Person's applicable RSU grant agreement, and does not represent a discretionary sale by the Reporting Person. The Reporting Person did not sell or otherwise dispose of any of the shares reported on this Form 4 for any reason other than to cover required taxes and fees.

The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $22.49 to $23.05, inclusive. Upon request by the Commission staff, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.

Each restricted stock unit ("RSU") represents the contingent right to receive, upon vesting of the RSU, one share of common stock.

RSUs vest on January 12, 2027.

Each RSU represents the contingent right to receive, upon vesting of the RSU, one share of the Issuer's common stock.

The RSUs were granted on January 10, 2025 and vest in three equal annual installments beginning on the first anniversary of grant date.

Each RSU represents the contingent right to receive, upon vesting of the RSU, one share of the Issuer's common stock.

RSUs vest in four equal annual installments beginning on first anniversary of grant date.

Stock options vest on January 12, 2027.

Stock options vest on January 12, 2027.

Represents shares of common stock sold to cover tax withholding obligations and other applicable fees in connection with the vesting of RSUs pursuant to mandatory "sell to cover" provisions contained in the Reporting Person's applicable RSU grant agreement, and does not represent a discretionary sale by the Reporting Person. The Reporting Person did not sell or otherwise dispose of any of the shares reported on this Form 4 for any reason other than to cover required taxes and fees.

The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $22.49 to $23.05, inclusive. Upon request by the Commission staff, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.

Each RSU represents the contingent right to receive, upon vesting of the RSU, one share of the Issuer's common stock.

The RSUs were granted on January 10, 2025 and vest in three equal annual installments beginning on the first anniversary of grant date.

Represents shares of common stock sold to cover tax withholding obligations and other applicable fees in connection with the vesting of RSUs pursuant to mandatory "sell to cover" provisions contained in the Reporting Person's applicable RSU grant agreement, and does not represent a discretionary sale by the Reporting Person. The Reporting Person did not sell or otherwise dispose of any of the shares reported on this Form 4 for any reason other than to cover required taxes and fees.

The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $22.49 to $23.05, inclusive. Upon request by the Commission staff, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.

Represents shares of common stock issued upon vesting of one third of the restricted stock units ("RSUs") granted on January 10, 2025.

Stock options vest as follows: (i) 25% of underlying shares of common stock on first anniversary of grant date and (ii) remainder of underlying shares of common stock in 36 equal monthly installments on last day of month following first anniversary of grant date.

Each RSU represents the contingent right to receive, upon vesting of the RSU, one share of common stock.

RSUs vest in four equal annual installments beginning on first anniversary of grant date.

Each RSU represents the contingent right to receive, upon vesting of the RSU, one share of the Issuer's common stock.

The RSUs were granted on January 10, 2025 and vest in three equal annual installments beginning on the first anniversary of grant date.

Stock options vest in 36 equal monthly installments starting one month after grant date of January 12, 2026.

Shares of common stock purchased pursuant to the Issuer's Amended and Restated Employee Stock Purchase Plan (ESPP) for the ESPP purchase period July 1, 2025 through December 31, 2025. In accordance with the ESPP, the shares of common stock were purchased at a price equal to 85% of the closing price of the Issuer's common stock on July 1, 2025.

Each RSU represents the contingent right to receive, upon vesting of the RSU, one share of the Issuer's common stock.

The RSUS were granted on January 5, 2023 and vest in three equal annual installments beginning on the first anniversary of January 5, 2023.

Represents shares of common stock sold to cover tax withholding obligations and other applicable fees in connection with the vesting of RSUs pursuant to mandatory "sell to cover" provisions contained in the Reporting Person's applicable RSU grant agreement, and does not represent a discretionary sale by the Reporting Person. The Reporting Person did not sell or otherwise dispose of any of the shares reported on this Form 4 for any reason other than to cover required taxes and fees.

The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $24.715 to $25.84, inclusive. Upon request by the Commission staff, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.