NKTX · Nkarta, Inc.

Represents shares sold to satisfy tax withholding obligations in connection with the vesting and settlement of Restricted Stock Units and does not represent a discretionary transaction by the Reporting Person.

Includes 2,000 shares acquired under the Issuer's 2020 Employee Stock Purchase Plan on May 31, 2026.

All shares subject to the option vest 100% on the first to occur of (i) June 10, 2027 or (ii) the day immediately preceding the first annual meeting of the Issuer's stockholders to occur after the date of grant of the award. Each grant, to the extent outstanding and otherwise unvested, will become fully vested should a "change in control" of the Issuer occur (as described in the applicable award agreement) or upon the Reporting Person's separation from service with the Issuer due to the Reporting Person's death or "disability" (as described in the applicable award agreement).

All shares subject to the option vest 100% on the first to occur of (i) June 10, 2027 or (ii) the day immediately preceding the first annual meeting of the Issuer's stockholders to occur after the date of grant of the award. Each grant, to the extent outstanding and otherwise unvested, will become fully vested should a "change in control" of the Issuer occur (as described in the applicable award agreement) or upon the Reporting Person's separation from service with the Issuer due to the Reporting Person's death or "disability" (as described in the applicable award agreement).

All shares subject to the option vest 100% on the first to occur of (i) June 10, 2027 or (ii) the day immediately preceding the first annual meeting of the Issuer's stockholders to occur after the date of grant of the award. Each grant, to the extent outstanding and otherwise unvested, will become fully vested should a "change in control" of the Issuer occur (as described in the applicable award agreement) or upon the Reporting Person's separation from service with the Issuer due to the Reporting Person's death or "disability" (as described in the applicable award agreement).

All shares subject to the option vest 100% on the first to occur of (i) June 10, 2027 or (ii) the day immediately preceding the first annual meeting of the Issuer's stockholders to occur after the date of grant of the award. Each grant, to the extent outstanding and otherwise unvested, will become fully vested should a "change in control" of the Issuer occur (as described in the applicable award agreement) or upon the Reporting Person's separation from service with the Issuer due to the Reporting Person's death or "disability" (as described in the applicable award agreement).

All shares subject to the option vest 100% on the first to occur of (i) June 10, 2027 or (ii) the day immediately preceding the first annual meeting of the Issuer's stockholders to occur after the date of grant of the award. Each grant, to the extent outstanding and otherwise unvested, will become fully vested should a "change in control" of the Issuer occur (as described in the applicable award agreement) or upon the Reporting Person's separation from service with the Issuer due to the Reporting Person's death or "disability" (as described in the applicable award agreement).

All shares subject to the option vest 100% on the first to occur of (i) June 10, 2027 or (ii) the day immediately preceding the first annual meeting of the Issuer's stockholders to occur after the date of grant of the award. Each grant, to the extent outstanding and otherwise unvested, will become fully vested should a "change in control" of the Issuer occur (as described in the applicable award agreement) or upon the Reporting Person's separation from service with the Issuer due to the Reporting Person's death or "disability" (as described in the applicable award agreement).

Under the Reporting Person's arrangement with RA Capital Management, L.P. (the "Adviser"), the Reporting Person holds the stock option for the benefit of the RA Capital Healthcare Fund, L.P. (the "Fund") and the RA Capital Nexus Fund, L.P. (the "Nexus Fund"). The Reporting Person is obligated to turn over to the Adviser any net cash or stock received upon exercise of the stock option, which will offset advisory fees owed by the Fund and the Nexus Fund to the Adviser. The Reporting Person therefore disclaims beneficial ownership of the stock option and underlying common stock.

All shares subject to the option vest 100% on the first to occur of (i) June 10, 2027 or (ii) the day immediately preceding the first annual meeting of the Issuer's stockholders to occur after the date of grant of the award. Each grant, to the extent outstanding and otherwise unvested, will become fully vested should a "change in control" of the Issuer occur (as described in the applicable award agreement) or upon the Reporting Person's separation from service with the Issuer due to the Reporting Person's death or "disability" (as described in the applicable award agreement).

All shares subject to the option vest 100% on the first to occur of (i) June 10, 2027 or (ii) the day immediately preceding the first annual meeting of the Issuer's stockholders to occur after the date of grant of the award, subject to Dr. Scheiner's continued service through the applicable vesting date. Each grant, to the extent outstanding and otherwise unvested, will become fully vested should a "change in control" of the Issuer occur (as described in the applicable award agreement) or upon the Dr. Scheiner's separation from service with the Issuer due to the his death or "disability" (as described in the applicable award agreement).

RA Capital Management, L.P. (the "Adviser") is the investment manager for RA Capital Healthcare Fund, L.P. (the "Fund") and RA Capital Nexus Fund, L.P. (the "Nexus Fund"). The general partner of the Adviser is RA Capital Management GP, LLC (the "Adviser GP"), of which Dr. Peter Kolchinsky and Mr. Rajeev Shah are the managing members. Each of the Adviser, the Adviser GP, the Fund, the Nexus Fund, Dr. Kolchinsky and Mr. Shah disclaims beneficial ownership of any of the reported securities, except to the extent of its or his respective pecuniary interest therein.

Under Dr. Scheiner's arrangement with the Adviser, Dr. Scheiner holds the option for the benefit of the Fund and the Nexus Fund. Dr. Scheiner is obligated to turn over to the Adviser any net cash or stock received upon exercise of the option, which will offset advisory fees owed by the Fund and the Nexus Fund to the Adviser. The Reporting Persons therefore disclaim beneficial ownership of the option and underlying common stock.

Represents shares sold to satisfy tax withholding obligations in connection with the vesting and settlement of Restricted Stock Units and does not represent a discretionary transaction by the Reporting Person.

Represents shares sold to satisfy tax withholding obligations in connection with the vesting and settlement of Restricted Stock Units and does not represent a discretionary transaction by the Reporting Person.

This option is scheduled to vest and become exercisable in 48 equal monthly installments occurring on the completion of each successive month of the Reporting Person's service to the Issuer following January 14, 2026.

This option is scheduled to vest and become exercisable in 48 equal monthly installments occurring on the completion of each successive month of the Reporting Person's service to the Issuer following January 14, 2026.

This option is scheduled to vest and become exercisable in 48 equal monthly installments occurring on the completion of each successive month of the Reporting Person's service to the Issuer following January 14, 2026.

Represents Restricted Stock Units ("RSUs") which vest in four equal annual installments beginning on January 14, 2027. Each RSU represents a contingent right to receive one share of Common Stock of the Issuer.

Represents Restricted Stock Units ("RSUs") which vest in four equal annual installments beginning on January 14, 2027. Each RSU represents a contingent right to receive one share of Common Stock of the Issuer.

Represents Restricted Stock Units ("RSUs") which vest in four equal annual installments beginning on January 14, 2027. Each RSU represents a contingent right to receive one share of Common Stock of the Issuer.

Includes 2,000 shares acquired under the Issuer's 2020 Employee Stock Purchase Plan on November 30, 2025.

The option is scheduled to vest and become exercisable as to 25% of the shares subject to the grant on July 23, 2026. The remaining portion of the option is scheduled to vest and become exercisable in 36 equal monthly installments occurring on the completion of each successive month of the Reporting Person's service to the Issuer following June 23, 2026.

Represents shares sold to satisfy tax withholding obligations in connection with the vesting and settlement of Restricted Stock Units and does not represent a discretionary transaction by the Reporting Person.

This transaction was executed in multiple trades at prices ranging from $1.76 to $1.79. The price reported above reflects the weighted average price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer or a security holder of the Issuer full information regarding the number of shares and prices at which the transaction was effected.

Includes 2,000 shares acquired under the Issuer's 2020 Employee Stock Purchase Plan on May 31, 2025.

All shares subject to the option vest 100% on the first to occur of (i) June 5, 2026 or (ii) the day immediately preceding the first annual meeting of the Issuer's stockholders to occur after the date of grant of the award. Each grant, to the extent outstanding and otherwise unvested, will become fully vested should a "change in control" of the Issuer occur (as described in the applicable award agreement) or upon the Reporting Person's separation from service with the Issuer due to the Reporting Person's death or "disability" (as described in the applicable award agreement).

All shares subject to the option vest 100% on the first to occur of (i) June 5, 2026 or (ii) the day immediately preceding the first annual meeting of the Issuer's stockholders to occur after the date of grant of the award. Each grant, to the extent outstanding and otherwise unvested, will become fully vested should a "change in control" of the Issuer occur (as described in the applicable award agreement) or upon the Reporting Person's separation from service with the Issuer due to the Reporting Person's death or "disability" (as described in the applicable award agreement).

All shares subject to the option vest 100% on the first to occur of (i) June 5, 2026 or (ii) the day immediately preceding the first annual meeting of the Issuer's stockholders to occur after the date of grant of the award. Each grant, to the extent outstanding and otherwise unvested, will become fully vested should a "change in control" of the Issuer occur (as described in the applicable award agreement) or upon the Reporting Person's separation from service with the Issuer due to the Reporting Person's death or "disability" (as described in the applicable award agreement).

The option is scheduled to vest and become exercisable as to 40% of the shares subject to the grant on June 5, 2026. The remaining 60% of the shares subject to the grant is scheduled to vest and become exercisable on June 5, 2027.

All shares subject to the option vest 100% on the first to occur of (i) June 5, 2026 or (ii) the day immediately preceding the first annual meeting of the Issuer's stockholders to occur after the date of grant of the award, subject to Dr. Scheiner's continued service through the applicable vesting date. Each grant, to the extent outstanding and otherwise unvested, will become fully vested should a "change in control" of the Issuer occur (as described in the applicable award agreement) or upon the Dr. Scheiner's separation from service with the Issuer due to the his death or "disability" (as described in the applicable award agreement).

RA Capital Management, L.P. (the "Adviser") is the investment manager for RA Capital Healthcare Fund, L.P. (the "Fund") and RA Capital Nexus Fund, L.P. (the "Nexus Fund"). The general partner of the Adviser is RA Capital Management GP, LLC (the "Adviser GP"), of which Dr. Peter Kolchinsky and Mr. Rajeev Shah are the managing members. Each of the Adviser, the Adviser GP, the Fund, the Nexus Fund, Dr. Kolchinsky and Mr. Shah disclaims beneficial ownership of any of the reported securities, except to the extent of its or his respective pecuniary interest therein.

Zachary Scheiner is a Principal of the Adviser who serves on the Issuer's board of directors. Under Dr. Scheiner's arrangement with the Adviser, Dr. Scheiner holds the option for the benefit of the Fund and the Nexus Fund. Dr. Scheiner is obligated to turn over to the Adviser any net cash or stock received upon exercise of the option, which will offset advisory fees owed by the Fund and the Nexus Fund to the Adviser. The Reporting Persons therefore disclaim beneficial ownership of the option and underlying common stock.

All shares subject to the option vest 100% on the first to occur of (i) June 5, 2026 or (ii) the day immediately preceding the first annual meeting of the Issuer's stockholders to occur after the date of grant of the award. Each grant, to the extent outstanding and otherwise unvested, will become fully vested should a "change in control" of the Issuer occur (as described in the applicable award agreement) or upon the Reporting Person's separation from service with the Issuer due to the Reporting Person's death or "disability" (as described in the applicable award agreement).

All shares subject to the option vest 100% on the first to occur of (i) June 5, 2026 or (ii) the day immediately preceding the first annual meeting of the Issuer's stockholders to occur after the date of grant of the award. Each grant, to the extent outstanding and otherwise unvested, will become fully vested should a "change in control" of the Issuer occur (as described in the applicable award agreement) or upon the Reporting Person's separation from service with the Issuer due to the Reporting Person's death or "disability" (as described in the applicable award agreement).

Under the Reporting Person's arrangement with RA Capital Management, L.P. (the "Adviser"), the Reporting Person holds the stock option for the benefit of the RA Capital Healthcare Fund, L.P. (the "Fund") and the RA Capital Nexus Fund, L.P. (the "Nexus Fund"). The Reporting Person is obligated to turn over to the Adviser any net cash or stock received upon exercise of the stock option, which will offset advisory fees owed by the Fund and the Nexus Fund to the Adviser. The Reporting Person therefore disclaims beneficial ownership of the stock option and underlying common stock.

The option is scheduled to vest and become exercisable as to 40% of the shares subject to the grant on June 5, 2026. The remaining 60% of the shares subject to the grant is scheduled to vest and become exercisable on June 5, 2027.

All shares subject to the option vest 100% on the first to occur of (i) June 5, 2026 or (ii) the day immediately preceding the first annual meeting of the Issuer's stockholders to occur after the date of grant of the award. Each grant, to the extent outstanding and otherwise unvested, will become fully vested should a "change in control" of the Issuer occur (as described in the applicable award agreement) or upon the Reporting Person's separation from service with the Issuer due to the Reporting Person's death or "disability" (as described in the applicable award agreement).

All shares subject to the option vest 100% on the first to occur of (i) June 5, 2026 or (ii) the day immediately preceding the first annual meeting of the Issuer's stockholders to occur after the date of grant of the award. Each grant, to the extent outstanding and otherwise unvested, will become fully vested should a "change in control" of the Issuer occur (as described in the applicable award agreement) or upon the Reporting Person's separation from service with the Issuer due to the Reporting Person's death or "disability" (as described in the applicable award agreement).

Represents shares sold as required by the applicable award terms to satisfy tax withholding obligations in connection with the vesting and settlement of Restricted Stock Units and does not represent a discretionary transaction by the Reporting Person.

Represents shares sold as required by the applicable award terms to satisfy tax withholding obligations in connection with the vesting and settlement of Restricted Stock Units and does not represent a discretionary transaction by the Reporting Person.

Represents shares sold as required by the applicable award terms to satisfy tax withholding obligations in connection with the vesting and settlement of Restricted Stock Units and does not represent a discretionary transaction by the Reporting Person.

Represents shares sold as required by the applicable award terms to satisfy tax withholding obligations in connection with the vesting and settlement of Restricted Stock Units and does not represent a discretionary transaction by the Reporting Person.

Represents shares sold as required by the applicable award terms to satisfy tax withholding obligations in connection with the vesting and settlement of Restricted Stock Units and does not represent a discretionary transaction by the Reporting Person.

Represents Restricted Stock Units ("RSUs") which vest in four equal annual installments beginning on January 14, 2026. Each RSU represents a contingent right to receive one share of Common Stock of the Issuer.

Represents Restricted Stock Units ("RSUs") which vest in four equal annual installments beginning on January 14, 2026. Each RSU represents a contingent right to receive one share of Common Stock of the Issuer.

Represents Restricted Stock Units ("RSUs") which vest in four equal annual installments beginning on January 14, 2026. Each RSU represents a contingent right to receive one share of Common Stock of the Issuer.

Includes 2,000 shares acquired under the Issuer's 2020 Employee Stock Purchase Plan on November 30, 2024.

This option is scheduled to vest and become exercisable in 48 equal monthly installments occurring on the completion of each successive month of the Reporting Person's service to the Issuer following January 14, 2025.

Represents Restricted Stock Units ("RSUs") which vest in four equal annual installments beginning on January 14, 2026. Each RSU represents a contingent right to receive one share of Common Stock of the Issuer.

This option is scheduled to vest and become exercisable in 48 equal monthly installments occurring on the completion of each successive month of the Reporting Person's service to the Issuer following January 14, 2025.

Represents Restricted Stock Units ("RSUs") which vest in four equal annual installments beginning on January 14, 2026. Each RSU represents a contingent right to receive one share of Common Stock of the Issuer.

Includes 2,000 shares acquired on May 31, 2024 and 2,000 shares acquired on November 30, 2024, in each case under the Issuer's 2020 Employee Stock Purchase Plan.

This option is scheduled to vest and become exercisable in 48 equal monthly installments occurring on the completion of each successive month of the Reporting Person's service to the Issuer following January 14, 2025.

This option is scheduled to vest and become exercisable in 48 equal monthly installments occurring on the completion of each successive month of the Reporting Person's service to the Issuer following January 14, 2025.

This option is scheduled to vest and become exercisable in 48 equal monthly installments occurring on the completion of each successive month of the Reporting Person's service to the Issuer following January 14, 2025.

Represents Restricted Stock Units ("RSUs") which vest in four equal annual installments beginning on January 14, 2026. Each RSU represents a contingent right to receive one share of Common Stock of the Issuer.

This option is scheduled to vest and become exercisable in 48 equal monthly installments occurring on the completion of each successive month of the Reporting Person's service to the Issuer following January 14, 2025.

Represents shares sold to satisfy tax withholding obligations in connection with the vesting and settlement of Restricted Stock Units and does not represent a discretionary transaction by the Reporting Person.

Includes 2,000 shares acquired under the Issuer's 2020 Employee Stock Purchase Plan on May 31, 2024.

The option is scheduled to vest and become exercisable as to 25% of the shares subject to the grant on July 29, 2025. The remaining portion of the option is scheduled to vest and become exercisable in 36 equal monthly installments occurring on the completion of each successive month of the Reporting Person's service to the Issuer following July 29, 2025.

The transaction reported in this Form 4 was effected automatically pursuant to a Rule 10b5-1 trading plan previously adopted by the Reporting Person on March 28, 2024.

This transaction is inadvertently filed late due to an administrative error.

This option is scheduled to vest and become exercisable in 48 equal monthly installments occurring on the completion of each successive month of the Reporting Person's service to the Issuer following July 15, 2024.