CGEM · Cullinan Therapeutics, Inc.

Transaction effected pursuant to a plan established pursuant to Rule 10b5-1 on August 7, 2025.

The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $20.00 to $20.69. The Reporting Person undertakes to provide to the Issuer, any shareholder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

25% of the shares vested on July 4, 2020, and the remaining shares vested in 36 equal monthly installments thereafter.

25% of the shares vested on July 4, 2020, and the remaining shares vested in 36 equal monthly installments thereafter.

Transaction effected pursuant to a plan established pursuant to Rule 10b5-1 on August 7, 2025.

The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $17.35 to $18.19. The Reporting Person undertakes to provide to the Issuer, any shareholder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

The reporting person is voluntarily reporting the acquisition of shares of the Issuer's common stock pursuant to the Issuer's 2021 Employee Stock Purchase Plan (the "ESPP"), for the purchase period of January 1, 2026 through June 30, 2026. This transaction is also exempt under Rule 16b-3(c).

In accordance with the ESPP, the shares were purchased based on 85% of the closing price of the Issuer's common stock on January 2, 2026.

The reporting person is voluntarily reporting the acquisition of shares of the Issuer's common stock pursuant to the Issuer's 2021 Employee Stock Purchase Plan (the "ESPP"), for the purchase period of January 1, 2026 through June 30, 2026. This transaction is also exempt under Rule 16b-3(c).

In accordance with the ESPP, the shares were purchased based on 85% of the closing price of the Issuer's common stock on January 2, 2026.

The option represents a right to purchase a total of 25,319 shares of the Issuer's Common Stock, which shall vest in full on the earlier of (i) June 16, 2027 or (ii) the date of the Issuer's next annual meeting, subject to the Reporting Person's continued service as a director on such vesting date.

The option represents a right to purchase a total of 25,319 shares of the Issuer's Common Stock, which shall vest in full on the earlier of (i) June 16, 2027 or (ii) the date of the Issuer's next annual meeting, subject to the Reporting Person's continued service as a director on such vesting date.

The option represents a right to purchase a total of 25,319 shares of the Issuer's Common Stock, which shall vest in full on the earlier of (i) June 16, 2027 or (ii) the date of the Issuer's next annual meeting, subject to the Reporting Person's continued service as a director on such vesting date.

The option represents a right to purchase a total of 25,319 shares of the Issuer's Common Stock, which shall vest in full on the earlier of (i) June 16, 2027 or (ii) the date of the Issuer's next annual meeting, subject to the Reporting Person's continued service as a director on such vesting date.

The option represents a right to purchase a total of 21,781 shares of the Issuer's Common Stock, which shall vest in full on the earlier of (i) June 16, 2027 or (ii) the date of the Issuer's next annual meeting, subject to the Reporting Person's continued service as a director on such vesting date.

The option represents a right to purchase a total of 21,781 shares of the Issuer's Common Stock, which shall vest in full on the earlier of (i) June 16, 2027 or (ii) the date of the Issuer's next annual meeting, subject to the Reporting Person's continued service as a director on such vesting date.

25% of the shares vested on July 4, 2020, and the remaining shares vested in 36 equal monthly installments thereafter.

Transaction effected pursuant to a plan established pursuant to Rule 10b5-1 on August 7, 2025.

The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $14.24 to $15.12. The Reporting Person undertakes to provide to the Issuer, any shareholder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

Transaction effected pursuant to a plan established pursuant to Rule 10b5-1 on August 7, 2025.

The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $15.56 to $15.60. The Reporting Person undertakes to provide to the Issuer, any shareholder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

Transaction effected pursuant to a plan established pursuant to Rule 10b5-1 on August 7, 2025.

The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $15.38 to $16.31. The Reporting Person undertakes to provide to the Issuer, any shareholder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

25% of the shares vested on July 4, 2020, and the remaining shares vested in 36 equal monthly installments thereafter.

Transaction effected pursuant to a plan established pursuant to Rule 10b5-1 on August 7, 2025.

The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $13.89 to $14.35. The Reporting Person undertakes to provide to the Issuer, any shareholder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

Sale of shares to cover personal income tax obligations upon vesting of restricted stock units.

Sale of shares to cover personal income tax obligations upon vesting of restricted stock units.

Sale of shares to cover personal income tax obligations upon vesting of restricted stock units.

Sale of shares to cover personal income tax obligations upon vesting of restricted stock units.

Transaction effected pursuant to a plan established pursuant to Rule 10b5-1 on August 7, 2025.

The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $13.68 to $14.31. The Reporting Person undertakes to provide to the Issuer, any shareholder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

Sale of shares to cover personal income tax obligations upon vesting of restricted stock units.

Sale of shares to cover personal income tax obligations upon vesting of restricted stock units.

Sale of shares to cover personal income tax obligations upon vesting of restricted stock units.

Sale of shares to cover personal income tax obligations upon vesting of restricted stock units.

25% of the shares vested on July 4, 2020, and the remaining shares vested in 36 equal monthly installments thereafter.

Sale of shares to cover personal income tax obligations upon vesting of restricted stock units.

Transaction effected pursuant to a plan established pursuant to Rule 10b5-1 on August 7, 2025.

The shares underlying the option vest over four years, with one forty-eighth (1/48th) of the shares vesting in equal monthly installments until the fourth anniversary of the grant date.

The shares underlying the option vest over four years, with one forty-eighth (1/48th) of the shares vesting in equal monthly installments until the fourth anniversary of the grant date.

The shares underlying the option vest over four years, with one forty-eighth (1/48th) of the shares vesting in equal monthly installments until the fourth anniversary of the grant date.

The shares underlying the option vest over four years, with one forty-eighth (1/48th) of the shares vesting in equal monthly installments until the fourth anniversary of the grant date.

The shares underlying the restricted stock unit vest on an annual basis over four years.

The shares underlying the restricted stock unit vest on an annual basis over four years.

The shares underlying the option vest over four years, with one forty-eighth (1/48th) of the shares vesting in equal monthly installments until the fourth anniversary of the grant date.

The shares underlying the option vest over four years, with one forty-eighth (1/48th) of the shares vesting in equal monthly installments until the fourth anniversary of the grant date.

Sale of shares to cover personal income tax obligations upon vesting of restricted stock units.

Transaction effected pursuant to a plan established pursuant to Rule 10b5-1 on August 7, 2025.

The reporting person is voluntarily reporting the acquisition of shares of the Issuer's common stock pursuant to the Issuer's 2021 Employee Stock Purchase Plan (the "ESPP"), for the purchase period of July 1, 2025 through December 31, 2025. This transaction is also exempt under Rule 16b-3(c).

In accordance with the ESPP, the shares were purchased based on 85% of the closing price of the Issuer's common stock on July 1, 2025.

Includes 2,001 shares of common stock that the Reporting Person purchased pursuant to the Issuer's 2021 Employee Stock Purchase Plan for the purchase period of January 1, 2025 through June 30, 2025 that were exempt under both Rule 16b-3(d) and Rule 16b-3(c).

Sale of shares to cover personal income tax obligations upon vesting of restricted stock units.

Transaction effected pursuant to a plan established pursuant to Rule 10b5-1 on August 7, 2025.

The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $9.99 to $10.09. The Reporting Person undertakes to provide to the Issuer, any shareholder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

Sale of shares to cover personal income tax obligations upon vesting of restricted stock units.

Sale of shares to cover personal income tax obligations upon vesting of restricted stock units.

Includes 2,017 shares of common stock that the Reporting Person purchased pursuant to the Issuer's 2021 Employee Stock Purchase Plan for the purchase period of January 1, 2025 through June 30, 2025 that were exempt under both Rule 16b-3(d) and Rule 16b-3(c).