IMA

The shares vest in full upon the earlier to occur of the first anniversary of the date of grant, the date of the Issuer's next annual meeting or a change of control as defined in the Issuer's 2025 Equity Incentive Plan.

The shares vest in full upon the earlier to occur of the first anniversary of the date of grant, the date of the Issuer's next annual meeting or a change of control as defined in the Issuer's 2025 Equity Incentive Plan.

The shares vest in full upon the earlier to occur of the first anniversary of the date of grant, the date of the Issuer's next annual meeting or a change of control as defined in the Issuer's 2025 Equity Incentive Plan.

The shares vest in full upon the earlier to occur of the first anniversary of the date of grant, the date of the Issuer's next annual meeting or a change of control as defined in the Issuer's 2025 Equity Incentive Plan.

On April 12, 2026, the Issuer entered into a securities purchase agreement (the "Purchase Agreement") with certain institutional and accredited investors, including the Reporting Persons. Pursuant to the terms of the Purchase Agreement, the Issuer issued and sold to the Reporting Persons in a private placement which closed on April 14, 2026 (the "Closing Date") pre-funded warrants ("Pre-Funded Warrants") to purchase up to an aggregate of 721,292 Shares. The price per Pre-Funded Warrant is $5.199.

The Pre-Funded Warrants are exercisable at any time after the date of issuance, subject to a 19.99% beneficial ownership blocker. The Pre-Funded Warrants will expire once exercised in full.

These securities are held of record by OrbiMed Private Investments VI, LP ("OPI VI"). OrbiMed Capital GP VI LLC ("GP VI") is the general partner of OPI VI. OrbiMed Advisors LLC ("OrbiMed Advisors"), a registered investment adviser under the Investment Advisers Act of 1940, as amended, is the managing member of GP VI. By virtue of such relationships, GP VI and OrbiMed Advisors may be deemed to have voting and investment power with respect to the securities held by OPI VI. OrbiMed Advisors exercises this investment and voting power through a management committee comprised of Carl L. Gordon, Sven H. Borho, and W. Carter Neild, each of whom disclaims beneficial ownership of the shares held by OPI VI.

This report on Form 4 is jointly filed by OrbiMed Advisors, GP VI, and Genesis GP. Each of the Reporting Persons disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1943, as amended (the "Exchange Act"), except to the extent of its pecuniary interest therein, if any. OrbiMed Advisors has designated a representative, David P. Bonita ("Bonita"), a member of OrbiMed Advisors, to serve on the Issuer's board of directors. This report shall not be deemed an admission that any of the Reporting Persons or Bonita is a beneficial owner of such securities for purposes of Section 16 of the Exchange Act, or for any other purpose.

On April 12, 2026, the Issuer entered into a securities purchase agreement (the "Purchase Agreement") with certain institutional and accredited investors. Pursuant to the terms of the Purchase Agreement, the Issuer issued and sold to OrbiMed Private Investments VI, LP ("OPI VI") and OrbiMed Genesis Master Fund, L.P. ("Genesis Master Fund") in a private placement which closed on April 14, 2026 (the "Closing Date") pre-funded warrants ("Pre-Funded Warrants") to purchase up to an aggregate of 721,292 Shares. The price per Pre-Funded Warrant is $5.199.

The Pre-Funded Warrants are exercisable at any time after the date of issuance, subject to a 19.99% beneficial ownership blocker. The Pre-Funded Warrants will expire once exercised in full.

These securities are held of record by OPI VI. OrbiMed Capital GP VI LLC ("GP VI") is the general partner of OPI VI. OrbiMed Advisors LLC ("OrbiMed Advisors"), a registered investment adviser under the Investment Advisers Act of 1940, as amended, is the managing member of GP VI. By virtue of such relationships, GP VI and OrbiMed Advisors may be deemed to have voting and investment power with respect to the securities held by OPI VI. OrbiMed Advisors exercises this investment and voting power through a management committee comprised of Carl L. Gordon, Sven H. Borho, and W. Carter Neild, each of whom disclaims beneficial ownership of the shares held by OPI VI.

Each of the Reporting Person, OrbiMed Advisors, GP VI, and Genesis GP disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1943, as amended (the "Exchange Act"), except to the extent of his or its pecuniary interest therein, if any. This report shall not be deemed an admission that any of the Reporting Person, OrbiMed Advisors, GP VI, or Genesis GP is a beneficial owner of such securities for purposes of Section 16 of the Exchange Act, or for any other purpose.

On April 12, 2026, the Issuer entered into a securities purchase agreement (the "Purchase Agreement") with certain institutional and accredited investors. Pursuant to the terms of the Purchase Agreement, the Issuer issued and sold to OrbiMed Private Investments VI, LP ("OPI VI") and OrbiMed Genesis Master Fund, L.P. ("Genesis Master Fund") in a private placement which closed on April 14, 2026 (the "Closing Date") pre-funded warrants ("Pre-Funded Warrants") to purchase up to an aggregate of 721,292 Shares. The price per Pre-Funded Warrant is $5.199.

The Pre-Funded Warrants are exercisable at any time after the date of issuance, subject to a 19.99% beneficial ownership blocker. The Pre-Funded Warrants will expire once exercised in full.

These securities are held of record by Genesis Master Fund. OrbiMed Genesis GP LLC ("Genesis GP") is the general partner of Genesis Master Fund. OrbiMed Advisors is the managing member of Genesis GP. By virtue of such relationships, Genesis GP and OrbiMed Advisors may be deemed to have voting and investment power with respect to the securities held by Genesis Master Fund. OrbiMed Advisors exercises voting and investment power through a management committee comprised of Carl L. Gordon, Sven H. Borho, and W. Carter Neild, each of whom disclaims beneficial ownership of the shares held by Genesis Master Fund.

Each of the Reporting Person, OrbiMed Advisors, GP VI, and Genesis GP disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1943, as amended (the "Exchange Act"), except to the extent of his or its pecuniary interest therein, if any. This report shall not be deemed an admission that any of the Reporting Person, OrbiMed Advisors, GP VI, or Genesis GP is a beneficial owner of such securities for purposes of Section 16 of the Exchange Act, or for any other purpose.

On April 12, 2026, the Issuer entered into a securities purchase agreement (the "Purchase Agreement") with certain institutional and accredited investors, including the Reporting Persons. Pursuant to the terms of the Purchase Agreement, the Issuer issued and sold to the Reporting Persons in a private placement which closed on April 14, 2026 (the "Closing Date") pre-funded warrants ("Pre-Funded Warrants") to purchase up to an aggregate of 721,292 Shares. The price per Pre-Funded Warrant is $5.199.

The Pre-Funded Warrants are exercisable at any time after the date of issuance, subject to a 19.99% beneficial ownership blocker. The Pre-Funded Warrants will expire once exercised in full.

These securities are held of record by OrbiMed Genesis Master Fund, L.P. ("Genesis Master Fund"). OrbiMed Genesis GP LLC ("Genesis GP") is the general partner of Genesis Master Fund. OrbiMed Advisors is the managing member of Genesis GP. By virtue of such relationships, Genesis GP and OrbiMed Advisors may be deemed to have voting and investment power with respect to the securities held by Genesis Master Fund. OrbiMed Advisors exercises voting and investment power through a management committee comprised of Carl L. Gordon, Sven H. Borho, and W. Carter Neild, each of whom disclaims beneficial ownership of the shares held by Genesis Master Fund.

This report on Form 4 is jointly filed by OrbiMed Advisors, GP VI, and Genesis GP. Each of the Reporting Persons disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1943, as amended (the "Exchange Act"), except to the extent of its pecuniary interest therein, if any. OrbiMed Advisors has designated a representative, David P. Bonita ("Bonita"), a member of OrbiMed Advisors, to serve on the Issuer's board of directors. This report shall not be deemed an admission that any of the Reporting Persons or Bonita is a beneficial owner of such securities for purposes of Section 16 of the Exchange Act, or for any other purpose.

Represents the number of shares of the Issuer's common stock ("Common Stock") underlying restricted stock units ("RSUs"). Each RSU represents the contingent right to receive one share of Common Stock upon settlement. 25% of RSUs will vest and settle into Common Stock on March 15, 2027, and the balance will vest in successive equal quarterly installments on each of the next 12 Standard Quarterly Dates thereafter, subject to the Reporting Person's Continuous Service (as defined in the Issuer's 2025 Equity Incentive Plan (the "2025 Plan")) through each such vesting date. The "Standard Quarterly Dates" are each of March 15, June 15, September 15 and December 15.

This option vests over four years, with 25% of the shares subject to this option vesting on March 15, 2027, and the remaining shares vesting in 36 substantially equal monthly installments thereafter, subject to the Reporting Person's Continuous Service (as defined in the 2025 Plan) through each such vesting date.

This option vests over four years, with 25% of the shares subject to this option vesting on July 15, 2026, and the remaining shares vesting in 36 substantially equal monthly installments thereafter, subject to the Reporting Person's Continuous Service (as defined in the 2025 Plan) through each such date.

Represents the number of shares of the Issuer's common stock ("Common Stock") underlying restricted stock units ("RSUs"). Each RSU represents the contingent right to receive one share of Common Stock upon settlement. 25% of RSUs will vest and settle into Common Stock on July 15, 2026, March 1, 2027, March 1, 2028 and March 1, 2029, in each case, subject to the Reporting Person's Continuous Service (as defined in the Issuer's 2025 Equity Incentive Plan (the "2025 Plan")) through each such date.

The award was granted as an Initial Grant as contemplated by the non-employee director compensation policy adopted by the Issuer's board of directors on December 18, 2025.

This option vests over a three-year period, with 1/36th of the shares subject to the option vesting in 36 substantially equal monthly installments, subject to the Reporting Person's Continuous Service (as defined in the Issuer's 2025 Equity Incentive Plan) through each such date.

The award was granted as an Initial Grant as contemplated by the non-employee director compensation policy adopted by the Issuer's board of directors on December 18, 2025.

This option vests over a three-year period, with 1/36th of the shares subject to the option vesting in 36 substantially equal monthly installments, subject to the Reporting Person's Continuous Service (as defined in the Issuer's 2025 Equity Incentive Plan) through each such date.

The award was granted as an Initial Grant as contemplated by the non-employee director compensation policy adopted by the Issuer's board of directors on December 18, 2025.

This option vests over a three-year period, with 1/36th of the shares subject to the option vesting in 36 substantially equal monthly installments, subject to the Reporting Person's Continuous Service (as defined in the Issuer's 2025 Equity Incentive Plan) through each such date.

In connection of the closing of the Merger between the Company (formerly known as Ikena Oncology, Inc. ("Ikena")) and Inmagene Biopharmaceuticals, shares of the combined company were issued on July 28 in exchange for certain options held by the holder in Ikena.

This option vests over four years, with 25% of the shares subject to this option vesting on July 25, 2026, and the remaining shares vesting in 36 substantially equal monthly installments thereafter.

Each restricted stock unit (collectively, the "RSUs") represents a contingent right to receive one share of the Issuer's common stock.

The RSUs vest over four years, with 25% of the shares subject to RSUs vesting on the one-year anniversary of the vesting commencement date and the remaining 75% of the shares vesting in equal quarterly installments over the following 12 quarterly dates.

Reflects a 1:12 reverse stock split effective on July 25, 2025 prior to the First Effective Time (as defined below) (the "Reverse Stock Split").

Under the terms of the Agreement and Plan of Merger, dated as of December 23, 2024, by and among, the Issuer, Merger Sub I, a wholly-owned subsidiary of the Issuer ("Merger Sub I"), Merger Sub II, a wholly-owned subsidiary of the Issuer ("Merger Sub II") and Inmagene Biopharmaceuticals ("Legacy Inmagene") (the "Merger Agreement"), on July 25, 2025, Merger Sub I merged with and into Legacy Inmagene (the "First Merger"), with Legacy Inmagene surviving the First Merger as a wholly-owned subsidiary of the Issuer, and immediately after the First Merger, Legacy Inmagene merged with and into Merger Sub II, with Merger Sub II surviving the Merger as a wholly-owned subsidiary of the Issuer (the "Second Merger" and together with the First Merger, the "Merger"). (continued in the next footnote).

Upon the closing of the First Merger, each Legacy Inmagene ordinary and preferred share was converted into the right to receive 0.003051 of shares of the Issuer common stock. Subsequent to the Merger, the name of the Issuer was changed from Ikena Oncology, Inc. ("Ikena") to ImageneBio, Inc. (continued in the next footnote).

Immediately prior to the effective time of the First Merger (the "First Effective Time"), each unexpired, unexercised and unvested option to purchase Ikena common stock (each, an "Ikena option") granted under the Ikena 2021 Stock Option and Incentive Plan (each, a "2021 Ikena option") was accelerated in full and, effective as of the First Effective Time, each unexpired, unexercised and fully vested 2021 Ikena option was automatically cancelled and extinguished and, in exchange, each former holder of any such 2021 Ikena option received a number of shares of Ikena common stock equal to (A) the product of (x) the aggregate number of shares of Ikena common stock subject to or underlying such Ikena option multiplied by (y) (i) $2.3647 minus (ii) the exercise or strike price of the Ikena option, divided by (B) $2.3647 (such transaction, the "2021 Ikena option acceleration").

Exchanged for 379 shares of Issuer following the 2021 Ikena option acceleration and the Reverse Stock Split.

This option is fully vested.

Under the terms of the Agreement and Plan of Merger, dated as of December 23, 2024, by and among, the Issuer, Merger Sub I, a wholly-owned subsidiary of the Issuer ("Merger Sub I"), Merger Sub II, a wholly-owned subsidiary of the Issuer ("Merger Sub II") and Inmagene Biopharmaceuticals ("Legacy Inmagene") (the "Merger Agreement"), on July 25, 2025, Merger Sub I merged with and into Legacy Inmagene (the "First Merger"), with Legacy Inmagene surviving the First Merger as a wholly-owned subsidiary of the Issuer, and immediately after the First Merger, Legacy Inmagene merged with and into Merger Sub II, with Merger Sub II surviving the First Merger as a wholly-owned subsidiary of the Issuer (the "Second Merger" and together with the First Merger, the "Merger"). (continued in the next footnote).

Upon the closing of the Merger, each Legacy Inmagene ordinary and preferred share was converted into the right to receive 0.003051 of shares of the Issuer common stock. Subsequent to the Merger, the name of the Issuer was changed from Ikena Oncology, Inc. ("Ikena") to ImageneBio, Inc.

Received in exchange for a stock option to acquire 9,000,000 shares of common stock of Legacy Inmagene with the exercise price of $0.014 per share pursuant to the Merger Agreement.

(i) 15,255 shares subject to the option vest as follows: 25% of such shares vested on the one year anniversary of the vesting commencement date and the balance of such shares will vest in a series of thirty-six (36) successive equal monthly installments measured from the first anniversary of the vesting commencement date and (ii) 12,204 shares subject to the option vest as follows: (a) 3,051 of such shares will vest at the end of the first anniversary of grantee's qualified move to San Diego ("QMSD") and (b) 9,153 of such shares will vest in equal annual installments over the following three (3) years measured from the first anniversary of the QMSD, subject to grantee's QMSD not being terminated.

Received in exchange for 1,000,000 ordinary shares of Inmagene Biopharmaceuticals ("Legacy Inmagene") pursuant to Agreement and Plan of Merger, dated as of December 23, 2024, by and among, the Issuer, Merger Sub I, a wholly-owned subsidiary of the Issuer ("Merger Sub I"), Merger Sub II, a wholly-owned subsidiary of the Issuer ("Merger Sub II") and Legacy Inmagene (the "Merger Agreement").

Under the terms of the Merger Agreement, on July 25, 2025, Merger Sub I merged with and into Legacy Inmagene (the "Merger"), with Legacy Inmagene surviving the Merger as a wholly-owned subsidiary of the Issuer, and immediately after the First Merger, Legacy Inmagene merged with and into Merger Sub II, with Merger Sub II surviving the Merger as a wholly-owned subsidiary of the Issuer (the "Second Merger" and together with the First Merger, the "Merger"). Upon the closing of the First Merger, each Legacy Inmagene ordinary and preferred share was converted into the right to receive 0.003051 of shares of the Issuer common stock. Subsequent to the Merger, the name of the Issuer was changed from Ikena Oncology, Inc. to ImageneBio, Inc.

Reflects a 1:12 reverse stock split effective on July 25, 2025 prior to the First Effective Time (as defined below) (the "Reverse Stock Split").

Under the terms of the Agreement and Plan of Merger, dated as of December 23, 2024, by and among, the Issuer, Merger Sub I, a wholly-owned subsidiary of the Issuer ("Merger Sub I"), Merger Sub II, a wholly-owned subsidiary of the Issuer ("Merger Sub II") and Inmagene Biopharmaceuticals ("Legacy Inmagene") (the "Merger Agreement"), on July 25, 2025, Merger Sub I merged with and into Legacy Inmagene (the "First Merger"), with Legacy Inmagene surviving the First Merger as a wholly-owned subsidiary of the Issuer, and immediately after the First Merger, Legacy Inmagene merged with and into Merger Sub II, with Merger Sub II surviving the Merger as a wholly-owned subsidiary of the Issuer (the "Second Merger" and together with the First Merger, the "Merger"). (continued in the next footnote).

Upon the closing of the First Merger, each Legacy Inmagene ordinary and preferred share was converted into the right to receive 0.003051 of shares of the Issuer common stock. (continued in FN 3 below). Subsequent to the Merger, the name of the Issuer was changed from Ikena Oncology, Inc. ("Ikena") to ImageneBio, Inc. (continued in the next footnote).

Immediately prior to the effective time of the First Merger (the "First Effective Time"), each unexpired, unexercised and unvested option to purchase Ikena common stock (each, an "Ikena option") granted under the Ikena 2021 Stock Option and Incentive Plan (each, a "2021 Ikena option") was accelerated in full and, effective as of the First Effective Time, each unexpired, unexercised and fully vested 2021 Ikena option was automatically cancelled and extinguished and, in exchange therefor, each former holder of any such 2021 Ikena option received a number of shares of Ikena common stock equal to (A) the product of (x) the aggregate number of shares of Ikena common stock subject to or underlying such Ikena option multiplied by (y) (i) $2.3647 minus (ii) the exercise or strike price of the Ikena option, divided by (B) $2.3647 (such transaction, the "2021 Ikena option acceleration").

These securities are held of record by OrbiMed Private Investments VI, LP ("OPI VI"). OrbiMed Capital GP VI LLC ("GP VI") is the general partner of OPI VI. OrbiMed Advisors LLC ("OrbiMed Advisors"), a registered investment adviser under the Investment Advisers Act of 1940, as amended, is the managing member of GP VI. By virtue of such relationships, GP VI and OrbiMed Advisors may be deemed to have voting and investment power with respect to the securities held by OPI VI. OrbiMed Advisors exercises this investment and voting power through a management committee comprised of Carl L. Gordon, Sven H. Borho, and W. Carter Neild, each of whom disclaims beneficial ownership of the shares held by OPI VI.

This report on Form 4 is jointly filed by OrbiMed Advisors, GP VI, and Genesis GP. Each of the Reporting Persons disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1943, as amended (the "Exchange Act"), except to the extent of its pecuniary interest therein, if any. OrbiMed Advisors has designated a representative, David P. Bonita ("Bonita"), a member of OrbiMed Advisors, to serve on the Issuer's board of directors. This report shall not be deemed an admission that any of the Reporting Persons or Bonita is a beneficial owner of such securities for purposes of Section 16 of the Exchange Act, or for any other purpose.

Under the terms of the Agreement and Plan of Merger, dated as of December 23, 2024, by and among, the Issuer, Insight Merger Sub I, a wholly-owned subsidiary of the Issuer ("Merger Sub I"), Insight Merger Sub II, a wholly-owned subsidiary of the Issuer ("Merger Sub II") and Inmagene Biopharmaceuticals ("Legacy Inmagene") (the "Merger Agreement"), on July 25, 2025, Merger Sub I merged with and into Legacy Inmagene (the "First Merger"), with Legacy Inmagene surviving the First Merger as a wholly-owned subsidiary of the Issuer, and immediately after the First Merger, Legacy Inmagene merged with and into Merger Sub II, with Merger Sub II surviving the First Merger as a wholly-owned subsidiary of the Issuer (the "Second Merger" and together with the First Merger, the "Merger"). (continued in the next footnote).

Upon the closing of the Merger, each Legacy Inmagene ordinary and preferred share was converted into the right to receive 0.003051 of shares of the Issuer common stock. Subsequent to the Merger, the name of the Issuer was changed from Ikena Oncology, Inc. ("Ikena") to ImageneBio, Inc.

Consists of 34,054 shares of the Issuer's Common Stock received in exchange for 11,161,633 Series C-1 Preferred Shares of Legacy Inmagene and 16,090 shares of the Issuer's Common Stock received in exchange for 5,273,871 Series C-2 Preferred Shares of Legacy Inmagene pursuant to the Merger Agreement.

HLC Healthcare HK Limited is controlled by HLC Partners III L.P., whose general partner is HLC GP III Company Limited ("HLC GP"). HLC GP is wholly owned by Mr. Wang. HLC GP also acts as the general partner of Galaxy Alpha L.P. and Magic Hat L.P.. The voting and investment power of shares held by HLC Healthcare HK Limited, Galaxy Alpha L.P. and Magic Hat L.P. is exercised by Mr. Wang. Accordingly, Mr. Wang has an indirect pecuniary interest over the shares of the Issuer held by HLC Healthcare HK Limited. Mr. Wang disclaims beneficial ownership of the shares held by HLC Healthcare HK Limited, except to the extent of his pecuniary interest therein, if any.

Under the terms of the Agreement and Plan of Merger, dated as of December 23, 2024, by and among, the Issuer, Merger Sub I, a wholly-owned subsidiary of the Issuer ("Merger Sub I"), Merger Sub II, a wholly-owned subsidiary of the Issuer ("Merger Sub II") and Inmagene Biopharmaceuticals ("Legacy Inmagene") (the "Merger Agreement"), on July 25, 2025, Merger Sub I merged with and into Legacy Inmagene (the "First Merger"), with Legacy Inmagene surviving the First Merger as a wholly-owned subsidiary of the Issuer, and immediately after the First Merger, Legacy Inmagene merged with and into Merger Sub II, with Merger Sub II surviving the First Merger as a wholly-owned subsidiary of the Issuer (the "Second Merger" and together with the First Merger, the "Merger"). (continued in the next footnote).

Upon the closing of the Merger, each Legacy Inmagene ordinary and preferred share was converted into the right to receive 0.003051 of shares of the Issuer common stock. Subsequent to the Merger, the name of the Issuer was changed from Ikena Oncology, Inc. ("Ikena") to ImageneBio, Inc.

Received in exchange for a stock option to acquire 2,000,000 shares of common stock of Legacy Inmagene with the exercise price of $0.014 per share pursuant to the Merger Agreement.

25% of the shares subject to the option vested on the one year anniversary of the vesting commencement date and the balance of the shares vested or will vest in a series of thirty-six (36) successive equal monthly installments measured from the first anniversary of the vesting commencement date.

In connection of the closing of the Merger between the Company (formerly known as Ikena Oncology, Inc. ("Ikena")) and Inmagene Biopharmaceuticals, shares of the combined company were issued on July 28 in exchange for certain options held by the holder in Ikena.

Reflects a 1:12 reverse stock split effective on July 25, 2025 prior to the First Effective Time (as defined below) (the "Reverse Stock Split").

Under the terms of the Agreement and Plan of Merger, dated as of December 23, 2024, by and among, the Issuer, Merger Sub I, a wholly-owned subsidiary of the Issuer ("Merger Sub I"), Merger Sub II, a wholly-owned subsidiary of the Issuer ("Merger Sub II") and Inmagene Biopharmaceuticals ("Legacy Inmagene") (the "Merger Agreement"), on July 25, 2025, Merger Sub I merged with and into Legacy Inmagene (the "First Merger"), with Legacy Inmagene surviving the First Merger as a wholly-owned subsidiary of the Issuer, and immediately after the First Merger, Legacy Inmagene merged with and into Merger Sub II, with Merger Sub II surviving the Merger as a wholly-owned subsidiary of the Issuer (the "Second Merger" and together with the First Merger, the "Merger"). (continued in the next footnote).

Upon the closing of the First Merger, each Legacy Inmagene ordinary and preferred share was converted into the right to receive 0.003051 of shares of the Issuer common stock. Subsequent to the Merger, the name of the Issuer was changed from Ikena Oncology, Inc. ("Ikena") to ImageneBio, Inc. (continued in the next footnote).

Immediately prior to the effective time of the First Merger (the "First Effective Time"), each unexpired, unexercised and unvested option to purchase Ikena common stock (each, an "Ikena option") granted under the Ikena 2021 Stock Option and Incentive Plan (each, a "2021 Ikena option") was accelerated in full and, effective as of the First Effective Time, each unexpired, unexercised and fully vested 2021 Ikena option was automatically cancelled and extinguished and, in exchange, each former holder of any such 2021 Ikena option received a number of shares of Ikena common stock equal to (A) the product of (x) the aggregate number of shares of Ikena common stock subject to or underlying such Ikena option multiplied by (y) (i) $2.3647 minus (ii) the exercise or strike price of the Ikena option, divided by (B) $2.3647 (such transaction, the "2021 Ikena option acceleration").

Under the terms of the Agreement and Plan of Merger, dated as of December 23, 2024, by and among, the Issuer, Insight Merger Sub I, a wholly-owned subsidiary of the Issuer ("Merger Sub I"), Insight Merger Sub II, a wholly-owned subsidiary of the Issuer ("Merger Sub II") and Inmagene Biopharmaceuticals ("Legacy Inmagene") (the "Merger Agreement"), on July 25, 2025, Merger Sub I merged with and into Legacy Inmagene (the "First Merger"), with Legacy Inmagene surviving the First Merger as a wholly-owned subsidiary of the Issuer, and immediately after the First Merger, Legacy Inmagene merged with and into Merger Sub II, with Merger Sub II surviving the First Merger as a wholly-owned subsidiary of the Issuer (the "Second Merger" and together with the First Merger, the "Merger"). (continued in the next footnote).

Upon the closing of the Merger, each Legacy Inmagene ordinary and preferred share was converted into the right to receive 0.003051 of shares of the Issuer common stock. Subsequent to the Merger, the name of the Issuer was changed from Ikena Oncology, Inc. ("Ikena") to ImageneBio, Inc.

Consists of 8,513 shares of the Issuer's Common Stock received in exchange for 2,790,408 Series C-1 Preferred Shares of Legacy Inmagene and 4,022 shares of the Issuer's Common Stock received in exchange for 1,318,468 Series C-2 Preferred Shares of Legacy Inmagene pursuant to the Merger Agreement.

HLC Healthcare HK Limited is controlled by HLC Partners III L.P., whose general partner is HLC GP III Company Limited ("HLC GP"). HLC GP is wholly owned by Mr. Wang. HLC GP also acts as the general partner of Galaxy Alpha L.P. and Magic Hat L.P.. The voting and investment power of shares held by HLC Healthcare HK Limited, Galaxy Alpha L.P. and Magic Hat L.P. is exercised by Mr. Wang. Accordingly, Mr. Wang has an indirect pecuniary interest over the shares of the Issuer held by HLC Healthcare HK Limited. Mr. Wang disclaims beneficial ownership of the shares held by HLC Healthcare HK Limited, except to the extent of his pecuniary interest therein, if any.

Reflects a 1:12 reverse stock split effective on July 25, 2025 prior to the First Effective Time (as defined below) (the "Reverse Stock Split").

Under the terms of the Agreement and Plan of Merger, dated as of December 23, 2024, by and among, the Issuer, Merger Sub I, a wholly-owned subsidiary of the Issuer ("Merger Sub I"), Merger Sub II, a wholly-owned subsidiary of the Issuer ("Merger Sub II") and Inmagene Biopharmaceuticals ("Legacy Inmagene") (the "Merger Agreement"), on July 25, 2025, Merger Sub I merged with and into Legacy Inmagene (the "First Merger"), with Legacy Inmagene surviving the First Merger as a wholly-owned subsidiary of the Issuer, and immediately after the First Merger, Legacy Inmagene merged with and into Merger Sub II, with Merger Sub II surviving the Merger as a wholly-owned subsidiary of the Issuer (the "Second Merger" and together with the First Merger, the "Merger"). (continued in the next footnote).

Upon the closing of the First Merger, each Legacy Inmagene ordinary and preferred share was converted into the right to receive 0.003051 of shares of the Issuer common stock. (continued in FN 3 below). Subsequent to the Merger, the name of the Issuer was changed from Ikena Oncology, Inc. ("Ikena") to ImageneBio, Inc. (continued in the next footnote).

Immediately prior to the effective time of the First Merger (the "First Effective Time"), each unexpired, unexercised and unvested option to purchase Ikena common stock (each, an "Ikena option") granted under the Ikena 2021 Stock Option and Incentive Plan (each, a "2021 Ikena option") was accelerated in full and, effective as of the First Effective Time, each unexpired, unexercised and fully vested 2021 Ikena option was automatically cancelled and extinguished and, in exchange therefor, each former holder of any such 2021 Ikena option received a number of shares of Ikena common stock equal to (A) the product of (x) the aggregate number of shares of Ikena common stock subject to or underlying such Ikena option multiplied by (y) (i) $2.3647 minus (ii) the exercise or strike price of the Ikena option, divided by (B) $2.3647 (such transaction, the "2021 Ikena option acceleration").

Exchanged for 379 shares of Issuer following the 2021 Ikena option acceleration and the Reverse Stock Split.

This option is fully vested.

Under the terms of the Agreement and Plan of Merger, dated as of December 23, 2024, by and among, the Issuer, Insight Merger Sub I, a wholly-owned subsidiary of the Issuer ("Merger Sub I"), Insight Merger Sub II, a wholly-owned subsidiary of the Issuer ("Merger Sub II") and Inmagene Biopharmaceuticals ("Legacy Inmagene") (the "Merger Agreement"), on July 25, 2025, Merger Sub I merged with and into Legacy Inmagene (the "First Merger"), with Legacy Inmagene surviving the First Merger as a wholly-owned subsidiary of the Issuer, and immediately after the First Merger, Legacy Inmagene merged with and into Merger Sub II, with Merger Sub II surviving the First Merger as a wholly-owned subsidiary of the Issuer (the "Second Merger" and together with the First Merger, the "Merger"). (continued in the next footnote).

Upon the closing of the Merger, each Legacy Inmagene ordinary and preferred share was converted into the right to receive 0.003051 of shares of the Issuer common stock. Subsequent to the Merger, the name of the Issuer was changed from Ikena Oncology, Inc. ("Ikena") to ImageneBio, Inc.

Received in exchange for 318,313,306 ordinary shares of Legacy Inmagene pursuant to the Merger Agreement.

Engene Inc.'s sole shareholder is YJH Trust of which Trident Trust Company (HK) Limited serves as trustee. Dr. Wang's spouse and daughter are the sole beneficiaries of YJH Trust. Accordingly, Dr. Wang has an indirect pecuniary interest over the shares of the Issuer held by Engene Inc. Dr. Wang disclaims beneficial ownership of the shares held by Engene Inc. except to the extent of his pecuniary interest therein, if any.

Under the terms of the Agreement and Plan of Merger, dated as of December 23, 2024, by and among, the Issuer, Insight Merger Sub I, a wholly-owned subsidiary of the Issuer ("Merger Sub I"), Insight Merger Sub II, a wholly-owned subsidiary of the Issuer ("Merger Sub II") and Inmagene Biopharmaceuticals ("Legacy Inmagene") (the "Merger Agreement"), on July 25, 2025, Merger Sub I merged with and into Legacy Inmagene (the "First Merger"), with Legacy Inmagene surviving the First Merger as a wholly-owned subsidiary of the Issuer, and immediately after the First Merger, Legacy Inmagene merged with and into Merger Sub II, with Merger Sub II surviving the First Merger as a wholly-owned subsidiary of the Issuer (the "Second Merger" and together with the First Merger, the "Merger"). (continued in the next footnote).

Upon the closing of the Merger, each Legacy Inmagene ordinary and preferred share was converted into the right to receive 0.003051 of shares of the Issuer common stock. Subsequent to the Merger, the name of the Issuer was changed from Ikena Oncology, Inc. ("Ikena") to ImageneBio, Inc.

Consists of 127,703 shares of the Issuer's Common Stock received in exchange for 41,856,123 Series C-1 Preferred Shares of Legacy Inmagene and 60,339 shares of the Issuer's Common Stock received in exchange for 19,777,018 Series C-2 Preferred Shares of Legacy Inmagene pursuant to the Merger Agreement.

HLC Healthcare HK Limited is controlled by HLC Partners III L.P., whose general partner is HLC GP III Company Limited ("HLC GP"). HLC GP is wholly owned by Mr. Wang. HLC GP also acts as the general partner of Galaxy Alpha L.P. and Magic Hat L.P.. The voting and investment power of shares held by HLC Healthcare HK Limited, Galaxy Alpha L.P. and Magic Hat L.P. is exercised by Mr. Wang. Accordingly, Mr. Wang has an indirect pecuniary interest over the shares of the Issuer held by HLC Healthcare HK Limited. Mr. Wang disclaims beneficial ownership of the shares held by HLC Healthcare HK Limited, except to the extent of his pecuniary interest therein, if any.

Under the terms of the Agreement and Plan of Merger, dated as of December 23, 2024, by and among, the Issuer, Merger Sub I, a wholly-owned subsidiary of the Issuer ("Merger Sub I"), Merger Sub II, a wholly-owned subsidiary of the Issuer ("Merger Sub II") and Inmagene Biopharmaceuticals ("Legacy Inmagene") (the "Merger Agreement"), on July 25, 2025, Merger Sub I merged with and into Legacy Inmagene (the "First Merger"), with Legacy Inmagene surviving the First Merger as a wholly-owned subsidiary of the Issuer, and immediately after the First Merger, Legacy Inmagene merged with and into Merger Sub II, with Merger Sub II surviving the First Merger as a wholly-owned subsidiary of the Issuer (the "Second Merger" and together with the First Merger, the "Merger"). (continued in the next footnote).

Upon the closing of the Merger, each Legacy Inmagene ordinary and preferred share was converted into the right to receive 0.003051 of shares of the Issuer common stock. Subsequent to the Merger, the name of the Issuer was changed from Ikena Oncology, Inc. ("Ikena") to ImageneBio, Inc.

Received in exchange for a stock option to acquire 12,500,000 shares of common stock of Legacy Inmagene with the exercise price of $0.0876 per share pursuant to the Merger Agreement.

25% of the shares subject to the option vested on the one year anniversary of the vesting commencement date and the balance of the shares vested or will vest in a series of thirty-six (36) successive equal monthly installments measured from the first anniversary of the vesting commencement date.

Under the terms of the Agreement and Plan of Merger, dated as of December 23, 2024, by and among, the Issuer, Merger Sub I, a wholly-owned subsidiary of the Issuer ("Merger Sub I"), Merger Sub II, a wholly-owned subsidiary of the Issuer ("Merger Sub II") and Inmagene Biopharmaceuticals ("Legacy Inmagene") (the "Merger Agreement"), on July 25, 2025, Merger Sub I merged with and into Legacy Inmagene (the "First Merger"), with Legacy Inmagene surviving the First Merger as a wholly-owned subsidiary of the Issuer, and immediately after the First Merger, Legacy Inmagene merged with and into Merger Sub II, with Merger Sub II surviving the First Merger as a wholly-owned subsidiary of the Issuer (the "Second Merger" and together with the First Merger, the "Merger"). (continued in the next footnote).

Upon the closing of the Merger, each Legacy Inmagene ordinary and preferred share was converted into the right to receive 0.003051 of shares of the Issuer common stock. Subsequent to the Merger, the name of the Issuer was changed from Ikena Oncology, Inc. ("Ikena") to ImageneBio, Inc.

Received in exchange for a stock option to acquire 1,505,000 shares of common stock of Legacy Inmagene with the exercise price of $0.014 per share pursuant to the Merger Agreement.

25% of the shares subject to the option vested on the one year anniversary of the vesting commencement date and the balance of the shares vested or will vest in a series of thirty-six (36) successive equal monthly installments measured from the first anniversary of the vesting commencement date.

OrbiMed Private Investments VI, LP ("OPI VI") purchased 83,611 shares of Issuer common stock on July 25, 2025 following the effective time of the Second Merger pursuant to that certain subscription agreement, dated as of December 23, 2024, by and between the Issuer and certain accredited investors (the "PIPE Investors"), pursuant to which, following the closing of the Merger, the PIPE Investors subscribed for and purchased an aggregate of 2,508,337 shares of Issuer common stock, after giving effect to the Reverse Stock Split, at a price of approximately $29.90 per share for aggregate gross proceeds of approximately $75.0 million.

Reflects a 1:12 reverse stock split effective on July 25, 2025 prior to the First Effective Time (as defined below) (the "Reverse Stock Split").

These securities are held of record by OPI VI. OrbiMed Capital GP VI LLC ("GP VI") is the general partner of OPI VI. OrbiMed Advisors LLC ("OrbiMed Advisors"), a registered investment adviser under the Investment Advisers Act of 1940, as amended, is the managing member of GP VI. By virtue of such relationships, GP VI and OrbiMed Advisors may be deemed to have voting and investment power with respect to the securities held by OPI VI. OrbiMed Advisors exercises this investment and voting power through a management committee comprised of Carl L. Gordon, Sven H. Borho, and W. Carter Neild, each of whom disclaims beneficial ownership of the shares held by OPI VI.

Each of the Reporting Person, OrbiMed Advisors, GP VI, and Genesis GP disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1943, as amended (the "Exchange Act"), except to the extent of his or its pecuniary interest therein, if any. This report shall not be deemed an admission that any of the Reporting Person, OrbiMed Advisors, GP VI, or Genesis GP is a beneficial owner of such securities for purposes of Section 16 of the Exchange Act, or for any other purpose.

Omega Fund VI, L.P. ("Omega VI") purchased 267,556 shares of Issuer common stock on July 25, 2025 following the effective time of the Second Merger pursuant to that certain subscription agreement, dated as of December 23, 2024, by and between the Issuer and certain accredited investors (the "PIPE Investors"), pursuant to which, following the closing of the Merger, the PIPE Investors subscribed for and purchased an aggregate of 2,508,337 shares of Issuer common stock, after giving effect to the Reverse Stock Split, at a price of approximately $29.90 per share for aggregate gross proceeds of approximately $75.0 million.

Reflects a 1:12 reverse stock split effective on July 25, 2025 prior to the First Effective Time (as defined below) (the "Reverse Stock Split").

Shares held directly by Omega VI. Omega Fund VI GP, L.P. ("Omega VI GP") is the sole general partner of Omega VI. Omega Fund VI GP Manager, Ltd. ("Omega VI Manager") is the sole general partner of Omega VI GP. The Reporting Person is a director of Omega VI Manager and disclaims beneficial ownership of the shares held by Omega VI except to the extent of his pecuniary interest therein, if any.

In connection of the closing of the Merger between the Company (formerly known as Ikena Oncology, Inc. ("Ikena")) and Inmagene Biopharmaceuticals, shares of the combined company were issued on July 28 in exchange for certain options held by the holder in Ikena.

In connection of the closing of the Merger between the Company (formerly known as Ikena Oncology, Inc. ("Ikena")) and Inmagene Biopharmaceuticals, shares of the combined company were issued on July 28 in exchange for certain options held by the holder in Ikena.

Under the terms of the Agreement and Plan of Merger, dated as of December 23, 2024, by and among, the Issuer, Insight Merger Sub I, a wholly-owned subsidiary of the Issuer ("Merger Sub I"), Insight Merger Sub II, a wholly-owned subsidiary of the Issuer ("Merger Sub II") and Inmagene Biopharmaceuticals ("Legacy Inmagene") (the "Merger Agreement"), on July 25, 2025, Merger Sub I merged with and into Legacy Inmagene (the "First Merger"), with Legacy Inmagene surviving the First Merger as a wholly-owned subsidiary of the Issuer, and immediately after the First Merger, Legacy Inmagene merged with and into Merger Sub II, with Merger Sub II surviving the First Merger as a wholly-owned subsidiary of the Issuer (the "Second Merger" and together with the First Merger, the "Merger"). (continued in the next footnote).

Upon the closing of the Merger, each Legacy Inmagene ordinary and preferred share was converted into the right to receive 0.003051 of shares of the Issuer common stock. Subsequent to the Merger, the name of the Issuer was changed from Ikena Oncology, Inc. ("Ikena") to ImageneBio, Inc.

Received in exchange for 47,142,857 Series Seed convertible preferred shares of Legacy Inmagene pursuant to the Merger Agreement.

Under the terms of the Merger Agreement, on July 25, 2025, Merger Sub I merged with and into Legacy Inmagene (the "Merger"), with Legacy Inmagene surviving the Merger as a wholly-owned subsidiary of the Issuer, and immediately after the First Merger, Legacy Inmagene merged with and into Merger Sub II, with Merger Sub II surviving the Merger as a wholly-owned subsidiary of the Issuer (the "Second Merger" and together with the First Merger, the "Merger"). Upon the closing of the First Merger, each Legacy Inmagene ordinary and preferred share was converted into the right to receive 0.003051 of shares of the Issuer common stock. Subsequent to the Merger, the name of the Issuer was changed from Ikena Oncology, Inc. to ImageneBio, Inc.

Received in exchange for a stock option to acquire 1,250,000 shares of common stock of Legacy Inmagene with the exercise price of $0.014 per share pursuant to the Merger Agreement.

25% of the shares subject to the option vested on the one year anniversary of the vesting commencement date and the balance of the shares vested or will vest in a series of thirty-six (36) successive equal monthly installments measured from the first anniversary of the vesting commencement date.

This option shall vest in full upon the earlier of (i) June 7, 2025 or (ii) the date of the next annual meeting; provided, however, that all vesting shall cease if the director resigns from the Board or otherwise ceases to serve as a director.