Amendment: SEC Form SCHEDULE 13G/A filed by Verastem Inc.

Biotechnology Value Fund, L.P. 44 Montgomery St., 40th Floor San Francisco, California 94104 BVF I GP LLC 44 Montgomery St., 40th Floor San Francisco, California 94104 Biotechnology Value Fund II, L.P. 44 Montgomery St., 40th Floor San Francisco, California 94104 BVF II GP LLC 44 Montgomery St., 40th Floor San Francisco, California 94104 Biotechnology Value Trading Fund OS LP PO Box 309 Ugland House Grand Cayman, KY1-1104 Cayman Islands BVF Partners OS Ltd. PO Box 309 Ugland House Grand Cayman, KY1-1104 Cayman Islands BVF GP Holdings LLC 44 Montgomery St., 40th Floor San Francisco, California 94104 BVF Partners L.P. 44 Montgomery St., 40th Floor San Francisco, California 94104 BVF Inc. 44 Montgomery St., 40th Floor San Francisco, California 94104 Mark N. Lampert 44 Montgomery St., 40th Floor San Francisco, California 94104

Biotechnology Value Fund, L.P. Delaware BVF I GP LLC Delaware Biotechnology Value Fund II, L.P. Delaware BVF II GP LLC Delaware Biotechnology Value Trading Fund OS LP Cayman Islands BVF Partners OS Ltd. Cayman Islands BVF GP Holdings LLC Delaware BVF Partners L.P. Delaware BVF Inc. Delaware Mark N. Lampert United States

As of the close of business on December 31, 2024, the Reporting Persons and a certain Partners managed account (the "Partners Managed Account") held an aggregate of 1,000,000 shares of Series A Convertible Preferred Stock (the "Series A Preferred Stock"), convertible for an aggregate of 833,333 Shares. A holder of the Series A Preferred Stock shall not have the right to convert any portion of the Series A Preferred Stock held by it to the extent that, after giving effect to such conversion, such holder, together with such holder's affiliates and any other person whose beneficial ownership of Shares would be aggregated with such holder's Shares for purposes of Section 13(d) or Section 16 of the Securities Exchange Act of 1934, as amended, including any "group" of which the holder is a member, would beneficially own a number of Shares in excess of 9.99% of the number of Shares outstanding immediately after giving effect to such conversion (the "Conversion A Limitation"). As of the close of business on December 31, 2024, the Conversion A Limitation does not limit the conversion of any of the Series A Preferred Stock held by the Reporting Persons and the Partners Managed Account. As of the close of business on December 31, 2024, the Reporting Persons and the Partners Managed Account held an aggregate of 2,500,000 Pre-Funded Warrants (the "Pre-Funded Warrants") exercisable for an aggregate of 2,500,000 Shares. The Pre-Funded Warrants are exercisable immediately at an exercise price of $0.001 per Share and may be exercised at any time until all of the Pre-Funded Warrants are exercised in full. A holder of the Pre-Funded Warrants will not be entitled to exercise any Pre-Funded Warrants that, upon giving effect to such exercise, would cause: (i) the aggregate number of Shares beneficially owned by such holder (together with its affiliates and other attribution parties) to exceed 9.99% of the number of Shares outstanding immediately after giving effect to the exercise; or (ii) the combined voting power of the Issuer's securities beneficially owned by such holder (together with its affiliates and other attribution parties) to exceed 9.99% of the combined voting power of all of the Issuer's securities outstanding immediately after giving effect to the exercise (the "Pre-Funded Warrants Blocker"). As of the close of business on December 31, 2024, the Pre-Funded Warrants Blocker limits the exercise of the Pre-Funded Warrants held by the Reporting Persons and the Partners Managed Account to 1,772,750 out of the 2,500,000 Shares underlying the Pre-Funded Warrants. As of the close of business on December 31, 2024, the Reporting Persons and the Partners Managed Account held an aggregate of 2,500,000 Warrants (the "Warrants") exercisable for an aggregate of 2,500,000 Shares. The Warrants are exercisable immediately at an exercise price of $3.50 per Share and may be exercised until 18 months from the date of issuance. A holder of the Warrants will not be entitled to exercise any Warrants that, upon giving effect to such exercise, would cause: (i) the aggregate number of Shares beneficially owned by such holder (together with its affiliates and other attribution parties) to exceed 9.99% of the number of Shares outstanding immediately after giving effect to the exercise; or (ii) the combined voting power of the Issuer's securities beneficially owned by such holder (together with its affiliates and other attribution parties) to exceed 9.99% of the combined voting power of all of the Issuer's securities outstanding immediately after giving effect to the exercise (the "Warrants Blocker"). As of the close of business on December 31, 2024, the Warrants Blocker prohibits the exercise of all the Warrants held by the Reporting Persons and the Partners Managed Account. As of the close of business on December 31, 2024, (i) BVF beneficially owned 2,790,352 Shares, including 451,917 Shares underlying the Series A Preferred Stock held by it and 1,396,290 Shares underlying certain Pre-Funded Warrants held by it, and excluding 1,396,290 Shares underlying the Warrants held by it, (ii) BVF2 beneficially owned 1,696,557 Shares, including 319,083 Shares underlying the Series A Preferred Stock held by it and 376,460 Shares underlying certain Pre-Funded Warrants held by it, and excluding 556,780 Shares underlying certain Pre-Funded Warrants held by it and 933,240 Shares underlying the Warrants held by it, and (iii) Trading Fund OS beneficially owned 182,755 Shares, including 44,583 Shares underlying the Series A Preferred Stock held by it, and excluding 100,150 Shares underlying the Pre-Funded Warrants held by it and 100,150 Shares underlying the Warrants held by it. BVF GP, as the general partner of BVF, may be deemed to beneficially own the 2,790,352 Shares beneficially owned by BVF. BVF2 GP, as the general partner of BVF2, may be deemed to beneficially own the 1,696,557 Shares beneficially owned by BVF2. Partners OS, as the general partner of Trading Fund OS, may be deemed to beneficially own the 182,755 Shares beneficially owned by Trading Fund OS. BVF GPH, as the sole member of each of BVF GP and BVF2 GP, may be deemed to beneficially own the 4,486,909 Shares beneficially owned in the aggregate by BVF and BVF2. Partners, as the investment manager of BVF, BVF2 and Trading Fund OS, and the sole member of Partners OS, may be deemed to beneficially own the 4,706,551 Shares beneficially owned in the aggregate by BVF, BVF2 and Trading Fund OS and held in the Partners Managed Account, including 36,887 Shares held in the Partners Managed Account, which includes 17,750 Shares underlying the Series A Preferred Stock held by the Partners Managed Account, and excludes 70,320 Shares underlying the Pre-Funded Warrants held by it and 70,320 Shares underlying the Warrants held by it. BVF Inc., as the general partner of Partners, may be deemed to beneficially own the 4,706,551 Shares beneficially owned by Partners. Mr. Lampert, as a director and officer of BVF Inc., may be deemed to beneficially own the 4,706,551 Shares beneficially owned by BVF Inc. The foregoing should not be construed in and of itself as an admission by any Reporting Person as to beneficial ownership of any Shares owned by another Reporting Person. BVF GP disclaims beneficial ownership of the Shares beneficially owned by BVF. BVF2 GP disclaims beneficial ownership of the Shares beneficially owned by BVF2. Partners OS disclaims beneficial ownership of the Shares beneficially owned by Trading Fund OS. BVF GPH disclaims beneficial ownership of the Shares beneficially owned by BVF and BVF2. Each of Partners, BVF Inc. and Mr. Lampert disclaims beneficial ownership of the Shares beneficially owned by BVF, BVF2 and Trading Fund OS and held in the Partners Managed Account, and the filing of this statement shall not be construed as an admission that any such person or entity is the beneficial owner of any such securities.

The following percentages are based upon a denominator that is the sum of (i) 44,506,526 Shares outstanding, which is the total number of Shares outstanding as of November 5, 2024, as disclosed in the Issuer's Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission on November 6, 2024, (ii) certain or all of the 833,333 Shares underlying the Series A Preferred Stock held by the Reporting Persons and Partners Managed Account, as applicable, and (iii) certain or all of 1,772,750 Shares underlying certain Pre-Funded Warrants held by the Reporting Persons, as applicable. As of the close of business on December 31, 2024, (i) BVF beneficially owned approximately 6.0% of the outstanding Shares, (ii) BVF2 beneficially owned approximately 3.8% of the outstanding Shares, (iii) Trading Fund OS beneficially owned less than 1% of the outstanding Shares, (iv) BVF GP may be deemed to beneficially own approximately 6.0% of the outstanding Shares, (v) BVF2 GP may be deemed to beneficially own approximately 3.8% of the outstanding Shares, (vi) Partners OS may be deemed to beneficially own less than 1% of the outstanding Shares, (vii) BVF GPH may be deemed to beneficially own approximately 9.5% of the outstanding Shares and (viii) each of Partners, BVF Inc. and Mr. Lampert may be deemed to beneficially own approximately 9.99% of the outstanding Shares (less than 1% of the outstanding Shares are held in the Partners Managed Account).

See Cover Pages Items 5-9.

See Cover Pages Items 5-9.

See Cover Pages Items 5-9.

See Cover Pages Items 5-9.

BVF GP, BVF GPH, Partners, BVF Inc. and Mr. Lampert share voting and dispositive power over the Shares beneficially owned by BVF. BVF GPH, Partners, BVF Inc. and Mr. Lampert share voting and dispositive power over the Shares beneficially owned by BVF2. Partners, BVF Inc. and Mr. Lampert share voting and dispositive power over the Shares beneficially owned by Trading Fund OS and held in the Partners Managed Account.

See Exhibit 99.1 to Amendment No. 1 to the Schedule 13G filed by the Reporting Persons with the Securities and Exchange Commission on February 14, 2020.