SCHEDULE 13G/A 0000950170-25-072020 0001493215 XXXXXXXX LIVE 2 Common Stock, $0.0001 par value 12/31/2025 0001526119 Verastem, Inc. 92337C203 117 Kendrick Street, Suite 500 Needham MA 02494 Rule 13d-1(b) RTW Investments, LP DE 0.00 7836346.00 0.00 7836346.00 7836346.00 9.9 IA PN Roderick Wong X1 0.00 7836346.00 0.00 7836346.00 7836346.00 9.9 HC IN Verastem, Inc. 117 Kendrick Street, Suite 500, Needham, MA, 02494. This statement is filed by: (i) RTW Investments, LP ("RTW Investments"), a Delaware limited partnership and the investment adviser to certain funds (the "RTW Funds"), with respect to shares of Common Stock, par value $0.0001 per share (the "Shares") of Verastem, Inc. (the "Company") directly held by the RTW Funds; and (ii) Roderick Wong, M.D. ("Dr. Wong"), the Managing Partner and Chief Investment Officer of RTW Investments, with respect to the Shares directly held by the RTW Funds. The foregoing persons are hereinafter sometimes collectively referred to as the "Reporting Persons." The filing of this statement should not be construed as an admission that any of the foregoing persons or any Reporting Person is, for the purposes of Section 13 of the Securities Exchange Act of 1934, as amended, the beneficial owner of the Shares reported herein. The address of the business office of each of the Reporting Persons is 40 10th Avenue, Floor 7, New York, New York 10014. RTW Investments is a Delaware limited partnership. Dr. Wong is a citizen of the United States. N IA HC The information required by Item 4(a) is set forth in Rows 5 - 9 of the cover page for each of the Reporting Persons and is incorporated herein by reference. The amounts reported herein assume the exercise of warrants held by the Reporting Persons to purchase 1,260,040 Shares (the "Warrants"), the maximum amount that may be exercised given the current number of outstanding shares and the shares held by the Reporting Persons. Pursuant to the terms of the Warrants, the Reporting Persons cannot exercise any of the Warrants to the extent the Reporting Persons would beneficially own, after any such exercise, more than 9.99% of the outstanding Shares. The percentages set forth in Row 11 of the cover pages are calculated based upon the sum of (i) 66,776,006 Shares outstanding as of November 3, 2025, as reported in the Issuer's Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission (the "SEC") on November 4, 2025, (ii) 10,405,863 Shares issued and sold in a public offering by the Company pursuant to the prospectus supplement dated November 13, 2025, filed with the SEC on November 17, 2025, including the issuance and sale of 1,862,069 Shares pursuant to the exercise in full of the underwriters' option to purchase additional Shares, and (iii) assume the exercise of Warrants held by the Reporting Persons to purchase 1,260,040 Shares. RTW Investments: 9.99% Dr. Wong: 9.99% RTW Investments: 0 Dr. Wong: 0 RTW Investments: 7,836,346 Shares Dr. Wong: 7,836,346 Shares RTW Investments: 0 Dr. Wong: 0 RTW Investments: 7,836,346 Shares Dr. Wong: 7,836,346 Shares Y N See Item 2. The RTW Funds have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the Shares reported herein. RTW Master Fund, Ltd., an RTW Fund, has the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of more than 5% of the Shares reported herein. Y Y Y N By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11. Exhibit 99.1 Joint Filing Agreement (incorporated by reference to Exhibit 99.1 to the Reporting Persons' Schedule 13G filed with the SEC on May 15, 2025). RTW Investments, LP /s/ Roderick Wong, M.D. 02/17/2026 Roderick Wong s/ Roderick Wong, M.D. 02/17/2026