Verastem, Inc.

Item 2.02. Results of Operations and Financial Condition Set forth below are certain preliminary unaudited financial results for the three months ended September 30, 2026 of Verastem, Inc. (the “Company”). The preliminary unaudited third quarter 2026 financial results included in this Current Report on Form 8-K (the “Preliminary Financial Information”) are preliminary and were prepared by the Company’s management, based upon the Company’s estimates, a number of assumptions and currently available information, and are subject to revision based upon, among other things, quarter-end closing procedures and/or adjustments, the completion of the Company’s interim financial statements and other operational procedures. The Company’s independent registered public accounting firm has not audited, reviewed, examined, compiled, nor applied agreed-upon procedures with respect to the Preliminary Financial Information. Accordingly, the Company’s independent registered public accounting firm does not express an opinion or any other form of assurance with respect thereto. The Preliminary Financial Information is subject to completion of the Company’s financial closing and review procedures and is not a comprehensive statement of the Company’s financial results or valuations as of, or for the period ended, September 30, 2026. Actual results may differ materially from this Preliminary Financial Information as a result of the completion of the Company’s financial closing and review procedures, final adjustments, valuation process and other developments that may arise between now and the time that the Company’s financial results for such period are finalized. Based on the Preliminary Financial Information: Net product revenue for the three months ended September 30, 2026 is estimated to be in the range of $23.9 million to $24.1 million, compared to $11.2 million for the three months ended September 30, 2025. Cash, cash equivalents and investments as of September 30, 2026 is estimated to be $172.8 million, compared to $137.7 million as of September 30, 2025. The information disclosed under this Item 2.02 is being “furnished” and shall not be deemed “filed” by the Company for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that Section, and shall not be deemed incorporated by reference into any filing under the Securities Act of 1933, as amended (the “Securities Act”), or the Exchange Act, except as shall be expressly set forth by specific reference in such filing.

Item 5.02. Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers Chief Executive Officer Transition On October 12, 2026, Daniel W. Paterson notified the Board of Directors (the “Board”) of the Company of his decision to retire as President and Chief Executive Officer of the Company, effective January 1, 2027 (the “Effective Date”). Mr. Paterson intends to continue to serve on the Company’s Board as a Class III director. His term will expire at the Company’s 2027 annual meeting of stockholders. In connection with the retirement of Mr. Paterson, Michael Bailey, 61, will be appointed to the position of President and Chief Executive Officer as of the Effective Date. In connection with his appointment, Mr. Bailey will continue to serve as a Class II director. His term will expire at the Company’s 2029 annual meeting of stockholders. The terms of Mr. Bailey’s compensation and employment arrangements as Chief Executive Officer will be established prior to the Effective Date and will be disclosed in an amendment to this Current Report on Form 8-K once finalized. Additionally, the Company expects that Mr. Paterson will serve as a consultant, with such service beginning on or around the Effective Date. The terms of Mr. Paterson’s consulting arrangements are expected to be established prior to the Effective Date. There are no arrangements or understandings between Mr. Bailey and any other person pursuant to which he was selected as an officer of the Company. There are no family relationships between Mr. Bailey and any director or executive officer of the Company, and Mr. Bailey has no direct or indirect material interest in any transaction required to be disclosed pursuant to Item 404(a) of Regulation S-K. Mr. Bailey served as president and chief executive officer of AVEO Pharmaceuticals, Inc. (“AVEO”), an LG Chem Ltd. company from January 2015 to June 2026, and has served as a member of its board of directors since January 2015. Prior to appointment as president and chief executive officer, Mr. Bailey served as chief business officer of AVEO from June 2013 to January 2015 and as chief commercial officer from September 2010 to June 2013. Prior to joining AVEO, Mr. Bailey served as senior vice president, business development and chief commercial officer at Synta Pharmaceuticals Corp., a biopharmaceutical company focused on research, development and commercialization of oncology medicines, from August 2008 to September 2010. From 1999 to 2008, Mr. Bailey worked at ImClone Systems Incorporated (“ImClone”), a biopharmaceutical company focused on the development and commercialization of treatments for cancer patients. During his nine-year tenure at ImClone, he was responsible for commercial aspects of the planning and launch of ERBITUX® (cetuximab) across multiple oncology indications, as well as new product planning for the ImClone development portfolio, which included CYRAMZA® (ramucirumab) and PORTRAZZA® (necitumumab). In addition, Mr. Bailey was a member of the strategic leadership committees for ImClone and its North American and worldwide partnerships and led its commercial organization, most recently as senior vice president of commercial operations. Prior to his role at ImClone, Mr. Bailey managed the cardiovascular new products development portfolio at Genentech, Inc., a biotechnology company, from 1997 to 1999. Mr. Bailey started his career in the pharmaceutical industry as part of Smith-Kline Beecham’s executive marketing development program, where he held a variety of commercial roles from 1992 to 1997, including sales, strategic planning and product management. Mr. Bailey received a B.S. in psychology from St. Lawrence University and an M.B.A. in international marketing from Mendoza College of Business at University of Notre Dame and continued his executive education in Finance at Harvard Business School and Board of Director Leadership at Wharton School of Business.

Item 7.01 Regulation FD Disclosure On October 14, 2026, the Company issued a press release announcing the CEO transition, a copy of which is furnished hereto as Exhibit 99.1 to this Current Report on Form 8-K. On October 14, 2026, the Company issued a press release announcing initial efficacy and updated safety and tolerability data in first multi-clinical cancer data update from the ongoing TARGET-D 101 Phase 1/2 clinical trial evaluating VS-7375, an oral KRAS G12D (ON/OFF) inhibitor, in patients with advanced KRAS G12D-mutated solid tumors, a copy of which is furnished hereto as Exhibit 99.2 to this Current Report on Form 8-K. On October 14, 2026, the Company posted its updated corporate presentation on its website, a copy of which is furnished hereto as Exhibit 99.3 to this Current Report on Form 8-K. The information disclosed under this Item 7.01, including Exhibits 99.1, 99.2, and 99.3, is being “furnished” and shall not be deemed “filed” by the Company for purposes of Section 18 of the Exchange Act, or otherwise subject to the liabilities of that Section, and shall not be deemed incorporated by reference into any filing under the Securities Act or the Exchange Act, except as shall be expressly set forth by specific reference in such filing.

Item 8.01 Other Events VS-7375 in mPDAC Efficacy was assessed in the modified intent-to-treat (mITT) population, defined as any patient that received at least one dose of VS-7375 and started therapy on or before July 22, 2026. A total of 22 patients that met the mITT criteria were included in the efficacy analysis and were treated with VS-7375 900 mg QD monotherapy with a median follow-up of 6.4 (0.8-10.9) months. Patients received a median of two prior lines of therapy (range 1 - 3), including standard-of-care (SoC) chemotherapy. Two patients were non-evaluable but included in the mITT: one died from coronary artery disease and stroke, while the other withdrew consent before the first assessment and died two months later; both deaths were unrelated to treatment. As of the data cutoff date of October 7, 2026, patients receiving 900 mg VS-7375 daily had a confirmed objective response rate (ORR) of 50% (4/8) in second line (2L) PDAC, a 41% confirmed ORR (9/22) in the 2L+ setting, including two complete responses, one confirmed and one unconfirmed (treatment ongoing), and a 36% confirmed ORR (5/14) in the 3L/4L setting. The disease control rate (DCR) was 86% (n=22) in 2L+, the six month landmark progression free survival (PFS) rate was 67%, and the landmark six-month overall survival (OS) rate was 80% with the majority of patients (16/22) remaining on treatment. Compared with 600 mg QD monotherapy (n=27 mITT), the 900 mg dose produced deeper tumor reductions and a higher response rate. At 600 mg, eight patients achieved objective responses, including four confirmed responses, and 11 of 27 patients remain on treatment. Pharmacokinetics & Biomarker Data in mPDAC In updated pharmacokinetic (PK) data, the 900 mg QD monotherapy dose (n=23) evaluated across KRAS G12D-driven tumors continues to achieve target plasma levels of VS-7375 and provides clear separation from the 600 mg QD monotherapy dose (n=59). In updated CA19-9 data, 15 of 17 patients with mPDAC treated with VS-7375 900 mg QD that had elevated baseline CA19-9 achieved greater than 50% reduction in the tumor marker. All these patients remain on treatment. Among 12 evaluable patients with KRAS G12D-mutant mPDAC treated with VS-7375 900 mg monotherapy in the second or later line setting who had detectable KRAS G12D circulating tumor DNA (ctDNA) at baseline, all patients (12/12) achieved a ≥ 50% reduction in KRAS G12D variant allele frequency (VAF) by cycle 3 day 1 treatment. Ninety-two percent of patients (11/12) achieved even deeper reductions (≥ 90%) and 58% (7/12) achieved a 100% clearance of KRAS G12D ctDNA during this same time period. VS-7375 First-line mPDAC Phase 3 Trial Verastem has reached alignment with the U.S. Food and Drug Administration (FDA) on the Phase 3 study design to evaluate VS-7375 in the first-line mPDAC setting. The three-arm study will evaluate a chemotherapy-free regimen of VS-7375 900 mg QD in combination with anti-EGFR, VS-7375 at 900 mg QD in combination with conventional three weeks on and one week off gemcitabine/nab-paclitaxel (GnP), and investigator choice of SoC chemotherapy (GnP or modified FOLFIRINOX). PFS and ORR will serve as dual-primary endpoints, with OS as the secondary endpoint. The Company plans to open the trial by year-end 2026. VS-7375 in mCRC Efficacy was assessed in the mITT population, defined as any patient that received at least one dose of VS-7375 and started therapy on or before July 22, 2026. A total of six patients met the mITT criteria, with one patient not evaluable for efficacy due to withdrawing consent prior to first disease assessment. Patients had received a median of two prior lines of SoC therapy (range 2 - 3). As of the data cutoff date of October 7, 2026, with a median follow up of 6.1 (0.4-7.0) months, patients receiving 900 mg QD in combination with anti-EGFR achieved a 33% ORR (2/6 with one confirmed and one unconfirmed response) in the 3L+ setting with five patients remaining on treatment. At 600 mg in combination with anti-EGFR (n=24 mITT), four patients achieved objective responses, including three confirmed responses and one unconfirmed response with 14 patients remaining on treatment. Compared with the combination of 600 mg VS-7375 with anti-EGFR, the 900 mg combination produced deeper tumor reductions. Patients are being enrolled at the 900 mg QD dose level in the TARGET-D 203 Phase 2 registration-directed 2L mCRC trial. VS-7375 in Advanced NSCLC Efficacy was assessed in the mITT population, defined as any patient that received at least one dose of VS-7375 and started therapy on or before July 22, 2026. A total of 23 patients met the mITT criteria and were included in the efficacy analysis. Patients received a median of one prior line of therapy (range 1-3) with SoC chemotherapy and immunotherapy. As of the data cutoff date of October 7, 2026, with a median follow up of 4.4 months (2.4-12.4), in patients treated with VS-7375 600 mg QD monotherapy, the confirmed ORR was 43% (10/23) in 2L+ NSCLC. Responses were observed as early as the first post-baseline scan at six weeks. The six-months landmark PFS rate was 72%, with the majority of patients (17/23) in the 600 mg NSCLC cohort remaining on treatment. The 900 mg QD dose level is currently being evaluated in the TARGET-D 202 Phase 2 registration-directed advanced NSCLC trial. The Company also shared preliminary data for VS-7375 600 mg with 1L triplet SOC (chemotherapy and immunotherapy). A total of eight patients met the mITT criteria, which was defined as any patient who received at least one dose of VS-7375 and started therapy on or before July 22, 2026, and were included in the efficacy analysis. One patient withdrew consent before the first post-baseline disease assessment, which was likely triggered by an infusion-related reaction to pembrolizumab. As of the data cutoff of October 7, 2026, with a median follow-up of 4.4 (0.9-5.8) months, patients treated with VS-7375 600 mg QD in combination with carboplatin, pemetrexed plus pembrolizumab or with pembrolizumab achieved a 75% ORR (6/8) in 1L KRAS G12D adenocarcinoma of the lung. Six patients remain on therapy. Evaluation of VS-7375 900 mg plus SoC is ongoing. Biomarker Data in NSCLC Among five evaluable patients with KRAS G12D-mutant advanced NSCLC who received VS-7375 600 mg monotherapy in the second-line or later setting and had detectable KRAS G12D ctDNA at baseline, all patients (5/5) achieved complete clearance of detectable KRAS G12D ctDNA. Updated Safety & Tolerability of VS-7375 Monotherapy and in Combination Across monotherapy and combination cohorts in TARGET-D 101, VS-7375 continued to demonstrate a safety profile at both the 600 mg and 900 mg dose levels consistent with prior observations and supported by increasing patient exposure and longer follow-up. As of the September 29, 2026 data cutoff, VS-7375 monotherapy demonstrated the following safety profile at 900 mg QD across different KRAS G12D driven tumor types (n=48): The discontinuation rate due to adverse events (AEs) was 2%. VS-7375 at 900 mg had a relative dose intensity level of 97% (median IQR 87-100%). Treatment-related adverse events (TRAEs) at 900 mg were primarily low-grade nausea, vomiting and diarrhea. Twenty-five percent of patients had no gastrointestinal (GI) AEs at the start of the first cycle and by month six approximately 40% of patients had no GI AEs. The vast majority of the GI side effects were effectively managed with standard supportive care measures, with only one reported Grade 3 case of nausea at the 900 mg QD dose that resolved in four days following optimization of anti-emetic agents. ─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────── Grade 3 TRAEs occurred in 10% of patients and only 2% of patients experienced any Grade 3 GI TRAE. The limited dose-response relationship observed for GI AEs is consistent with a localized irritant effect rather than systemic toxicity. There were only two cases of rash, no greater than Grade 2, at the 900 mg QD dose. There were no cases of mucositis or stomatitis. Importantly, no clinically meaningful cytopenias or liver function abnormalities were reported. No clinically significant cumulative toxicities have been observed to date and since the June 23, 2026 update. ─────────────────────────────────────────────────────────────────────────────────────────────────────────────── VS-7375 Safety with SoC Across Tumor Types In combinations of cetuximab with VS-7375 at 600 mg (n=41) and 900 mg (n=11), no overlapping adverse events with anti-EGFR therapy were observed, and rash was consistent with the known cetuximab safety profile. In combinations of GnP with VS-7375 at 600 mg (n=13) and 900 mg (n=8), hematologic adverse events and neuropathy were considered most likely attributable to GnP. With appropriate antiemetic prophylaxis, GI AE rates in the GnP and carboplatin pemetrexed and pembrolizumab combinations at 600 mg (n=9) were comparable to VS-7375 monotherapy. To date, in a limited number of patients, the frequency and severity of liver function test elevations and diarrhea in the carboplatin pemetrexed and pembrolizumab combinations have not differed meaningfully. Termination of ATM Prospectus Effective October 14, 2026, the Company suspended and terminated the prospectus (the “ATM Prospectus”) relating to the sale of its common stock, $0.0001 par value per share (the “Common Stock”) in an “at-the-market” offering pursuant to the terms of the Sales Agreement, dated August 8, 2025, by and between the Company and Cantor Fitzgerald & Co. (the “Sales Agreement”). As a result, the Company will not make any sales of its Common Stock pursuant to the Sales Agreement unless and until a new prospectus, prospectus supplement or registration statement is filed. Other than the termination of the ATM Prospectus, the Sales Agreement remains in full force and effect. As of the date of this Current Report on Form 8-K, no shares of Common Stock have been sold under the ATM Prospectus. New Drug Application On October 7, 2026, the FDA accepted for review our Blister Pack New Drug Application (the “NDA”) for the first quarter of 2027 and notified us that the NDA has been granted priority review.