8-K: Verastem's VS-7375 Shows Promising Early Trial Data

Verastem Oncology announced encouraging preliminary safety and anti-tumor activity data from the first two dose levels of its VS-7375 Phase 1/2a trial for KRAS G12D mutant solid tumors.

Summary

• Preliminary data from the first two dose levels of the VS-7375 Phase 1/2a clinical trial in patients with previously-treated advanced KRAS G12D mutant solid tumors were reported.
• VS-7375, an oral KRAS G12D (ON/OFF) inhibitor, cleared both the 400 mg daily (QD) and 600 mg QD monotherapy doses with no dose-limiting toxicities (DLTs) observed.
• The safety profile in PDAC and non-small cell lung cancer (NSCLC) patients was consistent with previously reported data from partner GenFleet Therapeutics' study in China.
• No nausea, diarrhea, or vomiting greater than Grade 1 were reported at the two dose levels evaluated in the U.S. cohorts.
• Four out of five efficacy evaluable patients in the VS-7375-101 study, with at least one scan, have had a tumor reduction and are still on treatment.
• Patient enrollment has been initiated for the first dose escalation combination cohort evaluating VS-7375 with cetuximab for advanced solid tumors, including colorectal cancer.
• Monotherapy dose escalation continues to 900 mg QD, after which the recommended Phase 2 dose is expected to be selected.
• An interim safety and efficacy update on the Phase 1/2a trial of VS-7375 is planned for the first half of 2026.

Sentiment

Score: 8

Explanation: The preliminary data is encouraging, showing good tolerability and early signs of anti-tumor activity in a difficult-to-treat cancer type with high unmet need. The initiation of combination therapy enrollment also indicates progress. However, the data is still early and from a small patient cohort.

Positives

• VS-7375 cleared both the 400 mg QD and 600 mg QD monotherapy doses with no dose-limiting toxicities (DLTs) observed.
• The safety profile was consistent with previous data, with no nausea, diarrhea, or vomiting greater than Grade 1 reported.
• Promising anti-tumor activity was observed, with four out of five efficacy evaluable patients showing tumor reduction and remaining on treatment.
• Initiated patient enrollment for a combination cohort with cetuximab, which is expected to accelerate clinical development.
• VS-7375 is positioned as a potential best-in-class oral KRAS G12D (ON/OFF) inhibitor.
• KRAS G12D is the most prevalent KRAS mutation in human cancers (26% of all KRAS mutations), and there are currently no FDA-approved therapies specifically targeting it, indicating a high unmet medical need.

Negatives

• The efficacy data is preliminary and based on a small number of efficacy evaluable patients (five).
• The remaining patients receiving either the 400 mg QD or 600 mg QD doses have not yet reached their first response assessment.
• Specific numerical efficacy data, such as the percentage of tumor reduction, was not provided beyond the qualitative statement of 'tumor reduction'.

Risks

• Uncertainties inherent in research and development, such as the possibility of negative or unexpected results of clinical trials.
• Risk that Verastem may not see a return on investment from the collaboration with GenFleet Therapeutics, or that GenFleet may fail to fully perform under the agreement.
• Development and commercialization of product candidates may take longer or cost more than planned, including due to additional studies or commercialization decisions.
• Data may not be available when expected, and preliminary and interim data may not be representative of more mature data.
• Uncertainties related to changes in the U.S. presidential administration, including regulatory and policy changes that may adversely affect the business.
• Risks associated with potential reductions to the FDA's workforce, which may lead to disruptions and delays in review and oversight.
• Product candidates may not receive regulatory approval, become commercially successful products, or result in new treatment options being offered to patients.
• General business risks and uncertainties as detailed in the Company's Annual Report on Form 10-K for the year ended December 31, 2024.

Future Outlook

Monotherapy dose escalation for VS-7375 will continue to 900 mg QD, followed by the selection of the recommended Phase 2 dose and advancement of efficacy and safety analysis in patient expansion cohorts for advanced PDAC and NSCLC. Subject to the results of the Phase 1 dose escalation combination of VS-7375 and cetuximab, Verastem plans to initiate a combination expansion cohort in colorectal cancer. An interim safety and efficacy update on the Phase 1/2a trial is expected in the first half of 2026.

Management Comments

• Dan Paterson, President and CEO, stated: "Preliminary safety and tolerability data from our ongoing Phase 1/2a trial indicate that VS-7375, a potential best-in-class oral KRAS G12D (ON/OFF) inhibitor, can be administered at efficacious doses while effectively managing gastrointestinal side effects."
• Dan Paterson also commented: "While still early, we are pleased to see anti-tumor activity among pre-treated patients with advanced pancreatic cancer and other solid tumors."
• Dan Paterson added: "By starting this combination cohort at a dose of VS-7375 that has previously demonstrated monotherapy efficacy, we expect to accelerate our clinical development program with other standard-of-care combination cohorts."
• John Hayslip, M.D., Chief Medical Officer, noted: "We're encouraged by the early safety experience in this study, including the GI tolerability we've seen to date and absence of cutaneous toxicities, along with the early signs of anti-tumor activity."
• John Hayslip further stated: "These preliminary findings are promising, and we look forward to the continued evaluation of VS-7375 both as monotherapy and now in combination with cetuximab as there remains a significant unmet need for treatments specifically targeting KRAS G12D-mutant cancers."

Industry Context

KRAS G12D is the most prevalent KRAS mutation in human cancers, accounting for 26% of all KRAS mutations, and is particularly common in pancreatic (37%), colorectal (12.5%), endometrial (8%), and non-small cell lung (5%) cancers. Currently, there are no FDA-approved therapies specifically targeting KRAS G12D mutations, highlighting a significant unmet medical need. Verastem's VS-7375, an oral KRAS G12D (ON/OFF) inhibitor, aims to address this critical gap, positioning itself as a potential best-in-class treatment in a high-demand oncology segment.

Comparison to Industry Standards

• The safety profile of VS-7375 in the U.S. cohorts was consistent with previously reported data from Verastem's partner, GenFleet Therapeutics, in its ongoing Phase 1/2 clinical study in China evaluating VS-7375 (known as GFH375).
• GenFleet Therapeutics chose 600 mg QD as their recommended Phase 2 dose in China, providing an internal benchmark for dose selection.

Stakeholder Impact

• Shareholders: Positive impact due to encouraging early clinical data, potentially increasing investor confidence and future valuation.
• Patients: Potential for a new, much-needed treatment option for KRAS G12D mutant solid tumors, which currently lack FDA-approved targeted therapies.
• Employees: Continued progress in clinical development supports job security and potential for future growth.
• Partners (GenFleet Therapeutics): Validation of their earlier findings and continued collaboration on a promising drug candidate.

Next Steps

• Continue monotherapy dose escalation to 900 mg QD.
• Select the recommended Phase 2 dose.
• Advance subsequent efficacy and safety analysis of monotherapy VS-7375 in patient expansion cohorts with advanced PDAC and NSCLC.
• Initiate a combination expansion cohort in colorectal cancer, subject to Phase 1 dose escalation combination results.
• Report an interim safety and efficacy update on the Phase 1/2a trial in the first half of 2026.

Key Dates

Recommendation

The preliminary Phase 1/2a data for VS-7375 is highly encouraging, demonstrating a favorable safety profile with no dose-limiting toxicities and early signs of anti-tumor activity in a challenging patient population (KRAS G12D mutant solid tumors) where there are currently no FDA-approved targeted therapies. The initiation of combination therapy enrollment further de-risks the development pathway and signals management's confidence. While early-stage, these positive results for a potential best-in-class inhibitor in an area of high unmet need suggest significant upside potential for Verastem Oncology, warranting a 'buy' recommendation for investors with a higher risk tolerance and long-term investment horizon.

Keywords

Verastem Oncology, VS-7375, KRAS G12D, solid tumors, pancreatic cancer, NSCLC, colorectal cancer, Phase 1/2a trial, oncology, biotechnology, clinical trial, drug development, GenFleet Therapeutics, cetuximab