Verastem's New Drug Shows Major Promise Against a Notorious Cancer Gene

BOSTON, MA – June 23, 2026 – In the relentless battle against cancer, some genetic mutations have long been considered 'undruggable,' leaving patients with few targeted options. The KRAS gene, particularly its G12D mutation, has been one of the most formidable of these foes. Today, Verastem Oncology has unveiled preliminary data that could represent a significant shift in this paradigm, offering a new beacon of hope for patients with some of the most challenging solid tumors.

The biopharmaceutical company announced positive initial results from its TARGET-D 101 Phase 1/2 trial for VS-7375, an investigational oral inhibitor targeting KRAS G12D. The data show encouraging clinical activity and a favorable safety profile in patients with advanced pancreatic, colorectal, and non-small cell lung cancers, suggesting a potential best-in-class therapy is on the horizon.

A Novel Attack on a Stubborn Target

The KRAS G12D mutation is the most common KRAS variant, driving tumor growth in a significant percentage of deadly cancers: approximately 40% of pancreatic cancers, 15% of colorectal cancers, and 5% of non-small cell lung cancers (NSCLC). For decades, its protein structure made it notoriously difficult to target with precision medicines. Verastem's VS-7375 tackles this challenge with a unique dual-action mechanism. It is designed as an 'ON/OFF' inhibitor, meaning it can bind to and block the KRAS G12D protein whether it's in its active (ON) or inactive (OFF) state. Preclinical studies suggest this dual approach may lead to a more complete and durable shutdown of cancer-promoting signals compared to inhibitors that only target one state.

The early clinical results appear to bear this out. In the trial, VS-7375 demonstrated compelling anti-tumor activity across multiple dose levels. The most striking data came from patients with heavily pretreated metastatic pancreatic ductal carcinoma (mPDAC), a disease with a notoriously grim prognosis. An impressive 93% of these patients (13 out of 14) on the 900 mg daily dose showed a greater than 50% reduction in the CA19-9 tumor marker, a key indicator of treatment response in pancreatic cancer. All patients in this group remain on treatment, signaling a durable benefit.

Promising signs of efficacy were also seen in patients with metastatic colorectal cancer (mCRC) and advanced NSCLC, setting the stage for broader investigation in these populations. The results position VS-7375 as a significant contender in a field that, until recently, had little to offer patients with this specific mutation.

Redefining Safety and Combination Potential

For any new cancer therapy to be truly transformative, efficacy must be paired with a manageable safety profile that preserves a patient's quality of life. Here, VS-7375 also appears to shine. The primary treatment-related side effects were low-grade gastrointestinal issues like nausea and diarrhea, which were reportedly well-managed with standard supportive care and, crucially, diminished significantly after the first treatment cycle. This suggests the body adapts to the drug, a vital characteristic for a long-term therapy. Importantly, no unexpected or severe toxicities, such as dangerous drops in blood counts or liver damage, were observed at the effective dose levels.

“VS-7375 has demonstrated a favorable safety profile that improves meaningfully beyond the first treatment cycle, underscoring its potential to be not only the best-in-class oral KRAS G12D inhibitor, but also the preferred treatment option for patients with KRAS-G12D-mutated cancers,” said Michael Kauffman, M.D., Ph.D., president of development at Verastem Oncology.

This favorable safety profile is critical for the drug's second major strength: its ability to be combined with other cancer treatments. The trial data showed VS-7375 pairs well with both anti-EGFR therapy (cetuximab) in colorectal cancer and standard-of-care chemotherapy (gemcitabine plus Nab-paclitaxel) in pancreatic cancer, without creating overlapping toxicities. This 'combinability' is essential, as the future of oncology lies in multi-pronged attacks that hit cancer from different angles. Preliminary data even suggested that adding an anti-EGFR antibody led to deeper and faster tumor reductions, hinting at powerful synergistic effects.

A Crowded Field, A Clear Strategy

Verastem is not alone in pursuing the lucrative and life-saving prize of a KRAS G12D inhibitor. The space has become a hotbed of innovation, with competitors like Incyte, AstraZeneca, and Eli Lilly advancing their own candidates. Other novel approaches are also emerging, such as protein degraders like setidegrasib, which aim to destroy the KRAS G12D protein entirely, and pan-RAS inhibitors like Revolution Medicines' daraxonrasib, which target multiple KRAS mutations.

In this competitive environment, speed and strategy are paramount. Verastem appears to be executing a nimble and aggressive plan. The company has already initiated three separate Phase 2 registration-directed trials for pancreatic, lung, and colorectal cancers. This rapid progression is bolstered by multiple Fast Track Designations from the U.S. Food and Drug Administration (FDA), which are intended to expedite the development of drugs for serious, unmet medical needs.

Further demonstrating its strategic foresight, Verastem also announced an intended collaboration with Erasca, Inc. The plan is to explore combining VS-7375 with ERAS-0015, a pan-RAS molecular glue, potentially creating an even more potent regimen against KRAS G12D-driven tumors. This move signals an understanding that the ultimate path to victory may involve layering multiple next-generation therapies.

“The momentum behind the VS-7375 program continues to accelerate,” said Dan Paterson, president and chief executive officer of Verastem Oncology. “The development strategy for VS-7375 is aimed at maximizing the therapeutic potential of this program across multiple tumor types and treatment settings and supporting multiple potential registration pathways.”

To that end, the company has laid out an ambitious timeline for the near future. Key milestones include:

• Reporting a further update on the TARGET-D 101 trial in the second half of 2026.
• Completing target enrollment in several key trial cohorts by the end of June 2026.
• Completing enrollment across all three Phase 2 trials by the end of 2026.
• Meeting with the FDA before year-end to review designs for pivotal Phase 3 trials.
• Enrolling the first patients in those Phase 3 trials in the first half of 2027.