Immunome's Varegacestat Shows Potent Results in Rare Tumor Trial as ADC Pipeline Gains Momentum

BOTHELL, WA – March 03, 2026 – By George Millen

Biotechnology firm Immunome, Inc. has unveiled a formidable one-two punch for the oncology market, reporting what analysts call “striking” late-stage clinical trial results for a new rare cancer therapy while simultaneously detailing a well-funded, multi-pronged attack on solid tumors with its next-generation drug platform.

The company announced that its pivotal Phase 3 RINGSIDE trial for varegacestat, an oral drug for patients with desmoid tumors, met all its primary and secondary goals with exceptional efficacy. The news, paired with a strong financial report showing a cash runway into 2028, positions Immunome for a potential transition from a clinical-stage entity to a commercial player while it builds out a sophisticated pipeline of antibody-drug conjugates (ADCs).

“Immunome made substantial progress in 2025,” said Clay B. Siegall, Ph.D., President and Chief Executive Officer of Immunome, in a statement. “The positive Phase 3 RINGSIDE results represent a significant milestone for patients living with desmoid tumors and will support our planned NDA submission for varegacestat in the second quarter of 2026.”

A Potential New Standard for a Rare Disease

Varegacestat’s success targets a significant unmet need in the treatment of desmoid tumors. These rare and locally aggressive soft tissue tumors, affecting just a few thousand people in the U.S. annually, do not spread to distant sites but can grow relentlessly, invading surrounding tissues and causing severe pain and functional impairment. Historically, treatment has been challenging, with high recurrence rates after surgery and limited systemic options.

The landscape saw a major shift in late 2023 with the FDA approval of Ogsiveo (nirogacestat), the first therapy specifically for desmoid tumors. However, Immunome’s data suggests varegacestat could set a new, higher bar for efficacy.

The RINGSIDE trial demonstrated that varegacestat achieved an 84% reduction in the risk of disease progression or death compared to placebo, a figure that surpasses the 71% reduction reported for Ogsiveo in its pivotal trial. Furthermore, varegacestat induced a tumor response in 56% of patients, a marked improvement over the 9% response rate in the placebo group and notably higher than Ogsiveo's 41% objective response rate. An exploratory analysis also revealed a median best change in tumor volume of -83% for patients on varegacestat, compared to +11% growth for those on placebo.

The drug was reported as generally well-tolerated, with a manageable safety profile consistent with its drug class of gamma secretase inhibitors. With these results in hand, Immunome is preparing to submit a New Drug Application (NDA) to the U.S. Food and Drug Administration in the second quarter of 2026, putting it on a clear path toward potential market entry.

Beyond the Headline Drug: Building an Arsenal Against Cancer

While varegacestat represents the company’s most immediate commercial opportunity, Immunome’s long-term strategy is heavily invested in the highly competitive and lucrative field of antibody-drug conjugates. ADCs are often described as “smart bombs” that use an antibody to deliver a potent cancer-killing payload directly to tumor cells, sparing healthy tissue.

Immunome is advancing a diversified ADC pipeline, headlined by its proprietary HC74 payload. The company's research, presented in late 2025, suggests HC74 has key advantages. It appears to overcome multi-drug resistance—a common reason cancer treatments fail—by evading cellular pumps that eject drugs from tumor cells. Additionally, its high membrane permeability creates a powerful “bystander effect,” allowing the payload to kill not only the targeted cancer cell but also adjacent tumor cells that may not have the antibody’s target, addressing the problem of tumor heterogeneity.

“We continue to advance our antibody-drug conjugate pipeline, with the Phase 1 study of IM-1021 ongoing,” Siegall noted. IM-1021, which targets ROR1, has already shown objective responses in B-cell lymphoma patients, with initial data expected to be presented later this year.

Looking ahead, the company plans to rapidly expand this platform. Immunome expects to submit Investigational New Drug (IND) applications for three more ADCs in 2026, targeting undisclosed solid tumor markers: IM-1617, IM-1340, and IM-1335. This aggressive push underscores the company’s confidence in its HC74 technology and its ambition to become a major player in the next generation of ADC therapies.

Financial Fortitude and Strategic Vision

Underpinning these ambitious clinical and preclinical programs is a robust financial foundation. Immunome ended 2025 with $653.5 million in cash and cash equivalents, bolstered by a successful financing round in December. The company reported a net loss of $212.4 million for the year, reflecting significant and planned investment in research and development.

This strong balance sheet provides a cash runway projected to last into 2028, a position of strength that is the envy of many clinical-stage biotech firms. This financial stability allows the leadership team, headed by ADC veteran Dr. Siegall—the former CEO of ADC pioneer Seagen—to execute its dual strategy without immediate financing pressures.

The company is now focused on the complex regulatory, manufacturing, and commercial readiness activities required to bring varegacestat to market, a critical step in its evolution. Simultaneously, its well-capitalized R&D engine is working to populate its pipeline with novel drug candidates designed to tackle some of the most difficult challenges in modern oncology. With multiple key milestones on the horizon, Immunome is poised for a transformative period of growth and innovation.