BOTHELL, Wash. — Immunome, Inc. (Nasdaq: IMNM), a biotechnology company committed to developing first-in-class and best-in-class targeted cancer therapies, today announced positive topline results from the global pivotal Phase 3 RINGSIDE trial of varegacestat, an investigational, oral, once-daily gamma secretase inhibitor (GSI), in patients with progressing desmoid tumors.
he trial met its primary endpoint of improving progression-free survival, demonstrating a statistically significant and clinically meaningful improvement vs. placebo, with an 84% reduction in the risk of disease progression or death (hazard ratio (HR) = 0.16, 95% CI: 0.071, 0.375; p<0.0001). The confirmed objective response rate (ORR) based on RECIST v1.1 was 56% with varegacestat vs. 9% with placebo (p<0.0001), as assessed by blinded independent central review. In an exploratory analysis, varegacestat demonstrated a median best change in tumor volume of -83% vs. +11% with placebo, as assessed by blinded independent central review. In addition, the trial met all key secondary endpoints, with varegacestat achieving statistically significant improvements vs. placebo in landmark tumor volume reduction and worst pain intensity.
Varegacestat was generally well tolerated, with a manageable safety profile consistent with the GSI class. The most common adverse events for participants in the treatment arm were diarrhea (82%), fatigue (44%), rash (43%), nausea (35%) and cough (34%). Most events were grade 1 or 2.
Based on these data, Immunome plans to submit a New Drug Application to the U.S. Food and Drug Administration in Q2 2026.
“RINGSIDE is the largest and most comprehensive clinical trial conducted to date in patients with desmoid tumors, and the topline results represent the highest objective response rate observed in a randomized clinical trial in this patient population,” said Immunome’s CEO Clay Siegall, Ph.D. “These findings demonstrate the potential of varegacestat to offer best-in-class results in a convenient, once-daily, oral medicine that may help patients reclaim their lives.”
“Desmoid tumors can have a devastating physical and emotional impact on patients given their unpredictable nature and the limitations of current treatment options,” said Mrinal M. Gounder, M.D., sarcoma medical oncologist and drug development specialist at Memorial Sloan Kettering Cancer Center, and RINGSIDE primary investigator. “The progression-free survival benefit, high response rate and reduction in tumor volume with varegacestat in the RINGSIDE trial are striking. These findings elevate the role of GSIs and confirm varegacestat could become standard of care in the treatment of desmoid tumors.”
Dr. Siegall added, “The RINGSIDE results represent a major milestone for Immunome as we advance our emerging pipeline of targeted oncology therapies that have exceptional potential to meaningfully improve the lives of patients.”
Immunome plans to share additional data from the RINGSIDE trial at an upcoming major medical conference.
About the RINGSIDE Trial
The global, randomized, double-blind, placebo-controlled Phase 3 RINGSIDE trial (NCT04871282) evaluated the efficacy and safety of varegacestat in patients with progressing desmoid tumors. A total of 156 patients were randomized to receive varegacestat 1.2 mg daily or placebo until disease progression or death. The primary endpoint of the trial was progression-free survival as assessed by blinded independent central review. Statistically controlled secondary endpoints were ORR using RECIST v1.1 and change in tumor volume at week 24, both determined by blinded independent central review, as well as change in pain intensity as determined using a patient reported outcome instrument. Additional secondary endpoints included duration of response, best reduction in tumor volume, patient-reported outcomes, and safety and tolerability. RINGSIDE includes an open-label extension phase, which is ongoing.
About Desmoid Tumors
Desmoid tumors (also known as aggressive fibromatosis or desmoid-type fibromatosis) are aggressive non-metastatic soft tissue tumors that are prone to recurrence. Approximately 1,000-1,650 people are diagnosed with desmoid tumors each year in the United States, and there are approximately 10,000-11,000 actively managed patients. Those affected face debilitating pain, deformity and, in some cases, life-threatening organ damage. The chronic pain and physical limitations associated with desmoid tumors lead to a high clinical burden and impaired quality of life. Although desmoid tumors are not considered cancerous, they often require systemic treatment to prevent permanent disability and alleviate disease burden.
About Varegacestat
Varegacestat (formerly AL102) is an investigational, oral, once-daily gamma secretase inhibitor. In December 2025, Immunome reported positive topline results for the Phase 3 RINGSIDE trial of varegacestat in adults with progressing desmoid tumors. Immunome plans to submit a New Drug Application for varegacestat to the U.S. Food and Drug Administration in Q2 2026.
About Immunome, Inc.
Immunome is a clinical-stage targeted oncology company committed to developing first-in-class and best-in-class targeted cancer therapies. We are advancing an innovative portfolio of therapeutics, drawing on leadership that previously played key roles in the design, development, and commercialization of cutting-edge therapies, including antibody-drug conjugate therapies. Our pipeline includes varegacestat, a late-clinical stage GSI; IM-1021, a clinical-stage ROR1 ADC; and IM-3050, a FAP-targeted radiotherapy that recently received IND clearance. We are also advancing a broad portfolio of early stage ADCs pursuing undisclosed solid tumor targets. For more information, visit www.immunome.com.
Dr. Gounder has financial interests related to Immunome.
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