Immunome has announced that the European Medicines Agency (EMA) has validated its Marketing Authorisation Application (MAA) for varegacestat, an investigational, oral, once-daily gamma secretase inhibitor, for the treatment of adults with desmoid tumours. The validation confirms that the application is complete and allows the EMA to begin its review under the centralised marketing authorisation procedure.

The application is supported by efficacy and safety data from the global Phase 3 RINGSIDE trial, which evaluated varegacestat in adults with progressing desmoid tumours. The study met its primary endpoint of progression-free survival, demonstrating an 84 percent reduction in the risk of disease progression or death compared with placebo.

The trial also achieved all key secondary endpoints. Varegacestat demonstrated an Objective Response Rate (ORR) of 56 percent, compared with 9 Percent for placebo, based on assessment by blinded independent central review. The treatment also showed a statistically significant improvement in worst pain intensity at week 12, with a clinically significant difference observed as early as the first assessment at week 4.

The RINGSIDE trial was a randomised, double-blind, placebo-controlled study involving 156 patients, making it the largest randomised study conducted in this patient population. Participants received either varegacestat at a dose of 1.2 mg once daily or placebo until disease progression or death. Progression-free survival, assessed through blinded independent central review, was the primary endpoint. Key secondary endpoints included confirmed ORR, change in tumour volume at week 24 and change in pain intensity at week 12. The study also evaluated duration of response, best reduction in tumour volume, patient-reported outcomes, safety and tolerability. Its open-label extension phase is ongoing.

The EMA validation follows the US Food and Drug Administration's (FDA) acceptance of Immunome's New Drug Application (NDA) for varegacestat in July 2026. The FDA has assigned a Prescription Drug User Fee Act (PDUFA) target action date of April 28, 2027. The detailed efficacy and safety findings from RINGSIDE were presented at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting.