Clinical-stage biotechnology company Arvinas Inc (Nasdaq:ARVN) and biopharmaceutical company Pfizer Inc (NYSE:PFE) on Tuesday announced positive topline results from the Phase 3 VERITAC-2 trial evaluating vepdegestrant in estrogen receptor-positive, human epidermal growth factor receptor 2-negative (ER+/HER2-) advanced or metastatic breast cancer.

The trial met its primary endpoint in the estrogen receptor 1-mutant population, showing a statistically significant and clinically meaningful improvement in progression-free survival compared to fulvestrant.

Vepdegestrant is the first PROTAC degrader to demonstrate clinical benefit in a Phase 3 trial. However, the trial did not achieve statistical significance in progression-free survival improvement in the intent-to-treat population.

Overall survival data remain immature, with the trial continuing to assess this secondary endpoint. Vepdegestrant was generally well tolerated, with a safety profile consistent with previous studies.

The companies plan to present detailed results at a medical meeting later this year and share data with regulatory authorities to support potential filings.