Pfizer Reports Primary Endpoint Met In First Randomized Phase 2 Study, FOURLIGHT-1, Showing 40% Reduction In Risk Of Disease Progression Or Death With Manageable Safety Profile

Pfizer Inc. (NYSE: PFE) announced positive results from its Phase 2 FOURLIGHT-1 study, demonstrating a 40% reduction in the risk of disease progression or death for patients with HR+, HER2- advanced breast cancer treated with atirmociclib in combination with fulvestrant. The study met its primary endpoint with a statistically significant improvement in progression-free survival (PFS) and showed consistent results across various patient subgroups. Over 90% of participants began treatment with atirmociclib within three months of prior CDK4/6 inhibitor therapy, while overall survival data remains immature with about 20% of participants having experienced an event.