Regeneron Pharmaceuticals Provides Update on Phase 3 Trial of Fianlimab Combination in First-Line Unresectable or Metastatic Melanoma

Published: 2026-05-16 08:51:14 ET REGN

Published on 05/16/2026 at 08:51 am EDT

Regeneron Pharmaceuticals, Inc. reviewed results from the Phase 3 trial evaluating two dose levels of fianlimab (LAG-3 inhibitor) in combination with cemiplimab (PD-1 inhibitor) as a first-line treatment for patients with unresectable locally advanced or metastatic melanoma. The trial did not reach statistical significance for the primary endpoint of improvement in progression-free survival (PFS) compared to pembrolizumab (PD-1 inhibitor) monotherapy. No new safety signals were identified with the fianlimab combination.

Detailed results from the trial will be presented at an upcoming medical meeting. A Phase 3 head-to-head trial, also in first-line unresectable or metastatic melanoma, evaluating the high-dose fianlimab combination versus Opdualag (nivolumab and relatlimab-rmbw) is ongoing. The potential uses of fianlimab and cemiplimab described above are investigational, and safety and efficacy of this combination have not been evaluated by any regulatory authority.

This randomized, double-blind Phase 3 trial is investigating the combination of fianlimab and cemiplimab versus pembrolizumab in patients 12 years of age or older with unresectable locally advanced or metastatic melanoma who have not received a previous systemic treatment for advanced disease. The trial enrolled 1,546 patients who were randomized to receive either: 1600 mg fianlimab and 350 mg cemiplimab (high-dose combination) every 3 weeks; 400 mg fianlimab and 350 mg cemiplimab (low-dose combination) every 3 weeks; placebo and 200 mg pembrolizumab every 3 weeks; or placebo and 350 mg cemiplimab every 3 weeks.