Efficacy and safety of cosibelimab in advanced cutaneous squamous cell carcinoma: Results from a Pivotal Open-label Study with a median follow-up of ≥2 years
- PMID: 41055628
- DOI: 10.1016/j.jaad.2025.09.009
Efficacy and safety of cosibelimab in advanced cutaneous squamous cell carcinoma: Results from a Pivotal Open-label Study with a median follow-up of ≥2 years
Abstract
Background: Cosibelimab-ipdl, a high-affinity, programmed death-ligand 1-blocking antibody, is approved by the US Food and Drug Administration for treatment of adults with metastatic cutaneous squamous cell carcinoma (mCSCC) or locally advanced CSCC (laCSCC) who are not candidates for curative surgery or radiation.
Objective: To report long-term efficacy and safety outcomes from a pivotal study of cosibelimab in mCSCC or laCSCC.
Methods: Patients received intravenous cosibelimab 800 mg every 2 weeks (mCSCC and laCSCC cohorts) or 1200 mg every 3 weeks (mCSCC cohort). The primary endpoint was objective response rate (ORR). Secondary endpoints included duration of response (DOR) and safety.
Results: With a median follow-up duration of 29.3 months for the mCSCC cohort (n = 78), ORR was 50.0% (complete response [CR], 12.8%), median DOR was not reached, and estimated 24-month DOR was 72.1%. With a median follow-up duration of 24.1 months for the laCSCC cohort (n = 31), ORR was 54.8% (CR, 25.8%), median DOR was not reached, and the estimated 24-month DOR was 80.2%. Immune-related adverse event rate was 27.6%; 3.6% grade 3, no grade ≥4 events.
Limitations: Nonrandomized; limited biomarker analysis.
Conclusion: Cosibelimab demonstrated robust and durable ORRs with increasing CR rates in advanced CSCC and low rates of severe immune-related adverse events.
Keywords: advanced cutaneous squamous cell carcinoma; cosibelimab; immune checkpoint inhibitors; immunotherapy; programmed death-ligand 1; skin cancer; skin neoplasms.
Copyright © 2025 The Author(s). Published by Elsevier Inc. All rights reserved.
Conflict of interest statement
Conflicts of interest ESR has served as a consultant for Checkpoint Therapeutics, Feldan Therapeutics, Merck & Co., Regeneron Pharmaceuticals, and Replimune. EM-C has served as a consultant and/or scientific advisor for Bristol Myers Squibb, Merck Sharp & Dohme, Novartis, Pierre Fabre, Roche, Sanofi, and Regeneron; received research funding from Merck Sharp & Dohme, Sanofi, and Bristol Myers Squibb; served as a speaker for Amgen, Bristol Myers Squibb, Merck Sharp & Dohme, Novartis, Pierre Fabre, and Regeneron; and served as a principal investigator for clinical trials for Amgen, Bristol Myers Squibb, GlaxoSmithKline, Merck Sharp & Dohme, Novartis, Pierre Fabre, Roche, Sanofi, Replimune, Iovance, and Bioinvent. HM has served as a consultant and/or scientific advisor for Bristol Myers Squibb, Merck Sharp & Dohme, and Pierre Fabre. MAB-G has served as a consultant, in an advisory role, or on a speakers’ bureau for Bristol Myers Squibb, Merck Sharp & Dohme, Regeneron, Novartis, and Pierre Fabre; and received financial support for travel or accommodation expenses from Bristol Myers Squibb, Merck Sharp & Dohme, Regeneron, Novartis, and Pierre Fabre. GQ has served as a consultant for Sanofi. CN has served as a consultant or member of an advisory board for Bristol Myers Squibb, Merck Sharp & Dohme, Regeneron, and Novartis; and received financial support for travel and accommodation expenses from Bristol Myers Squibb, Merck Sharp & Dohme, and Novartis. SD has received research funding from Bristol Myers Squibb, Merck Sharp & Dohme, and Pierre Fabre; honoraria from Bristol Myers Squibb, Merck Sharp & Dohme, and Regeneron; financial support for travel expenses from Bristol Myers Squibb and Merck Sharp & Dohme; and served as a member of a Data Safety Monitoring Board/advisory board for Bristol Myers Squibb and Merck Sharp & Dohme. RL has served as a consultant and/or scientific advisor for AstraZeneca, Merck Sharp & Dohme, and Sanofi and been a speaker for Merck Sharp & Dohme. MM has served as a scientific advisor and speaker for Merck Sharp & Dohme. DB has served on an advisory board for and received honoraria from Merck Sharp & Dohme. DH has received reimbursements for serving as a clinical investigator for the CK-301-101 trial sponsored by Checkpoint Therapeutics. SF has received honoraria from Merck Sharp & Dohme, MundiPharma, Roche, and Sanofi and serves as a board director for ICON Oncology Holdings Pty (Ltd), Drs. Alberts Bouwer Jordaan Inc., and Gamma Knife South Africa. DRM serves as director for Phoenix Pharma. JO is an employee of Checkpoint Therapeutics and holds stock and other ownership interests in the company and has served in leadership roles at Checkpoint Therapeutics. LNW is an employee of Checkpoint Therapeutics and holds stock and other ownership interests in the company. WGG is an employee of Checkpoint Therapeutics and holds stock and other ownership interests in the company and has served in leadership roles at Checkpoint Therapeutics. MCAG, JC, RYT, MB-B, HS, AT, and PC have no conflicts of interest to declare.
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