FDA Approves Cosibelimab for Cutaneous SCC

The US Food and Drug Administration (FDA) has approved the immune checkpoint inhibitor cosibelimab (Unloxcyt; Checkpoint Therapeutics, Inc.) for the treatment of adults with metastatic or locally advanced cutaneous squamous cell carcinoma (CSCC) who are not candidates for curative surgery or curative radiation. 

The programmed death ligand-1 (PD-L1)–blocking antibody is the first and only treatment of its kind approved for advanced CSCC, according to a Checkpoint Therapeutics press release. The FDA approval was based on findings from the multicenter, open-label Study CK-301-101 trial of 109 patients. 

In that trial, the objective response rate (ORR) was 47% in 78 patients with metastatic CSCC and 48% in 31 patients with locally advanced CSCC. Median duration of response (DOR) in treated patients was not reached in those with metastatic disease and was 17.7 months in those with locally advanced disease, according to the FDA approval notice.

Adverse reactions occurring in at least 10% of patients included fatigue, musculoskeletal pain, rash, diarrhea, hypothyroidism, constipation, nausea, headache, pruritus, edema, localized infection, and urinary tract infection.

The recommended treatment dose, according to the prescribing information, is 1200 mg given as an intravenous infusion over 60 minutes every 3 weeks until disease progression or unacceptable toxicity.

The agent offers “a differentiated treatment option versus available therapies by binding to PD-L1, rather than programmed death receptor-1 (PD-1), to release the inhibitory effects of PD-L1 on the anti-tumor immune response,” Checkpoint Therapeutics president and chief executive officer James Oliviero stated in the company press release. 

The agent has also “demonstrated the ability to induce antibody-dependent cell-mediated cytotoxicity, another potential differentiating feature of the drug compared to existing marketing therapies for CSCC,” Oliviero noted.

“CSCC is the second most common form of skin cancer, and those diagnosed with advanced disease that has recurred or metastasized face a poor prognosis,” stated Emily Ruiz, MD, academic director of the Mohs and Dermatologic Surgery Center at Brigham and Women’s Hospital and director of the High-Risk Skin Cancer Clinic at Dana-Farber Brigham Cancer Center. 

“With its dual mechanisms of action and compelling safety profile, this promising drug will provide US oncologists with an important new immunotherapy option for the treatment of CSCC,” she added. 

Sharon Worcester, MA, is an award-winning medical journalist based in Birmingham, Alabama, writing for Medscape, MDedge, and other affiliate sites. She currently covers oncology, but she has also written on a variety of other medical specialties and healthcare topics. She can be reached at[email protected] or on Twitter:@SW_MedReporter.