FDA Approves Cosibelimab-ipdl for Advanced Skin Cancer

On December 13, 2024, the Food and Drug Administration (FDA) granted approval for cosibelimab-ipdl, commercially known as Unloxcyt, developed by Checkpoint Therapeutics, Inc. This therapeutic agent is a PD-L1 blocking antibody intended for adult patients suffering from metastatic cutaneous squamous cell carcinoma (mCSCC) or locally advanced cutaneous squamous cell carcinoma (laCSCC) who are unsuitable for curative surgical interventions or radiation therapy. Details concerning the complete prescribing information for Unloxcyt will be made available through Drugs@FDA.

The effectiveness and safety of Unloxcyt were investigated in a study identified as CK-301-101 (NCT03212404). This trial was a multicenter, multicohort, open-label investigation involving 109 patients diagnosed with mCSCC or laCSCC, who were not eligible for surgical or radiation-based cures. Eligibility for this study excluded individuals with active or suspected autoimmune disorders, those who had undergone allogeneic transplants within six months prior to treatment, individuals with prior exposure to anti-PD-1/PD-L1 therapies or other immune checkpoint inhibitors, subjects with uncontrolled or severe cardiovascular conditions, those with an Eastern Cooperative Oncology Group Performance Status (ECOG PS) of 2 or higher, and individuals infected with HIV, hepatitis B, or hepatitis C.

The principal measures of efficacy were the objective response rate (ORR) and the duration of response (DOR), both evaluated by an independent central review committee (IRC) in accordance with RECIST version 1.1 guidelines. For patients with laCSCC displaying externally visible target lesions that were not assessable using radiologic imaging, the ORR was determined through ICR using digital photography based on WHO criteria. The findings demonstrated an ORR of 47% with a confidence interval of 95% ranging from 36 to 59 for patients with mCSCC (n=78), and an ORR of 48% with a 95% confidence interval of 30 to 67 for those with laCSCC (n=31). While the median DOR was not established for patients with mCSCC, it ranged between 1.4+ and 34.1+ months. For patients with laCSCC, the median DOR was observed to be 17.7 months, with a range between 3.7+ and 17.7 months.

Reported adverse reactions that occurred in 10% or more of patients included fatigue, musculoskeletal pain, rash, diarrhea, hypothyroidism, constipation, nausea, headache, pruritus, edema, localized infections, and urinary tract infections. The recommended dosage of cosibelimab-ipdl is set at 1,200 mg, administered intravenously over a duration of 60 minutes every three weeks. This treatment continues until there is either progression of the disease or the development of unacceptable toxicity levels.

The review process for this approval incorporated the Assessment Aid, a voluntary submission provided by the applicant to assist in the FDA’s evaluation. It is crucial for healthcare professionals to report any serious adverse events potentially linked to the use of medications or devices through the FDA’s MedWatch Reporting System. This can be done by utilizing the online platform or by contacting the provided phone number.