FDA Approves Checkpoint Therapeutics’ Unloxcyt for Metastatic or Locally Advanced Cutaneous Squamous Cell Carcinoma

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The FDA has approved Checkpoint Therapeutics’ Unloxcyt (cosibelimab-ipdl), a PD-L1 blocking antibody, for adults with metastatic or locally advanced cutaneous squamous cell carcinoma (cSCC) who are ineligible for curative surgery or radiation. Approval was based on results from the CK-301-101 study, which demonstrated clinically meaningful objective response rates (ORR) and duration of response data (DoR), as assessed by an independent central review committee.¹

“Today’s FDA approval of Unloxcyt—the first marketing approval for our company – is a significant milestone both for Checkpoint and for patients with advanced cSCC,” said James Oliviero, president, CEO, Checkpoint, in a press release. “This approval marks Checkpoint’s transformation to a commercial-stage company, with the opportunity to compete in a US market estimated to exceed $1 billion annually, where we believe Unloxcyt offers a differentiated treatment option versus available therapies by binding to PD-L1, rather than programmed death receptor-1, to release the inhibitory effects of PD-L1 on the anti-tumor immune response. Additionally, Unloxcyt has demonstrated the ability to induce antibody-dependent cell-mediated cytotoxicity, another potential differentiating feature of the drug compared to existing marketed therapies for patients with cSCC.”

The multicenter, multicohort, open-label CK-301-101 trial evaluated Unloxcyt in adults with advanced solid tumor cancers, including cSCC.1 As part of the trial, 78 patients with cSCC were administered Unloxcyt at a fixed dose of 800 mg every two weeks. Additionally, a total 201 patients were enrolled across all cohorts with advanced disease, including lung, head and neck, and endometrial cancers.

Results showed an ORR rate of 47% in patients treated with Unloxcyt. Of the patients with cSCC, 42 had evaluable responses, with an ORR of 55%, and five patients experiencing complete responses, 20 with ongoing responses, and 10 responses observed in six months or fewer by data cutoff. Common adverse events (AEs) included fatigue, anemia, rash, and nausea, with the most common treatment-related AEs being fatigue and rash.²

“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. cSCC remains a disease with a significant need for more effective and tolerable treatment options, particularly for patients with concomitant hematological malignancies, solid organ transplant recipients, or a history of autoimmune disorders,” said Emily Ruiz, MD, MPH, academic director, Mohs and Dermatologic Surgery Center at Brigham and Women’s Hospital, director of the High-Risk Skin Cancer Clinic at Dana Farber Cancer Center, and associate professor of dermatology at Harvard Medical School, in the press release. “Unloxcyt is the first FDA-approved PD-L1–blocking antibody to demonstrate clinically meaningful objective response rates with durable responses in advanced cSCC. With its dual mechanisms of action and compelling safety profile, this promising drug will provide U.S. oncologists with an important new immunotherapy option for the treatment of cSCC.”

According to the National Library of Medicine, cSCC represents 20% of all skin cancers, resulting in one million cases in the United States annually. Additionally, the lifetime risk of developing cSCC continues to grow rapidly and will likely continue to increase due to the growing aging population.³

“We are excited about the approval of Unloxcyt and are currently developing a commercial launch plan. We want to thank the patients, physicians, nurses, and clinical coordinators for their support and participation in our clinical program, and the FDA for their collaboration throughout this process,” said Oliviero, in the press release.

References

1. Checkpoint Therapeutics Announces FDA Approval of UNLOXCYT™ (cosibelimab-ipdl). Checkpoint. December 13, 2024. Accessed December 16, 2024. https://ir.checkpointtx.com/news-events/press-releases/detail/127/checkpoint-therapeutics-announces-fda-approval-of

2. Cosibelimab Achieves Promising Responses in Metastatic Cutaneous Squamous Cell Carcinoma. Cancer Network. February 2, 2024. Accessed December 16, 2024. https://www.cancernetwork.com/view/cosibelimab-achieves-promising-responses-in-metastatic-cutaneous-squamous-cell-carcinoma

3. Cutaneous Squamous Cell Carcinoma. NIH. Accessed December 16, 2024. https://pubmed.ncbi.nlm.nih.gov/30497667/#:~:text=Abstract,Diagnosis;%20Skin%20cancer;%20Treatment.