Checkpoint Therapeutics Announces Confirmation of Registration Path for Cosibelimab in Metastatic Cutaneous Squamous Cell Carcinoma

In Clinical Studies News by Barbara Jacoby

Source: Checkpoint Therapeutics


  • FDA feedback supports plan to submit Biologics License Application (BLA) based on data from ongoing Phase 1 trial
  • One-third enrollment complete in cohort of patients with metastatic cutaneous squamous cell carcinoma
  • Potential for cosibelimab to be differentiated and lower-cost alternative to available anti-PD-1/L1 mAbs

Checkpoint Therapeutics, Inc. (“Checkpoint”) (NASDAQ: CKPT), a clinical-stage immunotherapy and targeted oncology company, today announced that feedback from the U.S. Food and Drug Administration (“FDA”) has confirmed the company’s plan to submit cosibelimab for full approval as a treatment for patients with metastatic cutaneous squamous cell carcinoma (“CSCC”) based on efficacy and safety data from the ongoing open-label, multicenter, Phase 1 clinical trial, Study CK-301-101 (NCT03212404). This registration-enabling clinical trial is currently enrolling a cohort of patients with metastatic CSCC, with a target enrollment of approximately 75 to 100 patients and a primary efficacy endpoint of confirmed objective response rate (“ORR”) assessed by independent central review.

“We are pleased to have reached consensus with the FDA on the overall development program to support a BLA submission for cosibelimab in metastatic CSCC,” said James F. Oliviero, President and Chief Executive Officer of Checkpoint Therapeutics. “With approximately one-third of target patient enrollment in the metastatic CSCC cohort now reached, we anticipate completing enrollment by year-end and, subject to meeting the trial’s endpoints, submitting a BLA for cosibelimab in 2021. We look forward to positioning cosibelimab as a differentiated and lower-cost alternative to the approved therapy currently available for this indication.”

Positive interim results for cosibelimab were presented at the European Society for Medical Oncology (“ESMO”) Congress 2019 in Barcelona, Spain. The poster presentation provided interim efficacy and safety results from the ongoing clinical trial, including a 50% ORR by investigator assessment in the first 14 evaluable patients in the metastatic CSCC cohort. One patient achieved a complete response and six patients achieved partial responses. All seven responses (100%) were confirmed and ongoing at the time of analysis. Additionally, cosibelimab appeared to be safe and well-tolerated in 81 treated patients with diverse tumor types. A copy of the ESMO Congress poster presentation is available on the Publications page of the Pipeline section of Checkpoint’s website,

About Cutaneous Squamous Cell Carcinoma
Cutaneous squamous cell carcinoma (“CSCC”) is the second most common human cancer in the United States, with an estimated annual incidence of 700,000 cases. While most cases are localized tumors amenable to curative resection, approximately 8% of patients will experience a local recurrence, 5% of patients will develop nodal metastases, and an estimated 2% of patients will die from their disease. Ten-year survival rates are less than 20% for patients with regional lymph-node involvement. For those patients who develop distant metastases, the median survival time is estimated to be less than two years. In addition to being a life-threatening disease, CSCC causes significant functional morbidities and cosmetic deformities based on tumors commonly arising in the head and neck region and invading blood vessels, nerves and vital organs such as the eye or ear.

About Cosibelimab
Cosibelimab (formerly referred to as CK-301) is a high affinity, fully-human monoclonal antibody of IgG1 subtype that directly binds to programmed death ligand-1 (PD-L1) and blocks the PD-L1 interaction with the programmed death receptor-1 (PD-1) and B7.1 receptors. PD-L1 is an immune-inhibitory checkpoint molecule expressed on epithelial and vascular endothelial cells, as well as by a number of immune cells, and is utilized by tumor cells as an immune escape mechanism. Cosibelimab’s primary mechanism of action is based on the inhibition of the interaction between PD-L1 and its receptors PD-1 and B7.1, which removes the suppressive effects of PD-L1 on anti-tumor CD8+ T-cells to restore the cytotoxic T cell response. Cosibelimab is potentially differentiated from the currently marketed PD-1 and PD-L1 antibodies with a half-life that supports sustained >99% target tumor occupancy and the additional benefit of a functional Fc domain capable of inducing antibody-dependent cell-mediated cytotoxicity (“ADCC”) for potential enhanced efficacy in certain tumor types.

About Checkpoint Therapeutics
Checkpoint Therapeutics, Inc. (“Checkpoint”) is a clinical-stage immunotherapy and targeted oncology company focused on the acquisition, development and commercialization of novel treatments for patients with solid tumor cancers. Checkpoint is evaluating its lead antibody product candidate, cosibelimab, a potentially differentiated anti-PD-L1 antibody licensed from the Dana-Farber Cancer Institute, in an ongoing Phase 1 clinical trial in checkpoint therapy-naïve patients with selected recurrent or metastatic cancers, including ongoing cohorts intended to support one or more Biologics License Application submissions. In addition, Checkpoint is evaluating its lead small-molecule, targeted anti-cancer agent, CK-101, a third-generation epidermal growth factor receptor (“EGFR”) inhibitor, in a Phase 1 clinical trial for the treatment of patients with EGFR mutation-positive non-small cell lung cancer (“NSCLC”). Checkpoint is headquartered in New York City and was founded by Fortress Biotech, Inc. (NASDAQ: FBIO). For more information, visit