FDA Accepts Checkpoint Therapeutics' BLA Resubmission for Cosibelimab in Advanced Cutaneous Squamous Cell Carcinoma

Checkpoint Therapeutics, Inc., a clinical-stage company specializing in immunotherapy and targeted oncology treatments, recently announced that the U.S. Food and Drug Administration (FDA) has accepted their resubmission for the Biologics License Application (BLA) for cosibelimab. Cosibelimab is an anti-PD-L1 antibody intended as a treatment for adults with metastatic or locally advanced cutaneous squamous cell carcinoma (cSCC) who are not eligible for curative surgery or radiation. The FDA has set a Prescription Drug User Fee Act (PDUFA) goal date of December 28, 2024, for this review.

James F. Oliviero, President and CEO of Checkpoint, expressed satisfaction with the FDA's acceptance of their resubmission. He emphasized the company's commitment to working closely with the FDA to complete the review process, with the hope of offering cosibelimab’s unique dual mechanism of action to patients suffering from cSCC.

The FDA had previously issued a Complete Response Letter (CRL) in December 2023, citing issues discovered during a multi-sponsor inspection of Checkpoint's third-party contract manufacturing organization (CMO). However, the CRL did not raise any concerns about the clinical data, safety, or labeling of cosibelimab. The resubmission of the BLA aims to address these findings, potentially paving the way for approval.

Cosibelimab is described as a high-affinity, fully-human monoclonal antibody of the IgG1 subtype. It binds directly to PD-L1 and inhibits its interaction with PD-1 and B7.1 receptors. This blockage mitigates the suppressive effect of PD-L1 on anti-tumor CD8+ T-cells, thereby restoring the cytotoxic T cell response. Cosibelimab potentially stands out among existing PD-1 and PD-L1 antibodies due to its high tumor target occupancy and its functional Fc domain, which may enhance efficacy through antibody-dependent cellular cytotoxicity (ADCC).

Checkpoint Therapeutics focuses on developing and commercializing novel treatments for solid tumor cancers. Alongside cosibelimab, the company is also evaluating olafertinib, a third-generation epidermal growth factor receptor (EGFR) inhibitor. Olafertinib is being assessed as a potential treatment for patients with EGFR mutation-positive non-small cell lung cancer. The company operates out of Waltham, MA, and was founded by Fortress Biotech, Inc.

In summary, the FDA's acceptance of Checkpoint Therapeutics’ BLA resubmission for cosibelimab marks a significant step toward potentially providing a new treatment option for patients with metastatic or locally advanced cSCC. The set PDUFA goal date of December 28, 2024, will be pivotal in determining the future approval and commercial availability of cosibelimab.