Checkpoint Therapeutics Resubmits BLA for Cosibelimab to FDA for Advanced Skin Cancer Treatment
Checkpoint Therapeutics, Inc. ("Checkpoint") (NASDAQ:CKPT), a clinical-stage immunotherapy and targeted oncology company, today announced it has completed the resubmission of its Biologics License Application ("BLA") to the U.S. Food and Drug Administration ("FDA") for cosibelimab, its anti-programmed death ligand-1 ("PD-L1") antibody, as a potential new treatment for patients with metastatic or locally advanced cutaneous squamous cell carcinoma ("cSCC") who are not candidates for curative surgery or curative radiation.
The BLA resubmission follows Checkpoint recently reaching alignment with the FDA on its BLA resubmission strategy to potentially address all approvability deficiencies outlined in the complete response letter ("CRL") received last December, in which FDA only cited findings that arose during a multi-sponsor inspection of Checkpoint's third-party contract manufacturing organization ("CMO") as approvability issues to address in a BLA resubmission. The CRL did not state any concerns about the clinical data package, safety, or labeling for the approvability of cosibelimab.
The BLA resubmission is supported by the results of Checkpoint's studies in selected recurrent or metastatic cancers, including pivotal cohorts in metastatic and locally advanced cSCC. Safety and efficacy results from the metastatic cSCC cohort were published in October 2023 in the Journal for ImmunoTherapy of Cancer (JITC) (doi:10.1136/jitc-2023-007637).
Additionally, in July 2023, Checkpoint announced longer-term data for cosibelimab from its pivotal studies in locally advanced and metastatic cSCC demonstrating a deepening of response over time, resulting in higher complete response rates than previously reported (55% objective response rate; 26% complete response rate in locally advanced cSCC and 50% objective response rate; 13% complete response rate in metastatic cSCC).
Cosibelimab is a potential differentiated, high affinity, fully-human monoclonal antibody of IgG1 subtype that directly binds to PD-L1 and blocks the PD-L1 interaction with the programmed death receptor-1 ("PD-1") and B7.1 receptors. 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 through sustained high tumor target occupancy of PD-L1 to reactivate an antitumor immune response and the additional potential benefit of a functional Fc domain capable of inducing antibody-dependent cell-mediated cytotoxicity ("ADCC") for potential enhanced efficacy.