Checkpoint Therapeutics Strengthens Intellectual Property Protection for Cosibelimab With New US Patent Issuance

Checkpoint Therapeutics, Inc. recently announced the US Patent and Trademark Office (USPTO) has issued a new patent (US Patent No. 11,834,505) covering a method of treating various cancers, including cutaneous squamous cell carcinoma (cSCC), through the administration of cosibelimab.

The USPTO previously issued a composition of matter patent (US Patent No. 10,590,199), specifically covering cosibelimab, or a fragment thereof. Together, these patents protect Checkpoint’s differentiated and potential best-in-class anti-PD-L1 antibody, cosibelimab, in the US through at least May 2038, not including any potential patent term extension under the Hatch-Waxman Act.

Checkpoint’s Biologics License Application (BLA) for cosibelimab is currently under review by the US FDA as a potential new treatment for patients with locally advanced and metastatic cSCC, with an upcoming Prescription Drug User Fee Act (PDUFA) goal date of January 3, 2024.

“With less than 5 weeks remaining before our assigned PDUFA date for cosibelimab, we look forward to cosibelimab potentially joining an approved class of immunotherapies with combined worldwide annual sales exceeding $35 billion,” said James Oliviero, President and Chief Executive Officer of Checkpoint. “We believe our broad US patent portfolio, expiring no earlier than May 2038, provides the potential for cosibelimab to be further developed into a market leading drug, not only in cSCC, but also in additional indications, both as a monotherapy and as the PD-L1 backbone for new combination regimens.”

Cosibelimab is a potential best-in-class, 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. 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 >99% target tumor occupancy to reactivate an antitumor immune response and the additional benefit of a functional Fc domain capable of inducing antibody-dependent cell-mediated cytotoxicity for potential enhanced efficacy in certain tumor types.

Checkpoint Therapeutics, Inc. 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 potential best-in-class anti-PD-L1 antibody licensed from the Dana-Farber Cancer Institute, in an ongoing open-label, multi-regional, multicohort Phase 1 clinical trial in checkpoint therapy-naïve patients with selected recurrent or metastatic cancers, including cohorts in metastatic and locally advanced cSCC intended to support one or more applications for marketing approval. Based on positive topline and interim results in metastatic and locally advanced cSCC, respectively, Checkpoint submitted a BLA for these indications in January 2023, which application is filed and under review with a PDUFA goal date of January 3, 2024. Checkpoint is evaluating its lead small-molecule, targeted anti-cancer agent, olafertinib (formerly CK-101), a third-generation epidermal growth factor receptor (EGFR) inhibitor, as a potential new treatment for patients with EGFR mutation-positive non-small cell lung cancer. Checkpoint is headquartered in Waltham, MA, and was founded by Fortress Biotech, Inc. For more information, visit