Reflections on the FDA Filing Acceptance of Checkpoint’s BLA for Cosibelimab

The recent FDA filing acceptance of our BLA for cosibelimab – our investigational anti-PD-L1 antibody – represents a big step forward both for Checkpoint and for patients with metastatic cutaneous squamous cell carcinoma (cSCC) or locally advanced cSCC who are not candidates for curative surgery or radiation. We believe cosibelimab, if approved, will be uniquely positioned to provide an important new treatment option for cSCC patients currently underserved by available therapies.

Here’s why: Cosibelimab has a dual mechanism of action. Cosibelimab’s primary mechanism of action is, like other PD-L1 therapies, based on the inhibition of the interaction between PD-L1 and its receptor PD-1, which removes the suppressive effects of PD-L1 on anti-tumor T-cells to restore the cytotoxic T-cell response.

As a secondary mechanism of action, cosibelimab has a functional Fc domain that may bind and activate Natural Killer (NK) cells to enable antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) against tumor cells.

Targeting the PD-1/PD-L1 pathway using a monoclonal antibody has proven to be effective in many oncological indications as a monotherapy or in combination with other anti-tumor immune response potentiating compounds and targeted therapies. cSCC is no exception.

Yet, while U.S. prescription claims data shows approximately 11,000 cSCC patients were treated with systemic therapies in 2021, PD-1 inhibitors comprised less than half of those patient prescriptions. cSCC remains a disease with a need for more effective and tolerable treatment options, particularly for the significant number of cSCC patients with immunosuppressive conditions or autoimmune diseases that may make them poor candidates for PD-1 therapy. With its dual mechanism of action and compelling safety profile, we believe cosibelimab, if approved, may present a safe and effective alternative for those patients.

We look forward to continuing to work closely with the FDA as we strive to bring cosibelimab to patients in need as quickly as possible. The FDA has set a Prescription Drug User Fee Act (PDUFA) goal date of January 3, 2024, for its review of the cosibelimab marketing approval application.