On December 18, 2023, Checkpoint issued a press release announcing that the U.S. Food and Drug Administration had issued a complete response letter for the cosibelimab biologic license application for the treatment of patients with metastatic or locally advanced cutaneous squamous cell carcinoma who are not candidates for curative surgery or radiation. According to Checkpoint’s release, “[t]he CRL only cites findings that arose during a multi-sponsor inspection of Checkpoint’s third-party contract manufacturing organization as approvability issues to address in a resubmission.” Checkpoint’s President and Chief Executive Officer stated that “we believe we can address the feedback in a resubmission to enable marketing approval in 2024”.

On this news, Checkpoint’s stock price dropped 44.88%, to close at $1.83 per share on December 18, 2023.