Cosibelimab (CK-301) is an investigational fully-human monoclonal antibody that binds programmed death-ligand 1 (PD-L1) and blocks its interaction with Programmed cell death protein 1 (PD-1). PD-1 and its ligand PD-L1 are checkpoints of immune activation and play a very important role in negative regulation of T-cell effector function and proliferation. Cosibelimab’s primary mechanism of action is 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. Additionally, cosibelimab has a functional Fc domain that may be capable of inducing 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. We licensed the exclusive worldwide rights to cosibelimab from Dana-Farber Cancer Institute in March 2015.
Cosibelimab is being evaluated in a global, open-label, multicohort Phase 1 clinical trial in checkpoint therapy-naïve patients with selected recurrent or metastatic cancers, including ongoing cohorts in locally advanced and metastatic cutaneous squamous cell carcinoma (CSCC) intended to support one or more applications for marketing approval.