CK-301 Anti-PD-L1

CK-301 is a fully human antagonistic monoclonal antibody that binds 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. Physiological interaction between these molecules inhibits immune activation to prevent autoimmunity and to induce self-tolerance. Many different cancers take advantage of this pathway by expressing PD-L1 and triggering negative signaling in PD-1expressing tumor reactive T-cells thus blocking anti-tumor T-cell immune response.

Numerous preclinical and clinical studies have demonstrated that antibodies that block the interaction of PD-1 with its ligands or those that block only the interaction of PD-L1 with PD-1 can augment anti-tumor T-cell responses and lead to complete and lasting tumor eradication in a certain proportion of patients. Confirmed overall response rate (“ORR”) in the labels for the Food and Drug Administration (“FDA”) approved PD-1 and PD-L1 blocking antibodies was cited in the 20-45% range based on clinical trials in patients with metastatic melanoma and non-small cell lung cancer (“NSCLC”). Potent therapeutic anti-tumor responses due to blocking of PD-1/PD-L1 interaction has been demonstrated by these approved products in patients with various solid tumors including, but not limited to, NSCLC, melanoma, renal cell carcinoma (“RCC”), head and neck cancer, and urothelial carcinoma.

We are developing our anti-PD-L1 antibody for the treatment of patients with NSCLC, as well as other solid tumor oncology indications where studies of other PD-1/PD-L1 antibodies have shown to be effective. In March of 2015, we entered into a collaboration agreement to co-develop anti-PD-L1 antibodies for hematological oncological indications with TG Therapeutics, Inc. (“TGTX”). We retain the right to develop and commercialize our anti-PD-L1 antibodies in solid tumors.

We licensed the exclusive worldwide rights to anti-PD-L1 antibodies from Dana-Farber in March 2015. We commenced a phase 1 clinical study for CK-301 in October 2017.