Merck & Co and Taiho to co-promote cancer immunotherapy pembrolizumab in Japan

USA’s Merck & Co (NYSE: MRK) and Japanese drugmaker Taiho, a subsidiary of Otsuka (TYO: 4768), have announced a co-promotion agreement in Japan for the cancer treatment pembrolizumab.

Merck has filed an application for approval in Japan for the immune checkpoint inhibitor (anti-PD-1 therapy). Under the agreement, Taiho will co-promote pembrolizumab with the American giant, which will manufacture and distribute it.

Pembrolizumab is a humanized monoclonal antibody that blocks the interaction between PD-1 mainly expressed on activated lymphocytes with anti-tumor activity, and its ligands, PD-L1 and PD-L2 expressed mainly on tumor cells. By binding to the PD-1 receptor and blocking the interaction with the receptor ligands, pembrolizumab releases the PD-1 pathway-mediated inhibition of the immune response, including the anti-tumor immune response.