Anixa Biosciences, Inc. announced that its partner, Cleveland Clinic, has begun enrolling subjects in a treatment arm evaluating the combination of the Company's breast cancer vaccine with Keytruda® (pembrolizumab). An expansion of the ongoing Phase 1 dose escalation trial of Anixa's breast cancer vaccine, this treatment arm aims to determine if the vaccine/Keytruda combination increases immune response. Anixa's breast cancer vaccine is designed to generate T cells that target triple negative breast cancer. Keytruda, a therapy marketed by Merck, is approved for use with chemotherapy before surgery and then alone after surgery to treat both high-risk early-stage and advanced TNBC.  Keytruda is a type of immunotherapy known as a checkpoint inhibitor.

T cells, a type of white blood cell involved in the body's immune system, have receptor proteins on their surface called checkpoints. These checkpoints are utilized by other immune cells to modulate the activity of T cells. Cancer cells, such as TNBC cells, have developed mechanisms to target checkpoints to inhibit the activity of T cells, as well as other immune cells.

This inhibition enables the cancer cells to escape destruction by cytotoxic T cells. One of these key checkpoint receptors is known as PD-1 (Programmed Cell Death Protein-1). TNBC, like many other cancers, expresses a protein that binds to the PD-1 protein on T cells and essentially turns them "off." Keytruda is a monoclonal antibody, which blocks the ability of the cancer cells to inactivate T cells by shielding the PD-1 receptor.