SOUTH SAN FRANCISCO, CA, USA I July 25, 2016 I Calithera Biosciences, Inc. (CALA), a clinical-stage pharmaceutical company focused on discovering and developing novel small molecule drugs directed against tumor metabolism and tumor immunology targets for the treatment of cancer, today announced that the U.S. Food and Drug Administration (FDA) has accepted the company’s Investigational New Drug (IND) application for CB-1158 for the treatment of solid tumors. CB-1158 is a first-in-class, orally available small molecule inhibitor of the enzyme arginase.  

“We are pleased to be advancing the first arginase inhibitor into clinical trials. Arginase is a novel target in metabolic immuno-oncology, and these studies will allow us to assess the safety, pharmacokinetics and pharmacodynamics of this exciting new agent,” said Susan M. Molineaux, Ph.D., founder, Chief Executive Officer and President of Calithera Biosciences. “CB-1158 has demonstrated significant anti-tumor activity in preclinical models, and we look forward to reporting initial clinical results with this compound in 2017.”

Arginase exerts its immunosuppressive effect by depleting the amino acid arginine in the tumor microenvironment and prevents activation and proliferation of the immune system’s cytotoxic T-cells and natural killer (NK) cells. Inhibition of arginase activity reverses this immunosuppressive block and restores T-cell function. The Phase I clinical trial will enroll patients with advanced solid tumors treated with CB-1158 as a monotherapy, as well as in combination with an anti-PD1 antibody.

About Calithera Biosciences

Calithera Biosciences, Inc. is a clinical-stage pharmaceutical company focused on discovering and developing novel small molecule drugs directed against tumor metabolism and tumor immunology targets for the treatment of cancer.  Calithera’s lead product candidate, CB-839, is a potent, selective, reversible and orally bioavailable inhibitor of glutaminase. CB-839 takes advantage of the pronounced dependency many cancers have on the nutrient glutamine for growth and survival. It is currently being evaluated in Phase 1/2 clinical trials in combination with standard of care agents.  CB-1158 is a first-in-class immuno-oncology metabolic checkpoint inhibitor targeting arginase, a critical immunosuppressive enzyme responsible for T-cell suppression by myeloid-derived suppressor cells.  Arginase depletes arginine, a nutrient that is critical for the activation, growth and survival of the body’s cancer-fighting immune cells, known as cytotoxic T-cells.  Calithera is headquartered in South San Francisco, California.  For more information about Calithera, please visit www.calithera.com.

SOURCE: Calithera Biosciences