Calithera to Receive $12-Million Milestone Payment From Incyte

Calithera Biosciences, Inc. recently announced it has achieved pharmacokinetic and pharmacodynamic goals for CB-1158 which, under its agreement with Incyte Corporation, entitles the company to receive a $12-million payment from Incyte.

“We are very excited to achieve this early milestone under our collaboration with Incyte as CB-1158 has demonstrated the desired pharmacologic activity in humans, with a corresponding elevation in plasma arginine levels to those achieved with efficacious doses in preclinical models of cancer. Through our collaboration with Incyte, we will continue to evaluate the role of arginase inhibition in the immuno-oncology setting with CB-1158, and we expect to present additional clinical data mid-2017,” said Susan Molineaux, President and Chief Executive Officer of Calithera Biosciences.

In January 2017, Calithera and Incyte established a global collaboration and license agreement for the research, development, and commercialization of Calithera’s first-in-class, small molecule arginase inhibitor CB-1158 in hematology and oncology. CB-1158 is currently being studied in a monotherapy dose escalation clinical trial and also in combination with anti-PD-1 therapy. Additional studies are expected to evaluate CB-1158 in combination with other immuno-oncology agents.

Arginase is an enzyme produced by immunosuppressive myeloid cells, including myeloid-derived suppressor cells (MDSCs) and neutrophils, which prevents T-cell and natural killer (NK) cell activation in tumors. Arginase exerts its immunosuppressive effect by depleting the amino acid arginine in the tumor microenvironment, which subsequently prevents activation and proliferation of the immune system’s cytotoxic T-cells and NK-cells. Inhibition of arginase activity reverses this immunosuppressive block and restores T-cell function. In preclinical models, arginase inhibition has been shown to enhance anti-tumor immunity and inhibit tumor growth.

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 I/II 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. CB-1158 is currently in a Phase I clinical trial. Calithera is headquartered in South San Francisco, CA. For more information, visit www.calithera.com.