Calithera Biosciences, Inc. Presents Preclinical Study Findings For CB-839 At The 2015 Novel Cancer Therapeutics Summit

Potential to Combine With PD-1/PD-L1 Inhibitors and Other Immuno-Oncology Therapies

SOUTH SAN FRANCISCO, Calif., Nov. 16, 2015 (GLOBE NEWSWIRE) -- Calithera Biosciences, Inc. (Nasdaq:CALA), a clinical stage biotechnology company focused on the development of novel cancer therapeutics, will announce new preclinical data today for its lead therapeutic candidate, CB-839, at the 2015 Global Technology Community (GTC) Novel Cancer Therapeutics Summit in San Francisco, California. CB-839 is a potent, selective, orally bioavailable glutaminase inhibitor currently in phase I clinical trials. The first preclinical studies combining CB-839 with an immune checkpoint inhibitor were presented demonstrating that CB-839 significantly increases the rate of tumor regressions in syngeneic mice when CB-839 is added to anti-PD-L1.

“The new data presented at the GTC meeting provide us with the rationale to continue developing CB-839 in combination with multiple classes of therapeutics, and to expand our development program to include immunotherapy agents,” said Susan Molineaux, PhD, President and Chief Executive Officer of Calithera. “We continue to leverage our expertise in tumor and cellular metabolism to enhance our understanding of metabolic checkpoints in cancer.”

Preclinical data will be presented in an oral presentation titled, “Identification of Biomarkers and Combination Agents for the Glutaminase Inhibitor CB-839 for the Treatment of Cancer,” by Francesco Parlati, PhD, Senior Director of Biology at Calithera Biosciences. Included in the presentation are the results of studies investigating the preclinical anti-tumor activity of CB-839 in combination with an anti-PD-L1 antibody. The combination of CB-839 and anti-PD-L1 increased the number of tumor regressions seen with anti-PD-L1 treatment in the CT-26 syngeneic colon carcinoma model. Synergistic effects with CB-839 and anti-PD-L1 were also observed in a B16 melanoma model. PD-L1 ligation of PD-1 on the surface of T cells blocks metabolism of glucose and glutamine, depriving T cells of nutrients necessary for activation and differentiation. The mechanism of action of anti-PD-L1 combined with CB-839, two agents that effect metabolism in the tumor microenvironment, is being explored in further studies.

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 currently being evaluated in three Phase 1 clinical trials in solid and hematological cancers. 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

Help employers find you! Check out all the jobs and post your resume.

Back to news