Calithera Biosciences, Inc. is a clinical-stage company focused on the discovery, development and commercialization of first-in-class small molecule oncology therapeutics. The company is building a pipeline of targeted anti-cancer compounds that inhibit pathways critical to tumor growth and survival. Calithera's lead clinical candidate, CB-839, blocks glutaminase, an enzyme critical to tumor metabolism, and is currently being tested in patients with advanced solid and hematological cancers.