In July 2019 Calithera and Pfizer initiated a trial with the CDK 4/6 inhibitor IBRANCE®, in combination with telaglenastat. The Phase 1/2 trial (NCT03965845) is ongoing in patients with KRAS mutated colorectal cancer and KRAS mutated non-small cell lung cancer. In November 2020, Calithera announced the expansion of the study to include an additional cohort of patients with pancreatic ductal adenocarcinoma whose tumors harbor mutations in both KRAS and CDKN2A.