Calithera Biosciences, Inc. announced topline results from the CANTATA clinical study of the company’s glutaminase inhibitor telaglenastat in patients with advanced or metastatic renal cell carcinoma (RCC). As compared to treatment with cabozantinib, the combination of telaglenastat and cabozantinib did not meet the primary endpoint of improving progression free survival (PFS) in the study population. The primary study endpoint is PFS by blinded independent review. The hazard ratio was 0.94 (p=0.65). Median PFS was 9.2 months among patients treated with telaglenastat and cabozantinib as compared to 9.3 months with cabozantinib and placebo. Sixty-two percent of patients were treated with prior PD(L)-1 containing therapy, and the arms were well balanced. The frequency and severity of adverse events in the telaglenastat-treated population were comparable to that of cabozantinib alone. Calithera will focus its financial resources on the ongoing KEAPSAKE trial, the ongoing trial of the arginase inhibitor CB-280 in cystic fibrosis patients and pipeline programs. As a result of the outcome of CANTATA, Calithera will reduce its workforce by approximately 35 percent to allow the company to focus on ongoing programs. Calithera expects cash, cash equivalents and investments to be approximately $115 million at December 31, 2020 based on preliminary estimates, which management believes will be sufficient to meet its current operating plan through 2022, including the release of interim results of the KEAPSAKE trial and completion of the current cystic fibrosis study in 2021. Calithera anticipates the one-time severance-related charge associated with the workforce reduction to be approximately $1.3 million - $1.5 million, with the majority to be completed by the first quarter of 2021. More financial details will be provided by the company in its fourth quarter 2020 financial report in March 2021. The information relating to cash, cash equivalents and investments is preliminary, has not been audited and is subject to change upon completion of the audit of Calithera’s financial statements as of and for the year ended December 31, 2020. The CANTATA trial (NCT03428217) is a global, randomized, double-blind trial designed to evaluate the efficacy and safety of telaglenastat in combination with cabozantinib versus placebo with cabozantinib in patients with advanced or metastatic RCC who have been treated with one or two prior lines of systemic therapy, including at least one vascular endothelial growth factor (VEGF)-pathway targeted anti-angiogenic therapy or the combination of nivolumab and ipilimumab. The CANTATA trial enrolled 444 patients at multiple centers globally. Exelixis, Inc. provided cabozantinib for the trial through a material supply agreement with Calithera. Calithera will submit the CANTATA results for presentation at a medical meeting.