Bristol-Myers Squibb and Calithera Biosciences, Inc. have entered a clinical collaboration to evaluate BMS’ Opdivo in combination with Calithera’s CB-839 in patients with clear cell renal cell carcinoma (ccRCC). CB-839 is an orally administered glutaminase inhibitor currently in Phase 1/2 studies.   Preclinical data suggest that CB-839 may enhance the effects of checkpoint inhibitors and reverse tumor resistance to checkpoint inhibitors by altering the immune-suppressive environment and promot...