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 promoting an anti-tumor immune response. The companies will explore the potential of combining these two agents with the goal of achieving improved and sustained efficacy in ccRCC patients with cancer that is stable or growing on a PD-1 inhibitor therapy.
 
“Influencing the tumor microenvironment remains a key focus of research, and we are excited to explore the potential benefits of Opdivo plus CB-839 in an effort to advance new combination therapies for difficult to treat cancers,” said Fouad Namouni, M.D., senior vice president, Head of Oncology Development, Bristol-Myers Squibb.
 
“The combination with Opdivo follows our strategy to combine CB-839 with therapies to improve outcomes for RCC patients,” said Susan Molineaux, CEO of Calithera Biosciences. “We believe that by blocking glutamine consumption in tumors, and redirecting this key nutrient for cell growth and proliferation to T‑cells, CB-839 could enhance the effects of Opdivo. With support from Bristol-Myers Squibb, Calithera is excited to advance this combination into the Phase 2 portion of CX-839-004, our ongoing study in ccRCC patients.”
 
Opdivo was the first PD-1 immune checkpoint inhibitor to receive regulatory approval in July 2014, and currently has regulatory approval in 57 countries including the U.S., Japan, and in the EU.