Calithera Biosciences reports Phase 1 data on kidney cancer treatment
Calithera Biosciences announced that clinical data from its lead product candidate CB-839, a first-in-class glutaminase inhibitor, will be presented at the EORTC-NCI-AACR Symposium. "The data demonstrate the clinical activity, tolerability and unique mechanism of action of CB-839 in patients with renal cell carcinoma," the company noted, adding that "we are pleased to present combination data of CB-839 with everolimus that demonstrates high rates of disease control with a well-tolerated combination therapy." On the specific Phase 1 data to be presented, Calithera noted: "As of October 25, 15 renal cell carcinoma patients were treated and evaluable for response, including 12 clear cell patients, and three papillary patients. Ninety-three percent have disease control; one patient has a partial response, one patient has progressive disease, and 13 patients have stable disease. The median progression free survival is 8.5 months and for the majority of patients, their time on therapy is longer than their time on treatment in their prior therapy. In the clear cell patient population the disease control rate is 100% and eight patients remain on study. For comparison, in a separate trial of everolimus vs. cabozantinib, the progression free survival of patients in the everolimus group from the Meteor Phase 3 study in second and third line patients was 3.9 months... The addition of CB-839 to full dose everolimus has been well tolerated, with a similar safety profile to the known profile of everolimus alone. Grade 3 events include two events of hyperglycemia and one event each of diarrhea, anemia and fatigue." The company said that, on the basis of this efficacy and safety data, it plans to continue development in combination therapy for clear cell renal cell carcinoma.