The US Food and Drug Administration (FDA) has granted the drug CB-839 fast track development status when used in combination with cabozantinib for the treatment of patients with metastatic renal cell carcinoma (RCC) who received one or two prior courses of drug treatment (including at least one TKI).
Fast track status speeds up the review process to help with the development of drugs used to treat serious or life-threatening conditions and fill an unmet medical need.
CB-839 is a glutaminase inhibitor. Genetic changes in tumours often cause a change in cancer cell metabolism and an increase in the uptake of the nutrients glucose and glutamine. Some cancer cells need glutamine to grow, and when glutamine is removed, cancer cell growth slows or the cells die. Normal cells are not dependent on glutamine for growth. The enzyme glutaminase, which converts glutamine to glutamate, has been identified as critical in the use of glutamine by cancer cells. CB-839 blocks glutaminase and prevents cancer cells from being able to use glutamine, potentially leading to reduced cancer cell growth and/or cell death.
CB-839 is being assessed in the CANTATA trial; a randomised double-blind clinical study of cabozantinib in combination with CB-839 or placebo in 444 patients with clear cell RCC who had received one or two previous courses of drug treatment. The primary endpoint is progression free survival.
Patients treated with the CB-839/cabozantinib combination had a median progression free survival of 9.2 months compared to 9.3 months among patients who received cabozantinib with a placebo. The number and severity of side effects were similar between the two treatment groups.