The US Food and Drug Administration’s use of regular approval for cancer drugs based on single-arm studies: implications for subsequent evidence generation

Recently the US Food & Drug Administration (FDA) granted regular approval to dabrafenib–trametinib (Tafinlar® and Mekinist®; Novartis Pharmaceuticals Inc., Basel, Switzerland) for patients with BRAF V600E mutation in metastatic non-small-cell lung cancer (NSCLC). The approval was made on the basis of a 63% response rate (RR) in a single-arm study. Dabrafenib–trametinib is the second recent regular approval in NSCLC made based on RR—a 50% or greater shrinkage in tumor on serial computed tomography scans.