Cabozantinib Meets Primary Endpoint of Progression Free Survival in Phase 3 Pivotal Trial in Medullary Thyroid Cancer

Exelixis, Inc.

today reported data from the phase 3 pivotal trial of cabozantinib in patients with progressive, unresectable, locally advanced or metastatic medullary thyroid cancer (MTC). The trial, known as EXAM, met its primary endpoint of improving progression-free survival (PFS), with patients in the cabozantinib arm achieving a median PFS of 11.2 months compared with 4.0 months for patients in the placebo arm. Overall response rate (ORR), a secondary endpoint, was 28% in the cabozantinib arm and 0% in the placebo arm. Estimated PFS at one year was 47.3% with cabozantinib vs. only 7.2% with placebo. Data for overall survival (OS), another secondary endpoint, are not yet mature. Patients on the cabozantinib arm of the trial received a dose of 140 mg (free base equivalent). Adverse events were generally manageable allowing for treatment with cabozantinib for prolonged periods of time. Exelixis recently submitted a New Drug Application (NDA) for cabozantinib in MTC to the U.S. Food and Drug Administration (FDA).