Exelixis Announces Breakthrough Therapy Designation Granted to Cabozantinib for the Treatment of Patients with Previously Treated Radioactive Iodine-Refractory Differentiated Thyroid Cancer

– U.S. FDA designation based on an interim analysis of the phase 3 COSMIC-311 pivotal trial, in which cabozantinib demonstrated significant improvement in progression-free survival –

– Exelixis expects to submit supplementary New Drug Application in 2021 –

ALAMEDA, Calif.--(BUSINESS WIRE)-- Exelixis, Inc. (NASDAQ: EXEL) today announced that the U.S. Food and Drug Administration (FDA) has granted Breakthrough Therapy Designation to cabozantinib (CABOMETYX®) as a potential treatment for patients with differentiated thyroid cancer (DTC) that has progressed following prior therapy and who are radioactive iodine-refractory (if radioactive iodine is appropriate). The FDA’s Breakthrough Therapy Designation aims to expedite the development and review of drugs that are intended to treat serious or life-threatening diseases. To qualify for this designation, preliminary clinical evidence must indicate that the drug may demonstrate substantial improvement on at least one clinically significant endpoint over existing therapies.

“Receiving Breakthrough Therapy Designation is a testament to both the urgent need for effective treatments for patients with differentiated thyroid cancer who progressed after prior therapy and the promising data demonstrating cabozantinib significantly improved progression-free survival for these patients,” said Gisela Schwab, M.D., President, Product Development and Medical Affairs and Chief Medical Officer, Exelixis. “We look forward to submitting our regulatory application in 2021 and to working closely with the FDA during the review process, with the goal of bringing cabozantinib to this patient population with a high unmet medical need for whom there is currently no available standard of care.”

In December 2020, Exelixis announced that at a planned interim analysis, the phase 3 COSMIC-311 pivotal trial met the co-primary endpoint, demonstrating a significant reduction in the risk of disease progression or death of 78% with cabozantinib versus placebo (HR 0.22, 96% CI 0.13 – 0.36; p