FDA grants breakthrough therapy designation to Cabometyx for thyroid cancer subset
The FDA granted breakthrough therapy designation to cabozantinib for treatment of certain patients with thyroid cancer, according to the agent’s manufacturer.
The designation applies to use of the agent for patients with previously treated, radioactive iodine-refractory differentiated thyroid cancer.
Treatment for differentiated thyroid cancer typically consists of surgery followed by ablation of the remaining thyroid tissue with radioiodine.
Approximately 5% to 15% of patients are radioiodine-refractory, and life expectancy for these patients is 3 to 6 years from detection of metastatic lesions.
Cabozantinib (Cabometyx, Exelixis) is a multitargeted tyrosine kinase inhibitor.
The FDA based the breakthrough therapy designation on results of the randomized phase 3 COSMIC-311 trial, which included patients with radioactive iodine-refractory differentiated thyroid cancer who progressed after up to two prior VEGFR-targeted therapies.
Researchers assigned patients 2:1 to 60 mg cabozantinib or placebo once daily.
PFS and objective response rate served as co-primary endpoints.
Interim analysis results showed a 78% reduction in risk for disease progression or death with cabozantinib vs. placebo (HR = 0.22; 96% CI, 0.13-0.36).
“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,” Gisela Schwab, MD, president of product development and medical affairs and chief medical officer of Exelixis, said in a company-issued press release. “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.”