The FDA has granted approval to cabozantinib (Cabometyx®, Exelixis) for the treatment of patients with locally advanced or metastatic differentiated thyroid cancer (DTC) that has progressed following prior vascular endothelial growth factor receptor (VEGFR)–targeted therapy and who are 12 years of age and older and ineligible or refractory to radioactive iodine.
"Patients with radioiodine-refractory DTC previously treated with VEGFR-targeted therapy have aggressive disease and no available standard of care," wrote Marcia S. Brose, MD, PhD, Director of Cancer Services at the Sidney Kimmel Cancer Center and Emeritus Professor CE of Otorhinolaryngology: Head and Neck Surgery at the University of Pennsylvania Perelman School of Medicine, and colleagues, in their published results of the COSMIC-311 trial (NCT03690388), on which the approval was based. "The aim of this study was to evaluate the tyrosine kinase inhibitor cabozantinib in this patient population."
This double-blind, placebo-controlled, multicenter clinical trial enrolled 187 patients who were randomized 2:1 to receive either 60 mg cabozantinib or placebo orally once daily with best supportive care until disease progression or intolerable toxicity. The primary end points were progression-free survival in all patients and overall response rate in the first 100 randomized patients.
Cabozantinib was found to be statistically significant in reducing the risk of disease progression or death versus placebo (P<0.0001). The median progression-free survival was 11.0 months in the cabozantinib treatment arm versus 1.9 months in the placebo arm. The overall response rate was 18% and 0% in the cabozantinib and placebo treatment arms, respectively.
The most common adverse reactions occurring in at least 25% of patients were diarrhea, palmar-plantar erythrodysesthesia, fatigue, hypertension, and stomatitis. The prescribing information for cabozantinib includes a warning for hypocalcemia.
"Our results show that cabozantinib significantly prolongs progression-free survival and might provide a new treatment option for patients with radioiodine-refractory DTC who have no available standard of care," concluded Dr. Brose and colleagues in their August 2021 publication in The Lancet Oncology.
The recommended dose of cabozantinib is 60 mg orally once daily until disease progression or unacceptable toxicity; for pediatric patients at least 12 years old who have a body surface area less than 1.2 m2, the recommended dose is 40 mg once daily until disease progression or unacceptable toxicity.
For More Information
Brose MS, Robinson B, Sherman SI, et al (2021). Cabozantinib for radioiodine-refractory differentiated thyroid cancer (COSMIC-311): a randomised, double-blind, placebo-controlled, phase 3 trial. Lancet Oncol,22(8):1126-1138. DOI:10.1016/S1470-2045(21)00332-6
Clinicaltrials.gov (2021). A study of cabozantinib compared with placebo in subjects with radioiodine-refractory differentiated thyroid cancer who have progressed after prior vascular endothelial growth factor receptor (VEGFR)-targeted therapy. NLM identifier: NCT03690388.
Cabometyx® (cabozantinib) prescribing information (2021). Exelixis, Inc. Available at: https://www.accessdata.fda.gov/drugsatfda_docs/label/2021/208692s012lbl.pdf
US Food & Drug Administration (2021). FDA approves cabozantinib for differentiated thyroid cancer. Available at: https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-cabozantinib-differentiated-thyroid-cancer
Image credit: Yale Rosen. Licensed under CC BY-SA 2.0