On September 17, 2021, the FDA accelerated the approval of a new indication for Cabometyx (cabozantinib; from Exelixis), a kinase inhibitor, for the treatment of patients aged 12 years or older with locally advanced or metastatic differentiated thyroid cancer that progressed after VEGFR-targeted therapy and who are ineligible for, or whose disease is refractory (not responding) to, radioactive iodine therapy.
Cabometyx was previously approved for the treatment of kidney cancer. Radioactive iodine therapy is the main treatment available for patients with this type of thyroid cancer.
“Before today, patients with radioactive iodine–refractory differentiated thyroid cancer who have progressed following prior VEGFR-targeted therapy were facing aggressive disease and no standard treatment option,” said Marcia S. Brose, MD, PhD, of Sidney Kimmel Cancer Center, Jefferson Torresdale Hospital, and lead investigator of the clinical trial. “In the COSMIC-311 pivotal phase 3 trial, Cabometyx extended the time patients live without progression.”
“Patients with differentiated thyroid cancer who have progressed following prior therapy and are radioactive iodine-refractory often face a poor prognosis and have limited treatment options,” said Gary Bloom, Executive Director of ThyCa: Thyroid Cancer Survivors’ Association. “We are excited about the latest approval of Cabometyx, which will offer hope for patients with this type of thyroid cancer.”
This approval was based on the results of the COSMIC-311 clinical trial that included patients with locally advanced or metastatic differentiated thyroid cancer that had progressed after VEGFR-targeted therapy who were not able to use radioactive iodine therapy.
Patients were divided into 2 groups that received either Cabometyx or placebo. Cabometyx significantly reduced the risk of disease progression or death compared with placebo. The average time without disease progression was 11 months in the patients who received Cabometyx compared with 1.9 months in those who received placebo. The response rate was 18% in patients who received Cabometyx and 0% in those who received placebo.
The most common side effects with Cabometyx were diarrhea, rash, fatigue, hypertension, and mouth sores.
