FDA Approves Cabometyx For Thyroid Cancer Subset

The FDA approval of Cabometyx was based on results that showed that the drug was associated with improved outcomes in patients with radioactive iodine–refractory locally advanced or metastatic differentiated thyroid cancer.

The Food and Drug Administration (FDA) approved Cabometyx (cabozantinib) for patients with previously treated radioactive iodine-refractory differentiated thyroid cancer, according to Exelixis, the manufacturer of the drug.

The drug is approved for the treatment of both adult and pediatric patients 12 years of age and older with the disease.

“Before today, patients with radioactive iodine-refractory differentiated thyroid cancer who have progressed following prior VEGFR (vascular endothelial growth factor receptor)-targeted therapy were facing aggressive disease and no standard treatment option,” Dr. Marcia S. Brose, chief of Cancer Center Operation at Sidney Kimmel Cancer Center at Jefferson Torresdale Hospital and co-director of community based clinical trials at Sidney Kimmel Cancer Center at Thomas Jefferson University, both in Philadelphia, said in a statement. Brose was also the principal investigator of the trial that led to the approval, COSMIC-311.

Results from the phase 3 trial showed that those patients given Cabometyx had a progression-free survival (PFS, length of time during and after the treatment that a patient lives with the disease without it getting worse) of 11 months with a median follow-up of 10.1 months. This showed a significant improvement compared to the PFS of 1.9 months in patients who received placebo with the same follow-up time.

“In the COSMIC-311 pivotal phase 3 trial, Cabometyx extended the time patients live without progression of their cancer. The FDA approval of Cabometyx is an important advancement for these patients who are badly in need of new treatment options,” Brose said.

The most common side effects reported in at least 25% of patients include diarrhea, palmar-plantar erythrodysesthesia (swelling, redness and pain on the hands or feet), fatigue, hypertension (high blood pressure) and stomatitis (inflamed or sore mouth). Severe side effects occurred in at least 2% of patients, including diarrhea, pleural effusion (fluid buildup between the tissues that line the lungs and chest), pulmonary embolism (blood clots) and dyspnea (labored breathing). Fatal side effects like hemorrhage and pulmonary embolism were reported in 1.6% of patients.

“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.”

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