According to a story from The ASCO Post, the drug cabozantinib (marketed as Cometriq) was first approved by the US Food and Drug Administration (FDA) as a treatment for metastatic medullary thyroid cancer on November 29th, 2012. As this drug was approved for progressive, metastatic disease, meaning disease that has spread to other tissues beyond its area of origin, the treatment is typically used for the most severe cases. In this story, we will provide an overview of the use of cabozantinib in this form of thyroid cancer.
About Thyroid Cancer
Thyroid cancer affects the cells of the thyroid, a gland located in the neck which plays a role in the endocrine system. Rates of thyroid cancer have been rising in recent years, but this is probably due to more effective detection methods. There are a number of risk factors for thyroid cancer, such as exposure to radiation, prior thyroid disease, the genetic disorder multiple endocrine neoplasia type 2, an enlarged thyroid, and family history. Women and people of Asian descent are more likely to be affected. Symptoms include a noticeable lump in the neck, vocal changes, neck pain, and enlarged or swollen thyroid. Treatment for thyroid cancer may include surgery, Iodine-131, radiation, or other medications when the cancer has metastasized. Although survival rates vary depending on the type, the overall five year survival rate is 98 percent in the US, which is better than most cancers. To learn more about thyroid cancer, click here.
Cabozantinib functions as an inhibitor of several types of tyrosine kinases, including TIE-2, MET, RET, KIT, AXL, and VEGFR -1,-2,and -3; it also acts on FLT-3 and TRKB. The approval of the drug was based on an international clinical study that included a total of 330 patients with metastatic medullary thyroid cancer. The overall response rate was 27 percent and the drug reduced the risk of disease progression by 72 percent. The median duration of response was 14.7 months.
The drug is administered once per day in a 140 mg dose. The use of this therapy should be avoided if possible in patients with moderate to severe impairment of liver function. If severe toxicity or adverse effects occur with use, treatment should be temporarily withheld and then administered at a dose reduced by 40 mg. Adverse effects of cabozantinib include hypertension, oral pain, fatigue, weight loss and appetite loss, palmar-plantar erythrodysesthesia syndrome, diarrhea, and stomatitis.