Votrient is a multi-targeted tyrosine kinase inhibitor and it is currently approved for renal cell carcinoma. A recent study evaluated it in thyroid cancer. This phase II trial included 37 patients who had received up to two prior therapies, had measurable disease, and whose disease had progressed in the six months before they were enrolled in the study. Patients received 800 mg of Votrient daily.
Following a median of 12 four-week cycles of treatment with Votrient, there were 18 partial responses (PRs) to therapy.
Researchers estimated that PRs would last for one year in 66% of patients.
Median progression-free survival was 11.7 months.
Overall survival at one year was 81%.
When PR was measured according to thyroid cancer cell type, eight PRs were observed in11 patients with follicular cell type (72.7%), five PRs in 11 patients with Hürthle cell type (45.4%), and five PRs in 15 patients with papillary cell type (33.3%).
66.7% of patients who were antithyroidglobulin-negative (no antibodies to the protein thyroidglobulin, produced by the thyroid) experienced a decrease in thyroidglobulin of more than 30%.
Side effects were modest, but 15 patients did require a dose reduction due to adverse effects. Frequent side effects included diarrhea and hypertension.
The researchers concluded that Votrient is highly active in advanced differentiated thyroid cancer and well tolerated; the drug may therefore be a promising treatment for patients with this disease. Votrient will be further evaluated in this patient population in an upcoming Phase III clinical trial.
NCCN (p.FOLL-5) mentions Votrient as a level 2B recommendations in a footnote when clinical trials are not available for this specific uncommon situation.
Bible KC, Suman VJ, Molina JR, et at. Evidence of clinical efficacy of the multi-targeted tyrosine kinase inhibitor pazopanib in rapidly progressive radioiodine-refractory metastatic differentiated thyroid cancers: results of the Phase 2 consortium study MC057H. Presented at the 14th International Thyroid Congress, Paris, France, September 11-16, 2010. Abstract OC-022.