FDA Approves New Therapeutic for Thyroid Cancer
Yet more good news emanated from the U. S. Food and Drug Administration (FDA) last week when it announced the approval of lenvatinib (Lenvima) for the treatment of certain patients with thyroid cancer: those with locally recurrent or metastatic differentiated thyroid cancer that has progressed despite radioactive iodine therapy.
Differentiated thyroid cancers account for approximately 9 out of every 10 of the thyroid cancer diagnoses that are made in the United States each year. This translates into an estimated 56,205 new cases of differentiated thyroid cancer projected for 2015. Although the five-year survival rate for all U.S. patients diagnosed with thyroid cancer is almost 98 percent, it falls to just below 55 percent for those with metastatic disease.
Lenvatinib is the second molecularly targeted therapy approved by the FDA for the treatment of differentiated thyroid cancer. The first, sorafenib (Nexavar), was approved for this use in November 2013.
Like sorafenib, lenvatinib targets several molecules that promote the growth of differentiated thyroid cancers in various ways. Among the molecules targeted by lenvatinib are receptor families involved in the growth of new blood and lymphatic vessels, a process called angiogenesis, which supports tumor growth and survival. These receptor families include the vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF) receptor families, as well as platelet-derived growth factor receptor alpha. Lenvatinib also inhibits other molecules that have been implicated in tumor growth and cancer progression, including KIT and RET.
The FDA approval of lenvatinib was based on results from the randomized, double-blind, phase III study of (E7080) lenvatinib in differentiated cancer of the thyroid (SELECT) clinical trial, which were recently published in the New England Journal of Medicine. Briefly, lenvatinib increased more than fivefold the time to disease progression: progression-free survival was 18.3 months for those patients who received lenvatinib versus 3.6 months for those who received placebo.
In addition, 65 percent of patients who received lenvatinib saw a reduction in tumor size, compared with 2 percent of those who received placebo.
Given that angiogenesis is known to have an important role in promoting the growth of other solid tumors, lenvatinib is currently being tested in clinical trials as a potential treatment for a number of other types of cancer, including kidney, liver, and non-small cell lung cancers.