ASCO Annual Meeting
May 31, 2014
Results from a recent study show that the drug lenvatinib could become a new, effective treatment option for patients with differentiated thyroid cancer that is resistant to standard radioiodine (RAI) therapy. Differentiated thyroid cancer is the most common subtype of thyroid cancer. It is generally curable with surgery and RAI. However, about 5% to 15% of patients with this subtype develop resistance to RAI, which means that it is no longer able to control the cancer’s growth.
Lenvatinib is a type of targeted therapy, which is a treatment that targets the cancer’s specific genes, proteins, or the tissue environment that contributes to cancer growth and survival. Lenvatinib actually targets several different changes in cancer cells and is also being researched as a treatment for liver, lung, kidney, and other cancers.
In this study, 392 patients with differentiated thyroid cancer that was RAI resistant and had worsened within a year received either lenvatinib or an inactive treatment called a placebo. Patients receiving the placebo were offered treatment with lenvatinib if the cancer worsened.
About 65% of the patients receiving lenvatinib had the tumors shrink, usually within the first two months of treatment. Only 3% of patients receiving the placebo had the tumors shrink. In addition, researchers found that it took about 18 months for the disease to worsen for patients who received lenvatinib, compared with about four months for those who received the placebo.
The side effects of lenvatinib include high blood pressure, diarrhea, decreased appetite, decreased weight, and nausea. About 79% of patients needed to have their doses of lenvatinib reduced due to the side effects, although the lead author noted that these patients still benefitted from the lower doses.
What this means for patients
“We are confident that, based on our findings, lenvatinib will eventually become a standard treatment for radioiodine-resistant thyroid cancer,” said lead study author Martin Schlumberger, MD, a professor of oncology at the University Paris Sud in Paris, France. “As little as a year ago, this group of patients had no effective treatment options. It’s remarkable that today we now have two targeted therapies that could be potential options.” The targeted therapy sorafenib (Nexavar) is currently the only option outside of clinical trials available for patients with this type of thyroid cancer. It was approved by the U.S. Food and Drug Administration (FDA) in 2013. Lenvatinib is not currently approved by the FDA. Talk with your doctor about all of your treatment options for thyroid cancer, including clinical trials.
Questions to ask your doctor
- What type of thyroid cancer do I have?
- Is it RAI resistant? What does this mean?
- If it is RAI resistant, what treatment options are available?
- What clinical trials are open to me?
- What treatment plan do you recommend? Why?