(HealthDay News) — Oral lenvatinib delayed progression of advanced thyroid cancer by 18 months, compared with four months for patients treated with a placebo, according to results from a new clinical trial. Results of the study were published in the February 12 issue of the New England Journal of Medicine.
The international clinical trial for lenvatinib enrolled 392 patients from 21 countries, all of whom had thyroid cancer that had spread and become resistant to radioactive iodine. Steven Sherman, MD, an associate vice provost for clinical research, and professor and chair of Endocrine Neoplasia and Hormonal Disorders at the University of Texas MD Anderson Cancer Center in Houston, and colleagues treated 261 patients with lenvatinib, while 131 received a placebo. When their cancer started to progress again, patients in the placebo group could receive lenvatinib.
In addition to the nearly five-fold improvement in progression-free survival, the drug also appeared to be useful for treating more patients. About two-thirds of the patients given lenvatinib responded either fully or partially to the drug. “In our study, we not only saw a dramatic improvement in progression-free survival, there was also a 65 percent response rate — almost unprecedented results for thyroid cancer patients with such advanced disease,” Sherman said in a center news release. The clinical trial did not observe any improvement in overall survival due to lenvatinib.
Lenvatinib does come with some serious side effects, however. According to the researchers, >40% of patients who received lenvatinib experienced some type of reaction while on the medication. Hypertension was the most common side effect, occurring in two out of three patients who had a reaction to the drug. Other side effects included diarrhea, fatigue, nausea, and decreased appetite and weight. There were deaths related to side effects. Six of 20 deaths that occurred during the treatment period were determined to be drug-related. In addition, 37 patients discontinued the drug because of adverse effects, according to the study. Sherman said these side effects can be dealt with, either by adjusting dosage or by treating each of the side effects as individual symptoms.
The research was funded by Eisai, the manufacturer of lenvatinib.