A new targeted therapy called lenvatinib has been shown to improve progression-free survival among patients with advanced thyroid cancer that is not responsive to iodine-131.
In a clinical trial of almost 400 patients from 21 different countries, patients who took lenvatinib survived for a median of 18.3 months without displaying any signs of disease progression, while those who were given placebo only had a median progression-free survival of 3.6 months.
"The median progression-free survival in the placebo group in this study was shorter than the 8 months expected, indicating that these patients had aggressive thyroid cancer," write the authors of the study, which was published in the New England Journal of Medicine.
Bork / Shutterstock.com
In addition, 65% of those treated with lenvatinib had significant tumor regression and in some patients, the tumors disappeared altogether. Furthermore, most of these responses occurred rapidly, within two months of treatment beginning.
The researchers say the improvements seen with lenvatinib are much more significant than those observed for any other medicines used to treat this form of cancer so far. Until 2010, no solution to treating this cancer had been found and at best, patients could expect to live for just a few years.
Given the results of this trial, lenvatinib may become the standard treatment for patients resistant to idoine-131, says lead author Martin Schlumberger from the Department of Nuclear Medicine and Endocrine Oncology at Gustave Roussy in France.
Lenvatinib was associated with several adverse side effects in almost all (97.0%) patients who took the drug. The most common side effect was hypertension (67.8%) and in 42% of those cases, the hypertension was grade 3 or higher. The second most commons side effect was diarrhea (59.4%), followed by fatigue (59.0%), loss of appetite (50.0%), weight decrease (46.4%) and nausea (41.0%). The development of side effects led to a reduction in lenvatinib dose for 78% of patients, although this did not reduce the benefits of the drug.
Twenty deaths occurred while patients were being treated with lenvatinib, but most of those deaths were the result of disease progression.