Positive Phase III Data Reported for Sorafenib in Thyroid Cancer Patients
First effective therapy for patients with progressive disease after standard treatments
The kidney and liver cancer drug sorafenib (Nexavar, Bayer HealthCare/Onyx Pharmaceuticals) holds metastatic thyroid cancer at bay for nearly twice as long as placebo, according to a new study from the Abramson Cancer Center at the University of Pennsylvania, published in The Lancet.
Sorafenib is the first effective treatment for thyroid cancer patients who progress after standard treatments.
Preliminary results of this randomized phase III trial were presented at the American Society of Clinical Oncology’s annual meeting in 2013. Based on these data, the FDA approved sorafenib in November 2013 for the treatment of patients with locally recurrent or metastatic, progressive, differentiated thyroid carcinoma that is refractory to treatment with radioactive iodine.
Thyroid cancer is highly curable through surgery and radioactive iodine treatment, but about 10% of the 60,000 patients who are diagnosed with the disease each year fail to respond to standard therapies, with tumors eventually appearing in the lungs, lymph nodes, bones, and other sites. The only other drug for advanced thyroid cancer, doxorubicin (approved in 1974), is not used because it is highly toxic and is not effective, the authors said.
Of the 417 patients with metastatic thyroid cancer studied in the international trial, 207 were randomly assigned to treatment with sorafenib, an oral drug, and 210 were assigned to receive placebo. The study met its primary endpoint by showing that, among patients in the sorafenib group, median progression-free survival was 10.8 months compared with 5.8 months in the placebo group.
Moreover, 12% of patients experienced tumor shrinkage in the sorafenib arm compared with 0.5% of patients in the placebo arm. Importantly, the treatment also appeared to reduce disease progression even among many of those whose tumors did not achieve a partial response: 42% of patients treated with sorafenib had stable disease after 6 months compared with 33% of those given placebo.
The most common adverse events observed among patients taking sorafenib included hand–foot skin reactions, diarrhea, alopecia, rash, fatigue, weight loss, and hypertension, all of which were manageable.
The study also showed that sorafenib improved progression-free survival across all subgroups and in patients irrespective of BRAF or RAS mutations, which are common in patients with radioactive iodine-refractory differentiated thyroid cancer. Thus, those mutations are not predictive biomarkers for cancers treated with sorafenib.
Source: Perelman School of Medicine; April 24, 2014.