Genzyme, a Sanofi company (EURONEXT: SAN and NYSE: SNY), today announced it has received European Commission approval of a product label expansion for the use of Thyrogen® (thyrotropin alfa) with a wider irradiation dose range for postoperative thyroid remnant ablation. Thyrogen is used before radioiodine treatment to avoid temporarily discontinuing thyroid replacement therapy for postoperative thyroid remnant ablation. The revised indication in remnant ablation provides physicians with the option to administer a reduced dose of radioiodine (131-I). Previously the amount of radioiodine was specified at 100 mCi, whereas physicians may now select a dose from the range of 30 to 100 mCi.
"It has long been debated whether smaller amounts of radioiodine for patients with low-risk thyroid cancer would improve care," said Professor Martin Schlumberger, M.D., Institut Gustave Roussy, University Paris Sud, Paris, France. "The expanded Thyrogen indication provides a new option for many physicians who may be reducing radioiodine use due to uncertainty about impact on recurrences and mortality in low-risk patients as well as short- and long-term safety concerns."
The decision to approve the expanded indication for use of Thyrogen in Europe is based on the results of the two largest studies (HiLo and ESTIMABL) ever conducted in thyroid remnant ablation. The studies, published in the New England Journal of Medicine in May 2012, evaluated whether rates of successful ablation would be similar among patients receiving recombinant human thyrotropin (rhTSH), patients undergoing thyroid hormone withdrawal (THW), and among patients receiving low or high amount of radioiodine.
In the two studies, 30 mCi of radioiodine were well tolerated and showed similar success rates for low-dose radioiodine plus rhTSH vs. high-dose plus THW or rhTSH. In both studies, patients receiving Thyrogen rather than THW had fewer hypothyroid symptoms and better preserved quality of life.
"The best path to achieve thyroid remnant ablation must be one that involves the least whole body radiation dose, the least early and late side-effects, the best quality of life, and the least healthcare and societal costs, as demonstrated in the HiLo and ESTIMABL trials," said Ujjal Mallick, M.D., Northern Centre for Cancer Care, Freeman Hospital, Newcastle UK.