Genzyme granted additional approval for thyroid drug

Genzyme has announced it has received revised prescribing approval from the US Food and Drug Administration (FDA) for its Thyrogen drug.

The alteration related to the dose of radioiodine (RAI) when administered to patients for thyroid remnant ablation.

Thyrogen is given ahead of radioiodine treatment to enhance the efficacy of the radiotracer and reduces the chances of hypothyroidism as patients can begin and continue taking a thyroid hormone replacement therapy simultaneously.

While the FDA originally approved the drug with a fixed radioiodine level of 100 mCi, studies published in the New England Medicine Journal in 2012 showed it is effective in much smaller doses. After considering this data, the regulator has permitted physicians to prescribe doses between 30 and 100 mCi.

Ujjal Mallick, from the Northern Centre for Cancer Care, Freeman Hospital in Newcastle, said: "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 costs."