The FDA and Genzyme have entered into a legal settlement that will permit Genzyme to produce enough Thyrogen (recombinant thyroid stimulating hormone [TSH]) to meet the needs of patients for whom FDA considers Thyrogen to be medically necessary. This restriction will remain in place until Genzyme corrects manufacturing issues at their Allston Landing facility or transfers fill/finish manufacturing operations for Thyrogen to other manufacturing facilities operating in compliance with FDA regulations.
Thyrogen is used in the treatment and follow-up diagnosis of thyroid cancer. The FDA has developed a set of criteria to help healthcare professionals identify patients for whom Thyrogen is considered medically necessary.
- Patients undergoing initial radioiodine ablation of thyroid tissue remnants, post-thyroidectomy, deemed to be at significantly increased risk of side-effects/complications from undergoing thyroid hormone withdrawal.
- Follow-up testing of patients considered high risk for thyroid cancer recurrence and who have unmeasurable basal thyroglobulin (Tg) levels and are deemed to be at significantly increased risk of side-effects/complications from undergoing thyroid hormone withdrawal. The American Thyroid Association identifies “high‑risk” patients as those who have 1) macroscopic tumor invasion, 2) incomplete tumor resection, 3) distant metastases, and possibly 4) thyroglobulinemia out of proportion to what is seen on the post‑treatment scan. Initial rhTSH stimulation testing in patients not considered high risk for thyroid cancer recurrence may also be considered appropriate if such patients are at risk of side-effects/complications from prolonged hypothyroidism due to thyroid hormone withdrawal.
Generally, pediatric patients are not considered to be within the medically necessary category as they are more likely to tolerate a short period of hypothyroidism and can often mount an adequate elevation of endogenous TSH within two weeks of levothyroxine withdrawal.
For more information visit www.fda.gov/Drugs/DrugSafety/DrugShortages/ucm213008.htm.