Thyrotropin alfa

THYROGEN ® is a thyroid stimulating hormone indicated for: Adjunctive Diagnostic Tool for Well-Differentiated Thyroid Cancer: Use as an adjunctive diagnostic tool for serum thyroglobulin (Tg) testing with or without radioiodine imaging in the follow-up of patients with well-differentiated thyroid cancer who have previously undergone thyroidectomy. Limitations of Use: THYROGEN-stimulated Tg levels are generally lower than, and do not correlate with Tg levels after thyroid hormone withdrawal. Even when THYROGEN-Tg testing is performed in combination with radioiodine imaging, there remains a risk of missing a diagnosis of thyroid cancer or underestimating the extent of the disease. Anti-Tg Antibodies may confound the Tg assay and render Tg levels uninterpretable.

Thyrotropin (TSH) is a pituitary hormone that stimulates the thyroid gland to produce thyroid hormone. Binding of thyrotropin alfa to TSH receptors on normal thyroid epithelial cells or on well-differentiated thyroid cancer tissue stimulates iodine uptake and organification, and synthesis and secretion of thyroglobulin (Tg), triiodothyronine (T3) and thyroxine (T4). The effect of thyroid stimulating hormone activation of thyroid cells is to increase uptake of radioiodine to allow scan detection or radioiodine killing of thyroid cells. TSH activation also leads to the release of thyroglobulin by thyroid cells. Thyroglobulin functions as a tumor marker which is detected in blood specimens.

THYROGEN should be used by physicians knowledgeable in the management of patients with thyroid cancer. A two-injection regimen is recommended: THYROGEN 0.9 mg is administered intramuscularly, followed by a second 0.9 mg intramuscular injection 24 hours later.

If THYROGEN is administered with radioiodine, the contraindications to radioiodine also apply to this combination regimen. Refer to the radioiodine prescribing information for a list of contraindications for radioiodine.

THYROGEN-induced hyperthyroidism: Hospitalization for administration of THYROGEN and postadministrative observation should be considered for patients at risk. Stroke: Stroke in female patients as well as other neurologic events in patients with central nervous system metastases. Sudden rapid tumor enlargement: Sudden, rapid and painful enlargement in distant metastatic thyroid cancer. Risks associated with radioiodine (RAI) combination treatment: If THYROGEN is administered with RAI, the warnings and precautions for RAI also apply to this combination regimen.

The most common adverse reactions (>5%) reported in clinical trials were nausea and headache.

Store THYROGEN refrigerated at 2°C to 8°C (36°F to 46°F) in the original carton to protect from light.