TEPEZZA

What it is

TEPEZZA is a fully human IgG1 monoclonal antibody produced in Chinese Hamster Ovary cells by recombinant DNA technology. Teprotumumab binds to the insulin-like growth factor-1 receptor and blocks its activation and signalling. Each vial contains 500 mg of teprotumumab.

Approved indications

— Moderate to severe Thyroid Eye Disease in adults.

Dosing overview

The recommended dose of TEPEZZA in adults is an intravenous infusion of 10 mg/kg for the initial dose followed by an intravenous infusion of 20 mg/kg every three weeks for 7 additional doses. The diluted solution should be administered intravenously over at least 90 minutes for the first two infusions. If well tolerated, the minimum time for subsequent infusions can be reduced to 60 minutes.

Key safety warnings

TEPEZZA may cause severe hearing impairment including hearing loss, which in some cases may be permanent. Events associated with hearing impairment have been observed in clinical trials and include hearing loss, eustachian tube dysfunction, tinnitus and tympanic membrane disorder. In the double-masked treatment period, 13.8% of patients treated with TEPEZZA experienced hearing impairment compared to 2.3% for placebo. Patients' hearing should be assessed before, and routinely during and after treatment with TEPEZZA, including use of audiograms where clinically warranted. TEPEZZA may cause infusion reactions, which have been reported in approximately 4% of patients treated with TEPEZZA. Signs and symptoms include transient increases in blood pressure, feeling hot, tachycardia, dyspnoea, headache and muscular pain. Reported infusion reactions are usually mild or moderate in severity and can usually be successfully managed with corticosteroids and antihistamines. Hyperglycaemia or increased blood glucose may occur in patients treated with TEPEZZA. In double-masked TED clinical trials, 10% of patients experienced hyperglycaemia. Patients should be assessed for elevated blood glucose and symptoms of hyperglycaemia prior to infusion and continue to be monitored while on treatment. Patients with hyperglycaemia or pre-existing diabetes should be under appropriate glycaemic control before and while receiving TEPEZZA. TEPEZZA may cause an exacerbation of pre-existing inflammatory bowel disease. Patients with inflammatory bowel disease should be monitored for flare of disease.

Contraindications

TEPEZZA is contraindicated in patients with known hypersensitivity to teprotumumab or any other components of the product. TEPEZZA is contraindicated in pregnancy. Based on findings in animals and its mechanism of action inhibiting IGF-1R signalling, TEPEZZA may cause fetal loss and malformations when administered to a pregnant woman.

Regulatory history

TEPEZZA was first included in the Australian Register of Therapeutic Goods on 27 March 2025. The Pharmaceutical Benefits Scheme Advisory Committee initially recommended against listing in March 2025 for active, moderate-to-severe Thyroid Eye Disease, but recommended listing in May 2025 for treatment of active, moderate-to-severe Thyroid Eye Disease. This medicinal product is subject to additional monitoring in Australia to allow quick identification of new safety information.