Teprotumumab

How it works

It is a fully human monoclonal antibody that binds and inhibits the insulin-like growth factor-1 receptor (IGF-1R), interrupting the signalling that drives orbital fibroblast activation and the tissue expansion seen in thyroid eye disease.

Prescribing in practice

• It can cause or worsen hyperglycaemia, so blood glucose and glycaemic control should be assessed before and during treatment, particularly in patients with pre-existing diabetes.
• Infusion-related reactions can occur, and pre-existing inflammatory bowel disease may be exacerbated, so patients should be monitored and the diagnosis confirmed before starting.
• Hearing impairment, including some cases that may be persistent, has been reported, so auditory symptoms should be reviewed during therapy.

Monitoring

Monitor blood glucose, hearing, and ophthalmic response, and review symptoms suggestive of an infusion reaction or worsening inflammatory bowel disease throughout the treatment course.

Counselling the patient

• Report any new or worsening high blood sugar symptoms such as excessive thirst or passing more urine.
• Tell your clinician about any hearing changes, ringing in the ears, or new bowel symptoms.
• Effective contraception is advised because of potential harm to a developing baby.

Evidence & guidelines

Efficacy in reducing proptosis in active thyroid eye disease was established in randomised placebo-controlled trials that underpinned its regulatory approval for this indication.