, 2025-05-08 14:20:00
The Medicines and Healthcare products Regulatory Agency (MHRA) has approved teprotumumab (Tepezza, Amgen) as the first treatment to be licensed in the UK for adults with moderate to severe thyroid eye disease.
Thyroid eye disease, also known as Graves’ orbitopathy, affects up to 40% of individuals with this form of hyperthyroidism. Symptoms include prominent proptosis, dry or watery eyes, photophobia, diplopia, and pain or difficulty moving the eyes. In severe cases, vision may be compromised.
This condition results from an autoimmune attack on the soft tissues around and behind the eyes. It activates the insulin-like growth factor-1 receptor (IGF-1R) protein, causing inflammation and swelling in the periorbital muscles and fat.
Teprotumumab is a monoclonal antibody that binds to IGF-1R, blocking its activation and signalling.
Administration and Clinical Trials
Teprotumumab is administered via intravenous drip. The MHRA reported that the drug was studied in four clinical trials involving 287 adult patients with thyroid eye disease. Participants received teprotumumab or placebo infusions every 3 weeks for a total of eight infusions.
Patients treated with teprotumumab showed a greater reduction in proptosis and diplopia compared with those receiving placebo.
Efficacy and Previous Approvals
Teprotumumab has been approved in the US since 2020. In the major OPTIC trial, 83% of participants on teprotumumab experienced a significant reduction in proptosis, compared with 10% on placebo. The number needed to treat for a response was 1.36.
Diplopia response rates were 68% for teprotumumab versus 29% for placebo, and mean change in proptosis -2.82 mm versus -0.54 mm.
Additionally, clinical activity scores and overall scores on the Graves’ ophthalmopathy-specific quality-of-life questionnaire improved significantly in the treated group.
Expert Opinion
Dr Petros Perros, patron of the British Thyroid Foundation and retired consultant endocrinologist, described teprotumumab as “a big advance” during a webinar in November 2024. He noted that it works differently from existing therapies by blocking excess insulin-like growth factor-blocker. “For the first time, we have a medical treatment that reduces eye protrusion to a level similar to surgical decompression,” he said.
However, he cautioned that teprotumumab is expensive, and a significant proportion of treated patients may relapse. Some side effects, such as hearing problems, are also a concern. Perros mentioned that newer, similar drugs in development may offer more effectiveness with fewer side effects.
Side Effects
Minor side effects that may affect up to one in 10 people treated with teprotumumab. These include headache, diarrhoea, nausea, hair loss, muscle spasms, and fatigue. Serious side effects can include hyperglycaemia, infusion-related reactions, deafness, or worsening of inflammatory bowel disease. Teprotumumab is potentially teratogenic and must not be used in pregnant women.
Julian Beach, interim executive director of healthcare quality and access at the MHRA, stated in a press release: “We’re assured that the appropriate regulatory standards of safety, quality, and effectiveness for the approval of this new treatment have been met. As with all products, we will keep its safety under close review.”
The summary of product characteristics and patient information leaflets will be published on the MHRA products website within 7 days of approval.
Healthcare professionals are encouraged to report any side effects to the Yellow Card scheme.
Dr Sheena Meredith is an established medical writer, editor, and consultant in healthcare communications, with extensive experience writing for medical professionals and the general public. She is qualified in medicine and in law and medical ethics.
