Infusion treatment for thyroid eye disease: what the new drugs do, and what to ask before considering one

Is there now a drip that shrinks thyroid eye disease? There is a class of drug that comes close to that description, it has been in use in the United States since 2020, and a second drug in the same class was approved there on 26 June 2026. The honest answer has two halves. The drugs are a real advance for some people with thyroid eye disease. They also carry a warning about hearing that any patient should hear plainly before agreeing to one, and whether they can be obtained in Malaysia is a separate question that I will come to at the end.

What do the new thyroid eye disease infusions actually do?

They block a receptor called IGF-1R, the insulin-like growth factor-1 receptor, on the cells inside the eye socket. In thyroid eye disease, the immune system attacks the tissue behind the eye. The fibroblasts there, the cells that make connective tissue, carry a lot of this receptor, and it works together with the thyroid-stimulating hormone receptor to pass on the signals of the disease. Teprotumumab, the first drug in this class, is an antibody that binds the receptor and switches that signal off.

Think of the orbit, the bony socket, as a closed room. The muscles and fat inside swell, and because the walls do not give, the eye is pushed forward. That is proptosis, the medical name for a bulging eye. Steroids calm inflammation in general. These newer drugs go after one of the signals that keeps the swelling going, which is why they can reduce how far the eye protrudes and, in the trials, also improved double vision. I explain the wider picture of what is happening in the socket in bulging eyes, gritty vision and puffy lids: could it be thyroid eye disease.

Who are these infusions meant for?

The US prescribing information for teprotumumab, revised in August 2025, states the drug is indicated for thyroid eye disease regardless of disease activity or duration. That wording matters. Earlier trials enrolled people in the active, inflamed phase, and the label now covers longer-standing disease as well. The report on the newer drug, veligrotug, describes the same wording: approved on 26 June 2026 for thyroid eye disease regardless of activity or duration.

A label is a legal statement about what a regulator allowed, not a judgement about who benefits most. The questions that matter sit underneath it. Is the disease still active, with red, painful, swollen tissue, or has it settled? Is the main problem the bulging, the double vision, or the lids? Is there any threat to the optic nerve, which needs urgent treatment of a different kind? The National Eye Institute says the symptoms usually last one to two years and often go away on their own, so the decision is never automatic. It also names quitting smoking as the most important lifestyle change, because smoking makes the disease worse.

How much difference do the infusions make?

In the two placebo-controlled trials that supported teprotumumab, 171 people took part. At week 24, 71% of those on the drug in the first study had reduced their proptosis by 2 mm or more, compared with 20% on placebo. In the second study the figures were 83% and 10%. Improvement began as early as week 6 and continued through week 24. The 2021 European guideline, reviewing the follow-up of the same trials, reports that a year after the last dose the proptosis response was 67% and the double vision response 69%.

I would want a patient to keep two cautions next to those numbers. Two millimetres is a meaningful change, but it is not a return to a face before the disease. And the trial population was mostly White, with only 4% Asian, and the median age was 52. How far the results carry over to a Malaysian patient is not something these trials were designed to answer.

For veligrotug, the report on its approval says both trials met their primary and secondary end points and that proptosis fell as early as week 3. It also says plainly that there is no head-to-head comparison with teprotumumab, so nobody can say from the evidence that one is more effective or safer than the other.

Can these drugs damage hearing?

Yes, and the label says so in its warnings section. The teprotumumab label states that it may cause severe hearing impairment, including hearing loss, which in some cases may be permanent, and tells doctors to assess hearing before, during and after treatment. In the trials, hearing impairment was reported in 8 of 84 people on the drug, about 10%, and in none on placebo. The label counts a broad group under that heading, including tinnitus, a sense that your own voice echoes, and a blocked feeling in the ear, so not every case is deafness. But the drug's own label does not treat it as trivial, and neither do I.

The approval report for veligrotug likewise lists hearing impairment, including potentially permanent hearing loss, as a risk. The other warnings on the teprotumumab label are worth knowing before an appointment as well. Blood sugar can rise, in 10% of trial patients, two thirds of whom already had diabetes or impaired glucose tolerance. It can worsen inflammatory bowel disease. Infusion reactions occurred in about 4%. Muscle spasms affected 25% and hair loss 13%. It must not be used in pregnancy, and contraception is advised. Veligrotug's report lists similar concerns, including hyperglycaemia in 12% and infusion reactions in about 9%.

The practical action is simple. Ask for a hearing test before the first infusion, so there is a baseline, and ask who will repeat it and when. If hearing changes during treatment, ringing or muffled sound, say so at once rather than waiting for the next infusion.

Do the infusions replace steroids or surgery?

Not as a rule. The 2021 European guideline on medical management of thyroid eye disease recommends intravenous steroid combined with mycophenolate as first-line treatment for active moderate-to-severe disease, and lists teprotumumab as a second-line option. It gave its reasons: long-term data were pending, and so were availability, affordability and the need for later surgery. The guideline was written before the 2025 label revision and before veligrotug, so it is a snapshot, not the last word. The reasoning behind it, though, still applies. I go through what disease activity means and how steroids are used in thyroid eye disease and steroids.

Surgery is a separate matter. The same guideline says rehabilitative surgery, meaning orbital decompression, squint surgery and eyelid surgery, is for inactive residual disease. In the teprotumumab follow-up it reviews, a few people still needed decompression, and one developed dysthyroid optic neuropathy, damage to the optic nerve from crowding in the socket, four months after the last infusion. A drug can reduce swelling. It does not reposition a lid that has retracted, shrink fat, or realign a muscle that has scarred. Orbital decompression makes room for an eye that stays pushed forward, and I explain what dries or exposes the cornea when the lids will not close in thyroid eye disease and the eyes that will not close properly. Sight-threatening disease, where the optic nerve is being squeezed, needs urgent assessment and a different pathway from any of this.

Can I get these in Malaysia, and what should I ask?

I cannot give you a source that says whether either drug is registered or supplied in Malaysia, so I will not claim it. Availability varies between countries and can change, and it has to be confirmed with a specialist who treats thyroid eye disease. The European guideline itself lists restricted geographical availability, reimbursement and cost among the reasons these drugs were not first-line. If a clinic tells you a drug is available, ask which brand, under what registration or named-patient arrangement, and who supervises the infusions.

If you are considering one, or have been offered one, these are the questions I would want answered:

• Is my disease active or inactive, and how was that decided?
• Would steroids with mycophenolate be a reasonable first step, and why not?
• Has my hearing been tested, and who repeats the test?
• Do I have diabetes, bowel disease or a chance of pregnancy that changes the risk?
• What will this leave for surgery, and in what order would that happen?
• What would we do if my hearing changes?

Thyroid eye disease is one of several reasons eyes can look different from how they used to, and I place it among the other causes in what actually makes eyes look tired. The wider set of orbital and thyroid conditions is gathered under orbit and thyroid eye disease. What I would ask of anyone reading is to weigh the benefit against the hearing risk with an eye doctor who has seen the disease many times, and not with an advertisement.