Dive Brief:

• Argenx will stop developing its autoimmune drug Vyvgart for thyroid eye disease, announcing Monday that two Phase 3 trials testing the therapy in the ocular condition will be stopped early because treatment is likely to prove ineffective.
• A panel of trial monitors reviewed data from enrollees who had completed 24 weeks of treatment and concluded that the trials had met the criteria for “futility,” meaning Vyvgart was no better than a placebo at inducing a response.
• Already approved to treat myasthenia gravis and another autoimmune nervous system disorder, Vyvgart is a blockbuster that has already generated nearly $3 billion in sales this year. But Argenx has previously stumbled in trying to broaden use of the drug, which failed in late-stage testing in a skin condition and a type of blood disorder.

Dive Insight:

Argenx is testing Vyvgart against a variety of diseases, with trials currently underway in different muscle, glandular and skin conditions. The setback in thyroid eye disease setback “came as a bit of a surprise,” William Blair analyst Matt Phipps wrote in a note to clients, because similarly acting drugs have shown promise in treating a related condition known as Graves’ disease.

Phipps had projected that Vyvgart could reach $550 million in peak sales in thyroid eye disease. Bigger opportunities await, though. One Phase 3 readout in the muscle myositis is expected in 2026, while late-stage results in Sjögren’s syndrome should follow in 2027.

In thyroid eye disease, the immune system mistakenly attacks tissue around the eyes, causing bulging, dryness, eye pain and other symptoms. Argenx had been hoping Vyvgart could become a more convenient alternative to Amgen’s Tepezza, an intravenous treatment that gained approval based on its ability to reduce that eye bulging, which is known as proptosis. The version of Vyvgart Argenx was testing is administered as an under-the-skin injection.

In Argenx’s trials, though, the drug wasn’t able to help reduce proptosis significantly better than the placebo, as Tepezza did. The trials both enrolled 123 people with the disorder and randomized two-thirds of them to receive Vyvgart, with the rest getting a placebo injection. Participants were followed for 24 weeks to evaluate efficacy.

“We are disappointed the studies did not meet our desired outcome and we especially empathize with patients who are living with [thyroid eye disease] and seeking new therapies for this challenging disease,” said Luc Truyen, Argenx’s chief medical officer, in a statement.