Argenx halts Phase 3 Vyvgart study in Sjögren's disease after futility finding

Argenx stopped its Phase 3 trial of Vyvgart in Sjögren's disease on 8 October 2026, after an independent monitoring board recommended ending the study “for futility” following an interim analysis ¹. The drug did not beat placebo in the trial, the company said ².

What the company and analysts reported

The result came early. Analysts had not expected data from the study until the second half of 2027, and the interim stop caught investors off guard ¹. Argenx shares closed 15% lower that Thursday, according to BioPharma Dive, after a 13% drop earlier in the morning reported by STAT ¹².

Several analysts had left Sjögren's out of their sales models because they regarded it as high risk, although a positive outcome could have added as much as $1.4 billion in peak sales from that indication alone ¹. William Blair analyst Matt Phipps described the failure as the loss of another “blockbuster expansion opportunity” for the Vyvgart franchise ¹.

The core business remains large. Vyvgart and its subcutaneous form, Vyvgart Hytrulo, generated $1.5 billion in sales in the second quarter, and analyst forecasts for the drug's annual peak sales range from $11 billion to $17 billion even without Sjögren's ¹. Argenx carried a market value of around $50 billion after the fall ¹. Both products are approved for generalised myasthenia gravis, and Vyvgart Hytrulo also holds an approval in chronic inflammatory demyelinating polyneuropathy ¹.

Argenx paired the news with positive Phase 2 data for FB102, a coeliac disease drug it gained through its $2.2 billion purchase of Forte Biosciences this year ¹. The company said the study showed FB102 could prevent intestinal damage caused by gluten ¹. TD Securities analyst Yaron Werber models $988 million in peak sales for FB102 in coeliac disease ¹.

What it means for the market

Sjögren's has no approved therapy that changes the course of the disease, so the field remains open ¹. Novartis and Amgen have both reported successful Phase 3 trials of their own experimental Sjögren's drugs, and Johnson & Johnson had early success with a drug in the same FcRn inhibitor class as Vyvgart ¹. Immunovant is also developing an FcRn inhibitor ¹. The Argenx result leaves those programmes with one fewer late-stage rival, though the sources do not say whether the failure reflects the drug, the trial design or the FcRn mechanism in this disease.

For investors, the episode tests a strategy of growing one asset across many indications. The Sjögren's result follows earlier expansion setbacks: Argenx reported failed studies in primary immune thrombocytopenia and pemphigus in 2023 and stopped development in thyroid eye disease in 2025 ¹. Phipps argued that Phase 3 setbacks at Argenx have in the past led to sharp falls that later proved “buying opportunities” and said he remains optimistic about further expansion ¹. Werber framed FB102 as “derisking a second franchise rather than merely adding another Vyvgart indication” ¹.

The limits are plain. The Sjögren's conclusion rests on an interim analysis by the monitoring board rather than a completed readout, and the coeliac evidence comes from one Phase 2 study, which did not stop the share price falling on the day ¹.