Argenx shares tumble 15% after Phase 3 Sjögren’s study of Vyvgart halted for futility

Argenx reported that an independent monitoring board recommended stopping its Phase 3 trial of Vyvgart in Sjögren’s disease due to futility, based on an interim analysis. The decision came earlier than analysts expected, who had anticipated results in the second half of 2027.

The announcement sent the company’s shares down about 15% on the trading day. Analysts noted that many had not modeled any sales from a Sjögren’s indication because of the high risk, but they had hoped the trial could add up to $1.4 billion in peak sales.

In the same release, Argenx highlighted positive Phase 2 data for a new celiac disease candidate. However, the favorable data did not offset the negative market reaction to the failed Sjögren’s study.

The setback removes a potential blockbuster expansion for the Vyvgart franchise, which has been a key driver of Argenx’s market valuation, now around $50 billion.