Argenx said Thursday it will discontinue the Phase 3 UNITY study of efgartigimod subcutaneous in adults with moderate-to-severe Sjögren’s disease, following a recommendation from the independent data monitoring committee to stop the study for futility after an interim analysis. The committee concluded the study could not meet its primary endpoint. Argenx said safety was consistent with efgartigimod’s established profile and no new safety signals were identified.
The stoppage is a direct hit to an expansion program that had momentum. Efgartigimod, marketed as Vyvgart, generated $4.2 billion in product net sales in 2025, and the Sjögren’s program had carried FDA Fast Track status since June 2025. The drug had shown encouragement in earlier studies, but chief medical officer Luc Truyen called the disease “one of the most heterogeneous and complicated diseases in immunology.” Argenx will close out the study and analyze the full dataset to understand the outcome. The result lands weeks after Amgen announced a Phase 3 win for its own Sjögren’s therapy dazodalibep on September 22, which had suggested the indication was cracking open.
The same morning brought an offset. Argenx announced positive topline results from a Phase 2 study of FB102, a first-in-class CD122 inhibitor, in adults with celiac disease undergoing a gluten challenge. The study met its primary endpoint: change from baseline in the ratio of villus height to crypt depth at day 78 versus placebo, with p=0.0176. Secondary histologic and inflammatory measures, including intraepithelial lymphocyte density and the composite VCIEL score, plus symptom measures, were consistent with the primary endpoint. No new safety signals appeared, and argenx plans to advance FB102 into Phase 3.
FB102 is the first clinical readout from Forte Biosciences, which argenx acquired in August 2026 in a $2.2 billion deal. That transaction is already paying a visible return. But the market’s verdict Thursday centered on the loss: argenx shares plunged on the Sjögren’s news, a reminder that investors were pricing meaningful option value on the Vyvgart expansion program and that futility stops in heterogeneous autoimmune indications are not rare tail events.