Argenx Halts Phase 3 UNITY Trial of Efgartigimod in Sjögren's Disease
The decision follows a recommendation from an independent data monitoring committee, which determined following an interim analysis that the study would not be able to achieve its primary endpoint. The immunology group, listed on Euronext and Nasdaq, will now analyze all data collected.
Efgartigimod Subcutaneous Formulation Discontinued in Sjögren's
Argenx announced on October 8, 2026 the discontinuation of the phase 3 UNITY trial. This trial evaluated Efgartigimod in subcutaneous administration (Efgartigimod alfa combined with hyaluronidase-qvfc) in adults with moderate to severe Sjögren's disease. This is an autoimmune condition for which this formulation was being tested in this new indication.
A futility stop occurs when an analysis conducted during a trial indicates that it no longer has a reasonable chance of demonstrating the desired effect. This was the conclusion of the independent data monitoring committee (IDMC) regarding UNITY. The primary endpoint was the change from baseline in systemic disease activity as measured by the EULAR clinical index clinESSDAI, evaluated at the forty-eighth week of treatment.
Concretely, the trial was intended to establish that treated patients saw their disease activity score decrease more than those receiving placebo, over nearly a year of treatment. The interim analysis led the committee to estimate that this objective would not be achieved. Argenx followed this recommendation and decided to terminate the study.
Luc Truyen, medical director of the group, stated: "We are disappointed by this result, first and foremost for people with Sjögren's disease, who continue to await treatments capable of profoundly altering the course of their disease". He characterized Sjögren's disease as "one of the most heterogeneous and most complex diseases in immunology". The group committed to analyzing this data in depth and sharing the lessons learned with the community concerned by this pathology.
No New Safety Signals in a Randomized, Double-Blind Trial
Regarding tolerability, the data observed remained consistent with the established safety profile of Efgartigimod, and no new safety signals were identified, according to the group. The failure therefore concerns efficacy in this indication, and not the safety of the product. This distinction matters for reading the file, as the molecule is being evaluated in multiple contexts.
The trial methodology was rigorous. UNITY was a phase 3 randomized, double-blind, placebo-controlled, multicenter study, completed by an open-label extension phase. Patients were randomized in a 1:1 ratio to receive either weekly subcutaneous injection of Efgartigimod or placebo during the double-blind treatment period.
Inclusion criteria were precise. Participants were required to meet the 2016 ACR/EULAR classification criteria for primary Sjögren's disease and present anti-Ro/SSA autoantibodies. They were also required to display moderate to severe systemic disease activity, with a clinESSDAI score of 6 or greater, while receiving stable standard background therapy.
Among key secondary endpoints was the proportion of patients achieving low disease activity. The design thus aimed to measure the benefit of the molecule in addition to existing care, in patients selected based on biological and clinical markers.
Comprehensive Data Analysis Following Database Lock
The next step is set by the group: once the trial is closed and the database locked, Argenx will conduct a comprehensive analysis of the results. The stated objective is to understand the outcome of the trial and draw lessons likely to guide future research in Sjögren's disease.
This announcement comes shortly after the group's presentation on September 29, 2026 of new long-term clinical and real-world data on Vyvgart and pipeline candidates at the AANEM and MGFA congresses, held in Orlando from September 29 to October 2.
