argenx has reported the first Phase 2 evidence that blocking CD122 can protect the intestine from gluten damage in people with celiac disease — a condition with no approved drug therapy.
The trial, FB102-301, enrolled 126 adults with confirmed celiac disease who had been symptom-free on a strict gluten-free diet for at least a year. Participants were randomised 2:2:1 to two dose levels of FB102 or placebo and underwent a controlled eight-week oral gluten challenge. The primary endpoint was the change from baseline in the ratio of villus height to crypt depth — a histological measure of intestinal damage — at day 78 versus placebo. It was met with a p-value of 0.0176.
Secondary measures were consistent: intraepithelial lymphocyte density, a composite villus-height/crypt-depth/IEL score, and patient symptoms all pointed the same way, which the company says provides evidence of effect across histological, inflammatory and clinical dimensions. The safety profile matched earlier studies, with no new signals.
FB102 is a first-in-class anti-CD122 antibody. CD122 is a component of the IL-2 and IL-15 signalling pathways that activate and maintain disease-driving immune cells; the drug is designed to block it selectively, damping those inflammatory pathways while preserving regulatory T-cell function. The FDA has granted FB102 Fast Track designation for celiac disease.
The readout is the first clinical data from FB102 since argenx acquired Forte Biosciences in August 2026. argenx says it plans to move FB102 into Phase 3 and to keep testing it in other autoimmune diseases, including vitiligo and alopecia areata. Detailed results will be presented at an upcoming medical meeting.
The context is a large unmet need. Celiac disease — an autoimmune reaction to gluten in wheat, barley and rye — affects roughly one percent of people worldwide, and studies suggest incidence is rising by about 7.5 percent a year. The only current management is a strict gluten-free diet, which is difficult to maintain given how often gluten appears in packaged food, cosmetics, toothpaste and supplements.
