argenx Advances FB102 After Phase 2 Celiac Endpoint Hit, Setting Up A Faster Run At IL-15 Pathway Competition

argenx said FB102 met the primary endpoint in a phase 2 celiac disease trial, giving fresh momentum to a program it picked up through its $2.2 billion acquisition of Forte Biosciences in July. The readout matters beyond a single midstage win: it keeps argenx among the more advanced companies trying to treat celiac disease by interrupting IL-15 signaling, an area where several competitors have fallen away.

The company said the study showed statistically significant improvement in villus height–to–crypt depth, or Vh:Cd, versus placebo at Day 78 in 126 adults with celiac disease undergoing an oral gluten challenge. Argenx framed that result as evidence that blocking CD122 can prevent gluten-induced intestinal damage, and said it plans to move FB102 into phase 3 development.

The data

Vh:Cd, a measure of gut health, was the trial’s primary endpoint. Argenx also said the VCIEL result, which combines Vh:Cd with a measure of inflammation, was consistent with the primary endpoint. The company added that other measures also aligned with the main finding and said the results provided additional evidence of FB102’s histologic, inflammatory and clinical effects.

The disclosure was still limited. Argenx shared a 0.0176 p value for the Vh:Cd analysis but did not provide additional efficacy detail in the readout. Safety was consistent with prior studies, according to the company.

The competitive picture

The result arrives shortly after Teva’s TEV'408 cleared the bar in a phase 2a celiac disease trial last month. Both programs used Vh:Cd as a primary endpoint, but the two companies are taking different approaches within the same broader biology. FB102 targets CD122 to inhibit IL-2 and IL-15 pathways, while TEV'408 is an anti-IL-15 antibody.

That creates a practical opening for argenx. Fierce Biotech reported that Teva plans to run another phase 2 trial before starting pivotal development, which could give argenx a shot at reaching the market first if its phase 3 program moves cleanly. TD Cowen analysts wrote in July and September notes to investors that they expect FB102 could launch in celiac disease in 2031, followed by TEV'408 in 2034, and they view celiac disease as a blockbuster market.

For argenx, the program also has portfolio value. FB102 is being tested in vitiligo and alopecia as well, and success in celiac disease could help reduce reliance on efgartigimod, which the company sells as Vyvgart and Vyvgart Hytrulo. That diversification case became more relevant alongside the company’s separate disclosure that efgartigimod was stopped early in a phase 3 Sjögren’s disease trial because it was destined to fail.