San Diego-based First Tracks Biotherapeutics (Nasdaq: TRAX) reported positive topline results from Cohort 1 of a Phase Ib celiac disease trial of ANB033, a CD122 antagonist targeting IL-15 and IL-2 signaling. The drug achieved statistically significant improvements across three key histologic efficacy endpoints following a gluten challenge, supporting the company's plan to initiate a late-stage trial in 2027.
In the 32-patient efficacy population (17 ANB033, 15 placebo), participants received three subcutaneous loading doses at Weeks 0, 2, and 4, followed by a 14-day gluten challenge equivalent to approximately two slices of bread daily. At Week 6, ANB033 produced a placebo-adjusted improvement of +0.49 in villus height-to-crypt depth ratio (p=0.009), a reduction of 20.03 in intraepithelial lymphocyte density (p<escape><</escape>0.001), and an improvement of +3.33 on the VCIEL composite scale (p=0.002).
ANB033 also prevented an increase in gastrointestinal symptoms during the gluten challenge, with Celiac Disease Symptom Diary scores significantly lower than placebo from days one through seven and moderate-to-severe symptoms significantly reduced through day twelve. Only 6% of ANB033-treated patients required permitted medication to manage gastrointestinal symptoms, compared with 47% of placebo recipients.
In the 34-patient safety population (18 ANB033, 16 placebo), no serious adverse events occurred, and no ANB033 recipients experienced severe adverse events or discontinued treatment due to adverse events. Injection site erythema occurred in 27.8% of ANB033 recipients versus 12.5% on placebo, while nausea (5.6% versus 43.8%) and abdominal pain (11.1% versus 37.5%) were less frequent with ANB033.