Oral Presentation International Celiac Disease Symposium 2026

Evaluation of ANB033, an Investigational CD122 Antagonist Monoclonal Antibody, for the Treatment of Celiac Disease: A Novel Phase 1 Clinical Study Design (146837)

Juha Taavela 1 , Mark Rigby 2 , Jorma Isola 3 , Marilyn Geller 4 , Benjamin Lebwohl 5 , Maureen Leonard 6 , Fabiana Zingone 7 , Martin Dahl 2 , Kenneth Luu 2 , Priya Raina 2 , Khalil Saikali 2 , Anne Severtson 2 , Cailin Sibley 2 , John Kwon 2 , Paul Lizzul 2 , Joseph A. Murray 8
  1. Tampere University Hospital, Tampere, Finland
  2. First Tracks Biotherapeutics, San Diego, CALIFORNIA, United States
  3. Cancer Biology Tampere University, Tampere, Finland
  4. Celiac Disease Foundation, Woodland Hills, California, United States
  5. Columbia University Medical Center, New York, United States
  6. Harvard Medical School, Boston, Massachusetts, United States
  7. University-Hospital of Padova, Padova, Italy
  8. Mayo Clinic, Rochester, Minnesota, United States

Background & Objectives:

CD122 regulates immune cell activation and function through IL-15 and IL-2 signaling. ANB033, a novel CD122 antagonist monoclonal antibody binds with high affinity  and potently inhibits IL-15 and IL-2 signaling, thereby targeting two key drivers of epithelial injury and immune activation in celiac disease (CeD). A two-part, randomized, double-blind, placebo-controlled Phase 1 study assesses the safety, clinical pharmacology, tolerability, and potential efficacy of ANB033.

Materials & Methods:

Part A was conducted in healthy volunteers (HV) and assessed sequential, escalating doses of ANB033 in 4 IV/3 SC single ascending dose cohorts and 3 SC multiple ascending dose cohorts (~6 active:2 placebo /cohort). Part B included participants with CeD on a gluten-free diet for > 1 year. Randomization was 1:1 (ANB033:Placebo). Participants received 3 SC doses of study treatment at Week 0, 2, and 4, with 2 endoscopies with biopsies; symptoms were assessed throughout the study. Part B consists of 2 cohorts. Participants with relatively preserved mucosa (Vh:Cd > 2.0) were assigned to Cohort 1 and received a 14-day gluten challenge (GC; 6 g/day)(efficacy analysis at Week 6). Participants with broad range of mucosal injury and symptom severity were assigned to Cohort 2 and did not receive GC (efficacy analysis at Week 12).

Results:

In Part A, 83 participants were randomized. ANB033 was well tolerated, with no dose-limiting toxicities and only mild or moderate adverse events reported. The half-life of ANB033 was ~3 weeks.

Part B Cohort 1 (~30 participants)  is fully enrolled. Baseline characteristics, safety and tolerability, and histological changes  (e.g., Vh:Cd, IEL density) will be presented. Cohort 2 is ongoing.

Conclusion:

In HV, ANB033 demonstrated favorable safety, tolerability, bioactivity, and pharmacokinetics including one dose level in Part B. Top-line data in CeD from Part B/Cohort 1 GC will be available for presentation at ICDS.