Introduction: TAK-101 is an antigen-containing nanoparticle designed to induce gluten-specific tolerance in patients with celiac disease (CeD). Here, we report topline results from the phase 2 study of TAK-101.
Methods: The study included HLA-DQ2.5- and/or DQ8-positive adults (>18 years) with biopsy-proven CeD, on a gluten-free diet for ≥6 months with mild-to-no symptoms. Patients were randomized to receive placebo or TAK-101 intravenously (12.5, 25.0, or 50.0µg/kg) on Days (D) 1 and 8, and TAK-101 at Week 24. Patients received a single high-dose gluten challenge (GC) during run-in (3g), D15–17 (12g), D18–20 (6g), and at the beginning of Weeks 8, 14, and 20 (3g each). The primary endpoint was change from baseline (D15; start of the 6-day high-dose GC) to D20 in T-cell–mediated, gluten-stimulated interferon (IFN)-γ production, determined by a gliadin-specific enzyme-linked immunospot (ELISpot) assay. Safety endpoints included treatment-emergent adverse events (TEAEs) and immunogenicity.
Results: Of 232 screened patients, 102 were randomized and 91 completed the study. Patients were predominantly female, white, and ≥40 years. Gluten intake during GC was confirmed by self-reporting and measurement of urinary gluten immunogenic peptide. Immunological responses to GC, defined by a twofold increase in serum interleukin-2 expression at 4 hours post-GC, were observed in 72.3% of patients during run-in (3g GC), and in 89.7% on D15 (12g GC). However, there was no significant increase in the proportion of gut-homing T cells or IFN‑γ production following the 6-day high-dose GC (D15–20), in any group. Consequently, the primary endpoint measures were not interpretable. No new safety signals and no serious TEAEs were observed.
Conclusion: TAK-101 was generally well tolerated, but the expected T-cell response to a 6-day high-dose GC was not observed in the placebo group, rendering the primary endpoint data uninterpretable, highlighting considerations for future CeD studies.