Randomized Controlled Trial: Subcutaneous vs Intravenous Infliximab CT-P13 Maintenance in Inflammatory Bowel Disease

BACKGROUND & AIMS: This study compared pharmacokinetics, symptomatic and endoscopic efficacy, safety, and immunogenicity of a subcutaneous formulation of the infliximab biosimilar CT-P13 (CT-P13 SC) vs intravenous CT-P13 (CT-P13 IV) in patients with inflammatory bowel disease (IBD). METHODS: This randomized, multicenter, open-label, parallel-group, phase 1 study enrolled tumor necrosis factor inhibitor-naive patients with active ulcerative colitis (total Mayo score 6-12 points with endoscopic subscore >2) or Crohn's disease (Crohn's Disease Activity Index 220-450 points) at 50 centers. After CT-P13 IV induction at Week (W) 0/ W2, patients were randomized (1:1) to receive CT-P13 SC every 2 weeks (q2w) from W6 to W54 or CT-P13 IV every 8 weeks from W6 to W22. At W30, all patients receiving CT-P13 IV switched to CT-P13 SC q2w until W54. The primary endpoint was noninferiority of CT-P13 SC to CT-P13 IV for observed predose CT-P13 concentration at W22 (Ctrough,W22), concluded if the lower bound of the 2-sided 90% confidence interval (CI) for the ratio of geometric least-squares means exceeded 80%. RESULTS: Overall, 66 and 65 patients were randomized to CT-P13 SC and CT-P13 IV, respectively. The primary endpoint of noninferiority was met with a geometric least-squares means ratio for Ctrough, W22 of 1154.17% (90% CI 786.37-1694.00; n = 59 [CT-P13 SC]; n = 57 [CT-P13 IV]). W30/W54 clinical remission rates were comparable between arms. Other efficacy, safety, and immunogenicity assessments were also broadly comparable between arms, including after switching. CONCLUSIONS: The pharmacokinetic noninferiority of CT-P13 SC to CT-P13 IV, and the comparable efficacy, safety, and immunogenicity profiles, support the potential suitability of CTP13 SC treatment in IBD.