Two phase III trials have shown that subcutaneous CT-P13 (infliximab) may be effective and well-tolerated as maintenance therapy in patients with Crohn’s disease and ulcerative colitis, achieving clinical remission in 62.3% and 43.2% of patients with Crohn's disease and ulcerative colitis, respectively.

In the two studies, published in Gastroenterology, researchers conducted randomized, double-blind, placebo-controlled phase III trials to assess the efficacy and safety of subcutaneous CT-P13, a biosimilar formulation of intravenous infliximab, as maintenance therapy for Crohn’s disease and ulcerative colitis. The trials enrolled patients with moderate to severe Crohn’s disease or ulcerative colitis who exhibited inadequate responses or intolerance to corticosteroids and immunomodulators.

Patients initially received open-label intravenous CT-P13 (5 mg/kg) at weeks 0, 2, and 6. The patients who demonstrated a clinical response at week 10 were randomized in a 2:1 ratio to receive either 120 mg of subcutaneous CT-P13 or placebo every 2 weeks until week 54. The co-primary endpoints of the trials included clinical remission and endoscopic response for Crohn's disease, and clinical remission for ulcerative colitis.

A total of 396 patients with Crohn's disease and 548 patients with ulcerative colitis were included. At week 54, 62.3% of the patients with Crohn's disease receiving subcutaneous CT-P13 achieved clinical remission compared with 32.1% of the patients who received placebo (P < .0001). Endoscopic response rates were 51.1% for subcutaneous CT-P13 vs 17.9% for placebo (P < .0001). In the ulcerative colitis study, 43.2% of the patients receiving subcutaneous CT-P13 achieved clinical remission compared with 20.8% among those who received placebo (P < .0001). The subcutaneous CT-P13 group showed higher achievement of key secondary endpoints in both studies.

Subcutaneous CT-P13 was tolerated well, and no new safety signals were reported. During the maintenance phase, 72.3% of the patients with Crohn's disease and 67.6% of the patients with ulcerative colitis receiving subcutaneous CT-P13 experienced treatment-emergent adverse events, most commonly COVID-19 infections, headaches, and ulcerative colitis exacerbation. Treatment-emergent serious adverse events occurred in 6.7% of the patients with Crohn's disease and 6.4% of the patients with ulcerative colitis in the subcutaneous CT-P13 group compared with 7.6% and 2.9% among those in the placebo groups, respectively.

Subcutaneous CT-P13 demonstrated greater efficacy than placebo as a maintenance therapy in patients with moderately to severely active Crohn’s disease or ulcerative colitis who responded to intravenous CT-P13 induction.

Full disclosures can be found in the published study.