Subcutaneous Infliximab Outperforms IV in Ileal Crohn’s Disease Analysis

Subcutaneous (SC) infliximab was associated with higher rates of clinical remission and better endoscopic outcomes than intravenous (IV) infliximab in patients with ileum-involved Crohn’s disease (CD), according to a pooled, propensity score-matched analysis of 4 registrational trials. The findings were presented at the American College of Gastroenterology (ACG) 2026 Annual Scientific Meeting in Nashville, Tennessee, by Marla Dubinsky, MD, of the Icahn School of Medicine at Mount Sinai.¹

CD with ileal involvement responds less favorably than isolated colonic disease to many advanced therapies, and SC infliximab has shown consistent efficacy across disease locations in the phase 3 LIBERTY-CD trial.^1,2

How Did Investigators Compare SC and IV Infliximab?

The analysis pooled patient-level data from LIBERTY-CD, the phase 3 PLANETCD trial of IV infliximab, and 2 phase 1 studies of SC infliximab. Eligible patients had ileal (L1) or ileocolonic (L3) disease and received standard maintenance therapy with SC infliximab 120 mg every 2 weeks or IV infliximab 5 mg/kg every 8 weeks.^1,2,3

Of 884 patients across the 4 trials, 200 met eligibility criteria: 96 receiving SC and 104 receiving IV infliximab.¹ In the unmatched cohort, fewer SC-treated patients used immunomodulators at baseline (33.3% vs 54.8%; P = .004), and the SC group included a greater proportion of White patients (92.7% vs 69.2%; P <.001).¹

Investigators then used 1:1 nearest-neighbor propensity score matching, yielding 70 patients per group with well-balanced baseline characteristics. Clinical remission was defined as a Crohn’s Disease Activity Index score < 150, and endoscopic response as a reduction of ≥ 50% in the Simple Endoscopic Score for Crohn’s Disease (SES-CD).¹

Did SC Infliximab Outperform IV in Ileal Crohn’s Disease?

In the unmatched population, SC infliximab was associated with higher week 54 clinical remission (76.0% vs 55.8%; P = .003), endoscopic response (66.7% vs 32.7%; P <.001), and endoscopic remission (41.7% vs 18.3%; P <.001) than IV infliximab.¹

After matching, the differences persisted for clinical remission (71.4% vs 51.4%; P = .023), endoscopic response (65.7% vs 27.1%; P <.001), and endoscopic remission (41.4% vs 17.1%; P = .003).¹

Among 45 matched patients with isolated ileal (L1) disease, endoscopic response was higher with SC infliximab (52.2% vs 18.2%; P = .029). Endoscopic remission (47.8% vs 18.2%; P = .057) and clinical remission (56.5% vs 40.9%; P = .376) favored SC infliximab numerically but did not reach statistical significance.¹

What Role Did Drug Exposure Play?

In both treatment groups, endoscopic responders had higher steady-state serum infliximab concentrations than nonresponders.¹ Median concentrations were 15.6 vs 10.6 among SC-treated patients (P = .007) and 5.3 vs 1.7 among IV-treated patients (P = .037).¹

The investigators concluded the findings address an important evidence gap and called for prospective studies to confirm them.¹

References

1. Colombel JF, Hanauer SB, Sands BE, et al. Comparative efficacy of subcutaneous vs intravenous infliximab in Crohn’s disease with ileal involvement: a pooled analysis and propensity score-matched analysis of infliximab registrational studies. Presented at: American College of Gastroenterology 2026 Annual Scientific Meeting; October 9-14, 2026; Nashville, TN.

2. Hanauer SB, Sands BE, Schreiber S, et al. Subcutaneous infliximab (CT-P13 SC) as maintenance therapy for inflammatory bowel disease: two randomized phase 3 trials (LIBERTY). Gastroenterology. 2024;167(5):919-933. doi:10.1053/j.gastro.2024.05.006

3. Ye BD, Pesegova M, Alexeeva O, et al. Efficacy and safety of biosimilar CT-P13 compared with originator infliximab in patients with active Crohn’s disease: an international, randomised, double-blind, phase 3 non-inferiority study. Lancet. 2019;393(10182):1699-1707. doi:10.1016/S0140-6736(18)32196-2