Jersey City – October 11, 2026 -- Subcutaneous (SC) infliximab delivered clinical remission in 71.4% of matched patients with ileum-dominant Crohn's disease at Week 54, against 51.4% for intravenous (IV) infliximab, according to a late-breaking analysis Celltrion USA will present for ZYMFENTRA (infliximab-dyyb) at the American College of Gastroenterology (ACG) 2026 Annual Scientific Meeting in Nashville, Tennessee.
Matched analysis shows wider endoscopic gap for SC infliximab at Week 54
The pooled analysis used individual patient data from four infliximab registrational studies. Of 884 patients, 200 with ileal or ileocolonic Crohn's disease met eligibility criteria. They received either SC infliximab 120 mg every two weeks or IV infliximab 5 mg/kg every eight weeks. A 1:1 propensity score-matched analysis included 70 patients per arm.
SC infliximab outperformed IV infliximab on all three measures in the matched population:
- Clinical remission: 71.4% vs. 51.4% (P = 0.023)
- Endoscopic response: 65.7% vs. 27.1% (P < 0.001)
- Endoscopic remission: 41.4% vs. 17.1% (P = 0.003)
In both arms, endoscopic responders had significantly higher serum infliximab concentrations than nonresponders. Marla Dubinsky, M.D., of the Icahn School of Medicine at Mount Sinai, will present the data on Oct. 14 from 9:30 to 9:40 a.m. CT in Plenary Session 4B.
Prior antibody status did not change outcomes after IV treatment interruption
A separate post hoc analysis of the Phase 3 LIBERTY-CD and LIBERTY-UC studies covers placebo-arm patients who started SC infliximab 240 mg every two weeks after interrupting IV infliximab. Prior anti-drug antibody (ADA) positivity was common: 72.5% (37 of 51) of Crohn's patients and 92.2% (71 of 77) of ulcerative colitis patients. The median gap between the last IV infusion and SC initiation was 16 weeks in both ADA-positive and ADA-negative groups, across both diseases.
Clinical outcomes were generally similar regardless of ADA status. Clinical response in Crohn's disease and partial clinical response in ulcerative colitis appeared by 8±2 weeks and were sustained through 78 to 80 weeks. Serum infliximab concentrations rose after SC initiation and were generally comparable across ADA groups over time. Fecal calprotectin and C-reactive protein fell at the first post-treatment assessment and stayed lower through the final assessment.
ADA positivity declined among patients with pre-existing antibodies, while new ADA development was uncommon in patients without them. Dubinsky said ADAs to IV infliximab can compromise reinitiation after a treatment interruption, and that data on SC initiation after a drug holiday are limited. She said the findings indicate prior ADA status did not appear to compromise outcomes.
Dubinsky presents this analysis on Tuesday, Oct. 13, from 2:45 to 2:55 p.m. CT in Plenary Session 3A: IBD.
ZYMFENTRA is indicated for adults after IV induction
ZYMFENTRA is indicated in adults for maintenance treatment of moderately-to-severely active Crohn's disease and ulcerative colitis following treatment with an intravenously administered infliximab product. Its safety and efficacy in patients under 18 are not known. The label carries warnings for serious infections, including tuberculosis and invasive fungal infections, and for malignancies reported with TNF blockers.