Clinical Remission Reaches 71.4% With Subcutaneous Infliximab in Matched Crohn’s Disease Analysis

Celltrion USA, Inc. will present two analyses of ZYMFENTRA® (infliximab-dyyb), a subcutaneous (SC) formulation of infliximab, at the American College of Gastroenterology (ACG) 2026 Annual Scientific Meeting in Nashville, Tennessee. The presentations examine outcomes following intravenous (IV) infliximab interruption and compare SC and IV infliximab in ileum-dominant Crohn’s disease.

Prior ADA Status Did Not Appear to Compromise Outcomes

A post hoc analysis of the Phase 3 LIBERTY-CD and LIBERTY-UC studies evaluated patients who initiated SC infliximab 240 mg every two weeks after IV treatment interruption. Outcomes were assessed according to prior anti-drug antibody (ADA) status.

Prior ADA positivity was reported in 72.5% (37/51) of patients with Crohn’s disease and 92.2% (71/77) with ulcerative colitis. The median interval between the last IV infusion and SC treatment initiation was 16 weeks.

Clinical outcomes were generally similar regardless of prior ADA status. Clinical response in Crohn’s disease and partial clinical response in ulcerative colitis emerged at approximately 8 ± 2 weeks and were sustained through 78–80 weeks. Serum infliximab concentrations increased after SC treatment initiation and remained generally comparable between ADA-positive and ADA-negative patients. Fecal calprotectin and C-reactive protein levels decreased and remained lower through the final assessment.

ADA positivity declined among patients with pre-existing antibodies, while new ADA development was uncommon in patients without prior ADA positivity.

These findings suggest that prior ADA status may not necessarily preclude successful treatment reinitiation with SC infliximab. However, the post hoc findings apply to the studied population and do not establish that SC administration eliminates immunogenicity.

The presentation by Marla Dubinsky, M.D., Professor of Pediatrics and Director of the Inflammatory Bowel Disease Center at the Icahn School of Medicine at Mount Sinai, is scheduled for October 13, 2026, from 2:45 to 2:55 p.m. Central Time during Plenary Session 3A: IBD (Presentation 40).

SC Infliximab Shows Higher Week 54 Efficacy Rates

A second, late-breaking analysis compared SC infliximab 120 mg every two weeks with IV infliximab 5 mg/kg every eight weeks in patients with ileal or ileocolonic Crohn’s disease receiving maintenance treatment.

The pooled analysis included individual patient data from four registrational studies. Of 884 patients, 200 met the eligibility criteria; propensity score matching produced groups of 70 patients each.

At Week 54, clinical remission was achieved by 71.4% of SC-treated patients versus 51.4% receiving IV infliximab (P = 0.023). Endoscopic response rates were 65.7% versus 27.1% (P < 0.001), while endoscopic remission rates were 41.4% versus 17.1% (P = 0.003).

The largest absolute difference was in endoscopic response, at 38.6 percentage points. Patients achieving endoscopic response also had significantly higher serum infliximab concentrations than nonresponders in both treatment groups.

Although these findings favour SC infliximab in the matched population, propensity score matching cannot eliminate all potential confounding. The analysis therefore does not establish comparative superiority in a randomized head-to-head trial. The association between drug concentrations and endoscopic response also does not prove causation.

The presentation is scheduled for October 14, 2026, from 9:30 to 9:40 a.m. Central Time during Plenary Session 4B: Liver, Esophagus, CRC, IBD (Presentation 72). Both analyses will be presented by Dr. Dubinsky at the ACG meeting, running October 9–14, 2026.

ZYMFENTRA: Indication and Safety

ZYMFENTRA is indicated in the United States for maintenance treatment of adults with moderately to severely active Crohn’s disease or ulcerative colitis following treatment with an IV infliximab product. It blocks tumour necrosis factor-alpha (TNF-α), a protein involved in inflammation.

The product received US Food and Drug Administration approval through a Biologics License Application under Section 351(a) of the Public Health Service Act. Its safety and effectiveness in children younger than 18 years have not been established.

ZYMFENTRA carries warnings for serious infections, including tuberculosis and invasive fungal infections, and malignancies, including lymphoma. Patients require evaluation for tuberculosis and hepatitis B before treatment and monitoring for infections and viral reactivation.

Other risks include hepatotoxicity, new or worsening congestive heart failure, blood-cell abnormalities, severe hypersensitivity, injection-site reactions, neurological disorders and lupus-like syndrome. Concurrent use with other immunosuppressive biologics for Crohn’s disease or ulcerative colitis is not recommended. Live vaccines and therapeutic infectious agents should not be administered during treatment. The drug is contraindicated in patients with previous severe hypersensitivity to infliximab products, their inactive ingredients or murine proteins.

Common adverse reactions include injection-site reactions, COVID-19, anaemia, arthralgia and increased alanine aminotransferase in ulcerative colitis; reported reactions in Crohn’s disease also include headache, respiratory infections, diarrhoea, hypertension, urinary tract infection, neutropenia and leukopenia. Healthcare professionals should consult the full US prescribing information for complete safety details.

Reference

Celltrion, “Celltrion to Present New Analyses of ZYMFENTRA® (infliximab-dyyb) in Crohn’s Disease and Ulcerative Colitis at ACG 2026.” Celltrion USA Inc. 11 October 2026

CT-P13 (Infliximab) Subcutaneous Administration in Patients with Moderately to Severely Active Crohn’s Disease (LIBERTY-CD), ClinicalTrials.gov ID NCT03945019

CT-P13 (Infliximab) Subcutaneous Administration in Patients with Moderately to Severely Active Ulcerative Colitis (LIBERTY-UC), ClinicalTrials.gov ID NCT04205643