Celltrion USA said two analyses of ZYMFENTRA (infliximab-dyyb) will be given as oral presentations on Oct. 13 and 14 at the American College of Gastroenterology (ACG) 2026 Annual Scientific Meeting in Nashville, Tennessee. One is a late-breaking pooled and propensity score-matched analysis comparing subcutaneous and intravenous infliximab in patients with ileum-dominant Crohn's disease. The other is a post hoc analysis of the Phase 3 LIBERTY-CD and LIBERTY-UC studies assessing the impact of prior anti-drug antibody status on clinical outcomes after subcutaneous infliximab 240 mg was started following an interruption of intravenous infliximab treatment.
In the post hoc analysis, which looked at patients from the placebo arms of the two Phase 3 studies, 72.5% (37 of 51) of patients with Crohn's disease and 92.2% (71 of 77) of patients with ulcerative colitis who started subcutaneous infliximab 240 mg had prior ADA positivity, the company said. The median interval between the last intravenous infusion and the start of subcutaneous treatment was 16 weeks in ADA-positive and ADA-negative patients in both disease groups. Clinical outcomes were generally similar whether or not patients had antibodies before starting subcutaneous infliximab, with clinical response in Crohn's disease and partial clinical response in ulcerative colitis observed by 8±2 weeks and sustained through 78 to 80 weeks. Serum infliximab concentrations increased after subcutaneous initiation and were generally comparable over time across ADA-status groups, while fecal calprotectin and C-reactive protein levels decreased at the first assessment and remained lower through the final assessment. ADA positivity declined among patients who already had antibodies, and new ADA development was uncommon among those who did not.
The late-breaking abstract reports a pooled analysis of individual patient data from four infliximab registrational studies. Of 884 patients, 200 met the eligibility criteria, and the 1:1 propensity score-matched analysis included 70 patients in each treatment group, receiving standard maintenance treatment with subcutaneous infliximab 120 mg every two weeks or intravenous infliximab 5 mg/kg every eight weeks. In the matched population at Week 54, patients receiving subcutaneous infliximab had higher rates of clinical remission (71.4% vs. 51.4%, P = 0.023), endoscopic response (65.7% vs. 27.1%, P < 0.001) and endoscopic remission (41.4% vs. 17.1%, P = 0.003). The analysis also found that endoscopic responders in both treatment groups had significantly higher serum infliximab concentrations than nonresponders.
Both analyses will be presented by Marla Dubinsky, M.D., professor of pediatrics and director of the IBD Center at the Icahn School of Medicine, Mount Sinai, in New York. She said data on subcutaneous infliximab initiation after a drug holiday are limited, particularly regarding the impact of prior ADA status on clinical outcomes, and that the post hoc findings suggest prior ADA status did not appear to compromise outcomes after subcutaneous infliximab was started following the interruption of intravenous infliximab induction.
