SummaryBackgroundThe long‐term risk of relapse after switching from intravenous (IV) to subcutaneous (SC) infliximab remains unknown in inflammatory bowel disease (IBD).AimsTo assess the long‐term effectiveness and acceptability of switching from IV to SC infliximab in patients with IBD treated with or without an intensified IV regimen.MethodsWe extended the follow‐up of the REMSWITCH study including patients with IBD in clinical remission who were switched from IV to SC infliximab (120 mg/2 weeks). Relapse was defined as clinical relapse or faecal calprotectin increase ≥150 μg/g compared to baseline.ResultsAfter median follow‐up of 18 [15–20] months, among 128 patients, rates of relapse were 13.8% (8/58), 18.4% (7/38), 35.3% (6/17) and 86.7% (13/15) at last follow‐up (p < 0.001), in those receiving 5 mg/kg/8 weeks, 10 mg/kg/8 weeks, 10 mg/kg/6 weeks and 10 mg/kg/4 weeks at baseline, respectively. Among relapsing patients, dose escalation led to clinical remission in 82.1% (23/28). In multivariable analyses, factors associated with higher risk of relapse were IV infliximab 10 mg/kg/4 weeks (OR = 61.0 [6.1–607.0], p < 0.001) or 10 mg/kg/6 weeks (OR = 4.7 [1.1–20.2], p = 0.017), and decreased (OR = 5.6 [1.5–20.3], p = 0.004) or stable (OR = 5.0 [1.6–15.0], p = 0.009) serum levels of infliximab between baseline and first post‐switch visit. Acceptability was improved at 6 months and did not decrease over time (6.9 ± 1.6 before the switch vs. 8.8 ± 1.3 at 6 months and 8.8 ± 1.3 at last follow‐up; p < 0.001). No severe adverse events were reported.ConclusionsSwitching from IV to SC infliximab 120 mg every other week is safe and well accepted leading to low long‐term risk of relapse. Tight monitoring and dose escalation should be recommended for patients receiving 10 mg/kg/6 weeks and 4 weeks, respectively.