Effectiveness of Switching From Intravenous to Subcutaneous Infliximab in Patients With Inflammatory Bowel Diseases: the REMSWITCH Study

Background and AimsWe assessed the effectiveness of switching from intravenous to subcutaneous infliximab in patients with inflammatory bowel diseases (IBDs) treated with or without intensified intravenous regimen.MethodsIn this multicenter observational study, IBD patients in clinical remission (partial Mayo score ≤2 or Harvey-Bradshaw index ≤4) were switched to a unique dose of subcutaneous infliximab (120 mg every other week). Pharmacological and biological data were collected at baseline, visit 1 (4–8 weeks postswitch), visit 2 (8–16 weeks postswitch), and visit 3 (16–24 weeks postswitch). Relapse was defined as clinical relapse or fecal calprotectin increase ≥150 μg/g compared with baseline.ResultsAmong 184 eligible patients, 72.3% (n = 133 of 184) agreed to switch to subcutaneous infliximab. At visit 3, a relapse occurred in 10.2% (n = 6 of 59), 7.3% (n = 3 of 38), 16.7% (n = 3 of 18), and 66.7% (n = 10 of 15) (P < .001) of patients receiving 5 mg/kg every 8 weeks, 10 mg/kg every 8 weeks, 10 mg/kg every 6 weeks, and 10 mg/kg every 4 weeks, respectively. Dose escalation to 240 mg every other week led to recapture clinical remission in 93.3% (n = 14 of 15). Infliximab serum levels increased after the switch (P < .0001) except for patients receiving 10 mg/kg every 4 weeks. In multivariable analysis, 10 mg/kg every 4 weeks regimen (odds ratio, 12.4; 95% confidence interval, 1.6–98.4; P = .017) and fecal calprotectin >250 μg/g at baseline (odds ratio, 5.4; 95% confidence interval, 1.1–27.6; P = .042) had a higher risk of relapse as well as reduced (41.7%) or stable (36.8%) infliximab serum levels between baseline and visit 1 compared with increased serum levels (12.7%) (P = .020 and P = .019, respectively). Patients’ acceptability (10-point scale) was improved by the switch (6.9 ± 1.6 vs 8.6 ± 1.4; P < .0001). No severe adverse event was reported.ConclusionsSwitching from intravenous to subcutaneous infliximab 120 mg every other week is safe and well accepted, leading to a low risk of relapse in IBD patients except for those receiving 10 mg/kg every 4 weeks requiring 240 mg every other week.