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

BACKGROUND AND AIMS: We assessed the effectiveness of switching from intravenous to subcutaneous infliximab in patients with inflammatory bowel diseases (IBDs) treated with or without intensified intravenous regimen.METHODS: In this multicenter observational study, IBD patients in clinical remission (partial Mayo score 52 or Harvey-Bradshaw index 54) 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 2150 mg/g compared with baseline.RESULTS: Among 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 mg/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 & PLUSMN; 1.6 vs 8.6 & PLUSMN; 1.4; P < .0001). No severe adverse event was reported.CONCLUSIONS: Switching 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.