Switching from intravenous to subcutaneous infliximab maintenance therapy in inflammatory bowel disease: Post hoc longitudinal analysis of a randomized trial

Background Pharmacokinetic non-inferiority of subcutaneous (SC) to intravenous (IV) CT-P13 maintenance therapy was demonstrated in a randomized trial (NCT02883452). This post hoc analysis evaluated longitudinal clinical outcomes with the two infliximab treatment strategies. Methods Patients with Crohn's disease or ulcerative colitis received CT‑P13 IV loading doses (5 mg/kg; Week [W] 0 and W2) before randomization (1:1) to receive CT-P13 SC (body weight-based dosing every 2 weeks [Q2W]; W6–54; 'SC maintenance group') or CT‑P13 IV (5 mg/kg Q8W; W6–22) then CT-P13 SC (Q2W; W30–54; 'IV-to-SC switch group'). Paired W30/W54 patient-level data were analyzed. Results Fifty-three (IV-to-SC switch) and fifty-nine (SC maintenance) patients were analyzed. Median trough serum CT-P13 concentrations were significantly higher at W54 versus W30 in the IV-to-SC switch group (20.4 versus 2.3 µg/mL; p < 0.00001), while remaining consistent in the SC maintenance group. Statistically significant improvements in pharmacokinetics, efficacy, fecal calprotectin levels, and quality of life were seen following switch to SC administration at W30 in the IV-to-SC switch group; safety findings were similar pre- and post-switch. Conclusion Formulation switching from IV to SC infliximab maintenance therapy was well tolerated and may provide additional clinical improvements. Findings require confirmation in larger prospective studies.