Long-term infliximab maintenance therapy for ulcerative colitis: the ACT-1 and -2 extension studies

Background: The aim was to evaluate long-term efficacy, quality of life, and safety in ulcerative colitis patients who received infliximab during the ACT-1 and -2 extension studies.

Methods: Adults with moderate-to-severely active ulcerative colitis in the 54-week ACT-1 and 30-week ACT-2 studies who achieved benefit from infliximab were eligible to participate in extension studies and receive up to 3 additional years of therapy. Patients received randomized study medication until all sites were unblinded; placebo-treated patients were discontinued. Patients receiving 5 or 10 mg/kg infliximab continued to receive open-label infliximab every 8 weeks. Patients receiving infliximab 10 mg/kg could decrease to 5 mg/kg; patients receiving infliximab 5 mg/kg could increase to 10 mg/kg if response was lost.

Results: A total of 229 of 484 infliximab-treated patients from the ACT-1 and ACT-2 main studies entered the long-term extensions. Overall, 70 (30.6%) patients discontinued infliximab infusions for adverse events (24 [10.5%]), lack of efficacy (11 [4.8%]), required a colectomy (1 [0.4%]), or for other reasons (34 [14.8%]). Proportions of patients whose Physician's Global Assessment scores were indicative of no or mild disease (score = 0 or 1) were maintained during the extension studies; 76.5% at Extension week 0 and ranged between 90.0% and 94.3% through Extension week 152. Improvement in Inflammatory Bowel Disease Questionnaire scores observed in the main studies was maintained. During the long-term extension, the infliximab safety profile was consistent with that of the main studies; no new or unexpected safety signals were observed.

Conclusions: Long-term treatment with infliximab for up to 3 additional years was effective and well tolerated.