Tacrolimus therapy for ulcerative colitis: a retrospective study of factors associated with inducing and maintaining remission

Tacrolimus (TAC) is highly effective pharmacotherapy for refractory ulcerative colitis. However, the factors involved in achieving and maintaining remission are unclear, and the optimal maintenance therapy after inducing remission with TAC remains in question. This study involved 136 patients with ulcerative colitis who received TAC therapy from April 2009 to December 2021. The study examined the remission induction rate, overall and drug-specific remission maintenance rates after 52 weeks, factors associated with remission and maintenance, and adverse events. The overall remission rate was 72.7%, with significant differences by sex, endoscopic scores before and after TAC therapy, prior experience with biologic therapy, previous biologic therapy, post-TAC Lichtiger Colitis Activity Index (CAI) score, and LCAI reduction at 52 weeks. The remission maintenance rate at 52 weeks was 51.5% and differed significantly by sex, prior experience with biologic therapy, length of hospital stay, and total prednisolone dose during hospitalization. The 52-week maintenance rates by medication were 67% for azathioprine, 54% for TAC, and 37% for biologic agents. No serious side effects were observed with TAC therapy. TAC therapy effectively induced remission in patients with refractory ulcerative colitis. Findings also suggested that such remission can be maintained for up to 52 weeks by treating with either TAC or a biologic agent after inducing remission, even if azathioprine cannot be used as maintenance therapy.