Thiopurine naivety at tacrolimus induction is a predictor of long-term remission in patients with intractable ulcerative colitis who responded to tacrolimus

Background: The short-term efficacy of tacrolimus (Tac) for steroid-dependent and steroid-resistant refractory ulcerative colitis (UC) has been demonstrated; however, its long-term outcomes have not been well documented. Thus, this study aimed to clarify the long-term outcomes of patients who achieved Tac-induced remission and identify its predictors.

Methods: This study included patients with moderate-to-severe active UC who started receiving Tac at our hospital between July 2004 and December 2016. Short-term treatment response was assessed using the Lichtiger index 3 months after starting Tac, and responding patients were further followed up to assess long-term outcomes. The primary endpoint was the relapse-free survival after Tac-induced remission, and the secondary endpoint was the identification of factors associated with relapse after Tac-induced remission.

Results: The cumulative relapse-free survival rate at 10 years after Tac-induced remission was 33.2%. Multivariate analysis revealed that being thiopurine naïve at Tac induction was associated with the absence of relapse (hazard ratio: 0.45; 95% confidence interval: 0.22-0.92).

Conclusions: Approximately one-third of patients who achieved Tac-induced remission maintained long-term remission. Being thiopurine naïve at Tac induction was a predictor of the absence of relapse.