Comparison of Tacrolimus and Infliximab for Acute Severe Ulcerative Colitis in Hospitalized Adults: A Retrospective Study

ABSTRACT Objectives Comparative data on infliximab (IFX) and tacrolimus as salvage therapies for intravenous glucocorticoid (ivGC)‐refractory acute severe ulcerative colitis (ASUC) are limited. We aimed to evaluate the effectiveness and safety of IFX versus tacrolimus in hospitalized patients with ivGC‐refractory ASUC. Methods This retrospective study was conducted between 2017 and 2024 at a tertiary medical center, including inpatients with ASUC who failed ivGC and received IFX or tacrolimus. The primary outcome was colectomy‐free clinical response at discharge. Results Thirty‐seven patients received IFX (median age 27 years; 32.4% males), and 24 received tacrolimus (median age 32 years; 41.7% males). Compared with the patients who received IFX, those receiving tacrolimus had a longer disease duration (4 years vs. 1 year, p = 0.031) and a higher rate of prior exposure to advanced therapy (anti‐tumor necrosis factor agent: 58.3% vs. 2.7%, p = 1.05 × 10 −6 ; Janus kinase inhibitors: 20.8% vs. 0%, p = 0.007). The length of hospitalization was significantly longer among those receiving tacrolimus (median 19.5 days vs. 11.0 days, p = 0.019). Colectomy‐free clinical response rate at discharge (81.1% vs. 83.3%, multivariate analysis p = 0.956) and total colectomy rate in the following year (12.5% vs. 14.3%, p = 0.851) did not significantly differ between the IFX and tacrolimus groups. Safety profile during hospitalization was comparable between groups. Conclusions In ivGC‐refractory ASUC cases, IFX and tacrolimus showed comparable effectiveness and safety. Similar outcomes were observed despite a more treatment‐refractory profile in the tacrolimus group. These findings support the use of either agent as a feasible salvage option in this clinical setting.