Abstract
Background: In refractory cases of ulcerative colitis (UC) where tacrolimus treatment is ineffective, colectomy is often required. This study aimed to evaluate the efficacy and safety of dual therapy with tacrolimus and infliximab. We also assessed the effectiveness of infliximab monotherapy in maintaining remission after discontinuation of dual therapy. Methods: We included 21 patients with moderate-to-severe UC treated at our institution between March 2011 and August 2024, in which infliximab was added because clinical remission was not achieved with tacrolimus. In cases where clinical remission was achieved through dual therapy, tacrolimus was discontinued and maintenance therapy with infliximab alone was continued. The primary outcome was clinical remission at 8 weeks after initiation of dual therapy. Secondary outcomes included colectomy-free survival, relapse-free survival during infliximab maintenance, and adverse events. Results: The median duration of dual therapy was 77 days. Clinical remission was achieved in 38.1% (8/21) of patients, and a clinical response was observed in 42.9% (9/21) at week 8. The cumulative colectomy-free survival rate at one year after initiating dual therapy was 61.9% (95% CI: 44.3–86.6%). Among patients who achieved remission and continued infliximab maintenance therapy, the cumulative relapse-free survival rate at one year was 68.6% (95% CI: 44.5–100.0%). Adverse events during dual therapy were infrequent and included acute kidney injury, infections, and skin rash. Conclusions: Dual therapy with tacrolimus and infliximab demonstrated favorable efficacy and an acceptable safety profile. This strategy may represent a new treatment option for patients with refractory UC.