Efficacy of Biologics in Patients with Ulcerative Colitis Exhibiting Non-Response or Insufficient Response to Cytapheresis

<b>Background/Objectives</b>: Recent studies have investigated the effectiveness of second-line agents in patients with ulcerative colitis (UC) who have experienced failure with first-line biologics. Although cytapheresis (CAP) is an effective therapeutic strategy for refractory UC, the efficacy of second-line agents in patients with UC with previous CAP failure remains unexplored. Herein, we examined the efficacy of biologics in patients with refractory UC who experienced non-response or insufficient response to previous CAP. <b>Methods</b>: We retrospectively assessed the efficacy of biologics administered between January 2013 and June 2024 in patients with refractory UC who experienced non-response or insufficient response to previous CAP. Rates of clinical remission, steroid-free remission, and endoscopic improvement were also determined. Clinical remission was evaluated using Lichtiger's clinical activity index. <b>Results</b>: Eighty-one patients with refractory UC underwent CAP, thirty of whom were eligible for study inclusion. The use of biologics was associated with clinical and steroid-free remission rates of 75.9% and 44.8%, respectively. Clinical and steroid-free remission rates of biologics did not differ significantly between patients with an insufficient response to previous CAP and those with non-response to previous CAP. There were no significant differences in clinical or steroid-free remission rates of biologics between patients with steroid-dependent and steroid-refractory UC. Endoscopic improvement was observed in 54.5% of patients. <b>Conclusions</b>: Despite the limited number of patients, biologic therapy was effective in patients with refractory UC who had experienced a non-response or insufficient response to previous CAP. Accordingly, biologics may be a useful second-line therapy for patients with refractory UC who have failed CAP.