Efficacy of cytapheresis in patients with ulcerative colitis showing insufficient or lost response to biologic therapy

For the optimal management of refractory ulcerative colitis (UC), secondary loss of response (LOR) and primary non-response to biologics is a critical issue. This article aimed to summarize the current literature on the use of cytapheresis (CAP) in patients with UC showing a poor response or LOR to biologics and discuss its advantages and limitations. Further, we summarized the efficacy of CAP in patients with UC showing insufficient response to thiopurines or immunomodulators (IM). Eight studies evaluated the efficacy of CAP in patients with UC with inadequate responses to thiopurines or IM. There were no significant differences in the rate of remission and steroid-free remission between patients exposed or not exposed to thiopurines or IM. Three studies evaluated the efficacy of CAP in patients with UC showing an insufficient response to biologic therapies. Mean remission rates of biologics exposed or unexposed patients were 29.4 % and 44.2%, respectively. Fourteen studies evaluated the efficacy of CAP in combination with biologics in patients with inflammatory bowel disease showing a poor response or LOR to biologics. The rates of remission/response and steroid-free remission in patients with UC ranged 32%-69% (mean: 48.0%, median: 42.9%) and 9%-75% (mean: 40.7%, median: 38%), respectively. CAP had the same effectiveness for remission induction with or without prior failure on thiopurines or IM but showed little benefit in patients with UC refractory to biologics. Although heterogeneity existed in the efficacy of the combination therapy with CAP and biologics, these combination therapies induced clinical remission/response and steroid-free remission in more than 40% of patients with UC refractory to biologics on average. Given the excellent safety profile of CAP, this combination therapy can be an alternative therapeutic strategy for UC refractory to biologics. Extensive prospective studies are needed to understand the efficacy of combination therapy with CAP and biologics.