BACKGROUND: Ulcerative colitis is characterized by leucocyte infiltration into the colonic mucosa. Granulocyte-monocyte apheresis depletes these cells. AIM: To assess the non-inferiority of 5-10 apheresis treatments in patients with steroid-dependent or steroid-refractory ulcerative colitis. METHODS: A total of 196 adults with moderate-severe ulcerative colitis were randomized 1:1 to 5 (n = 96) or 10 (n = 90) open label apheresis treatments. The primary endpoint was non-inferiority of clinical activity index score after 12 weeks. RESULTS: The intent-to-treat population comprised 82 and 80 patients for the 5- and 10-treatment groups, respectively. The difference between the two groups in mean clinical activity index was 0.24 with an upper 95% confidence interval of 1.17, which was below a predefined non-inferiority threshold of 1.33. Clinical activity index score improved from baseline in both groups (from 8.7 to 5.6 with 5 treatments, and from 8.8 to 5.4 with 10), with no significant difference between the groups (P = 0.200). Outcomes for the 5- and 10-treatment groups were similar--clinical remission: 44% and 40%, respectively (P = 0.636); clinical response: 56% and 59%, respectively (P = 0.753). The treatment was well tolerated in both groups. CONCLUSIONS: This prospective study comparing apheresis regimens in ulcerative colitis demonstrates that 5 treatments were not inferior to 10 treatments in steroid-refractory or -dependent ulcerative colitis.
