Background: Risankizumab (RZB), a monoclonal antibody targeting interleukin-23 p19, was evaluated for maintenance therapy in patients with moderately to severely active ulcerative colitis (UC) and clinical response to RZB intravenous (IV) induction treatment in a phase 3 double-blind, placebo (PBO)-controlled withdrawal (WD) maintenance study, COMMAND (NCT03398135).

Methods: Patients with moderately to severely active UC who achieved a clinical response per Adapted Mayo score after 12 or 24 weeks (wks) of RZB IV treatment in the phase 2b and phase 3 INSPIRE induction studies (NCT03398148)¹ were randomized 1:1:1 in COMMAND to RZB 180 mg (RZB180), 360 mg (RZB360), or PBO (RZB withdrawal) subcutaneous (SC) treatment every 8 wks for 52 wks. The efficacy analysis included responders to 12 wk of RZB IV, while the safety analysis included responders to 12 or 24 wk of RZB IV. The primary endpoint was clinical remission per Adapted Mayo score at wk 52. Key secondary endpoints included endoscopic improvement, HEMI, endoscopic remission, steroid-free clinical remission, maintenance of clinical remission, no bowel urgency, and no abdominal pain at wk 52.

Results: At baseline of induction, demographics and disease characteristics were similar between treatment groups; 75% of 548 patients had history of inadequate response or intolerance to ≥ 1 advanced therapy (AT). Patients receiving RZB180 (40.2%) and RZB360 (37.6%) achieved significantly higher rates of clinical remission vs WD (25.1%) (adjusted treatment difference vs WD: 16.3% and 14.2%, respectively; P ≤ .01) (Table 1). Greater proportions of patients achieved endoscopic improvement, HEMI, endoscopic remission, steroid-free clinical remission, maintenance of clinical remission, no bowel urgency, and no abdominal pain with RZB180 and RZB360 vs WD. The overall rates of adverse events (AEs), and serious infections were similar among treatment groups (Table 2). Serious (presented as events/100 patient-years (E/100 PY) (RZB180: 5.9; RZB360: 6.3; WD: 11.4) and severe AEs (RZB180: 1.6; RZB360: 4.0; WD: 8.0) were lower in the RZB arms vs WD. No active tuberculosis, adjudicated anaphylaxis, serious hypersensitivity, or adjudicated major adverse cardiovascular events were reported in any treatment group.

Conclusion: In patients with moderately to severely active UC responding to 12-week RZB induction therapy, RZB maintenance dosing with 180 mg and 360 mg SC was superior to placebo in achieving clinical remission as well as other key clinical, endoscopic, and histological-endoscopic endpoints. RZB was well-tolerated, with no new safety concerns observed.

Gareth Parkes

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