Efficacy and safety of mirikizumab in psoriasis: results from a 52-week, double-blind, placebo-controlled, randomized withdrawal, phase III trial (OASIS-1).

Mirikizumab was superior to placebo at week 16 and maintained efficacy through week 52, with no new safety signals. What is already known about this topic? Interleukin (IL)-23 is a key cytokine in the pathogenesis of psoriasis. Drugs targeting the p19 subunit of IL-23 have recently been approved for the treatment of adult patients with moderate-to-severe plaque psoriasis. Patients with moderate-to-severe plaque psoriasis achieved significantly greater improvements in skin measures and patient-reported quality-of-life measures after 16 weeks when treated every 8 weeks with mirikizumab compared with placebo in a phase II clinical trial. What does this study add? Compared with placebo, mirikizumab demonstrated high levels of efficacy at week 16 in a large phase III trial; safety profiles were similar between the mirikizumab and placebo arms. After week 16, patients maintained on doses of mirikizumab 250 mg every 8 weeks (Q8W) or 125 mg Q8W showed similar efficacy and favourable safety profiles over 52 weeks, whereas patients switched to placebo gradually lost efficacy over time.