Long-term Safety and Efficacy of Risankizumab for the Treatment of Moderate to-Severe Plaque Psoriasis: Interim Analysis of Results From the LIMMitless Open-label Extension Trial Up to 5 Years of Follow-up

Risankizumab is a humanized immunoglobulin G1 monoclonal antibody that specifically inhibits interleukin 23 by binding to its p19 subunit. In the ongoing LIMMitless open-label extension study (NCT03047395), patients with moderate-to-severe plaque psoriasis initially randomized to receive risankizumab 150 mg in 5 phase 2/3 trials (UltIMMa-1/NCT02684370, UltIMMa-2/NCT02684357, SustaIMM/NCT03000075, NCT03255382, IMMvent/NCT02694523) continued open-label risankizumab 150 mg every 12 weeks. This interim analysis evaluated safety through the data cutoff (November 1, 2021; ≤304 weeks) and efficacy through 256 weeks of continuous risankizumab treatment; data beyond 5 years will be presented. Safety (adverse events, AEs) and efficacy, including mean improvement from baseline in Psoriasis Area and Severity Index (PASI) and proportion of patients who achieved ≥90%/100% improvement from baseline in PASI (PASI 90/100), absolute PASI ≤1/<3, Dermatology Life Quality Index of no effect on patient’s life (DLQI 0/1), and ≥4-point improvement in DLQI among patients with baseline DLQI ≥4, were assessed. Of 897 patients enrolled in LIMMitless, 706 were ongoing at data cutoff. Rates of AEs and AEs of safety interest were low through ≤304 weeks and consistent with previous reports. At week 256, 85.1% of patients achieved PASI 90, 52.3% achieved PASI 100, 71.8% achieved PASI ≤1, and 90.3% achieved PASI <3 (modified nonresponder imputation, mNRI). Mean (SE) improvement in PASI from baseline was 95.6% (0.3%; last observation carried forward). At week 256, 76.4% of patients achieved DLQI 0/1 and 96.8% achieved ≥4-point improvement in DLQI (mNRI). Risankizumab was well tolerated and demonstrated durable efficacy for up to 5 years of continuous treatment.