Impact of Ixekizumab Treatment on Itch and Psoriasis Area and Severity Index in Patients with Moderate-to-Severe Plaque Psoriasis: An Integrated Analysis of Two Phase III Randomized Studies

Introduction: We evaluated baseline itch and its impact on the efficacy of ixekizumab (IXE) in clearing psoriasis and improving quality-of-life measures, and we explored the relationship between itch and psoriatic skin improvement. Methods: Data were analyzed from two double-blind, randomized, controlled phase III studies (UNCOVER-2/3) comparing etanercept (ETN), IXE, and placebo (PBO) in patients with moderate-to-severe plaque psoriasis. Long-term analysis included UNCOVER-3 data from week 0 to week 156. Results: At week 12, a clinically meaningful improvement in itch [Itch Numeric Rating Scale (NRS) reduction ≥ 4] was seen in 70.0%, 88.6%, and 90.8% of the IXE-treated patients in the baseline Itch NRS 4–6, 7–8, and 9–10 groups, respectively (all itch severity groups p < 0.001 versus ETN and PBO). Also, 68.9%, 67.1%, and 73.6% of the IXE-treated patients in the baseline Itch NRS 4–6, 7–8, and 9–10 groups, respectively, showed an improvement of ≥ 90.0% in the Psoriatic Area and Severity Index (PASI) at week 12 as compared to the baseline (PASI 90) (all itch severity groups p < 0.001 versus ETN and PBO). For most patients, itch reduction preceded psoriatic plaque improvement. Sustained effects of IXE on itch and PASI were observed during 3 years of treatment. Conclusions: Regardless of baseline itch severity, IXE treatment provided a rapid improvement in itch followed by clinically meaningful improvements in psoriasis. Funding: Eli Lilly and Company. Trial registration: ClinicalTrials.gov identifiers, NCT01597245 and NCT01646177.