MATERIALS AND METHODS
Study Design, Population, and Treatments
Data were integrated from the 12-week induction periods of two multicenter, randomized, double-blind, placebo-controlled phase 3 clinical trials (UNCOVER-2, NCT01597245; UNCOVER-3, NCT01646177). Individual trial designs were previously published.10,11
Eligible patients were ≥18 years of age with a confirmed diagnosis of moderate-to-severe plaque psoriasis.11 Briefly, from week 0–12, patients were randomized to receive either subcutaneous placebo (PBO), etanercept 50 mg twice weekly (ETN), or ixekizumab 80 mg every 2 weeks (IXEQ2W) or every 4 weeks (IXEQ4W) after a 160-mg starting dose at week 0.
Study protocols were approved by the Institutional Review Board at each study center, and studies were conducted in accordance with the ethical principles of the Declaration of Helsinki, Council for International Organizations of Medical Sciences (CIOMS) International Ethical Guidelines, the ICH GCP Guideline [E6], and applicable laws and regulations. Written informed consent was obtained from each patient at study entry before any study procedures occurred.
Efficacy Outcomes
Co-primary efficacy endpoints were the proportions of patients achieving Psoriasis Area and Severity Index (PASI) 75 or higher and static Physician Global Assessment (sPGA) (0,1) with at least a 2-point reduction from baseline at week 12.10,11 Secondary efficacy endpoints at week 12 included proportions of patients achieving PASI 90, PASI 100, and sPGA (0; remission), and change from baseline in Nail Psoriasis Severity Index (NAPSI) score in patients with baseline fingernail involvement.
Patients were assessed at baseline for fingernail psoriasis using NAPSI. Each fingernail was divided with imaginary horizontal and longitudinal lines into quadrants scored for bed (score of 0–4) and matrix (score of 0–4) psoriasis depending on the presence (score of 1) or absence (score of 0) of any of the features of fingernail bed and fingernail matrix psoriasis in each quadrant. The NAPSI score of a fingernail is the sum of scores in fingernail bed and fingernail matrix from each quadrant (maximum of 8); then scores of all fingernails were added to obtain total NAPSI scores, ranging from 0 to 80 (no nail psoriasis to severe nail psoriasis, respectively). For the present analysis, patients were categorized by presence or absence of and severity of nail psoriasis as patients with nail psoriasis (NAPSI score >0 at baseline), patients without nail psoriasis (NAPSI=0 at baseline), patients with severe nail psoriasis (NASPI ≥16 at baseline), and patients with mild nail psoriasis (NAPSI <16 at baseline).
Statistical Analyses
In this post-hoc analyses, the number and percentage of patients achieving efficacy endpoints, including PASI 75/90/100 and sPGA (0,1)/(0), were summarized by severity of nail involvement category (with or without nail psoriasis; severe or mild nail psoriasis). Treatment-by-nail involvement inter-
