Treatment Persistence of Ixekizumab in Adults with Moderate-to-Severe Plaque Psoriasis Participating in the Canadian Patient Support Program.

Abstract

Patients with psoriasis (PsO) should adhere to and be persistent with treatment to maintain disease control. Patient support programs (PSPs) are useful to support patients with disease management. We aimed to understand the real-world patient profile and persistence of ixekizumab-initiating Canadian patients with moderate-to-severe PsO using PSP data. This retrospective observational study was conducted utilizing a Canadian PSP database (May 2016 to March 2020). Inclusion criteria were: age ≥ 18years with moderate-to-severe PsO, initiated ixekizumab, enrolled in the PSP for ≥ 6months, and provided informed consent. Psoriasis Area Severity Index (PASI), body surface area (BSA) involvement, and Dermatology Life Quality Index (DLQI) were collected at PSP entry. Adherence [using the proportion of days covered (PDC)] and persistence (using Kaplan-Meier curves) were assessed after 1-year and 2-year follow-ups. Differences in persistence between biologic-naïve and biologic-experienced patients were compared using Cox proportional hazards model after adjusting baseline parameters. In total, 1891 ixekizumab-treated moderate-to-severe patients with PsO were included. The mean [standard deviation (SD)] age was 52.3 (13.3) years; 51.1% of patients were 45-65years old and 61.4% were male. At baseline, the mean (SD) PASI score was 14.3 (8.1), the DLQI score was 16.5 (7.7), and BSA % was 17.4 (15.1). PsO lesions were commonly located on the hands (33.4%), face (28.6%), and feet (23.8%). Ixekizumab-treated patients were highly adherent [PDC ≥ 80%: 1-year (92.0%), 2-year (87.7%)] and persistent [1-year (90.4%), 2-year (85.6%)]. Biologic-naïve patients were more adherent (1-year, 94.6% versus 87.3%; 2-year, 90.3% versus 83.5%) than biologic-experienced patients. Significantly higher persistence in biologic-naïve versus biologic-experienced patients for 1-year (p < 0.01) and 2-year (p = 0.010) follow-up periods was observed after adjusting for baseline parameters. Patients with moderate-to-severe PsO overwhelmingly remained on ixekizumab treatment for more than 2years while participating in a PSP.