Characteristics and clinical outcomes of patients with systemic lupus erythematosus initiating anifrolumab in a real-world setting in Spain (AZAHAR study): an observational study protocol.

Introduction: Anifrolumab (Saphnelo) is approved for adult patients with moderate-severe systemic lupus erythematosus (SLE). Considering its commercialisation in Spain in 2023, observational studies describing the use of anifrolumab in routine clinical practice are limited. The aim of the AZAHAR study is to describe the characteristics and clinical outcomes of patients with SLE who initiated anifrolumab during its first year of marketing in Spain.

Methods and analysis: This is an observational retrospective study including ~120 patients with moderate-severe SLE who received anifrolumab in Spain in 20 centres from 1 June 2023 to 31 May 2024. Patients will be followed up every 6 months after the first infusion of anifrolumab for a period between 6 and 18 months until the end of the study (31 December 2024). Data will be obtained through the review of medical records, considering as primary outcomes disease activity measured by Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) 2000, clinical SLEDAI, Physician Global Assessment and Lupus Low Disease Activity State and remission, defined by Definitions of Remission in SLE-21, and as secondary outcomes, SLE treatment, flare incidence, anifrolumab adherence and persistence (time on treatment) and healthcare resources utilisation.

Ethics and dissemination: The final protocol of the study will be approved by ethics committees/institutional review boards (IRB)/independent ethics committees at each site.

Trial registration number: NCT06626945.