REAL-WORLD OBSERVATIONAL STUDY OF ANIFROLUMAB IN ADULT SYSTEMIC LUPUS ERYTHEMATOSUS: SINGLE-CENTER EXPERIENCE FROM THE UNITED ARAB EMIRATES

PV243 / #243 Poster Topic: AS24 - SLE-Treatment Background/Purpose Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by multiorgan organ damage, drug-related toxicities related to prolonged treatment, and early mortality.[1] Anifrolumab, a human monoclonal antibody targeting the type I interferon receptor, was approved in 2021 for the treatment of moderate to severe SLE [2]. However, its efficacy and safety profile has not yet been described in our region. In this study, we assessed the efficacy and safety of anifrolumab in an Arab population at a tertiary care center in the United Arab Emirates. Methods Patients with SLE were identified from the hospital’s electronic database between April 2015 and October 2024. Those aged 18 years or older who were receiving anifrolumab were included in the study. Data collected encompassed sociodemographic details, clinical features, SLE organ involvement, laboratory findings, previous and current medications along with their adverse effect profiles, and disease activity indices. Serial measurements of C3, C4, dsDNA, SLEDAI-2k, CLASI-A, and CLASI-D, as well as adverse effects related to anifrolumab, were tracked over a 12-month period. Descriptive statistics were used for data analysis. Results We identified 21 patients with SLE who were treated with anifrolumab. The majority were Emirati nationals (76%) and predominantly female (86%). The mean age at SLE diagnosis was 29.4 ± 10.5 years, with a mean age of presentation to the clinic of 32.8 ± 10.5 years, and an average disease duration of 94 ± 75.2 months. Non-SLE dermatological conditions included cystic acne (3 patients), alopecia areata (2 patients), atopic dermatitis (1 patient), and seborrheic dermatitis (1 patient). The most commonly affected SLE domains were mucocutaneous (71%), musculoskeletal (67%), hematological (57%), renal (14%), and neurological (14%). Serological results showed positive ANA in 76%, anti-Smith in 43%, SSA in 62%, and SSB in 19%. Anifrolumab treatment was initiated at a mean age of 36.4 ± 11.6 years and continued for an average of 9 ± 4.9 months. Concurrent therapies included hydroxychloroquine (67%), prednisolone (29%) with a mean dose of 7 ± 3.5 mg, azathioprine (24%), and mycophenolate mofetil (24%). Two patients reported minor adverse effects in the form of upper respiratory tract infections after starting anifrolumab, but did not require discontinuation of the medication (Table 1). Table 1. Baseline laboratory values included mean C3 (91 ± 22.5 mg/dL), C4 (19 ± 10.3 mg/dL), dsDNA (65 ± 102.4 IU/mL), CRP (9 ± 16.9 mg/L), and ESR (46 ± 27.9 mm/hr). Baseline disease activity scores were SLEDAI-2k (8.9 ± 3.1), CLASI-A (11.8 ± 6.9), and CLASI-D (3.8 ± 6.5). At the 12-month follow-up, disease activity scores showed numerical improvement with SLEDAI-2k (3.7 ± 1.7), CLASI-A (3.5 ± 2.2), and CLASI-D (2.7 ± 3.3) (Figure 1). Figure 1. Conclusions Anifrolumab was well tolerated, showing consistent improvements in disease activity scores across multiple organ domains over a 12-month follow-up period.