OBJECTIVES: Juvenile-onset systemic lupus erythematosus (jSLE) is a rare autoimmune disease. Belimumab, a monoclonal antibody targeting soluble B-Lymphocyte Stimulator, has been approved for pediatric use in France since 2020. This retrospective, multicentre study aimed to descriptively evaluate the real-world use, efficacy, and safety of belimumab after six months of treatment in jSLE patients. METHODS: Patients were diagnosed with SLE according to the 2019 EULAR/ACR criteria and belimumab therapy (intravenous or subcutaneous) was initiated before age 18. Efficacy was assessed using clinical (SLEDAI, LLDAS, corticosteroid dose) and biological parameters (anti-dsDNA, complement, proteinuria), along with qualitative and semi-quantitative symptom analysis. RESULTS: Twenty-one patients were included. The majority received intravenous belimumab (90.5%) for articular (66.7%) or cutaneous (23.8%) manifestations. At six months, SLEDAI scores showed no significant reduction, although there was a trend towards lower corticosteroid use (0.53 vs 0.15 mg/kg/day) and an increase in the proportion of patients achieving Low Disease Activity Status (LLDAS) (6.3% vs 37.5%). Marked improvement was observed in articular manifestations with 77.8% achieving complete resolution. Cutaneous, renal, and hematological responses were limited. Overall, treatment was well tolerated, though psychiatric symptoms led to treatment discontinuation in one patient. CONCLUSION: This retrospective, multicentre study found that belimumab, primarily administered intravenously, was effective for articular involvement and had a corticosteroid-sparing effect in jSLE, with a favorable safety profile. Its efficacy was limited for cutaneous, renal, and hematological manifestations. These findings support the potential benefit of belimumab in this population while highlighting the need for prospective, multicentre, and long-term studies to confirm these observations.
Bigey-Frau et al. (Thu,) studied this question.