Objective: To assess the efficacy and safety of belimumab in paediatric versus adult patients with systemic lupus erythematosus (SLE).
Methods: We performed across-study comparisons of patients with active SLE who received belimumab or placebo, plus standard therapy, in PLUTO (paediatric phase II) and BLISS-52, BLISS-76, BLISS-NEA and EMBRACE (adult phase III). Analysed efficacy data included Week 52 SLE Responder Index (SRI)-4 response rate (EMBRACE: SRI with modified Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) proteinuria scoring (SRI-S2K)); SRI-4 response rate (EMBRACE: SRI-S2K) according to baseline disease activity indicators (Safety of Estrogens in Lupus Erythematosus National Assessment-Systemic Lupus Erythematosus Disease Activity Index (SELENA-SLEDAI) score; anti-dsDNA/C3/C4 levels); Week 52 SRI-6 response rate; and time to first severe flare (SELENA-SLEDAI Flare Index) over 52 weeks.