Active implementation of low disease activity state as a treatment endpoint in childhood-onset systemic lupus erythematosus in routine practice is both feasible and associated with better outcomes.

INTRODUCTION: Treat-to-target (T2T) strategies aim to facilitate tight disease control to improve outcomes. No previous studies evaluated prospectively the feasibility and impact of the T2T strategy in routine practice in childhood-onset SLE (cSLE). METHODS: Adolescents and young adults (AYA) with cSLE were recruited for T2T implementation from a large tertiary centre over a period of 6 months and followed up at least twice over a prospective period of 12 months. RESULTS: During Oct 2022-April 2023, 135/162 (83.3%) AYA with cSLE had disease scores evaluated at their routine appointment to enable inclusion in the study, and 122/135 (91.2%) had their disease assessed, and a suitable treatment target agreed and documented at each routine clinical appointment over the 12 months prospective follow-up. T2T strategy led to improved disease control at 12 months: more AYA with cSLE achieved clinical remission off steroids (4.1% vs. 10.7%, P = 0.048), or minimum childhood-lupus low disease activity (cLLDAS) (81.9% vs. 91.8%, P = 0.022). Achieving minimum cLLDAS for longer than 3 months was associated with reduced damage accrual (HR = 1.7; 95%CI = 1.1-2.5; P < 0.0001) at 12 months. CONCLUSION: T2T strategy implementation was achievable and associated with improved cSLE control. Spending at least 3/12 months in cLLDAS led to less damage accumulation. Key Points • This is the first large prospective study in AYA with cSLE to evaluate the impact of active T2T implementation in routine practice. • T2T strategies were feasible to implement in 122/135 (91.2%) AYA with cSLE in routine practice. • The T2T approach was associated with improved disease control and decreased damage accrual at 12 months.