Risk factors and the effect of belimumab on flares during glucocorticoid tapering in systemic lupus erythematosus: A multicentre ANSWER-SLE cohort study

Abstract Objectives To identify factors associated with flare after glucocorticoid (GC) reduction in systemic lupus erythematosus (SLE) and determine whether belimumab influences this risk. Methods Using the ANSWER-SLE cohort, this retrospective multicentre study enrolled 388 patients with GC reduction from ≤5 mg/day. The primary outcome was time to overall flare (SLE Disease Activity Index 2000 [SLEDAI-2K] increase ≥3 or GC escalation). Multivariable Cox models identified factors associated with overall flare. Propensity score-based matching weights were applied, and weighted Cox models assessed the association between belimumab and flare risk. Results During one-year follow-up, 133 overall flares occurred (1-year cumulative incidence 39.9%). Higher clinical SLEDAI (hazard ratio [HR] 1.10, 95% confidence interval [CI] 1.03–1.17), SDI (HR 1.11, 95% CI 1.01–1.22), and GC dose reduction (HR 1.40, 95% CI 1.15–1.70) were associated with increased overall flare risk. GC reductions >1 mg were associated with flare (HR 2.53, 95% CI 1.54–4.15). In weighted analyses, belimumab was not associated with overall flare (HR 0.83, 95% CI 0.51–1.34). Conclusions In patients with SLE, carefully tapering GC doses from ≤5 mg/day according to disease activity and organ damage may be important, whereas belimumab was not associated with reduced flare risk.