Risk Factors and the Effect of Belimumab on Flares During Glucocorticoid Tapering in Systemic Lupus Erythematosus: A Multicentre ANSWER-SLE Cohort Study

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.