Belimumab in early systemic lupus erythematosus: A propensity score matching analysis.

Objective: This study aimed to evaluate the clinical efficacy of belimumab in patients with early systemic lupus erythematosus (SLE), defined as having a disease duration of less than 6 months.

Methods: We retrospectively identified patients with SLE in the early stage who received belimumab and standard of care (belimumab group) or standard of care alone (control group) since September 2020. Propensity score matching (PSM) was used to reduce potential bias. The primary endpoint was lupus low disease activity status (LLDAS) at weeks 12 and 24. The secondary endpoints were remission and the proportion of glucocorticoid dose tapering to 7.5 mg/day. The efficacy of belimumab in patients with lupus nephritis was also assessed.

Results: Out of 111 eligible patients, 16 patients in the belimumab group and 31 patients in the control group were identified by 1:2 PSM. At week 24, a significantly higher proportion of individuals achieved low disease activity state (LLDAS) in the belimumab group compared to the control group (56.3% vs. 19.4%, OR = 5.357, 95% CI = 1.417 to 20.260, p = 0.013). Furthermore, more patients in the belimumab group were reduced to low-dose glucocorticoid ( ≤ 7.5 mg/day) at week 24 (75.0% vs. 35.5%, OR = 5.182, 95%CI = 1.339 to 20.058, p = 0.017). Significant improvements in Patient Global Assessment scores were observed at Week 12 and 24 for those treated with belimumab compared to controls. In a subgroup analysis evaluating the efficacy of belimumab in patients with lupus nephritis, 42.9% of the seven individuals treated with belimumab achieved a complete renal response (CRR) by Week 24, and no instances of disease relapse were observed.

Conclusions: In SLE patients with a disease duration of less than 6 months, belimumab treatment can promote LLDAS achievement and reduce glucocorticoid dose, leading to a better prognosis. Introducing belimumab in the early stage of SLE may be a beneficial decision.