Clinical outcomes in lupus nephritis patients treated with belimumab in real-life setting: a retrospective comparative study in China

Objective The use of belimumab in treating lupus nephritis (LN) patients in China is still in its early stages. This retrospective comparative study aims to delineate the disease activity, associated therapies, clinical outcomes, and adverse events among LN patients treated with belimumab, reflecting real-world experience in southeastern China. Methods From May 2020 to December 2023, 54 LN patients treated with belimumab and 42 LN patients treated with conventional therapy were enrolled. All patients had a follow-up period of more than 3 months. The general information, presenting clinical and laboratory data, and outcomes were collected and compared. Results At 3 months of belimumab treatment, compared to baseline, there was a decrease in proteinuria from 74.1% to 64.8% (p < 0.001), a reduction in hematuria from 59.3% to 37.0% (p = 0.008), and an increase in partial or complete renal response from 53.7% to 75.9% (p < 0.001). The median SLEDAI score decreased from 10 to 5 (p < 0.001), and the proportion of patients achieving low lupus disease activity state (LLDAS) increased from 11.11% to 16.67% (p < 0.001) by the 3-month evaluation. Notably, there were significant reductions in oral corticosteroid dosages, with a median decrease from 30 to 17.5 mg/day (p < 0.001) by 3 months, and the proportion of patients requiring >5 mg/day of steroids decreased from 88.89% at baseline to 79.07% at six months (p < 0.001). Compared to the conventional therapy group, the belimumab group experienced a significant reduction in median steroid dosage and increased the proportion of patients achieving remission or LLDAS. The incidence of treatment-emergent adverse events (TEAEs) was significantly lower in the belimumab group (29.6% vs 52.4%, p = 0.024). Conclusion These findings support the potential of belimumab to improve renal and serological parameters, reduce disease activity, lessen corticosteroid dependence, and decrease the risk of TEAEs, demonstrating its safety and efficacy as an adjunct therapy in LN management.