Use of belimumab in treating patients with systemic lupus erythematosus: a single-center, real-world retrospective study

Objective To investigate the efficacy and safety of belimumab in the treatment of systemic lupus erythematosus (SLE) in a real-world setting and provide a valuable reference for clinical treatment. Methods In this retrospective study, 101 patients with SLE who came to our hospital from March 2020 to September 2022, 56 of whom with lupus nephritis (LN), were selected. All patients received belimumab in combination with standard of care(SoC)therapy regimen for more than 52 weeks and their clinical/laboratory data, assessment of disease activity, glucocorticoids dosage and occurrence of adverse events were recorded. Lupus Low Disease Activity State (LLDAS) and DORIS remission as a primary goal in the treatment of SLE. The groups were classified according to the Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2 K): SLEDAI-2 K < 6 was categorized as the mild group (mild activity) and SLEDAI-2 K >= 6 was categorized as the active group (moderate-severe activity). The disease of the two groups mentioned above were assessed using the SELENA-SLEDAI Flare Index (SFI) and the SLE Responder Index-4 (SRI-4), respectively. Furthermore, we used complete remission (CR) and partial remission (PR) in the kidney as the standard for efficacy evaluation for LN patients. Results After 52 weeks of treatment with belimumab, patients' complement levels increased significantly (p < 0.05); Other indicators such as 24-hour urine protein quantification and daily glucocorticoids dose decreased compared to pretreatment (p < 0.05). At 52 weeks, (i) after evaluation, the whole group of patients showed significant improvement in their condition; (ii) 55.4% of patients achieved LLDAS and 23.8% achieved DORIS remission; (iii) 73.2% of patients with LN achieved CR, 16.1% achieved PR. Adverse reactions were observed in 15 patients (14.9%), all of which normalized after symptomatic treatment. Conclusions In general, during treatment with belimumab, immunological and biochemical indices improved in SLE patients, urinary protein levels were reduced in LN patients, and the rate of renal function remission was effectively increased; At the same time, the use of belimumab is associated with a low frequency of side effects, good overall tolerability and a favorable safety profile.