Continuation of belimumab in patients with systemic lupus erythematosus in a real-world setting: A single-center retrospective cohort study

Objective This study aimed to investigate belimumab continuation and identify clinical parameters predicting belimumab continuation in patients with systemic lupus erythematosus (SLE) in a real-world setting. Methods A total of 38 consecutive patients with SLE who were newly treated with belimumab at our institution from 2018 to 2024 were retrospectively analyzed. The data were censored when belimumab was discontinued or the observation period ended. Clinical and laboratory data were retrospectively collected. Results The median follow-up time after starting belimumab was 37 months (IQR 12–52). The 1-year belimumab continuation rate was 29/38 (76%). During the entire observation period, 15 (39%) patients discontinued belimumab. Among the 10 patients who discontinued belimumab due to lack of efficacy, seven were switched to other biologics. The overall discontinuation rate was 13.4 per 100 person-years. Absence of serological activity (increased anti-dsDNA and/or hypocomplementemia) at baseline was a significant risk factor for belimumab discontinuation within 1 year ( p = 0.034), with a relative risk of 3.43 (95% CI, 1.01–11.6). The glucocorticoid dosage was significantly reduced in the 29 patients treated with belimumab for ≥12 months ( p < 0.001). Among the 33 patients who were not in the low disease activity state (LLDAS) at baseline, 19 (58%) were in the LLDAS at their final visit ( p < 0.001). Belimumab was temporarily discontinued in six patients due to infection, but all patients resumed it. Conclusion The belimumab continuation rate was high among patients with SLE in real-world settings; however, the absence of serological activity at belimumab initiation was a significant risk factor for discontinuation within 1 year.