Disease-modifying effect and long-term safety of belimumab in patients with systemic lupus erythematosus: A single-center retrospective study

Background: Disease modification in systemic lupus erythematosus (SLE) is important for minimizing disease activity while limiting treatment-associated toxicities. Belimumab can be used as a remission-induction/maintenance systemic lupus erythematosus therapy; however, its disease-modifying effects are unclear. We aimed to determine these effects in patients with systemic lupus erythematosus.Methods: This single-center retrospective cohort study included 92 patients with systemic lupus erythematosus treated with belimumab. We analyzed the changes in flare free rate/lupus low disease activity state (LLDAS) attainment rate/glucocorticoid dosage/Systemic Lupus International Collaborating Clinics and American College of Rheumatology damage index (SDI) score/drug retention rate after treatment initiation.Results: Fifty-two weeks after initiating belimumab, the flare rate decreased from 82.6% to 14.1% (p < .01). Until week 52 and 1000 days after initiating belimumab treatment, > 70% and similar to 90% of the patients attained lupus low disease activity state, respectively. Belimumab treatment significantly reduced glucocorticoid demand (initiation day, 8.88 (6.00-15.00) mg/d; week 52, 5.00 (2.00-7.00) mg/d; final day of the study period, 3.00 (0.46-6.06) mg/d, initiation day vs. week 52: p < .01, initiation day vs. final day: p < .01); at the end of the study period, 68.5% of patients required <= 5 mg/d prednisolone, and 22.8% discontinued glucocorticoids. Most patients were SDI progression-free (week 52, similar to 95%; day 1000, similar to 90%), and belimumab showed a high drug retention rate (week 52, 90%; day 1000 > 80%).Conclusion: Most patients experienced lupus low disease activity state, reduced flare rate and glucocorticoid demand, and a stable SDI trend after belimumab treatment initiation. Given its efficacy and retention rate, belimumab treatment may serve as a fundamental strategy in disease modification.