Efficacy and safety of belimumab in immune thrombocytopenia secondary to systemic lupus erythematosus

Objective We aimed to investigate the safety and effectiveness of belimumab for patients with refractory immune thrombocytopenia (ITP) secondary to systemic lupus erythematosus (SLE) Method This is a multi-centre, retrospective cohort study. Data from patients with SLE–ITP received belimumab in addition to basic drug therapy between January 2017 and January 2025 were retrospectively analysed. Results Fourteen patients were included in the study. The overall response rate of thrombocytopenia was 72.7% at week 2 and week 4, 71.4% at week 12, and 78.6% at week 24. At week 24. Nine patients with OR successfully withdrew glucocorticoids (GCs) to < 15 mg prednisone. The SLE Disease Activity Index (SLEDAI), Physician Global assessment (PGA) scores, and the mean dosage of GCs were significantly decreased (p < .05). The serum C3, lgG, and lgM level did not significantly change, whereas the serum IgA level significantly decreased at week 24 and the serum C4 increased significantly at week 24. There were two patients with adverse effects during weeks 4–12. Conclusion Belimumab appears to be effective, safe, and well-tolerated in refractory ITP patients with SLE; larger studies are needed to confirm the generalizability of these findings.