Real-world effectiveness of intravenous belimumab in adults with systemic lupus erythematosus: results of the observational OBSErve study in the Russian Federation.

Background: The real-world effectiveness of intravenous (IV) belimumab in treating systemic lupus erythematosus (SLE) has been demonstrated in various countries through the OBSErve (evaluation Of use of Belimumab in clinical practice SEttings) program. Here we describe the clinical effectiveness of IV belimumab for treating SLE in real-world clinical practice in the Russian Federation.

Methods: In the retrospective, observational OBSErve Russia study (GSK Study 215349), eligible physicians enrolled adults with SLE receiving IV belimumab as part of their standard care. De-identified data were collected from patient medical records from September 2021 to March 2022. The primary outcome was the physician-assessed overall clinical response at 6 months post-index versus index (belimumab initiation) among patients receiving belimumab for ≥6 months. Other endpoints included change in Safety of Estrogens in Lupus Erythematosus National Assessment - SLE Disease Activity Index (SELENA-SLEDAI) score and glucocorticoid use.

Results: Overall, 59 patients initiated IV belimumab, mainly due to the previous regimen not being effective and to decrease glucocorticoid use (76.3% each); 15.3% of patients started belimumab within the first year of SLE diagnosis. Only 13.6% of patients discontinued belimumab within the first 6 months, mainly due to loss to follow-up and loss of insurance/reimbursement. At 6 months post-index, among patients who completed ≥6 months of belimumab therapy (full analysis set, n = 53), 90.6% and 60.4% had an overall clinical improvement of ≥20% and ≥50%, respectively. Mean (standard deviation, SD) change in SELENA-SLEDAI score from index to 6 months post-index was -5.9 (4.3). Mean (SD) glucocorticoid dose decreased from 12.2 (7.3) mg/day at index to 8.6 (5.1) mg/day at 6 months post-index (n = 50).

Conclusions: Patients with SLE receiving IV belimumab for 6 months in real-world settings in the Russian Federation experienced overall clinical improvements and reductions in glucocorticoid use, which is an important long-term strategy of SLE treatment.