Real-World Effectiveness of Belimumab in the Treatment of Systemic Lupus Erythematosus: Pooled Analysis of Multi-Country Data from the OBSErve Studies

INTRODUCTION: The real-world effectiveness of belimumab for systemic lupus erythematosus (SLE) in six countries was evaluated in the OBSErve program. The aim of this post hoc analysis (GSK study 206351) was to pool individual patient OBSErve data to further evaluate the effectiveness of belimumab in a large sample of patients with SLE. METHODS: OBSErve (Argentina, Canada, Germany, Spain, Switzerland, and the USA) enrolled adults ≥ 18 years of age with SLE, who were prescribed belimumab as part of standard therapy (index: date of belimumab initiation). Endpoints (month 6 vs. index) included physician-assessed overall clinical response to belimumab in the overall population (primary) and high disease activity subgroups (secondary; patients with a SLEDAI-2K/SELENA-SLEDAI score ≥ 10 or patients with high anti-dsDNA or low complement at index); other secondary endpoints included changes in glucocorticosteroid (GCS) use and changes in disease activity. Factors associated with physician-assessed overall clinical response were also evaluated. RESULTS: In total, 830 patients were included in the overall population (mean [standard deviation (SD)] age: 41.9 [12.57] years; female: 89.3%; 60.4% from the USA). Nearly half (48.1%) of belimumab-treated patients experienced a ≥ 50% physician-assessed improvement in their overall manifestations, and 13% achieved a near normalization of their condition (equal to ≥ 80% improvement). Initiating belimumab while on high-dose (> 7.5 mg/day) GCS use was associated with ≥ 50% clinical improvement at month 6 (OR: 1.9, p = 0.003). Most (78.1%; n = 518/663) patients were able to reduce or discontinue their oral GCS dose after 6 months of belimumab, with a mean (SD) change of − 8.5 (10.74) mg/day prednisone-equivalent. The mean (SD) change from belimumab initiation in disease activity score (SLEDAI-2K/SELENA-SLEDAI) was − 5.7 (4.5; n = 344). CONCLUSIONS: Belimumab improves clinical manifestations of SLE and is associated with GCS dose reductions in a real-world clinical setting, supporting the real-world effectiveness of belimumab for SLE. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s40744-020-00243-2) contains supplementary material, which is available to authorized users.