Efficacy and Safety of Belimumab in Patients With Lupus Nephritis: Subgroup Analyses of a Phase 3 Randomized Trial in the East Asian Population.

RATIONALE & OBJECTIVE: Belimumab improved kidney outcomes in patients with active lupus nephritis (LN) in BLISS-LN, leading to its approval in the United States and the European Union. As data on treatment of East Asian patients with LN are limited, we evaluated the efficacy and safety of belimumab in the BLISS-LN East Asian subgroup. STUDY DESIGN: Prespecified subgroup analysis of BLISS-LN, a phase 3, placebo-controlled, randomized 104-week trial. SETTING & PARTICIPANTS: Adults with biopsy-proven, active LN were randomized (1:1) to belimumab or placebo, plus standard therapy. INTERVENTION: Patients were administered intravenous belimumab 10mg/kg, or placebo, plus standard therapy (oral glucocorticoids and either cyclophosphamide for induction followed by azathioprine for maintenance, or mycophenolate mofetil for both induction and maintenance). At the investigator's discretion, 1-3 intravenous pulses of methylprednisolone, 500-1,000mg each, could be administered during induction. OUTCOMES: The primary end point was primary efficacy renal response (PERR; ie, urinary protein-creatinine ratio≤0.7g/g, estimated glomerular filtration rate no more than 20% below preflare value or≥60mL/min/1.73m2, and no treatment failure) at week 104. Key secondary end points included complete renal response (CRR; urinary protein-creatinine ratio<0.5g/g, estimated glomerular filtration rate no more than 10% below preflare value or≥90mL/min/1.73m2, and no treatment failure) at week 104; PERR at week 52; time to kidney-related event or death; and safety. ANALYTICAL APPROACH: PERR and CRR were analyzed using a logistic regression model, and time to a kidney-related event or death was analyzed using a Cox proportional hazards regression model. RESULTS: 142 patients from mainland China, Hong Kong, South Korea, and Taiwan were included (belimumab, n=74; placebo, n=68). At week 104, more belimumab than placebo patients achieved PERR (53% vs 37%; OR, 1.76 [95% CI, 0.88-3.51]) and CRR (35% vs 25%; OR, 1.73 [95% CI, 0.80-3.74]). At week 52, more belimumab than placebo patients achieved PERR (62% vs 37%; OR, 2.74 [95% CI, 1.33-5.64]). Belimumab reduced the risk of a kidney-related event or death compared with placebo at any time (HR, 0.37 [95% CI, 0.15-0.91]). Safety was similar across treatment groups. LIMITATIONS: Small sample size and lack of formal significance testing. CONCLUSIONS: Safety and efficacy profiles were consistent with BLISS-LN overall population, supporting benefits of belimumab treatment in the East Asian subgroup with LN. FUNDING: This study was funded by GSK (GSK study no. BEL114054). TRIAL REGISTRATION: Registered at ClinicalTrials.gov with study number NCT01639339.

Impact of Belimumab on Organ Damage in Systemic Lupus Erythematosus.

Organ damage is a key determinant of poor long-term prognosis and early death in patients with systemic lupus erythematosus (SLE). Prevention of damage is a key treatment goal of the 2019 update of the European Alliance of Associations for Rheumatology (EULAR) recommendations for SLE management. Belimumab is a monoclonal antibody that inhibits B lymphocyte stimulator (BLyS) and is the only therapy approved for both SLE and lupus nephritis. Here, we review the clinical trial and real-world data on the effects of belimumab on organ damage in adult patients with SLE. Across 4 phase III studies, belimumab in combination with background SLE therapy demonstrated consistent reductions in key drivers of organ damage including disease activity, risk of new severe flares, and glucocorticoid exposure compared to background therapy alone. Long-term belimumab use in SLE also reduced organ damage progression measured by the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index, as reported in open-label extension studies, and propensity score-matched comparative analyses to background therapy alone. Results from a clinical trial showed that in patients with active lupus nephritis, belimumab treatment improved renal response, reduced the risk of renal-related events, and impacted features related to kidney damage progression compared to background therapy alone. The decrease of organ damage accumulation observed with belimumab treatment in SLE, including lupus nephritis, suggest a disease-modifying effect.

Phase III/IV, Randomized, Fifty-Two-Week Study of the Efficacy and Safety of Belimumab in Patients of Black African Ancestry With Systemic Lupus Erythematosus.

OBJECTIVE: Enrollment of patients of Black African ancestry with systemic lupus erythematosus (SLE) in phase II and phase III of the belimumab trials was not reflective of the racial distribution observed in the lupus population. This study was undertaken to assess the efficacy and safety of intravenous (IV) belimumab plus standard therapy in patients of self-identified Black race. METHODS: EMBRACE (GSK Study BEL115471; ClinicalTrials.gov identifier: NCT01632241) was a 52-week multicenter, double-blind, placebo-controlled trial in adults of self-identified Black race with active SLE who received monthly belimumab 10 mg/kg IV, or placebo, plus standard therapy. The optional 26-week open-label extension phase included patients who completed the double-blind phase. The primary end point of the study was SLE Responder Index (SRI) response rate at week 52 with modified proteinuria scoring adapted from the SLE Disease Activity Index 2000 (SLEDAI-2K) (SRI-SLEDAI-2K). Key secondary end points included SRI response rate at week 52, time to first severe SLE flare, and reductions in prednisone dose. RESULTS: The modified intent-to-treat population comprised 448 patients, of whom 96.9% were women and the mean ± SD age was 38.8 ± 11.42 years. The primary end point (improvement in the SRI-SLEDAI-2K response rate at week 52) was not achieved (belimumab 48.7%, placebo 41.6%; odds ratio 1.40 [95% confidence interval 0.93, 2.11], P = 0.1068); however, numerical improvements favoring belimumab were observed, in which the SRI-SLEDAI-2K response rates were higher in those who received belimumab compared with those who received placebo, especially in patients with SLE who had high disease activity or renal manifestations at baseline. The safety profile of belimumab was generally consistent with that observed in previous SLE trials. Adverse events were the primary reasons for double-blind phase withdrawals (belimumab 5.4%, placebo 6.7%). CONCLUSION: The primary end point of this study was not achieved, but improvement with belimumab versus placebo was observed, suggesting that belimumab remains a suitable treatment option for SLE management in patients of Black African ancestry.