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.

A secondary analysis of the Belimumab International Study in Lupus Nephritis trial examined effects of belimumab on kidney outcomes and preservation of kidney function in patients with lupus nephritis.

We performed a post hoc analysis of the Belimumab International Study in Lupus Nephritis (BLISS-LN), a Phase 3, multinational, double-blind, 104-week trial, in which 448 patients with lupus nephritis were randomized to receive intravenous belimumab 10 mg/kg or placebo with standard therapy (cyclophosphamide/azathioprine or mycophenolate mofetil). Add-on belimumab was found to be most effective in improving the primary efficacy kidney response and complete kidney response in patients with proliferative lupus nephritis and a baseline urine protein/creatinine ratio under 3 g/g. However, there was no observed improvement in the kidney response with belimumab treatment in patients with lupus nephritis and sub-epithelial deposits or with a baseline protein/creatinine ratio of 3 g/g or more. Belimumab significantly reduced the risk of kidney-related events or death and lupus nephritis flare in the overall population. Belimumab reduced the risk of a sustained 30% or 40% decline in estimated glomerular filtration rate (eGFR) versus standard treatment alone and attenuated the annual rate of eGFR decline in patients who remained on-study. Thus, our data suggest that the addition of belimumab to standard therapy could attenuate the risk of lupus nephritis flare and eGFR decline in a broad spectrum of patients with lupus nephritis.