Belimumab Treatment Linked to Positive Kidney Outcomes in Patients with SLE

Results of an analysis of over 3000 patients with systemic lupus erythematosus (SLE) receiving belimumab demonstrated favorable kidney outcomes compared with placebo plus standard therapy, according to a poster presented at the 2023 Congress of Clinical Rheumatology West titled “The Effect of Belimumab on Kidney Outcomes in Systemic Lupus Erythematosus: Results of a Large Integrated Analysis.”¹

Maria Dall’Era, MD

Credit: UCSF Health

Patients receiving belimumab treatment plus standard therapy experienced fewer kidney flares, greater kidney improvements by Safety of Estrogens in Lupus National Assessment–Systemic Lupus Erythematosus Disease Activity Index (SELENA-SLEDAI) standards, and less kidney worsening according to the British Isles Lupus Assessment Group (BILAG) definition. These patients were also less likely to demonstrate a ≥30% reduction in estimated glomerular filtration rate (eGFR) when compared with the cohort receiving placebo plus standard therapy.

“Phase 3 studies have demonstrated that belimumab improves kidney outcomes in patients with SLE without severe active lupus nephritis (LN) and in those with active LN requiring induction therapy,” wrote lead investigator Maria Dall’Era, MD, professor of medicine in the division of rheumatology at the University of California, San Francisco, and colleagues.

In this post-hoc analysis of 5 phase 3, double-blind, placebo-controlled clinical studies, investigators assessed the effects of belimumab treatment on kidney outcomes among patients with SLE without active lupus nephritis. A Cox proportional hazards model was used to compare time to kidney flare results among treatment groups, adjusting for the study and baseline SELENA-SLEDAI score (≤9 vs ≤10). A Fisher’s exact test was used to determine kidney improvement and worsening, and logistic regression models were used for eGFR reductions and for increases in serum creatine (sCr).

In total, 3086 patients were included in the analysis, with similar demographics observed across treatment groups. The mean (standard deviation [SD]) SELENA-SLEDAI score was 10.0 among patients receiving belimumab or placebo. The mean disease duration was 6.4 years in the belimumab cohort and 6.6 years in the placebo cohort. Most (94%) patients were female, and the mean age was 36.7 years in the belimumab group and 37.4 years in the placebo plus standard therapy group. At week 52, 18.8% (n = 352) of patients receiving belimumab and 23.7% (n = 289) patients in the placebo cohort withdrew from the study.

A lower proportion of patients in the belimumab treatment group experienced ≥1 kidney flare when compared with placebo in the overall population (4.5% [n = 85/1869] vs 6.4% [n = 78/1217], respectively). A similar trend was also seen in patients with baseline proteinuria >.5 g/24 h (belimumab-treated patients: 12.4% vs placebo: 18.5%).

Of patients who experienced a kidney flare, those in the belimumab cohort had a shorter median time to first flare in both the overall population and among those with baseline proteinuria >.5 g/24 h when compared with placebo. At week 52, the proportion of patients with ≥30% sCr increase was comparable between treatment groups. Of those with no baseline SELENA-SLEDAI kidney involvement, there was no significant difference in kidney worsening between both cohorts.

“The findings of this large analysis of the phase 3 trails further support the benefits of belimumab in the treatment of adults with SLE, particularly when there is kidney involvement,” investigators concluded.

References

1. ^{Dall'Era M, Fava A, Henning C, Jones-Leone AR, et al. The Effect of Belimumab on Kidney Outcomes in Systemic Lupus Erythematosus: Results of a Large Integrated Analysis. of Clinical Rheumatology. September 2023.}