WIP 154 - Belimumab for lupus nephritis in children

Poster Number: WIP 154
Publication Number: WIP 154.861

Background: Belimumab is a monoclonal antibody that targets the B-lymphocyte stimulator and has been shown to decrease steroid requirement and kidney disease activity in adults with lupus nephritis.

Objective: Determine the impact of belimumab on disease activity and steroid exposure at 26 weeks of therapy for patients ages 5 to 20 years with lupus nephritis ISN/RPS Class III/IV +/- V.

Design/Methods: Retrospective cohort study comparing patients treated with and without belimumab. We reviewed patients with biopsy-proven lupus nephritis ISN/RPS Class III/VI +/- V treated between Jan 1, 2019, and Sept 30, 2023, aged 5 to 20, at a single center in Atlanta, Georgia.

After patient identification using ICD9/ICD10 codes, we will collect demographic and clinical data of interest, including the reasons belimumab was given for treatment and the side effects experienced. We will compare outcomes at 26 weeks following initial or relapse treatment between the belimumab-treated group vs the non-treated group.

The primary outcome is cumulative steroid exposure at 26 weeks following initial or relapse treatment in mg/m2 (s). Secondary outcomes are lupus nephritis disease activity, assessed by proteinuria, lupus activity, evaluated by SLE disease activity index, and side effects.

For the analysis, we will collect urine protein to creatinine ratio at the time of starting therapy and at 26 weeks of treatment. We will compare the proportion of patients that achieve remission of proteinuria (UPCR < 0.5 mg/mg) at 26 weeks of therapy via Mann-Whitney U test analysis.

SLE disease activity index score will be collected at the time of starting therapy and at 26 weeks. We will compare the proportion of patients who achieve a two or more-point reduction goal at 26 weeks of therapy via Mann-Whitney U test analysis.

As for the timeline, at the time of abstract submission, we are collecting data. All results will be available by Apr 1, 2024. The IRB approved the study: STUDY00001761.