EFFECT OF ATACICEPT ON RENAL FUNCTION IN SLE PATIENTS

Abstract BACKGROUND AND AIMS Atacicept is a dual BLyS/APRIL inhibitor. APRIL-SLE was a double-blind, placebo-controlled phase 2 study, which randomized moderate-to-severe systemic lupus erythematosus (SLE) patients to atacicept 75 mg, atacicept 150 mg or placebo. The primary endpoint was the proportion of subjects who experienced a new flare during the 52-week treatment period. In total, 111 patients in the placebo group, 112 patients in the atacicept 75 mg group and 62 patients in the atacicept 150 mg group completed 52 weeks of treatment. Patients with severe renal disease were excluded, while patients with proteinuria and mild–moderate chronic kidney disease, as assessed by KDIGO criteria, were eligible. The effect of atacicept on measures of renal function in these patients has not previously been reported. METHOD The study excluded moderate to severe glomerulonephritis, as defined by either of the following: urinary protein/creatinine ratio > 1 mg/mg and/or hematuria or a significant renal impairment as defined by glomerular filtration rate (GFR) < 50 mL/min/1.73 m2. Urine protein/creatinine ratio (UPCR) and GFR were measured at baseline, week 2, and then every 4 weeks until week 52. RESULTS In the APRIL-SLE study, the analysis for GFR and UPCR are of all patients (62–111 per group) with up to 15% of patients having a history of SLE-related renal disease. GFR time course showed stability for the atacicept groups compared to a 4.3% decline in the placebo group at week 52 from baseline (figure and table). Furthermore, reductions in UPCR from baseline at week 52 were observed in the atacicept groups compared to an increase in the placebo group. CONCLUSION In this phase 2 APRIL-SLE study, analysis of renal data suggests potential for improved renal function with atacicept treatment in SLE renal disease.