P92 Quantifying the unmet need in lupus nephritis: EULAR/ERA- EDTA treatment targets, flares, and treatment modifications in the first year in a multicenter observational study

ObjectiveTo decide on the optimal positioning of combination therapies in lupus nephritis (LN), we aimed to determine renal response rates with standard-of-care (SoC) treatment at 3, 6 and 12 months according to EULAR/ERA- EDTA treatment targets in real-life clinical practice.Methods135 patients with recent LN (2015- present) were included in a retrospective/prospective cohort study. Demographic, clinical, and laboratory data, as well as treatment at baseline and every 3 months were collected. Response rates in the first year according to EULAR/ERA-EDTA, flares, and use of glucocorticoids were calculated. Uni- and multivariate regression analysis was performed to assess determinants of renal flares during follow-up.Results135 patients were included, of whom 107 completed a 12-month follow-up [82.2% female, median (IQR) age 38 (22), 35.5% with nephrotic range proteinuria at diagnosis]. Histologically, 13.6% had class III, 36.4% class IV, 18.9% class V, and 28% mixed class LN (III/IV +V). With SoC therapy [initial treatment 54.1% cyclophosphamide (CYC), (9.8% received Euro-Lupus), 30.1% mycophenolic acid (MPA), followed by maintenance], 73%, 82.9% and 84.4% achieved EULAR/ERA-EDTA renal response rates at 3, 6 and 12 months, respectively. Patients treated with CYC differed significantly in histological parameters compared to MPA (table 1). All patients received IV methylprednisolone at baseline [median (IQR) 2.0 (2.0) gr]. In class IV LN, median (IQR) daily prednisone starting dose was 50.0 (20.0) mg/day, and at 6 months 10.0 (10.0) mg. In class III and V LN, median (IQR) daily starting doses were lower, 40.0 (32.0) mg and 30.0 (25.0), respectively, whereas at 6 months median (IQR) doses were equal, 10.0 (15) mg and 10.0 (7.5), respectively. 22 (20%) patients experienced a flare during the first 12 months of follow-up; 4 (18.2%) and 7 (31.8%) patients were added or switched to a different immunosuppressive drug, respectively. Level of proteinuria at baseline was associated with increased risk for flare in univariate analysis (OR 1.18, p=0.025).ConclusionsAlthough the majority of LN patients achieve a complete response by 12 months, a considerable proportion experience flares that necessitate treatment modification to reach this target.Abstract P92 Table 1 Histological characteristics at 1 st kidney biopsy CYC group (n=72) MMF group (n=40) p-value Presence of crescents (n,%) 17 (24.3) 3 (7.5) 0.028 Interstitial fibrosis (n,%) 54 (76.1) 19 (51.4) 0.009 Tubular