#6649 SIGNIFICANT CLINICAL IMPROVEMENT OF PAEDIATRIC AND ADULT PATIENTS WITH DISTAL RENAL TUBULAR ACIDOSIS AFTER 6 YEARS OF TREATMENT WITH SIBNAYAL®

Abstract Background and Aims Distal renal tubular acidosis (dRTA) is a rare disease, inherited or acquired, characterized by hyperchloremic metabolic leading to negative effects on growth, bone kidney, with growth retardation, rickets in children osteomalacia adults, nephrolithiasis chronic kidney disease. No alkalizing treatment, necessary control the its consequences has been shown, date, disease long term. The aim of this clinical study describe cohort adult pediatric dRTA patients treated during 6 years Sibnayal®, new prolonged-release formulation, term control, long-term complications mineralization function. Method Thirty genetic taking previously standard care enrolled short-term B21CS study, were followed up for six average multicenter open-label extension trial (B22CS) evaluate impact treatment deviation score (SDS) height, SDS weight, body mass index (BMI), Z-score spine mineral density (BMD), phosphocalcic metabolism (up 4 years). glomerular filtration rate (GFR), nephrolithiasis, safety compliance also evaluated. Paired t-tests done from baseline end (EoS) when appropriate. covariance ANCOVA test was performed analyze BMD Z-score. Data are presented as mean ± error mean. Results Clinical observations cohort, after an confirmed adequate (plasma bicarbonate 22.0±0;6 mmol/L at 22.8±0.56 end). analysis, Month 48, demonstrated no significant change age blood alkaline phosphatases, decrease phosphorus level (from -0.5±0.7 -1.3±1.0, p = 0.03). From EoS, height weight increased significantly (-0.6±1.0 -0.3±0.9 0.04 0.2±1.5 0.7±1.4 0.03, respectively), without difference BMI. Z-score, relevant skeletal area both patients, underwent continuous increase values over (difference [95% CI] 0.404 [0.170; 0.639]). At improved pre- post-pubertal (mean 0.76±0.54 0.56±0.22 while it stabilized pubertal -0.01±0.39). There variation GFR between EoS. Nephrolithiasis slightly according patient, surgical intervention stones removal. Safety adherence remained good throughout study. Conclusion Our data show positive effect Sibnayal® BMD, nicely improved, who participated follow-up function these follow-up. This first report describing prevention distal Renal Tubular Acidosis under treatment.