New treatment for IgA nephropathy: enteric budesonide targeted to the ileocecal region ameliorates proteinuria

Background. Systemic corticosteroid treatment has been shown to exert some protection against renal deterioration in IgA nephropathy (IgAN) but is not commonly recommended for long-term use due to the well-known systemic side effects. In this study, we investigated the efficacy and safety of a new enteric formulation of the locally acting glucocorticoid budesonide (Nefecon®), designed to release the active compound in the ileocecal region. The primary objective was to evaluate the efficacy of targeted release budesonide on albuminuria. Methods. Budesonide 8 mg/day was given to 16 patients with IgAN for 6 months, followed by a 3-month follow-up period. The efficacy was measured as change in 24-h urine albumin excretion, serum creatinine and estimated glomerular filtration rate (eGFR). Results. The median relative reduction in urinary albumin excretion was 23% during the treatment period (interquartile range: −0.36 to −0.04, P = 0.04) with pretreatment values ranging from 0.3 to 6 g/24 h (median: 1.5 g/24 h). The median reduction in urine albumin peaked at 40% (interquartile range: −0.58 to −0.15) 2 months after treatment discontinuation. Serum creatinine was reduced by 6% (interquartile range: −0.12 to −0.02; P = 0.003), and eGFR [Modification of Diet in Renal Disease (MDRD)] increased ∼8% (interquartile range: 0.02–0.16, P = 0.003) during treatment. No major corticosteroid-related side effects were observed. Conclusions. In the present pilot study, enteric budesonide targeted to the ileocecal region had a significant effect on urine albumin excretion, accompanied by a minor reduction of serum creatinine and a modest increase of eGFR calculated by the MDRD equation, while eGFR calculated from Cockcroft–Gault equation and cystatin C was not changed. Enteric budesonide may represent a new treatment of IgAN warranting further investigation.