Budesonide delayed-release capsules to reduce proteinuria in adults with primary immunoglobulin A nephropathy.

INTRODUCTION: Immunoglobulin A nephropathy (IgAN) is characterized by mesangial deposition of immune complexes containing galactose-deficient IgA1 (Gd-IgA1). This Gd-IgA1 is believed to originate from mucosally sited B cells, which are abundant in the Peyer's patches-rich distal ileum. Nefecon is a targeted-release form of budesonide developed to act in the distal ileum, thereby exerting a direct action on the mucosal tissue implicated in the pathogenesis of the disease. AREAS COVERED: This review discusses IgAN pathophysiology and provides an overview of the current therapeutic landscape, focusing on Nefecon, the first drug to receive accelerated US approval and conditional EU approval for the treatment of patients with IgAN at risk of rapid disease progression. EXPERT OPINION: Nefecon trial data thus far have demonstrated a promising efficacy profile, with a predictable pattern of adverse events. Treatment with Nefecon for 9 months reduces proteinuria substantially (Part A of the Phase 3 trial and the Phase 2b trial). A nearly complete prevention of deterioration of renal function has been observed at 12 months in patients at greatest risk of rapid disease progression. Long-term data from Part B of the Phase 3 study will provide 24-month data, furthering understanding of the durability of the 9-month treatment course.