Nefecon (Targeted-Release Formulation of Budesonide) for IgAN: Two Case Reports

Introduction: Immunoglobulin A nephropathy (IgAN) is the most common primary glomerulonephritis worldwide, associated with a significant lifetime risk of kidney failure. We report two cases of IgAN illustrating key diagnostic features and clinical response to targeted-release formulation of budesonide (Nefecon) treatment. Case Description: Case 1--A 45-year-old previously healthy woman presented with elevated creatinine for 1 year and foamy urine for 6 months. Workup revealed dysmorphic urinary red blood cells (RBCs), creatinine 3.3 mg/dL, urine protein-creatinine ratio (UPCR) 1.9 g/g, and serum IgA (5.3 g/L). Kidney biopsy confirmed mesangioproliferative IgAN with 68% global glomerulosclerosis, 5% segmental sclerosis, 60% tubular atrophy, and 16% crescents (M1, E1, S1, T2, C1). Immunofluorescence showed 3+ IgA and 3+ C3 granular deposits. Initial treatment included methylprednisolone, prednisone, and telitacicept. Nefecon (16 mg/day) was started following a rise in proteinuria, with subsequent improvement in renal function (Figure 1A). Case 2--A 34-year-old man with untreated chronic hepatitis B (inactive carrier) for several years presented with 11 months of proteinuria. Initial workup revealed dysmorphic urinary red blood cells, creatinine 2.3 mg/dL, and UPCR 4.4 g/g. Pathology demonstrated IgA-dominant mesangioproliferative disease with 37% glomerulosclerosis, 26% segmental sclerosis, and 30% tubular atrophy (M1, E0, S1, T1, C0). Immunofluorescence demonstrated 3+ IgA and 3+ C3 granular deposits, with occasional HBsAg deposition. The patient received irbesartan and entecavir. As creatinine increased, Nefecon (16 mg/day) was initiated, leading to an improved renal function (Figure 1B). Discussion: These cases highlight the potential of Nefecon as an effective therapy for IgAN, even in patients with advanced histologic damage and impaired renal function. The observed clinical benefits, including reduction in proteinuria and stabilization of renal function, supports its therapeutic value in real-world settings.