budesonide
Tarpeyo (nefecon) is a targeted-release capsule of budesonide from Calliditas Therapeutics for adults with primary immunoglobulin A nephropathy (IgAN). It releases budesonide in the ileum to act on mucosal immunity. In the European Union the same medicine is authorised as Kinpeygo.
This page is based on the official US label for TARPEYO and the EMA medicine record for Kinpeygo; the mechanism is explained in plain language, and analogies are used only where they stay accurate.
How it works
Explains what the medicine does in the body, not dosing, side effects, or safety.
An analogy
In IgA nephropathy the immune tissue of the gut overproduces a faulty form of the antibody IgA, which later lodges in the kidneys and damages them. Nefecon is a capsule designed to open exactly where that faulty IgA is made, releasing its medicine onto the source instead of flooding the whole body.
In simple terms
Nefecon is a capsule taken once daily that releases budesonide, a corticosteroid, in the ileum, the last part of the small intestine. There it calms the overactive mucosal immune tissue (Peyer's patches) involved in IgA nephropathy, lowering production of the harmful IgA and helping protect kidney function.
In depth
Nefecon is an oral, targeted-release formulation of budesonide engineered to release the drug in the distal ileum, over the Peyer's patches thought to be a key site of IgA nephropathy pathogenesis. Locally released budesonide suppresses mucosal B-cell activation and reduces production of galactose-deficient IgA1, the aberrant antibody that forms immune complexes in the glomerular mesangium. Because budesonide undergoes extensive first-pass metabolism, systemic corticosteroid exposure stays low.
See it in motion
A schematic animation of the mechanism — simplified for clarity, not drawn to scale.
Nefecon is a capsule designed to open exactly where that faulty IgA is made, releasing its medicine onto the source instead of flooding the whole body.
- In IgA nephropathy the immune tissue of the gut overproduces a faulty form of the antibody IgA, which later lodges in the kidneys and damages them.
- The capsule releases budesonide in the ileum, the last part of the small intestine.
- Locally released budesonide suppresses mucosal B-cell activation and reduces production of galactose-deficient IgA1, the aberrant antibody that forms immune complexes in the glomerular mesangium.
- With less of the faulty IgA made, fewer immune complexes lodge in the kidneys, helping protect kidney function.
Target: Mucosal B-cell activation in Peyer's patches
The ileal mucosal immune response that produces the poorly glycosylated IgA1 driving immune-complex formation in the kidneys of people with IgA nephropathy.
Approved uses
Approved uses differ by country and change over time. Always follow your local prescribing information.
Approved uses in United States
FDA- Reduction of the loss of kidney function in adults with primary immunoglobulin A nephropathy (IgAN) who are at risk for disease progression
Approved uses in European Union
EMA- Treatment of adults with primary immunoglobulin A nephropathy (IgAN) with a urine protein excretion of at least 1.0 g/day (or urine protein-to-creatinine ratio of at least 0.8 g/g)
Official sources
The statements on this page trace back to these records.
- Kinpeygo (budesonide) — Summary of product characteristics and package leaflet, English version
European Medicines Agency
- DailyMed: TARPEYO (nefecon/budesonide) official US label
U.S. National Library of Medicine, DailyMed
- MedlinePlus: budesonide
MedlinePlus, U.S. National Library of Medicine
This page explains how the medicine works — it isn’t the patient leaflet. For anything that applies to you, read the leaflet that came with your medicine or ask your pharmacist.
MedUnfold provides educational content and is not medical advice. Always follow your local prescribing information and healthcare professional.