Abstract: INFO14-TH
Investigating Extended Nefecon Treatment Beyond Nine Months in Patients with IgAN: The Phase 4 NefXtend Trial
Session Information
- Informational Posters - 1
November 06, 2025 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- No subcategory defined
Authors
- Lafayette, Richard A., Stanford University School of Medicine, Stanford, California, United States
- Jones, Russell, Calliditas Therapeutics AB, Stockholm, Stockholm County, Sweden
- Mitchev, Krassimir, Calliditas Therapeutics AB, Stockholm, Stockholm County, Sweden
Description
Nefecon is an oral, targeted-release budesonide formulation approved for immunoglobulin A nephropathy (IgAN). Approval was based on the Phase 3 NefIgArd trial, which assessed urine protein–creatinine ratio (UPCR) and estimated glomerular filtration rate (eGFR) with nefecon 16 mg/day vs placebo over 9 months, followed by 15 months off treatment. The Phase 4 NefXtend open-label, multicenter trial (NCT06712407) aims to evaluate the efficacy and safety of extended nefecon treatment to 2 years in patients with IgAN.
We plan to enroll up to 60 participants across 40 US sites (currently recruiting). Inclusion criteria: ≥18 years old; biopsy-confirmed IgAN; ongoing 9-month commercial nefecon treatment (16 mg/day); proteinuria ≥0.5 g/day or UPCR ≥0.3 g/g; ≥8 weeks stable, ongoing renin–angiotensin system inhibitor treatment. Patients on a stable dose of sodium-glucose co-transporter-2 inhibitors will be eligible. Exclusion criteria: systemic immunosuppressive medications during commercial nefecon treatment; other glomerular diseases; current or planned dialysis; previous kidney transplantation; poorly controlled diabetes or hypertension.
After a 1-month screening period during Month 9 of commercial nefecon treatment, participants will seamlessly transition to a 6-month trial period of nefecon 16 mg/day followed by 9 months of nefecon 8 mg/day. They will then enter a 3-month follow-up, including a 2-week tapering period on nefecon 4 mg/day before treatment cessation (Figure).
The primary endpoint is the ratio of UPCR after 6 months of extended treatment vs baseline (completion of 9-month commercial nefecon treatment). Safety outcomes include adverse events (AEs), serious AEs, and AEs of special interest (steroid effects, infections).
This trial will evaluate whether extending nefecon treatment to 2 years may provide additional, better-sustained proteinuria reduction and more complete kidney function preservation vs only 9 months of treatment in patients with IgAN.
Funding
- This study was funded by Calliditas Therapeutics AB. Medical writing assistance was provided by Ushani Srenathan, of HCG, London, UK, with financial support from Calliditas Therapeutics AB and in accordance with the 2022 Good Publication Practice guidelines (https://www.ismpp.org/gpp-2022).