Viatris announces positive Phase 3 results for VR-205 (Nefecon®) in Japanese IgA nephropathy patients, showing significant proteinuria reduction and kidney protection. NDA planned for 2026
Written By: Farha Farheen, PharmD
Reviewed By: Pharmacally Editorial Team
Viatris Inc. has announced positive top-line results from a Phase 3 clinical trial evaluating VR-205 (targeted-release budesonide 16 mg, also known as Nefecon®) in Japanese adults with primary Immunoglobulin A Nephropathy (IgAN).
IgAN is a progressive immune-mediated kidney disease that can lead to end-stage renal disease (ESRD) and remains a significant healthcare challenge in Japan, which has the highest incidence of the disease worldwide.
Phase 3 Trial Met Primary Endpoint
The multicenter, open-label Phase 3 study (Study VR-205A-01-CAZ-3001) enrolled 39 adult patients with primary IgAN who were at risk of progressing to ESRD. Participants received a daily dose of 16 mg VR-205 for nine months, followed by a three-month observation period that included a two-week dose-tapering phase.
The trial successfully met its primary endpoint, demonstrating a statistically significant 33.75% reduction in urine protein-to-creatinine ratio (UPCR) at nine months compared with baseline (95% CI: -45.27% to -19.80%; p<0.001). Since proteinuria is a key marker of kidney damage and disease progression, these findings indicate a meaningful clinical benefit for patients.
Secondary Endpoints Showed Sustained Kidney Benefits
The positive results closely aligned with findings from previous global Phase 3 studies, further confirming the efficacy of VR-205. Beyond the primary endpoint, the treatment produced sustained reductions in proteinuria through 12 months and demonstrated improvements across several important secondary endpoints. Patients experienced better estimated glomerular filtration rate (eGFR), lower urine albumin-to-creatinine ratio (UACR), reduced serum creatinine levels, and improvements in microhematuria.
No participants progressed to dialysis, kidney transplantation, or severe renal impairment, defined as an eGFR below 15 mL/min/1.73 m², during the treatment period.
Safety Profile and Regulatory Plans
VR-205 was generally well tolerated, with a safety profile consistent with previous studies conducted in non-Japanese populations. These findings support the potential of the therapy as a disease-modifying treatment capable of slowing disease progression and preserving kidney function.
Philippe Martin, Chief Research and Development Officer at Viatris, stated that the positive data reinforce the potential of VR-205 to address a major unmet need in IgAN. He noted that, if approved, the therapy could become the first IgAN-specific targeted-release budesonide oral treatment available in Japan, representing an important milestone for patients living with this chronic kidney disease.
Yuko Asami, Head of Research and Development at Viatris Japan, highlighted that primary IgAN is recognized as a designated intractable disease in Japan and continues to pose a substantial burden on patients and the healthcare system. She emphasized that the encouraging Phase 3 results represent a significant step toward expanding treatment options and improving long-term outcomes for patients.
Viatris is aiming to submit a New Drug Application (NDA) in Japan by the end of 2026.
Licensing Agreement and Global Availability
The development of VR-205 stems from an exclusive licensing agreement signed in 2022 between Calliditas Therapeutics AB and Viatris Pharmaceuticals Japan Inc. The therapy is already approved and marketed as Tarpeyo® in the United States and Kinpeygo® in Europe. Given the limited availability of treatments that target the underlying cause of IgAN, the positive Phase 3 findings offer renewed hope for patients at risk of kidney failure and highlight the potential of VR-205 to transform the management of IgAN in Japan.
What This Means for Patients
The positive Phase 3 results indicate that VR-205 may offer a promising new treatment option for patients with primary IgA nephropathy. By significantly reducing proteinuria and improving key measures of kidney function, the therapy has the potential to slow disease progression and help preserve long-term kidney health. Importantly, no patients in the study progressed to dialysis, kidney transplantation, or severe renal impairment during treatment. If approved in Japan, VR-205 could become the first IgAN-specific targeted-release budesonide therapy available, providing a disease-focused approach that may help delay or prevent progression to end-stage renal disease.
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About the Writer
Farha Farheen, PharmD (LinkedIn) is a pharmacy professional with a strong interest in pharmacovigilance and clinical research. She has completed her Doctor of Pharmacy (Pharm.D) along with her internship as a Clinical Pharmacist. She has hands-on experience in adverse drug reaction (ADR) reporting, safety data documentation, and pharmacovigilance workflows, and is proficient in using VigiFlow. She is also a patent holder for an antibacterial formulation enriched with bioactive substances, granted by the German Patent and Trademark Office.