Viatris Reports Positive Phase 3 Results for VR-205 in Japanese Adults with IgA Nephropathy, Targets 2026 NDA Submission
核心洞察
VR-205 achieved a 33.75% reduction in geometric mean urine protein-to-creatinine ratio at 9 months compared to baseline [95% CI: -45.27 to -19.80; p < 0.001], meeting the primary endpoint.
The targeted-release budesonide formulation was well tolerated in Japanese patients, with a safety profile consistent with global Phase 3 studies.
No study participants progressed to dialysis, kidney transplant, or severe renal impairment by the end of the 9-month treatment period.
Viatris Inc. announced positive top-line results from a Phase 3 clinical trial evaluating VR-205, a targeted-release budesonide formulation also known as Nefecon®, in Japanese adult patients with primary immunoglobulin A nephropathy (搜索) (IgAN) at risk of developing end-stage renal disease (搜索). The company is targeting submission of a New Drug Application (NDA) in Japan by the end of 2026, a move that could bring the first IgAN-specific, targeted-release budesonide oral therapy to the country with the highest reported incidence of the disease globally.
Trial Design and Patient Population
The Phase 3 study (VR-205A-01-CAZ-3001) was a multicenter, interventional, open-label trial conducted in Japan. A total of 39 participants were enrolled and treated with 16 mg of VR-205 daily, administered as four capsules, over a nine-month treatment period. Following completion of treatment, participants entered a three-month follow-up period that included a two-week dose taper to 8 mg of VR-205 (two capsules) daily at the start of follow-up.
Efficacy Results
The study met its primary endpoint, with VR-205 demonstrating a 33.75 percent reduction in geometric mean urine protein-to-creatinine ratio (UPCR) at 9 months compared to baseline [95% CI: -45.27 to -19.80; p < 0.001]. These results were statistically significant and clinically meaningful, and were consistent with those observed in the global Phase 3 program for the product.
Beyond the primary endpoint, VR-205 demonstrated statistically significant and clinically meaningful reductions in UPCR at both 6 and 12 months. The treatment also produced significant improvements in estimated glomerular filtration rate (eGFR) and reductions in serum creatinine and urine albumin-to-creatinine ratio (UACR) at 9 months compared to baseline. The overall therapeutic benefit was further supported by improvements in microhematuria and sustained proteinuria reduction.
Notably, no study participants progressed to dialysis, kidney transplant, or severe renal impairment — defined as eGFR ≤15 mL/min per 1.73 m² — by the end of the study.
Safety Profile
VR-205 was generally well tolerated over the nine-month treatment period, with a safety profile consistent with the known safety profile of targeted-release budesonide observed in non-Japanese patients.
Executive Commentary
"We are pleased with these top-line results, which highlight VR-205 as a potentially meaningful, disease-modifying treatment option for patients with primary IgAN," said Viatris Chief R&D Officer Philippe Martin. "In Japan, where IgAN incidence is the highest globally, VR-205 could become the first IgAN-specific, targeted-release budesonide oral therapy. This progress reflects the continued execution of Viatris' strategy focused on building a differentiated and increasingly innovative portfolio in Japan, with an emphasis on delivering therapies that provide meaningful value and address significant unmet needs."
Yuko Asami, Head of R&D at Viatris Japan, added: "Primary IgAN is a designated intractable disease in Japan, and remains a significant unmet need, with no curative treatment despite the risk of progression to end-stage renal disease (搜索). These top-line results mark an important step toward expanding treatment options for patients and healthcare providers."
Disease Burden in Japan
IgAN is a progressive, immune-mediated kidney disease and the most common primary glomerulonephritis worldwide. Japan reports the highest incidence rates globally, at 39 to 45 cases per million population per year, with peak age at diagnosis between 30 and 39 years. In Japan, adult-onset IgAN progresses to end-stage renal disease (搜索) — requiring dialysis or transplantation — in approximately 15–20 percent of patients within 10 years. Chronic glomerulonephritis, with IgAN as a leading underlying cause, accounts for 23.4 percent of Japan's more than 340,000 dialysis patients. The total national cost of maintenance hemodialysis in Japan is approximately JPY 1.5 trillion per year.
Regulatory and Commercial Context
In 2022, Calliditas Therapeutics AB and Viatris Pharmaceuticals Japan Inc., a subsidiary of Viatris Inc., entered into an exclusive license agreement to obtain marketing authorization and commercialize VR-205 for the treatment of primary IgAN in Japan. The drug is currently approved and marketed as Tarpeyo® in the U.S. and as Kinpeygo® in Europe as a specialty drug. Viatris is now targeting an NDA submission in Japan by the end of 2026.