Clinical biopharma giant Renalys Pharma has announced that its Phase III clinical trial of sparsentan (RE-021) achieved positive topline results in Japanese patients with IgA nephropathy (IgAN), paving the way for a planned New Drug Application in Japan in 2026.

 

The study, which enrolled 35 Japanese patients, evaluated the percent change from baseline in the 24-hour urine protein-to-creatinine ratio (UPCR) after 36 weeks of oral sparsentan treatment. Sparsentan was well-tolerated, with a safety profile consistent with global trials and no new safety signals in Japanese patients.

 

BT Slingsby, Chairman, CEO, and Co-Founder of Renalys, said: "In Japan, treatment options for IgAN remain limited, and unmet medical needs are extremely high. Sparsentan has already been approved in the United States and Europe, and from the perspective of addressing the drug lag, it is imperative that we deliver this therapy to Japanese patients who need it as soon as possible."

 

Ryutaro Shimazaki, Chief Development Officer of Renalys, added: "This Phase III study in Japan was able to be conducted as a small-scale bridging study following extensive discussions with the PMDA, enabling the use of data from large-scale overseas clinical trials."

 

"The study included both adult and pediatric patients aged 10 years and older, and strong reductions in proteinuria consistent with international trial results were observed across all age groups. We extend our deepest gratitude to the patients, investigators, and all those involved in conducting this study."

 

Naoki Kashihara, President of the Japan Kidney Association, noted: "For rare kidney diseases such as IgAN, progress in developing effective therapies had long been limited. It is encouraging to see accelerated drug development in this field. Sparsentan has demonstrated strong proteinuria-lowering effects and a favorable safety profile, as shown in both large global clinical trials and this clinical study in Japanese patients."

 

"Furthermore, sparsentan is expected to have potential not only for rare kidney diseases such as FSGS and Alport syndrome but also more broadly for chronic kidney disease (CKD), which is one of the unique advantages of this therapy. Prior to this clinical study in Japanese patients, the Japanese Society of Nephrology used its large patient database to clarify the relationship between proteinuria and renal outcomes in Japanese patients with IgAN. We will continue working with related academic societies and contribute to evaluating appropriate clinical endpoints, including in international initiatives."

 

Sparsentan, an oral dual endothelin and angiotensin II receptor antagonist (DEARA) developed by Travere Therapeutics, is licensed exclusively to Renalys for development and commercialization in Japan and several other Asian territories.