Retrophin’s sparsentan succeeds in phase 2 study in rare kidney disorder

Sparsentan was tested on 109 patients with FSGS, which is a rare kidney disorder that leads to end-stage renal disease.

Patients treated with 200, 400 and 800 mg/day of sparsentan (n=64) showed a mean reduction of proteinuria from baseline of 44.8% after eight weeks of treatment compared to 18.5% for those (n=32) receiving 300 mg/day of irbesartan (p=0.006).

The 400 mg and 800 mg sparsentan cohorts also demonstrated superiority to 300 mg of irbesartan, 47.4% vs. 19.0%

However, each of the individual doses of sparsentan did not achieve statistically significant improvement over irbesartan, despite clear indications of relative benefit, Retrophin said.

The company intends to present the data at an upcoming medical conference or submit it for publication.

Retrophin CEO Stephen Aselage said:  "We are very pleased with the robust top-line results from DUET, which suggest sparsentan could be a significant advancement in the treatment of FSGS.

"FSGS patients today face poor outcomes with limited medical options; we look forward to working with the FDA to find the most expeditious path forward that would deliver the first approved pharmacologic treatment to the FSGS community."

Sparsentan's dual mechanism of action unites angiotensin receptor blockade with endothelin receptor type A blockade.

Last year, the US Food and Drug Administration and European Commission each granted sparsentan orphan drug designation for the treatment of FSGS.