WALTHAM, Mass., Jan. 4, 2013 /PRNewswire/ -- Proteon Therapeutics, Inc., a private biopharmaceutical company developing novel, first-in-class pharmaceuticals to address the critical medical needs of patients with kidney and vascular diseases, today announced results from its Phase 2 clinical trial of PRT-201 in chronic kidney disease (CKD) patients undergoing surgical placement of an arteriovenous fistula (AVF) in preparation for hemodialysis. The Phase 2 results demonstrated that treatment with PRT-201 prolonged primary unassisted patency and improved the rate of AVF maturation. Additionally, PRT-201 was well tolerated at the doses tested. The arteriovenous fistula is the optimal form of vascular access for hemodialysis patients because it is associated with reduced morbidity and lower costs. However, AVFs frequently suffer from neointimal hyperplasia and stenosis formation, resulting in maturation failure and loss of patency. "AVF patency loss and non-maturation are significant problems, necessitating multiple endovascular (angioplasty) and surgical procedures to restore or maintain blood flow and resulting in prolonged use of dialysis catheters, which have a very high rate of infection. This results in poorer outcomes and significantly increases morbidity and cost," said Dr. Prabir Roy-Chaudhury, Professor of Medicine at the University of Cincinnati, Academic Health Center, Cincinnati, OH. "In this context, the safety and efficacy results of this Phase 2 study are very encouraging and warrant further evaluation of PRT-201 in this patient population." The randomized, double-blind, placebo-controlled Phase 2 study evaluated the safety and efficacy of PRT-201 delivery immediately following surgical creation of an AVF. A total of 151 patients were randomized to one of two doses of PRT-201, or placebo. The primary endpoint was the duration of unassisted primary patency, defined as the time from surgical creation of the AVF until thrombosis or the occurrence of a procedure to maintain or restore patency (e.g., balloon angioplasty). AVF maturation was a secondary efficacy endpoint.