Proteon Therapeutics Initiates Second Phase III Clinical Study

Proteon Therapeutics Inc. recently announced that the first patient has been treated in a second Phase III clinical study of investigational vonapanitase (formerly PRT-201), the company’s lead product candidate.

The second Phase III study complements the first Phase III study, which was initiated in July 2014 and is expected to complete enrollment by the end of 2015. Both Phase III studies are evaluating the safety and efficacy of a single treatment of vonapanitase in patients with chronic kidney disease (CKD) undergoing surgical creation of a radiocephalic arteriovenous fistula (AVF) for hemodialysis. Vonapanitase, a locally acting recombinant human elastase, is an investigational drug that may prolong the patency and reduce the failure of hemodialysis vascular access in patients with CKD.

The first patient in the second Phase III study was enrolled at Saint Luke’s Hospital of Kansas City, by Christie Wynette Gooden, MD, Clinical Assistant Professor, Department of Surgery at the University of Missouri-Kansas City School of Medicine.

“One of the greatest challenges for patients with CKD is securing reliable, consistent vascular access for hemodialysis. A radiocephalic AVF is the preferred form of vascular access, which is a hemodialysis patient’s lifeline,” said Dr. Gooden. “Radiocephalic AVFs are at risk of reduced blood flow and patency loss, which results in additional corrective procedures and reduced AVF survival. There are no approved therapies currently available to prolong AVF patency, which we will be evaluating in this clinical study.”

The second randomized, double-blind, placebo-controlled Phase III clinical trial will enroll 300 patients at approximately 40 centers in the US and Canada. Immediately after surgical creation of a radiocephalic AVF, each patient will receive either 30 micrograms of vonapanitase or placebo, delivered in a single, local administration to the external surface of the AVF. The primary efficacy endpoint, measured over 12 months, is primary patency, the time from AVF creation until a thrombosis or a procedure to restore or maintain patency. The secondary efficacy endpoint, also measured over 12 months, is secondary patency, defined as the time from AVF creation until AVF abandonment.

“Initiating the second Phase III study of vonapanitase is a significant achievement for Proteon,” said Timothy Noyes, President and Chief Executive Officer of Proteon. “Proteon has its roots in Kansas City, and I am thrilled that a local institution enrolled the first patient in this important clinical study evaluating a potential new treatment for patients requiring vascular access.”

Proteon is also conducting an ongoing Phase 1 clinical study of vonapanitase in patients with symptomatic peripheral artery disease (PAD).

In the most severe stage of CKD, also known as kidney failure, the kidneys can no longer function to sustain life. The majority of patients with kidney failure require hemodialysis and need a high-flow vascular access to repeatedly connect the patient’s bloodstream to a hemodialysis machine for this life-saving, chronic treatment: Three times per week for 3 to 4 hours each session, blood is pumped from the body and passed through a dialysis machine that removes waste and excess water normally excreted by the kidneys. The preferred form of vascular access, used by two-thirds of hemodialysis patients in the US, is an arteriovenous fistula (AVF). An AVF is created when a surgeon connects a vein to an artery, typically at the wrist or elbow, resulting in a substantial increase in blood flow and vein dilation. A radiocephalic AVF is created between the radial artery and cephalic vein at the wrist.

Vonapanitase (formerly PRT-201) is an investigational drug designed to improve arteriovenous fistula (AVF) patency, the period of time during which an AVF remains open with adequate blood flow to enable hemodialysis. Vonapanitase is applied in a single administration and is currently being studied in two Phase III clinical trials in patients with CKD undergoing surgical creation of a radiocephalic arteriovenous fistula for hemodialysis. Vonapanitase has received fast track and orphan drug designations from the US FDA, and orphan medicinal product designation from the European Commission, for hemodialysis vascular access indications. Vonapanitase may have multiple surgical and endovascular applications in which vessel injury leads to blockages in blood vessels and reduced blood flow, and is currently being evaluated in a Phase I clinical trial in patients with symptomatic PAD.

Proteon Therapeutics is committed to improving the health of patients with kidney and vascular diseases through the development of novel, first-in-class therapeutics. Proteon’s lead product candidate, vonapanitase is designed to improve AVF patency, the period of time during which an AVF remains open with adequate blood flow to enable hemodialysis. Proteon is currently evaluating vonapanitase in two Phase III clinical trials in patients with CKD undergoing surgical creation of a radiocephalic arteriovenous fistula for hemodialysis and a Phase I clinical trial in patients with symptomatic PAD. For more information, visit www.proteontherapeutics.com.