Proteon Therapeutics Studies Investigational Vonapanitase to Treat Symptomatic PAD

August 21, 2015—Proteon Therapeutics Inc. recently announced top-line results from its phase 1 study of investigational vonapanitase in patients with symptomatic peripheral artery disease (PAD). The study evaluated the safety and technical feasibility of a single treatment of vonapanitase via a drug-delivery catheter on atherosclerotic human arteries. Vonapanitase (formerly PRT-201) is an investigational recombinant human elastase drug that is designed to improve arteriovenous fistula (AVF) patency for hemodialysis. It is applied in a single administration. 

According to Proteon Therapeutics, the data indicate that catheter-based treatment with vonapanitase was generally well tolerated and technically feasible. The company stated that it is conducting a full analysis of safety and technical feasibility data from the study, and expects that complete data from the phase 1 study will be presented at an upcoming medical meeting.

The open-label, single-center, phase 1, dose-escalation study enrolled 14 patients being treated with balloon angioplasty for symptomatic PAD of the superficial femoral or popliteal artery. Immediately after successful angioplasty, vonapanitase was delivered to the arterial wall using an endovascular microinfusion catheter. 

Christopher D. Owens, MD, was the Principal Investigator for the study. Dr. Owens is Associate Professor of Surgery for the Division of Vascular and Endovascular Surgery at the University of California San Francisco.

In the company’s press release, Dr. Owens commented, “There is a significant unmet medical need to improve results in patients with symptomatic PAD. The safety and technical feasibility results of this phase 1 study are encouraging, and merit further study of vonapanitase in patients with PAD to explore whether vonapanitase will demonstrate efficacy in the improvement of symptomatic PAD results.”

The company noted that this is the sixth clinical study evaluating vonapanitase. There are currently two phase 3 clinical studies of vonapanitase in patients with chronic kidney disease (CKD) undergoing surgical creation of a radiocephalic AVF for hemodialysis. The company previously completed three clinical studies evaluating vonapanitase in patients with CKD undergoing surgical creation of an AVF or arteriovenous graft for hemodialysis.

Vonapanitase has received fast track and orphan drug designations from the US Food and Drug Administration and orphan medicinal product designation from the European Commission for hemodialysis vascular access indications, stated Proteon Therapeutics.

In January 2015, the company announced the publication of nonclinical data from an ex vivo study that evaluated the effect of a single treatment of vonapanitase on atherosclerotic human arteries. Steven K. Burke, MD, et al published the findings in the Journal of Cardiovascular Pharmacology (2014;64:530–535). Dr. Burke is Proteon’s Senior Vice President and Chief Medical Officer.