Company Expects to Report Top-Line Data in December of 2016

WALTHAM, MA, USA I November 2, 2015 I Proteon Therapeutics Inc. (PRTO), a company developing novel, first-in-class therapeutics to address the medical needs of patients with kidney and vascular diseases, today announced that it has completed enrollment in PATENCY-1, the first of two Phase 3 clinical studies of investigational vonapanitase (formerly PRT-201), the company’s lead development candidate. The Company expects that top-line data from this study will be available in December of 2016.

PATENCY-1 is a multicenter, randomized, double-blind, placebo-controlled clinical study evaluating the safety and efficacy of a single administration of vonapanitase in patients with chronic kidney disease (CKD) undergoing surgical creation of a radiocephalic arteriovenous fistula (AVF) for hemodialysis. Vonapanitase, a recombinant human elastase, is an investigational drug that is intended to improve AVF patency, the period of time during which an AVF remains open with adequate blood flow to enable hemodialysis.

The study enrolled 311 patients at 31 centers in the United States. Immediately after surgical creation of a radiocephalic AVF, each patient received either 30 micrograms of vonapanitase or placebo, delivered in a single, local administration to the external surface of the AVF. The primary efficacy endpoint is primary unassisted patency, the time from AVF creation until a thrombosis or a procedure to restore or maintain patency. The secondary efficacy endpoint is secondary patency, the time from AVF creation until AVF abandonment. Patients will be evaluated for safety and efficacy outcomes for 12 months.

“Completing enrollment in the first Phase 3 study of vonapanitase ahead of schedule is a significant achievement for Proteon,” said Timothy Noyes, President and Chief Executive Officer of Proteon. “As there are no therapies currently available to prolong AVF patency, study enrollment benefited from strong interest in the physician community.”

Proteon continues to enroll patients in PATENCY-2, the second Phase 3 clinical study of vonapanitase in patients with CKD undergoing surgical creation of a radiocephalic AVF for hemodialysis. That study will enroll 300 patients at approximately 40 centers in the United States and Canada.

About Chronic Kidney Disease, Hemodialysis and Vascular Access

In the most severe stage of chronic kidney disease (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 three to four 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 United States, 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.

About Vonapanitase

Vonapanitase (formerly PRT-201) is an investigational drug intended 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 3 clinical trials in patients with chronic kidney disease (CKD) undergoing surgical creation of a radiocephalic arteriovenous fistula for hemodialysis. Vonapanitase has received fast track and orphan drug designations from the U.S. Food and Drug Administration (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 has completed a Phase 1 clinical trial in patients with symptomatic peripheral artery disease (PAD).

About Proteon Therapeutics

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 (formerly PRT-201), is an investigational drug intended to improve arteriovenous fistula (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 3 clinical trials in patients with chronic kidney disease (CKD) undergoing surgical creation of a radiocephalic AVF for hemodialysis and has completed a Phase 1 clinical trial in patients with symptomatic peripheral artery disease (PAD). For more information, please visit www.proteontherapeutics.com.

SOURCE: Proteon Therapeutics