WALTHAM, Mass., Nov. 10, 2016 (GLOBE NEWSWIRE) -- Proteon Therapeutics, Inc. (Nasdaq:PRTO), a company developing novel, first-in-class therapeutics to address the medical needs of patients with kidney and vascular diseases, today announced the first patient was dosed in a Phase 1 clinical study evaluating a single administration of investigational drug vonapanitase delivered immediately following angioplasty to patients with peripheral artery disease (PAD). "While angioplasty can provide short-term symptom relief for patients with PAD below the knee, the procedure lacks durability, often resulting in return of symptoms and repeat interventions. There is a substantial need for new therapies that could improve the outcomes associated with angioplasty procedures, and I look forward to evaluating the potential of vonapanitase in this study," said Jihad A. Mustapha, M.D., F.A.C.C., F.S.C.A.I., Director of Cardiovascular Research at Metro Health Hospital, and the study's lead investigator. The multicenter, randomized, double-blind, placebo-controlled, dose-escalation Phase 1 study will enroll up to 40 patients with PAD undergoing angioplasty of an artery below the knee. Immediately following angioplasty, patients will receive a single administration of either vonapanitase or placebo via a drug-delivery catheter, the Bullfrog® Micro-Infusion Device developed and manufactured by Mercator MedSystems. The study will assess the safety and technical feasibility of vonapanitase administration and will also capture exploratory outcome measures. The Company previously reported the successful completion of a Phase 1 study examining the safety and technical feasibility of administering vonapanitase via the Bullfrog Micro-Infusion Device to patients undergoing angioplasty of an artery above the knee. Nonclinical studies suggest that vonapanitase, a recombinant human elastase, fragments elastin fibers in blood vessel walls without affecting collagen, which preserves vessel strength. These studies also demonstrated that vonapanitase treatment at sufficient concentrations caused substantial elastin fragmentation in the vessel wall, resulting in acute, localized, permanent arterial dilation.