Proteon Therapeutics, Inc. is a late-stage biopharmaceutical company, which focuses on the development of pharmaceuticals to address the needs of patients with renal and vascular disease. The Company is involved in research and development activities. The Company's product candidate, product candidate, vonapanitase, formerly PRT-201, is a recombinant human elastase that it is developing to manage vascular access failure in patients with chronic kidney disease undergoing or planning for hemodialysis, a lifesaving treatment that cannot be conducted without a functioning vascular access. The Company has completed Phase II trial of vonapanitase in patients undergoing creation of an arteriovenous fistula (AVF). The Company initiated the first of two Phase III trials, PATENCY-1, for vonapanitase in radiocephalic AVFs. Its vonapanitase product candidate is a recombinant human elastase under development as a treatment to prevent AVF and arteriovenous graft (AVG) patency loss.