As of January 9, 2020, Proteon Therapeutics, Inc. was acquired by ArTara Therapeutics, Inc., in a reverse merger transaction. Proteon Therapeutics, Inc., a late-stage biopharmaceutical company, focuses on the development of pharmaceuticals to address the needs of patients with renal and vascular disease. Its lead product candidate is vonapanitase, an investigational drug intended to enhance hemodialysis vascular access outcomes. The company develops vonapanitase, a recombinant human elastase, which has completed Phase II and Phase III clinical trials for patients with chronic kidney disease. It is also evaluating vonapanitase in a Phase I clinical trial in patients with peripheral artery disease. The company was founded in 2001 and is based in Waltham, Massachusetts.