Proteon Therapeutics

Proteon Therapeutics, Inc. was a biopharmaceutical firm established in 2001 by Dr. F. Nicholas Franano, based on technology developed at Johns Hopkins University. The company focused on creating pharmaceuticals for patients with kidney and vascular diseases. Its primary business was the development and clinical testing of its lead product candidate, vonapanitase (formerly PRT-201). This drug, a recombinant human elastase, was designed for single-dose application during vascular surgery to improve blood flow and the longevity of arteriovenous fistulas for hemodialysis patients.

The company's operations were heavily centered on research and development, funded by significant venture capital investments totaling over $72 million from firms like MPM Capital, Rockhill Partners, and TVM Capital. A major milestone occurred in 2009 when the company secured an option agreement to be acquired by Novartis for up to $550 million, though this was not ultimately exercised. Proteon went public with an IPO in 2014, trading on the Nasdaq under the symbol PRTO. The business model was contingent on the successful commercialization of vonapanitase, targeting a critical unmet need in chronic kidney disease treatment. The intended market was patients requiring hemodialysis, a segment where vascular access failure leads to high morbidity and healthcare costs.

Despite promising early trial results and receiving Fast Track and Orphan Drug designations from the FDA, vonapanitase failed to meet its primary endpoints in two separate Phase 3 clinical trials, PATENCY-1 and PATENCY-2, in 2016 and 2019 respectively. These setbacks led to a dramatic drop in the company's stock price and a strategic decision to halt further development of the drug. In September 2019, facing limited options, Proteon Therapeutics entered into a definitive merger agreement with ArTara Therapeutics, a private biopharmaceutical company. The all-stock transaction was completed in January 2020, resulting in the formation of a new entity operating as ArTara Therapeutics (now Protara Therapeutics) and focusing on ArTara's pipeline of rare and specialty disease treatments.

Keywords: biopharmaceutical, kidney disease, vascular disease, vonapanitase, clinical trials, arteriovenous fistula, hemodialysis, reverse merger, ArTara Therapeutics, drug development