Proteon Therapeutics Inc. closed a private placement of 22,000 of its series A convertible preferred stock, for gross proceeds of $22 million.

The company sold the preferred stock to a syndicate of existing and new investors led by Deerfield Management. Abingworth, Fairmount Funds, Intersouth Partners, Perceptive Advisors, Pharmstandard, RA Capital, Skyline Ventures and TVM Capital also participated in the transaction.

The 22,000 shares of preferred stock are convertible to 22,112,775 common shares, equivalent to an initial conversion price of 99.49 cents apiece.

Proteon Therapeutics plans to use proceeds to complete its ongoing Patency-2 trial and fund continued market access activities. The financing also extends the company's cash runway to the fourth quarter of 2019.

Additionally, Deerfield Management partner Jonathan Leff joined Proteon Therapeutics' board as the preferred stockholders' designee.