Apparently they misled investors about their anticoagulant drug in order to raise money to fund the Brilacidin trials.
snip> The April 2011 stock offering was designed primarily to fund another PolyMedix experimental compound, called PMX-30063, that is intended to treat bacterial skin infections, according to the suit. The plaintiffs called that compound “the company’s only remaining chance at redemption.” The suit seeks "tens of millions of dollars" allegedly lost by investors who purchased PolyMedix stock between March 7, 2011, and May 10, 2012. The complaint brings claims under the Securities and Exchange Act of 1934. <snip