 Liquidia Technologies, Inc. LQDA, a late-stage clinical biopharmaceutical company focused on the development and commercialization of novel products utilizing its proprietary PRINT technology, today announced that United Therapeutics Corporation UTC filed a patent infringement action under the Hatch-Waxman Act against the Company in the U.S. District Court for the District of Delaware asserting infringement of U.S. Patent Nos. This lawsuit is in response to the New Drug Application NDA the Company filed with the U.S. Food and Drug Administration FDA requesting approval to market LIQ861, a dry powder inhalation of treprostinil for the treatment of PAH. 