United Therapeutics (NASDAQ:UTHR) has filed a lawsuit in a Delaware district court against Liquidia Technologies (NASDAQ:LQDA) for infringement of the following patents relating to the company's Tyvaso (treprostinil) Inhalation Solution: U.S. Patent Nos. 9,604,901 and 9,593,066, both of which expire in December 2028.
The lawsuit is based on an NDA by Liquidia seeking marketing approval for LIQ861, a dry powder inhalation formulation of treprostinil.
In April 2020, UTHR received a notification letter from Liquidia indicating that its NDA contains a certification alleging that LIQ861 will not infringe any of the patents then listed in the Orange Book for Tyvaso, as those patents are not valid, not enforceable, and/or will not be infringed by the commercial manufacture, use, or sale of LIQ861.
In March 2020, Liquidia filed petitions for inter partes review seeking to invalidate the '901 and '066 patents.
United Therapeutics filed lawsuit within 45 days of receipt of notice. As a result, under the Hatch-Waxman Act, the FDA is automatically precluded from approving Liquidia's NDA for up to 30 months or until the resolution of the litigation, whichever occurs first.
