United Therapeutics Corporation Files Lawsuit Alleging Infringement of Tyvaso Patent Already Found to Be Invalid by U.S. Patent Office

(NASDAQ: LQDA) (Liquidia or the Company), announced today that United Therapeutics Corporation (UTHR) filed a patent infringement action under the Hatch-Waxman Act in the U.S. District Court for the District of Delaware (District Court) asserting infringement of U.S. patent No. 10,716,793 (‘793 patent) in response to Liquidia’s amendment to add the PH-ILD indication to the tentatively approved New Drug Application (NDA) for YUTREPIA™ (treprostinil) inhalation powder. The ‘793 patent was previously found to be unpatentable by the PTAB in an inter partes review (IPR) in July 2022, a decision that was reaffirmed by the PTAB in February 2023.

Dr. Roger Jeffs, Chief Executive Officer of Liquidia, said: “Our focus is and will always be on bringing better therapies and treatment options to patients. While we are disappointed that United Therapeutics has elected to file this lawsuit alleging that YUTREPIA infringes this same patent that has already been litigated and already found by the PTAB to be invalid, it was expected. We will use the same aggressive and dedicated approach to defending this lawsuit as we have used in successfully resolving prior litigation that has been brought against us by United Therapeutics.”

The ‘793 patent asserted in this litigation will trigger and support an automatic regulatory stay on the FDA’s final approval of YUTREPIA. The regulatory stay for final approval would last until the earlier of either (1) resolution of the lawsuit in Liquidia’s favor with respect to the ‘793 patent, or (2) 30 months after the date in July 2023 when United Therapeutics received notice of Liquidia’s Paragraph IV certifications in connection with the amendment to the NDA.

In the prior lawsuit in which the ‘793 patent was asserted against Liquidia, the District Court ruled against Liquidia in August 2022 finding that all of the asserted claims of the ‘793 patent were both valid and infringed based on the arguments presented by Liquidia to the District Court. That decision was recently affirmed by the Court of Appeals for the Federal Circuit (Federal Circuit). However, if the Federal Circuit affirms the PTAB’s decision in the ‘793 IPR currently under appeal, then the entire ‘793 patent would be invalidated and the ‘793 patent would no longer be a barrier to final approval of YUTREPIA. The appeal of the PTAB decision is expected to be completed in the fourth quarter of 2023 or the first half of 2024.