Liquidia shares plunged nearly 50% Wednesday after the U.S. District Court for the District of Delaware ruled that YUTREPIA infringed two foundational claims of United Therapeutics’ U.S. Patent No. 11,826,327. The upheld claims cover treating pulmonary hypertension associated with interstitial lung disease, or PH-ILD, with inhaled treprostinil and certain dry-powder delivery features; the court invalidated four other asserted claims. In a related order, the court denied Liquidia’s motion to strike evidence concerning United Therapeutics’ patent ownership, finding that Liquidia had adequate notice before trial and did not object in time. United Therapeutics shares rose 12.3% to $540.54, while Liquidia was on track to lose about $3.18 billion in market value if the decline held. Liquidia CEO Roger Jeffs said the company disagrees with the decision and will pursue appellate options. Liquidia also plans to ask the FDA to remove PH-ILD from YUTREPIA’s label. The parties must submit a proposed judgment, including remedies, within one week, and United Therapeutics has sought injunctive relief that could restrict YUTREPIA’s availability. YUTREPIA was approved in 2025 for pulmonary arterial hypertension and PH-ILD.