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Liquidia slumps after US court rules for United Therapeutics in patent fight

By Thomson Reuters Sep 30, 2026 | 2:41 PM

Sept 30 (Reuters) – Liquidia shares plunged nearly 50% on Wednesday after a federal judge ruled that its lung drug infringes key patent held by rival United ​Therapeutics, dealing a major blow to the treatment’s commercial ‌outlook.

The US District Court for the District of Delaware found that Liquidia’s dry-powder drug, Yutrepia, infringed two foundational claims of United Therapeutics’ ‘327 patent.

The patent covers methods of treating pulmonary hypertension-associated interstitial lung disease, or PH-ILD, ‌using ​inhaled treprostinil and certain dry-powder delivery ⁠features.

In a related order, ⁠the court denied Liquidia’s motion to throw out evidence regarding United Therapeutics’ patent ownership, ruling that Liquidia had received adequate notice before trial and failed to make timely objections.

“This ​is a key element of the case for Liquidia, and denial of the motion to strike has negative readthrough ⁠to the final decision on the ⁠case,” said Raymond James analyst Ryan Deschner.

The decision ​strengthens legal protections for United Therapeutics’ blockbuster inhalation treatment, Tyvaso. ​Its shares jumped 12.3% to $540.54 on the ruling.

Leerink Partners ‌analysts said the court ruling gives United Therapeutics what looks like a “‘win’, essentially” by confirming that Yutrepia infringes a “valid UTHR patent.” While, RBC Capital Markets analyst Lisa Walter said it “significantly ⁠clouds the path” for Yutrepia to compete.

“We respectfully disagree with the court’s decision … and are fully prepared to pursue all available appellate ⁠options,” Liquidia CEO ‌Roger Jeffs said in a statement.

Liquidia, Jeffs ⁠said, plans to ask the US FDA to ​remove ‌the PH-ILD indication from Yutrepia’s label.

Shares of ​Liquidia hit their ⁠lowest level in nearly four months, putting the company on track to lose about $3.18 billion from its market value, if losses hold.

A final judgment is expected in about a week, analysts said.

(Reporting by Christy Santhosh and Kamal Choudhury in Bengaluru; Editing ​by Shilpi Majumdar)