The Yutrepia patent ruling delivered a decisive win to United Therapeutics on Wednesday, September 30, 2026. The U.S. District Court for the District of Delaware found that Liquidia’s pulmonary hypertension drug Yutrepia infringes two valid claims of United Therapeutics’ ‘327 patent. Liquidia’s shares plunged on the decision, while United Therapeutics stock rallied.
The court held that claims 1 and 14 of the patent are valid and infringed, and it found the four other asserted claims invalid. Liquidia says it disagrees with the outcome, plans to appeal and intends to ask the FDA to remove the interstitial lung disease indication from Yutrepia’s label.
What the Court Decided in the Yutrepia Patent Case
The ruling concerns U.S. Patent No. 11,826,327, titled “Treatment for Interstitial Lung Disease.” The patent covers treating pulmonary hypertension associated with interstitial lung disease (PH-ILD) with inhaled treprostinil, including dry-powder formulations. United Therapeutics asserted six claims against Liquidia in the case before Judge Richard G. Andrews. Two of them, claims 1 and 14, were found valid and infringed. The other four were found invalid.
Infringement was effectively settled before the decision. According to Bloomberg Law, Liquidia conceded before a June 2025 bench trial that Yutrepia infringes claims 1 and 14, which left only validity for the court to decide. The judge rejected Liquidia’s challenges to those two claims.
Liquidia Shares Plunge While United Therapeutics Rallies
Investors reacted immediately. According to Yahoo Finance data published with an Investing.com report, Liquidia shares fell by more than half during Wednesday’s session, while United Therapeutics shares rose by more than 13%. Intraday moves change, so closing figures may differ.
Liquidia told investors it cannot estimate the range of possible outcomes or its financial exposure, citing the potential for appeals and further proceedings.
What Happens Next for Yutrepia
The court has directed both sides to submit a proposed form of judgment, including the remedy, within one week. United Therapeutics asked for injunctive relief in its post-trial briefs, a step that could limit the availability of Yutrepia. Liquidia has said possible remedies range from removing the PH-ILD indication from Yutrepia’s label to broader restrictions on the product.
Liquidia chief executive Roger Jeffs said the company will pursue appellate options and plans to file a supplement to Yutrepia’s New Drug Application asking the FDA to remove PH-ILD from the label. Yutrepia (treprostinil) inhalation powder won FDA approval in 2025 for pulmonary arterial hypertension and PH-ILD. The patent claims upheld by the court relate to PH-ILD.
Background: A Long-Running Patent Fight
United Therapeutics sued under the Hatch-Waxman Act, the law that governs patent disputes over follow-on drugs. Its earlier claims over a different patent, the ‘793 patent, were dropped in February 2024 after the Federal Circuit affirmed a finding by the Patent Trial and Appeal Board that the ‘793 patent is unpatentable, according to Liquidia’s annual report. United Therapeutics then pressed its case on the ‘327 patent, which targets the PH-ILD use.
In May 2024 the same court weighed a request to block the PH-ILD launch at the preliminary stage and concluded that United Therapeutics had not shown that Liquidia’s obviousness challenge lacked substantial merit. The final ruling went the other way on validity for claims 1 and 14. Separately, Liquidia disclosed that United Therapeutics filed a complaint in May 2025 over another patent, the ‘782 patent.
Why the Yutrepia Patent Ruling Matters
For patients with PH-ILD, the case is about access to inhaled treprostinil options. If Yutrepia’s PH-ILD indication is removed or restricted, clinicians may have fewer dry-powder choices for that group. The practical effect will depend on the remedy the court orders and on whether any restriction is paused during an appeal.
For the industry, the decision shows how method-of-use patents can shape follow-on competition even after a drug wins FDA approval. A company can hold approval for an indication and still face limits if a court finds a valid patent covers that use. Appeals to the Federal Circuit usually take time, so uncertainty is likely to continue.
For related regulatory and pharmaceutical coverage, read our reports on the FDA’s expedited IND pilot and the FDA approval of Mirum’s Atebrioz, or browse our pharmaceutical news section.
Key Facts at a Glance
- Ruling date: September 30, 2026, U.S. District Court for the District of Delaware
- Patent: U.S. Patent No. 11,826,327, covering inhaled treprostinil for PH-ILD
- Outcome: claims 1 and 14 valid and infringed; four other asserted claims invalid
- Drug: Yutrepia (treprostinil) inhalation powder, approved in 2025 for PAH and PH-ILD
- Next step: proposed form of judgment and remedy due within one week
- Liquidia response: appeal planned, plus an FDA supplement to remove PH-ILD from the label
- Market reaction: Liquidia down by more than half, United Therapeutics up more than 13%
Frequently Asked Questions About the Yutrepia Patent Ruling
What did the court rule about Yutrepia?
The Delaware court found that claims 1 and 14 of United Therapeutics’ ‘327 patent are valid and infringed by Liquidia’s Yutrepia. It found the four other asserted claims invalid.
Does the ruling stop Yutrepia sales?
Not yet. The remedy has not been set. Both sides must propose a judgment within a week, and United Therapeutics has asked for an injunction. Liquidia says outcomes could range from a label change to broader restrictions.
What is Liquidia doing in response?
Liquidia says it disagrees with the ruling on claims 1 and 14 and will pursue appellate options. It also plans to ask the FDA to remove the PH-ILD indication from Yutrepia’s label.
What does the ‘327 patent cover?
The patent covers treating pulmonary hypertension associated with interstitial lung disease using inhaled treprostinil, including dry-powder formulations.
This report is based on court-ruling coverage and company disclosures, and details may change as the remedy is decided. It is for information only and is not investment advice.