Courts clear hurdles for Liquidia's Yutrepia, potentially allowing for new rival to United's PAH franchise

With one injunction lifted and another denied late last week in lawsuits filed by United Therapeutics, rival Liquidia Corporation says the FDA has clearance to approve its pulmonary arterial hypertension (PAH) treatment Yutrepia.

Thursday in U.S. District Court in Delaware, in United’s original patent case against Liquidia, Judge Richard Andrews removed an injunction that had prohibited the FDA from approving Yutrepia. United has appealed the decision.

A day later, in federal court in Washington, D.C., Judge John Bates denied a motion for a temporary restraining order in litigation filed by United against the FDA.

The decisions came shortly before the expiration on Sunday of United’s regulatory exclusivity for its PAH blockbuster Tyvaso (treprostinil) to treat pulmonary hypertension associated with interstitial lung disease (PH-ILD). The developments could spell the end of the short reign of exclusivity for United’s successful dry powder inhaler (DPI) formulation of the drug.

The new version of Tyvaso was approved in May of 2022 and accounted for 59% ($731 million) of the franchise's sales of $1.23 billion last year. Tyvaso DPI sparked United to a company record of $2.33 billion in revenue in 2023, a 20% increase from 2022.

The FDA accepted Liquidia’s application for a dry powder version of treprostinil in 2020 and then rejected it with a complete response letter seven months later. A year later, the FDA granted tentative approval to Yutrepia.

Last year, the FDA accepted Liquidia’s amendment to the filing which sought the addition of a second indication, pulmonary hypertension associated with interstitial lung disease (PH-ILD).

That prompted United to sue the FDA, claiming that the regulator allowed Liquidia to sidestep “rules, precedents and procedures” in accepting the amendment. United contended that the FDA should have required Liquidia to submit an entirely separate application to treat PH-ILD.

“Our commercial team is fully prepared to launch Yutrepia in both PAH and PH-ILD should the FDA grant final approval," Roger Jeffs, CEO of Liquidia, said in a release. "Once launched, we are confident that Yutrepia’s convenient, low-effort delivery and wide dosing range will propel the therapy towards our goal of establishing Yutrepia as the prostacyclin of first choice.”

United did not respond immediately to a request for comment.

The company has filed an additional lawsuit against Liquidia in federal court in Delaware alleging that Yutrepia would infringe a patent that was issued in November of last year. United has filed for another preliminary injunction in that case which would prevent Liquidia from launching Yutrepia for PH-ILD.