Yutrepia® (treprostinil inhalation powder)
Case Name: Liquidia Techs., Inc. v. FDA, No. 24-2428 (D.D.C. Feb. 27, 2025) (Kelly, J.)
Drug Product and Patent(s)-in-Suit: Yutrepia® (treprostinil inhalation powder)
Nature of the Case and Issue(s) Presented: On January 24, 2020, Liquidia filed a 505(b)(2) NDA for its proposed drug Yutrepia®, a treprostinil inhalation powder. Liquidia’s NDA referenced Tyvaso®, but while Liquidia’s NDA was pending, UTC filed a 505(b)(2) NDA for its own treprostinil inhalation powder, Tyvaso DPI®, which FDA approved on May 23, 2022. UTC’s NDA for Tyvaso DPI® including five clinical studies: TRIUMPH I and INCREASE, submitted with the original Tyvaso® NDA; MKC-475-001, characterizing the pharmacokinetics of Tyvaso DPI®; BREEZE, designed to evaluate the “safety and tolerability” of Tyvaso DPI®, while also assessing pharmacokinetics; and TIP-PH-102, which was the pivotal bioavailability study.
Subsequent to approval, FDA determined that Tyvaso DPI® qualified for a 3-year exclusivity because the NDA included a new clinical investigation (other than a bioavailability study) that was essential to approval. This was the BREEZE study. FDA concluded that the three-year exclusivity period precluded approval of Liquidia’s Yutrepia® NDA. The court affirmed that conclusion.
Why FDA prevailed: The NDA for Tyvaso DPI® did not contain a new active moiety, meaning it was eligible for exclusivity only if it contained a new clinical investigation (other than bioavailability studies) that were essential to the approval of the NDA. FDA found that Tyvaso DPI® was eligible for exclusivity based on the BREEZE study.
First, the court found that BREEZE was a clinical investigation, other than a bioavailability study. While bioavailability was relevant for some secondary endpoints, the court agreed that BREEZE was not solely a bioavailability study. Importantly, the court explained that under the relevant statute, a bioavailability study is a study that is primarily intended to study bioavailability and a study with a secondary, bioavailability-related purpose does not transform it into a “bioavailability study.” The court explained that FDA did not depart from an alleged prior determination that BREEZE was a bioavailability study. In particular, Liquidia identified an FDA document characterizing BREEZE as a bioavailability study. The court explained, however, that this was only an internal report, and, regardless, the next sentence of the study stated that BREEZE examined safety and tolerability.
Second, the court found that FDA was correct to determine that BREEZE was a new clinical investigation. Under FDA regulations, to be “new,” a “clinical investigation” must meet two requirements: FDA cannot have previously relied on the results of that investigation when considering a prior drug product, and the investigation cannot merely “duplicate the results” of a prior investigation. Liquidia only challenged the second element, arguing that BREEZE merely duplicated the studies leading to the approval of Tyvaso®. The court disagreed and found that the BREEZE study was materially different than any prior clinical study because none involved dry-powder inhaled treprostinil.
Third, the court found that FDA was correct to conclude that BREEZE was essential to the approval of Tyvaso DPI®. A clinical investigation is “essential to approval” when “there are no other data available that could support approval of the NDA.” Liquidia argued that BREEZE only confirmed safety and efficacy data produced by other studies, meaning that FDA could have approved Tyvaso DPI® without this study. The court concluded that FDA was correct in concluding otherwise. Indeed, no other clinical study had used dry-powder inhaled Treprostinil, meaning that BREEZE was essential to FDA approval.
