Liquidia Corporation: FDA Still Reviewing NDA to Add PH-ILD Indication for Treprostinil Inhalation Powder

Credit: US Food and Drug Administration

The US Food and Drug Administration has declined to provide Liquidia Corporation an action letter in time for the January 24, 2024 PDUFA date and the review of the company’s New Drug Application to add a pulmonary-hypertension with interstitial lung disease (PH-ILD) indication to the labeling of treprostinil inhalation powder (Yutrepia), according to an announcement from the company.

Announced on January 25, 2024, the company noted the FDA had informed them it is confirming the process for adding and the agency’s review remains ongoing. The company also noted the FDA did not request any additional information to support the NDA and declined to issue a new PDUFA goal date.¹

“We are in active communication with the FDA regarding the process we followed to amend our NDA to add PH-ILD to the labeled indication. Whether the NDA is amended or supplemented, we will continue to prepare for the final FDA approval of YUTREPIA to treat both PAH and PH-ILD patients following the expiration of regulatory exclusivity for Tyvaso® on March 31, 2024,” said Roger Jeffs, PhD, chief executive Officer of Liquidia Corporation.¹ “As communicated by the tentative approval to treat PAH, YUTREPIA has already met the regulatory standards for quality, safety and efficacy. We remain committed to addressing the unmet needs across all patients whose lives may be improved by the unique benefits of YUTREPIA.”

Billed as an inhaled dry powder formulation of treprostinil designed using Liquidia’s PRINT® technology, treprostinil inhalation powder is delivered via a palm-sized dry powder inhaler. The basis of the application for an expanded indication is data from the phase 3, open-label INSPIRE trial.^1,2

A multicenter trial assessing use of the agent in adult patients with PAH, INSPIRE enrolled 121 patients who are naïve to inhaled treprostinil or who are transitioning from nebulized treprostinil. Evaluation of efficacy measures from the trial suggested patients using inhaled treprostinil remained stable or improved over 1 year of treatment. Analysis of safety outcomes from the trial indicated most adverse events were mild to moderate but considered to be treatment-related and expected for prostacyclin therapy administered by inhalation.³

The road to a potential decisionfor treprostinil inhalation powder has not been direct. In January 2020, Liquid announced the submission of a New Drug Application for treprostinil inhalation powder in the management of PAH. In November 2020, the company would announce the receipt of a Complete Response Letter for this NDA.⁴

In 2021, the company announced the resubmission of its NDA for the agent for the treatment of PAH to improve exercise ability in adult patients with New York Heart Association Functional Class II-III symptoms, which received tentative approval from the FDA in November 2021. In September 2023, Liquid Corporation announced the FDA’s acceptance of an amendment to the tentatively approved NDA to include the treatment of pulmonary hypertension associated with interstitial lung disease on the label.⁵

Liquidia has noted on multiple occasions the potential availability of treprostinil inhalation powder in both indications remains subject to the successful resolution of the ongoing litigation with United Therapeutics. According to the January 25, 2024 announcement, the company believes the final FDA approval for YUTREPIA will not be subject to any statutory 30-month stay arising from the New Hatch-Waxman Litigation per Section 505(c)(3)(C) of the Federal Food, Drug and Cosmetic Act.¹

References:

1. Liquidia. Liquidia Corporation provides update on New Drug Application for yutrepiaTM (Treprostinil) inhalation powder. Liquidia Press Releases. January 25, 2024. Accessed January 25, 2024. https://liquidia.com/news-releases/news-release-details/liquidia-corporation-provides-update-new-drug-application.
2. Liquidia. FDA grants tentative approval for Liquidia’s YUTREPIATM (Treprostinil) inhalation powder. Liquidia Press Releases. November 8, 2021. Accessed January 24, 2024. https://www.liquidia.com/news-releases/news-release-details/fda-grants-tentative-approval-liquidias-yutrepiatm-treprostinil.
3. Hill NS, Feldman JP, Sahay S, et al. INSPIRE: Safety and tolerability of inhaled Yutrepia (treprostinil) in pulmonary arterial hypertension (PAH). Pulm Circ. 2022;12(3):e12119. Published 2022 Jul 1. doi:10.1002/pul2.12119
4. Liquidia. Liquidia receives complete response letter from FDA for Liq861 (treprostinil) inhalation powder for the treatment of pulmonary arterial hypertension. Liquidia Press Releases. November 25, 2020. Accessed January 24, 2024. https://www.liquidia.com/news-releases/news-release-details/liquidia-receives-complete-response-letter-fda-liq861.
5. Liquidia. FDA accepts submission to add ph-ILD to YUTREPIATM label. Liquidia Press Releases. September 25, 2023. Accessed January 24, 2024. https://www.liquidia.com/news-releases/news-release-details/fda-accepts-submission-add-ph-ild-yutrepiatm-label.