United Therapeutics commences litigation with FDA on drug review process

United Therapeutics (UTHR) announced the commencement of litigation with the FDA. In the litigation, United Therapeutics alleges that the FDA mistakenly permitted Liquidia (LQDA) to skirt longstanding FDA rules, precedents, and procedures on how pending drug approval applications are handled by the agency. In doing so, the company alleges that the FDA inappropriately denied United Therapeutics its right to obtain a stay of Liquidia’s final approval until United Therapeutics’ pending patent infringement claim against Liquidia can be resolved. This litigation addresses the FDA’s handling of Liquidia’s alleged unlawful amendment to a pending new drug application, or NDA, seeking to add a second indication, pulmonary hypertension associated with interstitial lung disease, to the label of its proposed inhaled dry powder treprostinil product. United Therapeutics alleges in the litigation that the FDA’s rules, precedents, and procedures require that Liquidia seek approval for this second indication by filing a new NDA rather than filing an amendment to a pending NDA. United Therapeutics believes this distinction is critical to ensure the proper review and approval of new drug applications in a fair, equitable manner consistent with the FDA’s prior practices with which industry has complied for decades. The company said, “Under the Hatch-Waxman Act, when a company like Liquidia seeks approval of an application that relies on another drug’s prior approval and may infringe patents listed for that drug, a timely filed action for patent infringement prevents the FDA from approving an NDA for up to 30 months or until the resolution of the litigation, whichever occurs first. By filing an amendment to its existing NDA rather than a new NDA, Liquidia avoided a 30-month stay of approval for PH-ILD despite Liquidia’s decision to rely on United Therapeutics’ prior approval for Tyvaso. By filing this litigation, United Therapeutics seeks to protect the equity afforded true pharmaceutical and biotech innovators through the correct and consistent interpretation of the FDA’s rules, precedents, and procedures. If United Therapeutics is successful in its litigation with FDA, a stay of up to 30 months could prevent final approval for Liquidia’s PH-ILD indication to allow separate patent litigation to be resolved.”