Introduction
The litigation between United Therapeutics Corporation (UTC) and Liquidia Technologies, Inc. is a complex and multifaceted case that involves patent infringement, validity challenges, and regulatory approvals in the pharmaceutical industry. This article delves into the key aspects of the case, including the patents in question, the legal proceedings, and the implications of the court's decisions.
Background
The Patents and Products Involved
The dispute centers around two patents held by UTC: U.S. Patent Nos. 9,593,066 (’066 patent) and 10,716,793 (’793 patent). These patents relate to inhaled formulations of treprostinil, a drug used to treat pulmonary hypertension. UTC's product, Tyvaso®, and Liquidia's product, Yutrepia™, are both directed towards this therapeutic area[4].
Litigation Overview
District Court Decision
The litigation began when UTC sued Liquidia Technologies under § 505(c)(3)(C) of the Food, Drug, and Cosmetic Act, alleging infringement of the ’066 and ’793 patents. The District Court for the District of Delaware found that claims 1, 4, and 6-8 of the ’793 patent were not invalid and were infringed by Liquidia Technologies. However, claims 1-3 of the ’066 patent were deemed invalid as anticipated, although they were otherwise found to be infringed[1][4].
Appeal to the Federal Circuit
Liquidia Technologies appealed the decision to the Federal Circuit, raising several issues:
- The district court's construction of the claim limitation "treating pulmonary hypertension" in claim 1 of the ’793 patent.
- The enablement and written description support for the asserted claims of the ’793 patent.
- The finding of induced infringement of claims 1, 4, and 6-8 of the ’793 patent.
- The infringement of claims 1-3 of the ’066 patent[1].
UTC also raised issues on cross-appeal, including the district court's findings on the invalidity and non-infringement of certain claims of the ’066 patent[1].
Key Decisions and Rulings
Enablement and Written Description
The Federal Circuit upheld the district court's decision that the specification of the ’793 patent sufficiently enables the scope of the claims and that the claims are supported by adequate written description. This ruling is significant as it clarifies the application of the enablement and written description provisions of 35 U.S.C. § 112 to method-of-treatment claims[1].
Anticipation Analysis
The court reiterated that the anticipation analysis for product-by-process claims does not require an anticipatory product to have been made by the claimed process. This means that even if a product was not made using the exact process described in the patent, it can still be considered anticipatory if it meets the product's characteristics[1].
Safety and Efficacy
The Federal Circuit rejected Liquidia's argument that the claims should include safety and efficacy limitations. The court stated that absent specific limitations related to safety and efficacy, such concerns do not fall under the purview of the court, and it declined to insert FDA responsibilities into the claims[1].
Inter Partes Review (IPR) Proceedings
Liquidia challenged the validity of the ’793 patent in an ongoing IPR (No. IPR2021-00406). The Patent Trial and Appeal Board (PTAB) found that claims 1-5, 8, and 9 were unpatentable, but did not demonstrate the unpatentability of claims 6 and 7. The Federal Circuit upheld the PTAB's obviousness determination for the dependent claims, affirming that the Board's decision was supported by substantial evidence[2][4].
Regulatory and Market Implications
FDA Approval and Injunction
Liquidia's product, Yutrepia™, had not yet obtained FDA approval at the time of the litigation. The District Court enjoined Liquidia from marketing its version of the drug until after the expiration of the ’793 patent, expected on May 14, 2027. However, if the PTAB were to hold the asserted claims of the ’793 patent invalid, Liquidia could seek to have the injunction lifted[4].
Financial Implications
The litigation has significant financial implications. For instance, a court found that United Therapeutics' interference with the launch of a generic treprostinil injection caused losses of more than $137 million to Liquidia and its partner Sandoz[5].
Counterclaims and Additional Litigation
Liquidia filed a response to UTC's lawsuit, seeking dismissal of all claims related to the ’793 patent based on prior findings of invalidity affirmed by the Federal Circuit. Liquidia also requested a declaration that the ’327 patent is not infringed, is invalid, and is unenforceable. Additionally, Liquidia filed counterclaims asserting that UTC failed to properly disclose prior art references and additional material information during the prosecution of the ’327 patent[3].
Expert Insights and Statistics
Industry Expert Views
Industry experts highlight the importance of clear claim construction and the need for robust enablement and written description support in pharmaceutical patents. For example, "The specification of the patent must sufficiently enable the scope of the claims to ensure that a skilled artisan can practice the invention without undue experimentation"[1].
Market Impact
The litigation underscores the competitive landscape in the pharmaceutical industry, particularly in the treatment of pulmonary hypertension. The market for treprostinil formulations is significant, with Tyvaso® being a major player. The injunction against Liquidia's Yutrepia™ until the patent expiration in 2027 gives UTC a temporary monopoly in this market segment.
Key Takeaways
- Patent Validity and Infringement: The Federal Circuit upheld the validity of certain claims of the ’793 patent and found infringement by Liquidia Technologies.
- Enablement and Written Description: The court clarified the application of 35 U.S.C. § 112 to method-of-treatment claims, emphasizing the importance of sufficient enablement and written description.
- Regulatory Implications: The litigation affects the regulatory approval and market launch of generic treprostinil formulations.
- Financial Consequences: The case has significant financial implications, including losses and potential future revenues.
FAQs
What are the main patents involved in the litigation between UTC and Liquidia Technologies?
The main patents involved are U.S. Patent Nos. 9,593,066 (’066 patent) and 10,716,793 (’793 patent), both related to inhaled formulations of treprostinil.
What was the District Court's decision regarding the ’793 patent?
The District Court found that claims 1, 4, and 6-8 of the ’793 patent were not invalid and were infringed by Liquidia Technologies.
How did the Federal Circuit rule on the enablement and written description of the ’793 patent?
The Federal Circuit upheld the district court's decision that the specification of the ’793 patent sufficiently enables the scope of the claims and that the claims are supported by adequate written description.
What are the implications of the PTAB's decision in the IPR proceedings?
The PTAB found certain claims of the ’793 patent unpatentable, but this decision can be challenged, and if successful, could lead to the lifting of the injunction against Liquidia's product.
What financial losses did Liquidia incur due to UTC's actions?
Liquidia incurred losses of more than $137 million due to UTC's interference with the launch of a generic treprostinil injection.
Sources
- Haug Partners, "Takeaways From United Therapeutics Corporation v. Liquidia Technologies Incorporated," July 24, 2023.
- CAFC, "UNITED THERAPEUTICS CORPORATION v. LIQUIDIA TECHNOLOGIES, INC.," June 27, 2024.
- Liquidia Corporation, "Liquidia Corporation Files Response to United Therapeutics Lawsuit and Files Counterclaims," January 8, 2024.
- Patent Docs, "United Therapeutics Corp. v. Liquidia Technologies, Inc. (Fed. Cir. 2023)," February 8, 2024.
- Liquidia Corporation, "Court Finds United Therapeutics' Interference with Launch of Generic Treprostinil Injection Caused Losses of More Than $137 Million," September 16, 2024.
