Federal Circuit Refuses To Import Safety And Efficacy Limitations Into Method Of Treatment Claims And Affirms Induced Infringement Finding
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  • Federal Circuit Refuses To Import Safety And Efficacy Limitations Into Method Of Treatment Claims And Affirms Induced Infringement Finding

    On July 24, 2023, the Court of Appeals for the Federal Circuit (CAFC) affirmed a decision of the United States District Court for the District of Delaware in Case No. 1:20-cv-00755-RGA-JLH, Judge Richard G. Andrews, finding claims of one asserted patent valid and infringed and claims of another asserted patent anticipated but otherwise infringed.  United Therapeutics Corp. v. Liquidia Techs., Inc., __ F.3d __ (Fed. Cir. July 24, 2023).  In its precedential decision, the CAFC held, inter alia, that the district court did not err in declining to import safety and efficacy limitations into method of treatment claims in the first patent, and also did not err in finding that a decision of unpatentability by the U.S. Patent Trial and Appeal Board (“PTAB”) of the U.S. Patent and Trademark Office, currently on appeal, did not bar liability for induced infringement.

    Patent owner cross-appellant holds a New Drug Application (“NDA”) for Tyvaso®, an inhaled solution formulation of treprostinil approved for the treatment of pulmonary hypertension (“PH”).  Patent owner alleges that its ’793 and ’066 patents—patents generally directed to methods of treating pulmonary hypertension using treprostinil and pharmaceutical compositions comprising treprostinil—cover Tyvaso.

    Defendant appellant subsequently filed its own NDA for Yutrepia™ under § 505(b)(2) of the Food, Drug, and Cosmetic Act (herein, the “Act”).  Yutrepia is a dry powder inhalation formulation of Treprostinil, but is not a generic version of any currently marketed drug.  Pursuant to the Act, patent owner sued defendant in district court for infringement of its ’793 and ’066 patents within 45 days of receipt of notice of defendant’s NDA.

    With respect to the ’793 patent, patent owner argued that, although Defendant’s proposed product had not yet been marketed, when marketed, it (1) would directly infringe claims 1, 4, and 6–8, which are directed to methods of treating pulmonary hypertension comprising inhalation of treprostinil and (2) would also induce infringement of those claims.  Defendant responded that the asserted claims were invalid as lacking adequate enablement and written description under 35 U.S.C. § 112.

    The district court found that patent owner showed that a single administration of treprostinil, as required by claim 1 of the ’793 patent, improves a patient’s hemodynamics, establishing that administration of defendant’s Yutrepia at the claimed doses will also improve a patient’s hemodynamics.  On that basis, the court concluded that administration of Yutrepia will directly infringe claims 1, 4, and 6–8 of the ’793 patent.  The district court also found induced infringement and that the asserted claims were not invalid for lack of enablement or written description.

    With respect to the ’066 patent, patent owner argued in district court that defendant infringed claims 1–3, 6, 8, and 9, which are directed to a pharmaceutical composition comprising treprostinil (claims 1–3, 6, and 9) and a process of preparing a pharmaceutical product comprising treprostinil (claim 8).  Defendant responded that claims 1–3, 6, and 9 were invalid as anticipated by prior art reference “Moriarty,” and that claims 1–3 and 6 were invalid as lacking written description support.  The district court found that patent owner showed that defendant’s Yutrepia would infringe claims 1–3 of the ’066 patent because Yutrepia met the impurities limitations of claim 1, but would not infringe claims 6, 8, and 9.  But the court also found that claims 1–3, 6, and 9 were invalid as anticipated.

    Defendant raised five issues on appeal, and patent owner raised two issues on cross-appeal.  The CAFC addressed each issue in turn.

    First, the CAFC addressed defendant’s challenge to the district court’s determination that the claim term “treating pulmonary hypertension” does not require a showing of safety and efficacy. The CAFC agreed with patent owner that no such safety or efficacy requirements were recited in the claims—other than that the recited “therapeutically effective single event dose” refers to a dose given in a single treatment session that causes an improvement in a patient’s hemodynamics.  The CAFC further noted that questions of safety and efficacy in patent law have long fallen under the purview of the Food and Drug Administration (“FDA”) rather than the courts.

    Based on this claim construction, CAFC concluded that apparent undisputed safety and efficacy concerns associated with performing the claimed methods on a certain class of patients—concerns not addressed in the ’793 patent—did not bar patentability for lack of enablement or written description, as defendant had asserted on appeal.

    In reaching this decision, the CAFC also rejected defendant’s arguments that, even under the district court’s construction of “treating pulmonary hypertension,” the claimed methods would not, without undue experimentation, improve hemodynamics in one of the types of patients (Group 2 PH patients) encompassed by the claims, and that there is no written description of such a broadly applicable method.  The CAFC rejected these arguments because it found the district court’s finding—namely, that the claimed methods would improve hemodynamics, and in this way treat all types of hypertension patients—was supported by substantial evidence.  The CAFC further explained that it would be incorrect to fractionate a disease or condition that a method of treatment claim is directed to, and to require a separate disclosure in the specification for each individual variant of the condition in order to satisfy the enablement and written description provisions of 35 U.S.C. § 112, unless these variants are specified in the claims.

    The CAFC also rejected defendant’s appeal of the district court’s finding of induced infringement.  Defendants had argued that an Inter Partes Review Final Written Decision from the U.S. Patent Trial and Appeal Board (“PTAB”), currently on appeal, finding all claims of the ’793 patent unpatentable, barred a finding of the requisite intent to induce infringement.  In rejecting this argument, the CAFC explained that a pending, non-final litigation does not negate an intent to infringe that is otherwise supported by evidence.  The CAFC further noted that it had previously held that an IPR decision does not have collateral estoppel effect until that decision is affirmed or the parties waive their appeal rights.

    The CAFC further found defendant’s appeal of the district court’s finding of infringement of claims 1–3 of the ’066 patent moot in view of the CAFC’s affirmance of the district court’s finding that these claims are invalid, a finding from which patent owner cross-appealed.

    In affirming this invalidity finding, the CAFC concluded that claims 1–3 (as well as claims 6 and 9) of the ’066 patent—each a product-by-process claim to a pharmaceutical composition comprising, inter alia, Treprostinil and having certain impurities—were disclosed by the Moriarty prior art reference even though Moriarty’s compositions were made using a different process.  The CAFC noted that patent owner did not provide any expert or fact witness rebutting defendant’s expert’s opinions or providing testimony identifying any structural or functional differences between the treprostinil disclosed in Moriarty and the claimed treprostinil.

    Last, the CAFC addressed patent owner’s assertion that the district court clearly erred in finding that defendant does not infringe claims 6 and 8 of the ’066 patent, each requiring that a treprostinil salt ingredient be stored at ambient temperature.  In affirming the district court decision, the CAFC credited defendant’s representations to the FDA that it would not store treprostinil sodium at room temperature.  The CAFC also concluded that patent owner provided no evidence showing that defendant used ambient-temperature-stored batches of treprostinil in its manufacturing process as required by claim 6 or claim 8.
    Categories: Prior ArtSection 112

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