Facts
United Therapeutics Corporation (“United Therapeutics”) holds New Drug Application (“NDA”) No. 022387 for Tyvaso®, an inhaled solution formulation of treprostinil used to treat pulmonary hypertension (“PH”). (Slip Op. at 2.) United Therapeutics owns the ’793 and ’066 patents, which are “directed to methods of treating pulmonary hypertension and to pharmaceutical compositions comprising treprostinil.” (Slip Op. at 3.) Both patents are listed in the FDA’s Orange Book for Tyvaso®. Id.
Liquidia Technologies, Inc. (“Liquidia”) filed NDA No. 213005 under section 505(b)(2) for Yutrepia™, a dry powder inhalation formulation of treprostinil, seeking approval to market prior to expiration of the ’066 patent. (Slip Op. at 3-4). United Therapeutics sued Liquidia within 45 days, alleging infringement of the ’066 patent. (Slip Op. at 4). The ’793 patent subsequently issued, and was added to the district court litigation. Id.
The ’793 patent
Claim 1 of the ’793 patent is directed towards a method of treating PH by inhalation of treprostinil with a dose from 15 micrograms to 90 micrograms delivered in one to three breaths. (Slip Op. at 5.) Additional dependent claims include “limitations directed to dry powder inhalers (claim 4), powder formulations (claim 6), powder formulations comprising particles less than 5 micrometers in diameter (claim 7), and formulations containing no metacresol (claim 8).” Id.
The district court held that the administration of Yutrepia™ will directly infringe claims 1, 4, and 6–8 of the ’793 patent because the administration of Yutrepia™ improves a patient’s hemodynamics. Id. The district court also concluded that United Therapeutics proved that Liquidia will induce infringement of claims 1, 4, and 6–8 of the ’793 patent because Yutrepia™’s label instructions will inevitably lead to the administration of a single dose of treprostinil. (Slip Op. at 6.) Finally, the district court held that the asserted claims were not invalid for lack of enablement or written description. Id.
The ’066 patent
Claim 1 of the ’066 patent is a product-by-process claim reciting a pharmaceutical composition comprising treprostinil made by a process wherein an impure starting batch of treprostinil is isolated as a salt and impurities are reduced. (Slip Op. at 7.) Dependent claim 6 is directed to “the pharmaceutical composition of claim 1 wherein the isolated treprostinil salt is stored at ambient temperature.” Id. Independent claim 8 is directed to a process of preparing a composition of treprostinil salt at ambient temperature, storing the product at ambient temperature, and preparing a product from the treprostinil salt after storage. (Slip Op. at 7-8.) “Additional asserted dependent claims are directed to crystalline forms (claim 2), a base selected from the group consisting of sodium, ammonia, potassium, calcium, ethanolamine, diethanolamine, N-methylglucamine, and choline (claim 3), and a pharmaceutical product prepared by the process recited in claim 8 (claim 9).” (Slip Op. at 8.)
The district court held that Yutrepia™ would infringe claims 1–3 of the ’066 patent, but that claims 1–3, 6, and 9 were invalid as anticipated by Moriarty. (Slip Op. at 9.) The district court also found that United Therapeutics failed to show that Yutrepia™’s production process stored treprostinil at ambient temperature, and therefore found that claims 6, 8, and 9 were not infringed. Id. Finally, the district court held that claims 1–3 and 6 of the ’066 patent were not invalid for lack of written description. (Slip Op. at 9-10.)
Issues on appeal
Liquidia raised five issues in its appeal: whether the district court erred in (1) construing the claim limitation “treating pulmonary hypertension” in claim 1 of the ’793 patent not to include safety and efficacy; (2) finding the asserted claims of the ’793 patent enabled; (3) finding the asserted claims of the ’793 patent supported by written description; (4) finding Liquidia liable for induced infringement of claims 1, 4, and 6–8 of the ’793 patent; and (5) finding claims 1–3 of the ’066 patent to be infringed. (Slip Op. at 10.)
United’s cross-appeal raised two additional issues: whether the district court erred in (1) finding that Liquidia does not infringe claims 6 and 8 of the ’066 patent; and (2) finding that claims 1–3, 6, and 9 of the ’066 patent are invalid as anticipated by Moriarty. (Slip Op. at 10-11.)
Holding
The Federal Circuit affirmed the district court’s findings on all seven issues. (Slip Op. at 23.)
First, the Court rejected Liquidia’s argument that the “treating pulmonary hypertension” language of the ’793 patent claims required a showing of safety and efficacy because “[q]uestions of safety and efficacy in patent law have long fallen under the purview of the FDA.” (Slip Op. at 12-13.) Thus, the Court “decline[d] to insert the FDA’s responsibilities into claims by importing requirements where they do not recite such limitations.” (Slip Op. at 14.)
Second and third, the Court concluded that the ’793 patent’s claims are adequately enabled and supported by adequate written description. (Slip Op. at 15-18.) The Court held that the district court’s findings on enablement were appropriately supported by expert testimony and the record evidence. (Slip Op. at 16.) Further, the Court found that it was improper to “fractionate a disease or condition” and require separate disclosures for every variant of a condition in order for a patent to adequately describe a claimed genus. (Slip Op. at 17.)
Fourth, the Court held that the district court did not clearly err in finding that Liquidia induced infringement of the ’793 patent because Liquidia’s label “instruct[ed] doctors and patients to administer a therapeutically effective single event dose.” (Slip Op. at 18.) Although the ’793 patent was found to be unpatentable in an IPR, the Court held that “[a] pending, non-final litigation does not negate an intent to infringe that is otherwise supported by evidence[,]” and that “an IPR decision does not have collateral estoppel effect until that decision is affirmed or the parties waive their appeal rights.” (Slip Op. at 19.) Further the Court held that “the Board’s final written decision does not cancel claims; the claims are cancelled when the Director issues a certificate confirming unpatentability[.]” Id.
Fifth and sixth, the Court held that the issue of infringement of claims 1–3 of the ’066 patent was rendered moot because the district court did not clearly err in finding that those claims are invalid as anticipated by Moriarty. (Slip Op. at 20-21.) Noting that “a product-by-process claim is a product claim, even if claimed by a process by which it can be made[,]” the Court determined that Moriarty disclosed treprostinil having the same impurity levels as would the treprostinil claimed by the ’066 patent, and United Therapeutics had not identified any structural or functional differences between the two. (Slip Op. at 21.) Moriarty therefore anticipated the claimed product, even if Moriarty disclosed a different process for making the claimed product. Id.
Finally, the Court held that the district court did not clearly err in finding that Liquidia does not infringe claims 6 and 8 of the ’066 patent because United Therapeutics did not demonstrate that Liquidia stored treprostinil at ambient temperature as required by the claims. (Slip Op. at 22-23.)
Key Takeaways
- The Federal Circuit will not automatically interpret a method of treatment claim as requiring safety and efficacy unless there is a specific reason to do so.
- A claim to a method of treating a class of patients may be found enabled and adequately described even if there is a subset of those patients for whom the method does not work.
- An IPR decision finding claims unpatentable does not preclude a finding of induced infringement of such claims until the unpatentability decision is affirmed or the parties waive their appeal rights.
