A Mixed Bag: Some Claims Found Unpatentable but Others Are Patentable


In Liquidia Applied sciences, Inc. v. United Therapeutics Corp., IPR2020-00770, Paper 45 (P.T.A.B. Oct. 8, 2021), the Patent Trial and Attraction Board (“PTAB”) issued a Closing Written Determination (“FWD”) discovering seven of the challenged claims unpatentable and two of the challenged claims not unpatentable.  


Petitioner challenged claims 1-9 of U.S. Patent No. 9,604,901 (“the ’901 Patent”) on two obviousness grounds: Phares and Moriarty/Phares. Declare 1, the one impartial declare, learn:

1. A pharmaceutical batch consisting of treprostinil or a salt thereof and impurities ensuing from (a) alkylating a benzindene triol, (b) hydrolyzing the product of step (a) to kind an answer comprising treprostinil, (c) contacting the answer comprising treprostinil from step (b) with a base to kind a salt of treprostinil, (d) isolating the salt of treprostinil, and (e) optionally reacting the salt of treprostinil with an acid to kind tresprostinil, and whereby the pharmaceutical batch incorporates not less than 2.9 g of treprostinil or its salt.

Claims 6 and seven, the 2 claims that survived the inter partes evaluate (“IPR”) problem to the ’901 patent, learn:

6. A methodology of making ready a pharmaceutical product from a pharmaceutical batch as claimed in declare 1, comprising storing a pharmaceutical batch of a salt of treprostinil as claimed in declare 1 at ambient temperature, and making ready a pharmaceutical product from the pharmaceutical batch after storage.

7. A methodology as claimed in declare 6, whereby the salt of treprostinil is a diethanolamine salt.

The examiner issued an anticipation rejection based mostly on Moriarty throughout prosecution of the ’901 patent. Because the claims are drafted in product-by-process format, willpower of patentability relies solely on the product with out regard to the method. In re Thorpe, 777 F.2nd 695, 697 (Fed. Cir. 1985). In keeping with the examiner, “[a]lthough the method of Moriarty and the steps recited in the instant claims are not identical, the product obtained is the same.” FWD at 10. The examiner additionally rejected claims as apparent over Moriarty and Phares.[1] The applicant overcame the rejections with declare amendments and knowledgeable declarations.


The PTAB construed “pharmaceutical batch” in declare 1 to not require storage stability, opposite to Patent Proprietor’s argument. Id. at 20. The PTAB additionally construed the phrases “storing” and “storage” to require precise storage for a interval of not less than three months. Id. at 25.  This was totally different from the way in which the PTAB construed these phrases within the Determination to Institute, which was largely based mostly on the prosecution historical past of the dad or mum patent. Id. at 20-21.  Lastly, the PTAB construed declare 1 step (c) to require the answer shaped in step (b) because the beginning materials for forming the salt in step (c) (not treprostinil remoted from step (b)). Id. at 27.

The PTAB discovered that Petitioner confirmed by a preponderance of proof that claims 1-5, 8 and 9 have been unpatentable as apparent over Moriarty and Phares. “Petitioner has shown that an ordinarily skilled artisan would have had a reason to combine Moriarty and Phares, and would have had a reasonable expectation of success when doing so.” Id. at 34. “[W]e are persuaded that an ordinarily skilled artisan would have had a reason to start with the treprostinil free acid of Moriarty and convert it into a diethanolamine salt.” Id. at 36. “Phares, even if it does not improve[] the purity, improves at least the bioavailability, of treprostinil of Moriarty….This provides a sufficient reason for a [POSA] to combine the teachings of Moriarty and Phares.” Id. at 37. The PTAB famous that the motivation to mix doesn’t must be the identical as that of the inventor. Id. Nor does the suggestion to mix must be specific within the prior artwork; it might come from the information of 1 expert within the artwork. Id. at 38. Within the present case, the PTAB discovered enough motivation within the “universal” need “to enhance commercial opportunities by improving a product or process.” Id.

With respect to an affordable expectation of success, the PTAB discovered {that a} well-known chemical purification approach within the prior artwork would have offered such cheap expectation to a POSA. Id. at 43.

The PTAB rejected Patent Proprietor’s goal proof of nonobviousness as “conclusory at best,” noting that Patent Proprietor didn’t “demonstrate how any alleged unexpected results were unexpected compared with the closest prior art.” Id. at 46. Patent Proprietor’s citations to the specification and knowledgeable declarations with out rationalization are inadequate. Nor did Patent Proprietor present that the alleged storage stability benefits have been commensurate in scope with the claims. Id.

The conclusion concerning claims 6 and seven was totally different. Though Petitioner argued that Phares inherently taught the “storing”/ “storage” limitation, the PTAB agreed with Patent Proprietor that Petitioner was complicated “relative thermodynamic stabilities with actual stability.” Id. at 47. Phares taught Type A and Type B of treprostinil diethanolamine salt and that Type B seems to be “thermodynamically more stable” than the “metastable” Type A. Id. But “nothing in Phares suggests the salt would be stable for at least three months,” as required by the PTAB’s declare building. Id. at 48. The PTAB rejected Petitioner’s argument that such an understanding would have been throughout the stage of peculiar talent on the time of the invention.  Id. at 48.


This case offers an instance of a Petitioner efficiently overcoming a 35 U.S.C. § 325(d) argument by convincing the PTAB that the examiner erred in her analysis throughout prosecution. By addressing the potential § 325(d) situation within the petition and explaining the examiner’s error and the way the identical references have been being introduced otherwise, Petitioner was capable of keep away from a discretionary denial underneath § 325(d).

This case reminds us that goal proof of surprising outcomes should “exhibit how any alleged surprising outcomes have been surprising in contrast with the closest prior artwork.

And we’re reminded that the target proof is to be commensurate in scope with the claimed invention.

[1] The PTAB rejected Patent Proprietor’s arguments in its Preliminary Response that the IPR petition needs to be denied based mostly on 35 U.S.C. § 325(d) as a result of the examiner already thought of Moriarty and Phares throughout prosecution. “Although it is undisputed that the Office considered both Phares and Moriarty during the prosecution of the ’901 patent, we find that the examiner erred in evaluating these references.” IPR2020-00770, Paper 7, at 7 (P.T.A.B. Oct. 13, 2020). Specifically, “the examiner erred in relying on the applicant’s argument on the improved purity profile to allow the challenged claims.” Id. at 15.

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