Clinical Efficacy a Functionally Unrelated Limitation That Creates No Patentability, CAFC Finds

Today, the U.S. Court of Appeals for the Federal Circuit (CAFC) issued a precedential decision in Bayer Pharma Aktiengesellschaft v. Mylan Pharmaceuticals Inc. affirming-in-part a final written decision by the Patent Trial and Appeal Board (PTAB) invalidating Bayer’s patent claims for methods of reducing the risk of cardiovascular events in patients. The Federal Circuit nixed Bayer’s arguments that the claim term “clinically proven effective” requires proof of clinical efficacy, although the appellate court did agree that the PTAB erred in construing a different claim term, vacating and remanding the Board’s decision with respect to some of Bayer’s claims.

Patentees Cannot Add Unrelated Limitations to Indefinitely Patent Known Methods

The present appeal stems from inter partes review (IPR) proceedings petitioned by Mylan and other respondents to challenge claims of Bayer’s U.S. Patent No. 10828310, Reducing the Risk of Cardiovascular Events. In its final written decision, the PTAB invalidated all claims of Bayer’s ‘310 patent, including independent claim 1, which recites a method of reducing the risk of myocardial infarction by administering rivaroxaban and aspirin, and independent claim 5, reciting a similar method involving once daily administration of “a first product comprising rivaroxaban and aspirin, along with their respective dependent claims. Mylan’s obviousness grounds were based on a pair of journal articles describing clinical trials involving the administration of rivaroxaban and aspirin without disclosing the trial results.

Bayer argued that the PTAB erred in finding that the claim term “clinically proven effective” was non-limiting and inherently anticipated. On appeal, the Federal Circuit evaded Bayer’s argument, finding that even if the claim term were limiting, it is functionally unrelated and fails to make Bayer’s challenged claims patentable. Functionally unrelated limitations do not contribute to patentability so as to prevent the indefinite patenting of known products and methods by including novel, unrelated limitations. The CAFC has previously explained this reasoning in King Pharmaceuticals v. Eon Labs (2010), in which the appellate court found that an otherwise anticipated method of treatment was not made patentable by “informing the patient” about the method’s anticipated benefits.

Finding King’s rationale applicable to the current appeal, the Federal Circuit found it troubling that Bayer’s anticipated method of cardiovascular treatment could be “claw[ed] back from the public domain” by merely adding that the claimed method performed well in clinical trials. Even if that claim term required clinical efficacy, such a requirement would in no way alter the claimed method of administering rivaroxaban and aspirin in the amounts and frequencies recited, the Federal Circuit held.

The Federal Circuit distinguished Allergan Sales v. Sandoz (2019), which according to Bayer required the appellate court to treat “clinically proven effective” as material to patentability. Importantly, the CAFC noted that the claims in Allergan were written in open format using a “wherein” clause that modified the overall composition by specifying minimum safety and efficacy requirements for the claimed topical eye treatment. The CAFC thus found that Allergan’s “wherein” clauses were functionally limiting because they limited the open-ended universe of potential compositions including the claimed active pharmaceuticals, whereas the claims of Bayer’s ‘310 patent already specified the exact dosages of rivaroxaban and aspirin to administer to a patient.

PTAB’s Ruling Vacated-in-Part Over Erroneous ‘First Product’ Construction

Bayer also appealed the PTAB’s construction of the term “first product” appearing in claims 5 through 8 of the ‘310 patent. Here, the Federal Circuit agreed that the PTAB erred in finding that the “first product” is not limited to a single dosage of rivaroxaban and aspirin. According to the appellate court, the plain language of the claims requires a single dosage and does not allow for sequential administration of the active ingredients. Whereas the PTAB found that references in the ‘310 patent’s specification to a broader “combination therapy” involving separate dosages, the limiting claim language of “a first product comprising rivaroxaban and aspirin” indicated a combination dosage form.

The remainder of Bayer’s arguments on appeal were not persuasive to the Federal Circuit. The appellate court found substantial evidence supporting the PTAB’s finding that a skilled artisan would be motivated to combine the prior art scientific journal articles, both of which taught dosing regimens for reducing the risk of cardiovascular events consistent with the active ingredients and dosing ranges of the ‘310 patent. Finally, Bayer’s offered secondary characteristics of unexpected clinical efficacy had no nexus with the merits of the claimed invention due to the functionally unrelated nature of the limitation.

Although the Federal Circuit affirmed the PTAB’s obviousness findings with regards to claims 1 through 4 of the ‘310 patent, the appellate court remanded the ruling to the PTAB with regards to claims 5 through 8 for proper construction of the claim term “first product.”

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