Federal Circuit IP
Bayer Pharma AG v. Mylan Pharmaceuticals Inc.
Bayer Pharma AG v. Mylan Pharmaceuticals Inc., No. 2023-2434, 2025 WL 2698408
(Fed. Cir. Sept. 23, 2025) (Moore, C.J., Cunningham, J., Scarsi, J.)
Issues:
At issue was whether claim language “clinically proven effective” was non-limiting and whether the claim language, “first product comprising rivaroxaban and aspirin,” required a single dosage form containing both drugs or allowed separate dosage forms.
Facts/Procedural Posture:
Plaintiff asserted U.S. Patent No. 10,828,310, directed to methods of reducing cardiovascular risk using rivaroxaban and aspirin. Mylan, Teva, and InvaGen challenged the patent in inter partes review. The Board found claims 1–2 unpatentable as anticipated and claims 1–8 unpatentable as obvious. The prior art disclosed the dosages of the drugs claimed in the asserted patent but without the information about the result of clinical trials. Bayer appealed, contesting claim construction of terms including “clinically proven effective” and “first product.” The Federal Circuit affirmed invalidity of claims 1–4 and vacated and remanded as to claims 5–8 based on a corrected claim construction.
Holdings:
The Federal Circuit held that “clinically proven effective”—even if limiting—was a functionally unrelated limitation incapable of imparting patentability. The Court vacated the unpatentability of claims 5–8 because the Board incorrectly construed “first product comprising rivaroxaban and aspirin” too broadly where “first product” required a single dosage form containing both drugs.
Reasoning:
The “clinically proven effective” language lacked a functional relationship with the claimed treatment method; it merely described a subsequent recognition of efficacy, not a technical feature of the method itself (citing King Pharmaceuticals v. Eon Labs, 616 F.3d 1267 (Fed. Cir. 2010)). It rejected Bayer’s analogy to Allergan Sales, LLC v. Sandoz, Inc., 935 F.3d 1370 (Fed. Cir. 2019) because that case involved “wherein” clauses that set safety and efficacy benchmarks impacting the overall composition. In contrast, the “clinically proven effective” language did not further define the dosages of claimed drugs.
As to claims 5−8, the panel found that the claims’ recitation of “a first product comprising rivaroxaban and aspirin” required a single dosage form containing both drugs, not separate dosage forms when giving effect to all terms in the claim and when interpreted in view of the specification’s recitation of “a combination dosage form containing both rivaroxaban and aspirin.”
Key Takeaways:
Informational phrases must have a “new and unobvious functional relationship” to how the claimed invention operates and claim construction must still give effect to all terms.