Takeda Pharmaceutical Company et al. v. Zydus Pharmaceuticals USA, Inc.

Docket No. 2013-1406

February 20, 2014

Brief Summary: Claim term “400 μm or less” construed to refer to exactly “400 μm” and not “400 μm (+10%)” as determined by the DC. Claims also found not be invalid indefiniteness, written description or enablement (regarding measurement techniques).

Summary: Zydus appealed from DC final judgment that Takeda’s US 6,328,994 related to Prevacid® SoluTabTM (disintegratable tablet containing lansoprazole) was infringed and not invalid under 35 USC § 112. The DC construed the claim term “fine granules having an average particle diameter of 400 μm or less” to mean “400 μm (+10%) or less”, rejecting Zydus’ arguments that it should be construed as “precisely 400 μm”. The issue of infringement turned on how particle size was measured (measuring only individual cores (Takeda’s argument) or also including “multi-cored granules…known as ‘hard agglomerates’” (Zydus’ argument)). The DC determined that the patent requires measuring “each core, regardless of how many cores are in a given hard agglomerate” and therefore concluded that Zydus infringed. The FC panel disagreed with the DC construction because “there is no indication in the claim that 400 μm was intended to mean anything other than exactly 400 μm” (“phrase…is not qualified by the word ‘about’ or any other indicator of imprecision”) and “the specification confirms that the inventors did not intend to deviate from that clear and unambiguous plain meaning” (“contrasts the ‘fine granules’ of the claimed invention with larger ‘conventional’ granules, which it defines as 400 μm or more of average particle diameter” as “produc[ing] a feeling of roughness in the mouth-one of the very problems the claimed invention purports to solve.”) As such, “there can be little doubt that the narrower construction ‘most natural aligns with the patent’s description of the invention” (citing Renishaw, FC 1998). In addition, the opinion explains, “the specification goes on to explain that the maximum particle size is ‘practically 425 μm or less,’ where ‘practically’means that ‘the particles may include a small quantity (about 5 weight % or less) of particles whose particle diameter is out of above described range” making it “impossible for a tablet to comply with the specification’s maximum particle diameter” and a “median particle diameter of 440 μm (meaning that 50% of the particles are larger than 440 μm), as the district court’s claim construction would permit” (“This tension means that the inventors did not intend to incorporate a +10% deviation into the average particle diameter of claim 1.”) The opinion also explained that “[t]he word about is used to modify the phrase ‘400 μm or less’ only three times in the specification”, it twice states that the diameter is “preferably 350 μm or less” and “the word ‘about’ is immediately followed by a preference for an average particle size lower than 400 μm.” In addition, “about” was used later in the claim, showing “the inventors knew how to express ambiguity in claim language” but decided not to do so. Thus, the claim construction decision was reversed. Zydus also argued that the claims were indefinite because there are several methods that could potentially be used to measure the particles but the FC disagreed because the experts agreed that the methods accurately report average particle diameter (constrasting this case from Amgen, FC 2003 (differing EPO glycosylation patterns)). The FC also rejected Zydus’ arguments that claim 1 failed under the written description requirement because it addressed the average particle size of the finished tablet but the specification only teaches how to measure particle size pre-tableting because “the evidence established only a hypothetical possibility that tableting could affect particle size in a relevant way.” The FC also agreed with the DC that the enablement requirement was met “because the patent identifies laser diffraction as a viable measurement teachnique” (noting, however, that if the DC had been correct regarding agglomerated particles, they would have reached a different conclusion).  

This entry was posted in Claim Construction, Enablement, Generics / ANDA, Indefiniteness, Infringement, Written description. Bookmark the permalink.

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