A Blog About Intellectual Property Litigation and the District of Delaware

Judge Stark issued a claim construction ruling in a large multi-district ANDA case last week, touching on interesting questions regarding the nature of intrinsic evidence and the impact of disclaimers on child applications.

The parties to In re Entresto (SacubitriWalsartan) Patent Litigation, C.A. No. 20-2930-LPS presented the Court with just a few issues for resolution.

First, the Court considered whether independent claims of two of the patents-in-suit directed to administration of a "combination" of active ingredients should be limited to administering those ingredients as "two separate components," or whether it was broad enough to encompass administration of complexed active ingredients. Judge Stark noted that the intrinsic record was "silent" on whether the active ingredients need to be separate, and thus the claims were not so limited.

The Court also considered the patentee's submission in requesting a patent term extension for the two patents (in which the patentee represented to the USPTO that the patents covered the drug including complexed active ingredients). The Court explained that while there is "little helpful authority" regarding whether such a submission is intrinsic or extrinsic evidence, it did not change the unambiguous meaning of a claim term in this case and thus would likely be considered by a POSA in divining the meaning of the claim.

Although the Court adopted plaintiff's construction, it pointed out a potential problem on the horizon:

[Plaintiff] Novartis admits that its two patents "do not disclose or suggest" a one-unit-dose-form embodiment. . . . This seems to be an admission by Novartis that, at the very least, there will be a non-frivolous issue of written description and/or lack of enablement as this case proceeds on Novartis's preferred construction.

Nonetheless, because plaintiff's proposed construction was not "necessarily consigning the asserted claims to a judgment of invalidity" and because the construction was "otherwise supported," the Court adopted it.

In resolving the second set of disputes, the Court ruled that a disclaimer of non-substantially-pure crystalline embodiments in a parent application carried over to the child (divisional application). However, only the claims of the divisional containing the "crystalline" limitation inherited the purity disclaimer:

The parties agree that the '938 patent requires a substantially pure, crystalline compound. . . . A child patent (such as the ' 134 patent) that uses the same claim language as the parent patent (such as the '938 patent) imports the same disclaimed meaning as the parent patent. . . . Moreover, the '134 patent, as a divisional, incorporates the reasons for allowance of the '938 patent, which is explicitly confirmed in an office action in the' 1 34 patent's prosecution history. . . . Even though Novartis never expressly agreed with the Examiner's reasoning and never otherwise disclaimed non-substantially pure forms . . . the disclaimer carries over to the crystalline claims of the ' 134 patent . . . . The other claims of the '134 patent, not being limited to the crystalline form, do not carry the substantially pure limitation.

The Court's rulings here demonstrate the importance of carefully reviewing the entirety of the file history, including the file histories of related patents and quasi-intrinsic evidence, for relevant statements or actions by the patentee or the examiner(s).

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