Slip of the Tongue? Specification Describing "Present Invention" Limits Claim Scope
Finding that the use of the phrase “present invention” in the specification limited the scope of a patent’s claims, the US Court of Appeals for the Federal Circuit vacated a district court judgment and remanded the case, instructing the district court to reconsider non-obviousness and non-infringement findings under the corrected claim construction. Forest Laboratories, LLC v. Sigmapharm Laboratories, LLC, Case Nos. 17-2369, -2370, -2372, -2373, -2374, -2375, -2376, -2389, -2412, -2436, -2438, -2440, -2441 (Fed. Cir. March 14, 2019) (Moore, J).
Forest owns a patent directed to a sublingually administered, atypical antipsychotic containing asenapine. Forest sued several pharmaceutical companies for patent infringement, asserting that their proposed generic versions of the drug Saphris infringed Forest’s patent. Following a bench trial, the district court held that the defendants had not established that the asserted claims were invalid and that Forest had not established infringement of certain claims against two of the defendants, Alembic and Breckenridge. The defendants appealed the district court’s invalidity determination, and Forest cross-appealed the district court’s non-infringement finding.
The Federal Circuit noted that the district court limited the claim to “buccal and sublingual formulations,” despite the absence of any express language in the claim itself. The Court further noted that the patent described the features of the “present invention” as relating to a sublingual or buccal pharmaceutical composition, which strongly supported the district court’s construction. The Court explained that the patent’s title, “Sublingual or Buccal Pharmaceutical Composition,” and additional language in the specification focused the invention on the benefits of sublingual and buccal treatment over the prior art and further supported limiting the claim to “buccal and sublingual formulations.”
The district court found that the defendants had not established that there was a motivation to combine asenapine maleate into a sublingual or buccal form. However, because the district court failed to make a finding as to whether compliance concerns for patients with trouble swallowing would provide a motivation to combine, the Federal Circuit remanded the case, instructing the district court to address this narrow question.
As to the district court’s non-infringement finding against Alembic and Breckenridge, the Federal Circuit found that the district court had erred in treating “excitation” as being limited to “excitation disorders.” The Court noted that the claim language and the specification indicated that “excitation” refers to a symptom rather than a “disorder.” The use of the conjunction “and” before “psychotic and schizophrenic disorders” indicates that “psychotic and schizophrenic disorders” is a distinct item on the list, and that unlike the terms “psychotic” and “schizophrenic,” the words “tension,” “excitation” and “anxiety” are not describing “disorders” but rather symptoms. Accordingly, the Court vacated the judgment of non-infringement as to Breckenridge and Alembic, and remanded for reconsideration under the revised construction.
Practice Note: This case illustrates the Federal Circuit’s willingness to deviate from its normal restraint in importing limitations from the specification into the claims during claim construction. The Court emphasized that language describing “the present invention as a whole” may have the effect of limiting the scope of the invention, especially when contrasted with the prior art. Accordingly, practitioners should be cautious when making statements in the specification that appear applicable to the entire invention as opposed to a particular embodiment. Similarly, during litigation a party may be able to argue that despite any explicit language, a particular claim should be limited in scope based on the disclaimers in the specification.