Forest Laboratories Inc. v. Teva Pharmaceuticals USA Inc.
16-2550
Fed. Cir.
Dec 11, 2017

Background

  • Adamas (owner) and Forest (exclusive licensee) asserted six related patents claiming extended‑release memantine formulations (e.g., Namenda XR) against Teva after Teva filed an ANDA with a Paragraph IV certification.
  • Representative claim 1 of the ’209 patent recites an extended‑release memantine composition that, when administered, “provides a plasma memantine concentration profile, as measured in a single‑dose human PK study, characterized by a change in memantine concentration as a function of time (dC/dT) that is less than 50% that of an immediate release dosage form … measured between 0 to Tmax of the immediate release form.”
  • Forest proposed either leaving the highlighted phrase unconstrued or construing it so the immediate‑release comparator could be the computer‑generated profile shown in Figures 1A/2D; Teva argued the claim is indefinite because it requires human PK measurements but provides no adequate study design, producing variable results.
  • The district court construed the claim to require human pharmacokinetic studies for the compared concentration profiles and held the claims indefinite under 35 U.S.C. § 112, ¶ 2 because the specification and prosecution history did not specify a study design and extrinsic evidence showed wide variability among human PK studies.
  • The Federal Circuit affirmed, rejecting Forest’s proposed human‑to‑computer comparison, finding the intrinsic record requires human‑study comparisons and that Forest waived the alternative argument that both profiles must be measured in the same human study because it had expressly opposed that position below.

Issues

Issue Plaintiff's Argument Defendant's Argument Held
Whether the claim term requiring a dC/dT comparison is indefinite under § 112, ¶ 2 Forest: claim should be read to allow comparison of an extended‑release human PK profile to the computer‑generated immediate‑release profile in Figures 1A/2D (or otherwise be left unconstrued) Teva: claim requires human PK measurements for the comparison but the patent/specification do not specify study design, and human studies vary, making the claim indefinite Court: claim requires human PK measurements for both profiles; because no adequate study design is specified and extrinsic evidence shows wide variability, the claims are indefinite and invalid
Whether the immediate‑release comparator may be the computer‑generated profile in Figures 1A/2D Forest: figures supply the immediate‑release baseline for the claim comparison Teva: figures are illustrative computer predictions and do not define the claimed comparator; intrinsic and prosecution history point to human studies Court: figures are merely illustrative and do not define the claim comparator; intrinsic evidence (and prosecution history) require human PK comparisons
Whether the claim should be construed to require that both profiles be measured in the same human study Forest (on appeal): court should adopt Teva’s alternative construction requiring the same study (if court rejects Forest’s main construction) Teva: the same‑study requirement is a proper construction and avoids indefiniteness Court: Forest expressly and repeatedly opposed the same‑study construction below and thus waived this argument on appeal; court did not adopt same‑study construction
Whether extrinsic evidence can cure indefiniteness by identifying a study design or technique a POSA would know to use Forest: extrinsic evidence could identify appropriate studies or show how to implement the claim Teva: extrinsic evidence shows PK results vary widely across legitimate study designs Court: extrinsic evidence showed wide variability and did not point to a single, defined technique; accordingly indefiniteness remains

Key Cases Cited

  • Nautilus, Inc. v. Biosig Instruments, Inc., 134 S. Ct. 2120 (establishes the reasonable certainty standard for indefiniteness)
  • Sonix Tech. Co. v. Publications Int'l, Ltd., 844 F.3d 1370 (standard of review: indefiniteness de novo; factual findings based on extrinsic evidence reviewed for clear error)
  • UltimatePointer, L.L.C. v. Nintendo Co., Ltd., 816 F.3d 816 (same standard of review principles)
  • Dow Chem. Co. v. Nova Chems. Corp. (Canada), 803 F.3d 620 (claims indefinite where required measurements vary by technique and patent does not specify which technique to use)
  • Honeywell Int'l, Inc. v. Int'l Trade Comm'n, 341 F.3d 1332 (indefiniteness when claimed measured quantity depends on varying techniques and intrinsic record fails to specify technique)
  • Liberty Ammunition, Inc. v. United States, 835 F.3d 1388 (specification can supply a point of comparison when it identifies a conventional baseline)
  • Interactive Gift Exch., Inc. v. Compuserve Inc., 256 F.3d 1323 (issues with urging new or inconsistent claim constructions on appeal)
  • N. Telecom Ltd. v. Samsung Elecs. Co., 215 F.3d 1281 (disfavor of appealing claim constructions that the party advocated below)
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