IBSA Institut Biochimique, S.A. v. Teva Pharms. USA, Inc.

Tirosint®/levothyroxine sodium

July 31, 2020

GENERICally Speaking: A Hatch Waxman Litigation Bulletin

Case Name: IBSA Institut Biochimique, S.A. v. Teva Pharms. USA, Inc., No. 2019-2400 (Fed. Cir. July 31, 2020) (Circuit Judges Prost, Reyna, and Hughes presiding; Opinion by Prost, C.J.) (Appeal from D. Del., Andrews, J.)

Drug Product and Patent(s)-in-Suit: Tirosint® (levothyroxine sodium); U.S. Pat. No. 7,723,390 (“the 390 Patent”)

Nature of the Case and Issue(s) Presented: The 390 patent claimed pharmaceutical formulations used to treat thyroid disorders. The parties’ primary dispute was the claim construction of “half-liquid.” The intrinsic record did not define “half-liquid.” IBSA argued that this term meant “semi-liquid, i.e., having a thick consistency between solid and liquid.” Teva argued that the term was indefinite, or, in the alternative, that it should be construed as “a non-solid, non-paste, non-gel, non-slurry, non-gas substance.”

IBSA presented evidence that an earlier Italian Application used the term “semiliquido” in the same places that the 390 patent used “half-liquid,” indicating that a POSITA would understand “half-liquid” and “semi-liquid” to be synonyms. But the district court explained that there were a number of differences between the certified translation and the 390 patent specification and gave no weight to that document. The district court also noted that, during prosecution, the applicant proposed a dependent claim using the term “semi-liquid,” which depended from an independent claim that recited a “half-liquid.” As to the extrinsic record, the district court found that IBSA failed to present evidence that the term “half-liquid” was known in the art.      

The district court next attempted to determine whether a skilled artisan could nevertheless ascertain a reasonably certain meaning for “half-liquid.” Based on the claim language, the district court noted that “half-liquid” was neither a liquid nor a solid. Further, reading the specification, a POSITA would have understood that a “half-liquid” was not, or at least was not necessarily, a gel or a paste. And after reviewing the prosecution history, the district court determined that the applicant disclaimed some portion of the claim’s scope that might have otherwise qualified as a half-liquid. In the end, the district court determined that ambiguity rendered it impossible for a POSITA to know, with reasonable certainty, the scope of the term “half-liquid” and found the ‘390 patent invalid as indefinite. The Federal Circuit affirmed.

Why Teva Prevailed: The Federal Circuit noted that the claim language did not make “half-liquid” reasonably clear. It next looked to the specification and concluded that the passage explaining that “said soft capsule contains an inner phase consisting of a liquid, a half-liquid, a paste, a gel, an emulsion or a suspension comprising the liquid (or half-liquid) vehicle and the thyroid hormones together with possible excipients in suspension or solution” provided no greater clarity. As to the prosecution history, the Federal Circuit agreed with Teva’s conclusion that a POSITA would consider the different usage of “half liquid” and “semiliquido” in the Italian Application to be intentional, indicating that the different words had different scopes.

Oren D. Langer


Managing Partner, New York Office
Member of Executive Board

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