Inadequate Translation of a Non-English Application Leads to US Patent Invalidation

October 13, 2020 – Article

The IBSA Institut Biochimique (“IBSA”) appealed a decision by the U.S. District Court for the District of Delaware holding the claims of U.S. Patent 7,723,390 (“the ’390 patent”) (assigned to IBSA) invalid as indefinite under 35 U.S.C. § 112.

The ’390 patent for “Pharmaceutical Formulations For Thyroid Hormones” claims priority from Italian Patent Application written in Italian. The U.S. application, which matured into the ‘390 patent, is an English translation of the Italian Application and does not incorporate the Italian Application by reference. The ’390 patent provides “pharmaceutical formulations based on thyroid hormones enabling a safe and stable oral administration” and is listed in the Orange Book for IBSA’s Tirosint® product. Tirosint® is a soft gel capsule formulation containing the active ingredient levothyroxine sodium. Teva Pharmaceuticals USA, Inc. (“Teva”) sought to market a generic version of Tirosint® and filed ANDA which included a Paragraph IV certification that the ’390 patent is invalid, unenforceable, or will not be infringed by Teva’s generic product. IBSA filed a lawsuit alleging infringement of certain claims of the ‘390 patent. The district court held the ‘390 patent invalid under 35 U.S.C. § 112. IBSA appealed.

Central to the appeal was the parties’ dispute over the construction of the term “half-liquid” in independent claim 1 reciting (partially) “a soft elastic capsule consisting of a shell of gelatin material  containing a liquid or half-liquid inner phase comprising said thyroid hormones.”

IBSA proposed that the term “half-liquid” should be construed to mean “semi-liquid, i.e., having a thick consistency between solid and liquid.” Teva argued that the term “half-liquid” was indefinite or should be construed as “a non-solid, non-paste, non-gel, non-slurry, non-gas substance.”

The court found, first, that IBSA’s proposed construction was unsupported by the record and, second, that the meaning of “half-liquid” was not otherwise reasonably ascertainable from the record.

The district court first reviewed the intrinsic evidence presented by IBSA. IBSA argued that the Italian Application used the term “semiliquido” in the same places where the ’390 patent used “half-liquid,” and where a certified translation of the Italian Application used “semi-liquid,” pointing that there is a link between these terms such that a person of ordinary skill in the art (“POSA”) would understand “half-liquid” and “semi-liquid” to be synonyms. The district court disagreed.

The court observed that there were a number of differences (and added material) between the certified translation and the ’390 patent’s specification, besides the use of “half-liquid.” Because of these differences, the district court reasoned that the document that best reflected the applicant’s intent was the U.S. application.  The district court gave the Italian Application and the certified translation no weight in its analysis and determined that differences between the certified translation and the ’390 patent’s specification were intentional.

The district court then noted that, during prosecution, the applicant proposed a dependent claim using the term “semi-liquid” which depended on an independent claim that used the term “half-liquid.”  This portion of the prosecution history was “evidence that the applicant did not mean ‘semi-liquid’ when he used the term ‘half-liquid.’” Also, in overcoming an obviousness rejection, the applicant stated that the claimed invention “is not a macromolecular gel-latticematrix” and that the claimed invention is not a “high concentration slurry.” The district court determined that the “applicant disclaimed some portion of the claim’s scope that might otherwise qualify as a half-liquid” and concluded that the “ambiguity renders it impossible for a POSA to know, with reasonable certainty, whether they are dealing with a half-liquid within the meaning of the claim.”

The district court further determined that citation to pharmaceutical references which used the term “semi-liquid,” did not show that “half-liquid” meant “semi-liquid,” and showed that the applicant knew of the term “semi-liquid” yet intentionally chose not to use it. The court found IBSA’s extrinsic evidence “minimally probative” and “unpersuasive”  and that IBSA’s reliance on dictionary definitions, other patents and expert’s opinion (extrinsic evidence) did not support IBSA’s position because they were not in the context of the claimed invention and that it was “exceedingly unlikely that [‘half-liquid’] was a term of art at the relevant date.”

After determining that IBSA’s proposed construction was not supported by the record, the district court sought to determine whether a skilled artisan could nevertheless ascertain a reasonably certain meaning for “half-liquid.” The court determined that claim 1’s language only supported that a “half-liquid” is neither a liquid nor a solid and that a POSA reading the specification would understand that a “half-liquid” is not necessarily a gel or a paste, relying on some passages of the ’390 patent. The district court held the claims invalid as indefinite. IBSA timely appealed.

The Federal Circuit Court looked at the language of the claim and specification and agreed with the district court that the claim language clarifies only that a “half-liquid” differs from a liquid and the specification does not support IBSA’s proposed construction.

 The Court next turned to the prosecution history and disagreed with IBSA that a POSA would find that “half-liquid” and “semi-liquid” are synonyms. The Court noted that besides the differences between the Italian Application and the ’390 patent, Teva also pointed out that claim 1 of the ’390 patent incorporated the fourth embodiment of the ’390 patent, which was not found in the Italian Application, and, unlike the ’390 patent, the Italian Application does not use the term “gel.” The Court agreed with Teva that “a POSA would likely consider the discrepant usage of “half-liquid” and “semiliquido” between the ’390 patent and the Italian Application to be intentional, implying that the different word choice has a different scope.” “[W]hen discrepancies between a foreign priority document and the U.S. filing exist, it may be proper to view the discrepancies as intentional.”

The Court concluded that the intrinsic evidence failed to establish the boundaries of a “half-liquid” and turned to the extrinsic evidence. The Court agreed that extrinsic evidence, including dictionary definitions, other patents, and expert testimony do not support IBSA’s proposed construction. The Court affirmed the judgment of the district court.

This case provides an example how an inadequate English translation of a foreign priority application could lead to invalidation of the US patent. To minimize problems down the road, a U.S. application should incorporate the foreign priority application by reference. As an option, the U.S. application may be drafted by a U.S. attorney.

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