Teva Pharmaceuticals and its related firms (“The Petitioners” or “Teva”) are the owners of a patent on a manufacturing method for a drug known as Copaxone, used for treating multiple sclerosis (the “drug”). 

Sandoz Inc. and other firms (“The Respondents”) submitted Abbreviated New Drug Applications (ANDAs) on the drug. The application was brought before the Food and Drug Administration (FDA) to produce and market generic versions of Copaxone. 

On getting to know about the Respondents’ application,  Teva sued the Respondents for patent infringement. Teva relied on two claims before the District Court. 


At the District Court, Teva’s claims centered on using different molecular weight methods to distinguish between polymer samples. However, the District Court failed to distinguish between the different methods. Instead, it held that the claims were not indefinite, as argued by the Respondents. Hence, it held that the patent claims were sufficiently definite and valid, amounting to patent infringement by the Respondents. 

Dissatisfied, the Respondents appealed to the United States Court of Appeals ( the “Federal Circuit”). The Federal Circuit found the molecule weight term indefinite and the patent invalid. In arriving at its decision, the Federal Circuit reviewed all aspects of the claim construction issue de novo, including the determination of subsidiary facts. 

Teva sought further review before the Supreme Court. One of the issues for determination at the Supreme Court was whether a District Court’s finding of fact on a patent claim could be reviewed de novo for the first time as done by the Federal Circuit. 

In a majority opinion of 7-2 led by Justice Breyer, it was held that a federal appellate court could only overturn the lower court’s finding of fact if it is clearly erroneous. The Supreme Court majority relied on the Federal Rule of Civil Procedure 52(a)(6). 

It was further held that the construction of a patent claim is essentially a factual determination. Thus, it should be governed by well-established standards as laid down in the Federal Rule of Civil Procedure. The Supreme Court also found that the Federal Circuit did not accept Teva expert’s explanation while reviewing de novo. Thus, it also failed to see whether the District Court’s decision was clearly erroneous. 

On this note, the Supreme Court remanded the case back to the Federal Circuit with an order that the Federal Circuit should apply the correct legal standards. It also ordered that the proper legal measures be used to determine whether the claims were definite or otherwise. 

In the leading dissenting opinion, the Supreme Court held that patent construction claims were a question of law. Thus, the Federal Rule of Procedure was not the controlling standard. Instead, the rule of procedure applied only to questions of fact. As a result, he held that the Federal Circuit was right to have used the de novo standard of review. 


Justice Thomas, who wrote the leading dissenting opinion, explained further that a District Court’s determination was factual if it dealt with the historical fact of the case. It was legal if it had applicable rules. 

As in this case, patent construction claims should be considered a question of law. 


Disclaimer: The views and opinions expressed throughout this blog are the views and opinions of the individual author(s) and/or contributor(s) and do not necessarily reflect the views and opinions of our firm, CIONCA IP Law. P.C.

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  • CIONCA IP TEAM (SE)11/12/2021 4:56:57 PM

    Medical Patents

Marin Cionca | Founder of CIONCA IP

Marin Cionca, Esq.

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