Teva Pharm. United States, Inc. v. Sandoz, Inc.

Background

A pharmaceutical company (Teva) sued a rival generic drug maker (Sandoz) over a patent covering Copaxone, a multiple sclerosis drug whose active ingredient was described as having "a molecular weight of 5 to 9 kilodaltons." The parties disputed what "molecular weight" meant because scientists use different ways to calculate it. The trial judge heard expert testimony and found that a skilled scientist would read the patent to mean the peak average measurement, so the judge held the patent definite and valid. The appeals court reversed, treating the trial judge’s factual findings as open to full review.

Reasoning

The Court addressed whether an appeals court should accept or redecide technical factual findings a trial judge makes when interpreting patent claims. Relying on the long-standing rule that an appeals court must accept trial-court factual findings "unless clearly erroneous," the Court held that subsidiary factual disputes about technical terms must be reviewed for clear error. The Court explained that the judge’s ultimate legal interpretation of the written claim remains a legal question the appeals court reviews anew, but not the underlying factual determinations about expert evidence and technical meaning.

Real world impact

This ruling sends the case back to the Federal Circuit for reconsideration under the deferential "clear error" review of the trial judge’s factual findings. It means district judges’ credibility calls about experts and technical details will usually stand unless plainly wrong, while appellate courts still decide the final legal meaning of claim language.

Dissents or concurrances

A dissent argued that claim interpretation involves no true factual findings and that appeals courts should continue full de novo review to preserve uniform patent law interpretations.