Teva Pharm. United States, Inc. v. Sandoz, Inc.
The Supreme Court ruled that when a trial judge resolves a factual dispute about scientific evidence while interpreting the wording of a patent, appeals courts must accept that factual finding unless it was clearly wrong -- they cannot simply redo the fact-finding themselves.
The decision came in a fight over a multiple sclerosis drug patent, where experts disagreed about how to read a chemistry term in the patent. The ruling changes how the specialized patent appeals court reviews trial court decisions nationwide, giving more weight to what happens at trial.
“We hold that the appellate court must apply a "clear error," not a de novo, standard of review.”
The Court's core holding on how appeals courts must review factual findings in patent claim construction.
How it got here: A federal trial court found the patent valid after weighing expert testimony; the Federal Circuit reviewed the trial court's factual findings from scratch and found the patent invalid; Teva asked the Supreme Court to review that standard.
The Case in Depth
What happened
Teva Pharmaceuticals owns a patent covering a manufacturing method for Copaxone, a multiple sclerosis drug, describing its active ingredient as having a "molecular weight of 5 to 9 kilodaltons." Sandoz, seeking to sell a generic version, argued the patent was invalid because "molecular weight" could mean three different things and the patent never specified which. Both sides presented expert testimony to the trial court about how a skilled scientist would read the term.
The question before the Court
When a patent dispute turns on a judge's factual findings about scientific evidence, should appeals courts review those findings from scratch, or accept them unless clearly wrong?
Why it matters
Patent owners and companies challenging patents now know that a trial judge's resolution of underlying scientific or technical fact disputes will carry real weight on appeal, rather than being freely second-guessed. This is likely to make trial court proceedings -- including expert testimony -- more consequential in patent litigation and could reduce the number of claim-construction rulings the Federal Circuit reverses.
What changes now
The case returns to the Federal Circuit, which must reconsider its ruling that the patent was invalid, this time reviewing the trial court's factual findings about the disputed scientific chart only for clear error rather than starting over. The Federal Circuit must also address two other factual findings Teva says were wrongly overturned. The underlying question of whether the patent is valid remains open pending that further review.
What this does not decide
The Court did not decide whether Teva's patent is actually valid, or whether the specific factual findings at issue were correct -- only that they must be reviewed for clear error rather than from scratch. It left it to the Federal Circuit to apply this standard on remand, including as to two additional disputed findings.
Concurrences and dissents
Dissent — Justice Thomas
“Because it does not, Rule 52(a)(6)does not apply, and the Court of Appeals properly applied a de novo standard of review.”The dissent's central objection that claim construction findings are not true 'findings of fact.'
Justice Thomas, joined by Justice Alito, agreed there is no special exception to Rule 52(a)(6) for claim construction, but argued the real question is whether claim construction ever produces genuine 'findings of fact' at all. He argued patents are more like statutes than contracts or deeds because they are government-issued grants binding the public at large, so subsidiary determinations like how a 'skilled artisan' would understand a term are really legal conclusions, not historical facts. He would have held the Federal Circuit's de novo review was proper.
How the Court got there
The legal reasoning, step by step
- The Court started from Federal Rule of Civil Procedure 52(a)(6), which says appeals courts 'must not set aside' a trial court's factual findings unless they are 'clearly erroneous' -- a deferential standard that applies broadly, without carving out particular categories of facts.
- The Court explained that its earlier decision in Markman v. Westview Instruments, which held that judges rather than juries interpret patent claims, was about who decides the ultimate legal question -- not about creating an exception to the ordinary rule that underlying factual findings get deferential review.
- Interpreting a patent claim is similar to interpreting other written documents like deeds or contracts: usually it is purely a legal question, but when a document uses technical terms not commonly understood, courts may need to hear evidence and make factual findings about how those terms were understood, and such findings are treated like any other factual finding.
- Because patent claim construction sometimes requires resolving competing expert testimony -- including judging which expert's account of scientific understanding is more credible -- that resolution is a factual determination, and practical considerations (trial judges' greater familiarity with the evidence and witnesses) reinforce deferential review.
- Applying this framework, the Court held that when a trial judge resolves a dispute between experts about how a skilled scientist would understand a technical term, that resolution must be reviewed only for clear error, while the judge's ultimate legal conclusion about what the claim means remains open to fresh review on appeal.
- The Court then applied this rule to the specific dispute over a data chart in the patent, concluding that the appeals court failed to identify any clear error in the trial judge's finding about how the chart's peak should be read, so the appeals court's rejection of that finding could not stand.
Doctrinal impact
Cases affected by this decision
Reaffirms Markman v. Westview Instruments, Inc. (517 U.S. 370)
The Court relies on Markman's rule that judges, not juries, interpret patent claims, clarifying it doesn't exempt factfinding from normal appellate review.
Reaffirms Pullman-Standard v. Swint (456 U.S. 273)
The Court relies on this case's rule that Rule 52(a) applies to both subsidiary and ultimate facts without exceptions.