Amarin Corp Plc (AMRN)

[IgnoranceIsBliss]

“De Novo” Standard of Review

De novo review gives no deference to the trial court. The appellate court is free to write on a clean slate, so appellants desire this form of review over all others. Appellees, on the other hand, will do their best to frame issues in a way that avoids this nondeferential standard of review.

The Federal Circuit applies de novo review to questions of law,2 such as statutory interpretations, patent claim constructions, and grants or denials of judgment as a matter of law.3 It also reviews de novo the legal aspects of patent validity, including the ultimate conclusion of obviousness and whether a claim is directed to statutory subject matter, lacks enablement, or is indefinite.4 However, when the legal conclusion rests on factual underpinnings, the Federal Circuit will review those factual underpinnings under the clearly erroneous standard or the substantial evidence standard, discussed below.5

“Clearly Erroneous” Standard of Review

When a trial judge finds facts, such as in a bench trial, Federal Rule of Civil Procedure 52(a)(6) dictates that the Federal Circuit may not set aside those findings unless they are “clearly erroneous.“6 A finding is “clearly erroneous” when, although there is evidence to support it, the entire record leaves the reviewing court with a definite and firm conviction that a mistake was made.7 The reviewing court cannot reverse the trial judge’s account of the evidence if it is plausible in light of the entire record, even if the reviewing court is convinced that it would have weighed the evidence differently.8 Although the same “clearly erroneous” standard applies to findings based on documentary evidence as to those based on oral testimony, in practice, the Federal Circuit often gives special deference to the trial judge’s credibility determinations.