The Supreme Court on Monday, March 31, 2014, granted certiorari in Teva Pharmaceuticals USA, Inc. v. Sandoz, Inc., Case 13-854 (Mar. 31, 2014), a case that has the potential to overturn years of precedent leading back to the 1998 en banc decision in Cybor Corp. v. FAS Techs., Inc., 138 F.3d 1448 (Fed. Cir. 1998). Cybor held that claim construction is reviewed de novo (without deference) by the Federal Circuit. The issue before the Supreme Court is whether a district court’s factual finding in support of its construction of a patent claim term may be reviewed de novo as the Federal Circuit requires and did in the present case, or only for clear error as Federal Rule of Civil Procedure 52(a) requires.
One consequence of de novo claim construction review is the high reversal rate of district court claim construction rulings – the Federal Circuit reverses over 33% of the claim construction rulings that it reviews. As a result, patent litigation is lengthy, expensive, and difficult to predict. The Federal Circuit in recent years, however, has issued several sharply written dissents urging the court to revisit its decision in Cybor. For example, in Retractable Techs., Inc. v. Becton, Dickinson & Co., No. 2010-1402 (Fed. Cir. Oct. 31, 2011), Chief Judge Rader, Judge Moore and Judge O'Malley opined that the “no deference” rule of Cybor needed reconsideration.
At issue before the district court and on appeal was construction of the claim term “molecular weight” found in pharmaceutical compound claims that recite a product called copolymer-1 and methods of making copolymer-1. Teva asserted its patent in an attempt to block multiple companies from selling a generic version of its blockbuster multiple-sclerosis drug Copaxone®. Defendants argued that "molecular weight" can be calculated at least three different ways, which makes the claim indefinite. The district court rejected this argument, and made factual findings with respect to how a person of ordinary skill in the art would understand the term. The Federal Circuit reversed after reviewing the claim construction decision interpreting “molecular weight” de novo, reaching a different conclusion from the evidence presented to the district court.
The Supreme Court will assess whether factual findings in patent claim construction are subject to de novo review or are entitled to the more deferential standard of review for clear error. Absent an extension, amicus briefs in support of the petitioner (Teva) will be due on May 22, 2014, and amicus briefs in support of the respondents will be due on June 23, 2014.
 Ted Sichelman, Myths of (Un)Certainty at the Federal Circuit, 43 Loy. L.A. L. Rev. 1161 (2010); http://www.law360.com/articles/433763/reconsidering-claim-construction-standard-of-review