Federal Circuit Narrows “Factual Findings” Requiring Deference During Claim Construction

The Disposition:  On remand from the Supreme Court, the Federal Circuit affirmed its earlier decision finding the claims of Teva’s Orange Book patent for Copaxone invalid as indefinite.  See Teva Pharmaceuticals USA, Inc. et al. v. Sandoz, Inc. et al., No. 12-1567 (June 18, 2015).

Case History.  In its initial review, the Federal Circuit reversed the district court’s ruling that the claims of U.S. Patent No. 5,800,808 (“the ʼ808 patent”) were not indefinite.  See Teva Pharms. USA, Inc. v. Sandoz, Inc., 723 F.3d 1363 (Fed. Cir. 2013)As we previously wrote, the Supreme Court vacated the Federal Circuit’s finding, concluding that Teva identified at least one factual finding made by the district court that the Federal Circuit should have reviewed for clear error.  Teva Pharms. USA, Inc. v. Sandoz, Inc., 135 S. Ct. 831 (U.S. 2015).  The Supreme Court held that while the ultimate construction of a claim term is a legal conclusion subject to de novo review, a district court’s factual findings underlying its claim construction should be reviewed only for clear error.

The Issue.  On remand, the same issue was before the Federal Circuit as in 2013— whether the district court erred in determining that one of skill in the art would have understood the claim term “molecular weight” to mean peak average molecular weight, known as Mp.  It was undisputed that “molecular weight” can refer to Mp, Mw (weight average), or Mn (number average), and that each of these values is calculated differently and will yield different results for the same polymer.

The Federal Circuit’s Analysis.  Despite the change in standard of review of claim by the Supreme Court, the Federal Circuit once again reversed the district court’s ruling, and found the claim term indefinite.  The Federal Circuit reviewed the district court’s factual findings with deference, and found no clear error.  But the Federal Circuit minimized the relevance of these findings—which generally concerned the impact that various statements made during prosecution would have had on one of skill’s understanding of “molecular weight”—to the legal analysis.  As the Court explained, “the determination of the significance of statements made during prosecution to the claim construction is a question of law.”  “A party cannot transform into a factual matter the internal coherence and context assessment of the patent simply by having an expert offer an opinion on it.”

This case involved a relatively unique situation.  The inventors had defined “molecular weight” to mean two different things (Mp vs. Mw) during prosecution of two continuation applications of the patent-in-suit.  During prosecution of the first of these continuations, the applicants overcame an indefiniteness rejection by arguing that one of skill would have understood “molecular weight” to refer to Mw because the referenced unit, kilodaltons, implies that method of measurement.  Teva successfully proved at the district court that this statement was scientifically incorrect.  The Federal Circuit accepted this finding, but considered it irrelevant to the inquiry.  “The fact that [the inventors’] explanation contained further elaboration which itself included a scientific error does not undermine the statement’s legal import.”  At the end of the day, the Court found that no factual disputes could overcome the legal import of a claim term having multiple meanings coupled with inconsistent statements made during prosecution adopting two different meanings.

This ruling demonstrates that even though the Court must limit its review of a district court’s factual findings for clear error, it will not discount those findings to the extent they relate to the impact that intrinsic evidence would have had on the understanding that one of skill would have gleaned from statements in the intrinsic record.”  It remains to be seen, however, whether the Federal Circuit will maintain a strong stance on this issue when the statements at issue lack the clarity presented by the statements made during prosecution of the patent at issue in Teva v. Sandoz.