Monday, April 16, 2018

CAFC does organic chemistry enantiomers in SUMITOMO case; "organic chemistry textbooks as irrelevant"

Initially, the CAFC noted:

This Hatch-Waxman appeal requires us to construe
the scope of a claim depicting a compound’s chemical
structure. Although the compound can exist in two different
three-dimensional orientations that are mirror images
of each other [enantiomers], only one is portrayed in the claim. The
district court construed the claim to cover the two threedimensional
orientations in isolation—both the one shown
in the claim and its mirror image—as well as mixtures of
the two in any ratio. The parties then stipulated to
infringement and the entry of an injunction. We agree
that, at a minimum, the claim encompasses the specific
orientation depicted.


As explained below, the plain claim language and
specification demonstrate that, at a minimum, claim 14
covers what it depicts: the (–)-enantiomer. This suffices
to resolve the parties’ dispute because Appellants concede
that the district court’s judgment can be affirmed if we
conclude that claim 14 at least covers the (–)-enantiomer.
See Oral Arg. at 8:40–9:10, http://oralarguments.

Of past history:

This outcome comports with previous cases rejecting
similar attempts to limit claims to racemic mixtures.
Although differences in the patents’ specifications make it
such that they are not factually identical to the current
appeal, this does not detract from the convincing intrinsic
evidence we have required in cases confining otherwiseunrestricted
claims to racemic mixtures. For example, in
Pfizer, Inc. v. Ranbaxy Laboratories Ltd., Ranbaxy sought
to limit a claim depicting a specific three-dimensional
orientation to a racemic mixture. 457 F.3d 1284, 1288–89
(Fed. Cir. 2006). The compound at issue had four isomers:
R-trans, S-trans, R-cis, and S-cis.1 The specification
disclaimed the R-cis and S-cis isomers, and it only disclosed
reaction sequences that produced racemic mixtures.
Ranbaxy argued that the specification’s disclosure,
combined with the convention that a racemate is often
represented by drawing one of the constituent enantiomers,
justified limiting the claim to a racemic mixture.
We rejected these arguments because the claim itself
depicted the R-trans enantiomer, and unlike other claims
in the same patent, it was not limited by the “trans-(±)”
designation. Id. at 1289.


Appellants’ claim construction arguments conflict
with Pfizer and other precedent because they seek to
import limitations from the specification into the claim.

Of textbooks:

Finally, Appellants’ organic chemistry textbooks and
expert testimony do not compel a different result. Extrinsic
evidence is, in general, “less significant than the
intrinsic record in determining ‘the legally operative
meaning of claim language.’” Phillips, 415 F.3d at 1317
(quoting C.R. Bard, Inc. v. U.S. Surgical Corp., 388 F.3d
858, 862 (Fed. Cir. 2004)). This is particularly so here,
where the intrinsic record demonstrates that claim 14’s
structure covers at least the (–)-enantiomer. See Vitronics
Corp., 90 F.3d at 1583 (“In most situations, an analysis of
the intrinsic evidence alone will resolve any ambiguity in
a disputed claim term. In such circumstances, it is improper
to rely on extrinsic evidence.”). In any event, we
see no clear error in the district court’s rejection of the
organic chemistry textbooks as irrelevant or contradictory
to Appellants’ construction. See Teva, 135 S. Ct. at 841.
And while Appellants’ expert contends that it is conventional
in the art to use a single enantiomer as shorthand
for a racemic mixture, he does not state that a person of
ordinary skill would always understand the depiction of a
single enantiomer to exclude the very enantiomer depicted.
See J.A. 1015–16 ¶ 27


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