On January 20, 2015, the US Supreme Court rendered its
precedent-setting decision in Teva1 that
reversed the Federal Circuit's practice of reviewing all
District Court claim constructions de novo on appeal.
Instead the Supreme Court found that some decisions are entitled to
deference as a consequence of certain factual findings that require
Courts of Appeal to apply a "clear error" standard of
review, and consequently, bringing the review of US claims
constructions methodology more in line with the Canadian
The phrase within the claim at issue in Teva was
"molecular weight of 5 to 8 kilodaltons", which Sandoz
argued was "fatally indefinite" as the claim did not
establish which method of calculation should be used. After
considering the expert evidence, the District Court concluded the
claim was sufficiently definite as the skilled person would
understand "molecular weight" to be calculated by
"peak average molecular weight". The Federal Circuit
disagreed, finding, on a de novo review, that the term
"molecular weight" was indefinite and thus, the patent
invalid. In Canada, interference with the construction on appeal
would be doubtful, as patents are construed with a mind willing to
understand from the perspective of the skilled
In reversing the Federal Circuit's decision, the US Supreme
Court held that a Court of Appeals must not set aside a District
Court's findings of fact unless it is "clearly
erroneous". While the Supreme Court identified that claims
construction is a question of law, sometimes construction may have
"evidentiary underpinnings" that require a District Court
to resolve subsidiary factual disputes, which like all factual
determinations, must be reviewed for clear error3. While
the Dissent in Teva argued that claims construction does
not involve factual findings, the Majority held that this reasoning
overlooked instances, as was present in Teva, where
parties present competing fact-related claims by different experts,
which must be resolved by the court4.
In describing how to apply a "clear error" standard to
claims construction, the Supreme Court held that often times,
construction requires only an examination of the claim language
without underlying factual disputes, and in these instances,
construction amounts solely to a determination of law that a Court
of Appeals will review de novo. However, where the
District Court must consult extrinsic evidence in order to
understand, for example, the science or meaning of a term, the
District Court will need to make a subsidiary factual finding,
which must be reviewed for clear error on appeal5. The
Supreme Court confirmed however that after resolving any factual
dispute, the ultimate interpretation is still a legal conclusion,
that the Court of Appeal must review de novo. It is only
where the Court of Appeal seeks to overturn the Judge's finding
on an underlying factual dispute that a "clear error"
The decision in Teva brings US claims construction
methodology closer in line with the Canadian approach. While the
use of expert evidence to understand the terms and underlying
science in a claim6 is routinely used by courts in
Canada, construction is purely a question of law7,
reviewable on a "correctness" standard8.
However, as concluded in Teva, a Canadian judge's
assessment of expert evidence and his or her factual determinations
as to the state of the art are considered factual findings, that
may only be reversed on appeal in light of a "palpable and
overriding error"9. Consequently, both Canada and
now the US permit judicial deference on review for factual
determinations during a claim construction.
1 Teva Pharmaceuticals
USA, Inc. v. Sandoz, Inc., No. 13-854 [Teva].
2 Whirlpool Corp. v.
Camco Inc., 2000 SCC 67 at para. 49.
3 Supra note 1 at
4 Ibid at
5 Ibid at
6 Supra note 2
7 Ibid at para.
8 Canamould Extrusions
Ltd. v. Driangle Inc., 2004 FCA 63 at para. 3.
9 Corlac Inc. v.
Weatherford Canada Inc., 2011 FCA 228 at para. 24.
A recent Saskatchewan Court of Queen's Bench decision allowed a court-appointed receiver to sell and transfer intellectual property rights free and clear of encumbrances, finding that a license to use improvements of an invention was a contractual interest and not a property interest.
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