A recent decision of the Federal Court in Allergan Inc. v.
Apotex Inc. et al. (2016 FC 344), relating to the drug
Gatifloxacin, appears to have regressed the issue of expert
"blinding" in patent cases. Expert "blinding"
is a relatively recent trend in patent litigation where a litigant
intentionally "blinds" its expert witness to certain
issues and materials in an effort to afford their opinions a higher
degree of credibility. In the Gatifloxacin decision, the Court
appears to have endorsed expert "blinding" in patent
cases as not only de rigueur but, perhaps necessary; while other
recent decisions of the very same Court have seriously questioned
the value of the recent trend.
In the Gatifloxacin case, the Federal Court was persuaded by
Apotex that Allergan's expert evidence was flawed by not being
properly "blinded". Allergan's experts had reviewed
Apotex's Notice of Allegation, as well as the patent-in-suit,
prior to preparing their opinions. The Court agreed that the
opinions of Apotex's experts should be preferred over those of
Allergen as they were "blinded" from the patent when
giving evidence on the common general knowledge, and
"blinded" from the parties' positions throughout.
A few years ago, the "blinding" of experts in patent
cases was virtually unheard of. Indeed, one might ask: how could an
expert assist a court in understanding, for example, the art and
science of a patent and its claims, without having first read the
The "blinding" trend gained momentum in some
pharmaceutical patent decisions involving Apotex. Indeed, in the
Gatifloxacin case, Apotex relied on three of its own cases in
support of its "blinding" argument: (i) AstraZeneca
v. Apotex, 2014 FC 638
("AstraZeneca"); (ii) Teva Canada v.
Apotex, 2014 FC 1070 ("Teva"); and
(iii) Takeda v. Apotex, 2015 FC 570.
These decisions have been distinguished, however, in other
decisions of the Federal Court.
For example, in Eli Lilly Canada Inc. v. Apotex Inc.,
2015 FC 875 ("Lilly"),
published on July 20, 2015, the Court rejected Apotex's
"blinding" argument. The Court found that Apotex had
applied the Teva and AstraZeneca decisions
"out of context", noting that "[n]either case can be
read for the position that Apotex sought to advance here, namely,
that in any case where one party blinds its experts but the other
does not, the former's evidence is to be preferred" and
that "these two decisions must be limited to the facts that
arose in [those] cases".
Even more recently, but before publication of the Gatifloxacin
decision, the Court held in Shire Canada Inc. v. Apotex
Inc., 2016 FC 382 ("Shire") that
"favouring the evidence of experts who have been blinded has
not been raised to the level of a legal principle that must be
applied in all cases, and is merely persuasive". In addition,
the Court noted that "the blinding of witnesses is no
guarantee that the expert evidence before the Court is
In deciding the Gatifloxacin case, the Court addressed neither
Lilly nor Shire on the issue of expert
"blinding". It would appear these cases were not brought
to the Court's attention on this point in the parties'
Accordingly, there may be some difficulty in understanding how
these decisions fit together and what, if any, significance can be
attributed to the "blinding" of an expert. Nor is there
clear guidance in the cases as to how an expert is properly
"blinded". For example, should an expert read the whole
of the patent-in-suit or just the claims? If just the claims then
which ones: those in dispute or all of them? And, how can the
expert assist in determining the characteristics of the person
skilled in the art of the patent without reading it, when it is
that perspective which is supposed to be brought to bear in reading
It is possible that the Federal Court of Appeal will soon
clarify the issue of expert "blinding", as the
Gatifloxacin decision is currently under appeal.
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The Federal Court dismissed a motion by Apotex seeking particulars from Allergan's pleading relating to the prior art, inventive concept, promised utility and sound prediction of utility of the patents at issue.
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