In a surprising decision in Teva Canada Ltd. V. Pfizer Canada
Inc. 2012 SCC 60, the Supreme Court of Canada has unanimously ruled
that Pfizer's patent covering ViagraTM is invalid.
The decision paves the way for Teva and others to market generic
versions of ViagraTM before the patent's 2014
The ruling comes more than five years after Teva commenced
proceedings under the Patented Medicines (Notice of Compliance)
Regulations challenging Pfizer's patent.
Teva initially alleged that Pfizer's patent was invalid for
obviousness, lack of utility, and insufficiency of disclosure.
However, the Federal Court found Teva's allegation unjustified
and issued an Order prohibiting the Minister of Health from issuing
a Notice of Compliance to Teva, preventing it from marketing a
generic version of ViagraTM.
Teva then appealed to the Federal Court of Appeal, dropping the
allegation of obviousness, but the appeal was dismissed. Teva
appealed again - to the Supreme Court.
The Supreme Court unanimously found that Pfizer's patent did
not meet the requirements for sufficiency of disclosure and was
The patent related to use of sildenafil (the active compound in
ViagraTM) and various other compounds for the treatment
of erectile dysfunction (ED). Sildenafil was initially developed by
Pfizer in the mid 1980's for the treatment of hypertension and
The patent contained seven claims of progressively narrower
scope. Claim 1 encompassed a staggering 260 quintrillion compounds,
while claims 6 and 7 related to individual compounds. Claim 7
relates specifically to sildenafil.
Sildeafil had been shown to be effective in treating erectile
disfunction prior to filing the patent application. None of the
other claimed compounds had.
The patent specification stated that"one of the especially
preferred compounds induces penile erection in impotent
males", but did not identify that the compound was
The Supreme Court held that for the disclosure of the
specification to be sufficient it must enable the"public to
make the same successful use of the invention as the inventor could
at the time of the application". Pfizer's patent
specification failed this test because it did not indicate that
sildenafil was the effective compound. Expert evidence showed that,
even if only claims 6 and 7 were considered, a person skilled in
the art would not have known which the effective compound was.
Further testing would have been required.
The Court stated that"Pfizer gained benefit under the Act -
exclusive monopoly rights - while withholding disclosure in spite
of its disclosure obligations. As a matter of policy and sound
statutory interpretation, patentees cannot be allowed to
"game" the system this way."
Having concluded that the disclosure of the specification was
insufficient, the Court ruled the patent invalid. This is somewhat
surprising, considering that the case arose under the Patented
Medicines (Notice of Compliance) Regulations. The typical remedy
under these Regulations would be to simply allow the Minister of
Health to issue a Notice of Compliance.
Pfizer is challenging the ruling on the basis that the Supreme
Court did not have jurisdiction to invalidate the patent, but in
the meantime the ruling is proving problematic. The Federal Court
recently granted summary judgement to another generic drug
manufacturer - Apotex - inApotex Inc. vPfizer Ireland Pharma, 2012
FC 1339 declaring Pfizer's patent invalid, as "no result
is possible other than a finding that the '466 patent is
invalid" in view of the Supreme Court's ruling.
Whatever the outcome of Pfizer's challenge, the decision
provides a strong reminder of the obligation to fully disclose an
invention in the specification, and the potentially dire
consequences of withholding information. If Pfizer had disclosed
that sildenafil was the compound that had worked, the case may well
have been decided in its favour.
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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.
Last year we saw the Canadian Courts release trademark decisions that granted a rare interlocutory injunction, issued jailed sentences for failure to comply with injunctive relief, grappled with trademark and internet issues...
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