In a recent decision, the Supreme Court of Canada held that
Pfizer's patent relating to sildenafil, the effective compound
in Viagra, did not meet the disclosure requirements of the
Patent Act, R.S.C. 1985, c. P 4. The Court deemed the
patent to be invalid because of Pfizer's failure to comply with
those requirements. As a result of the decision, other
pharmaceutical companies, including the appellant Teva Canada
Limited, will have an opportunity to begin selling generic versions
of the drug in advance of the patent's expiry date in 2014. The
Court's full decision can be found here. Pfizer has just recently announced that it is reducing
the cost of Viagra in order to remain competitive with generic
offerings of the drug.
The central issue on appeal was whether or not Pfizer had
complied with the disclosure requirements of the Patent
Act. Pfizer's patent application included seven different
"cascading" claims relating to various combinations of
compounds. Only claim 6 and claim 7 related to individual
compounds, with claim 7 pertaining specifically to sildenafil. At
the time the patent application was filed, Pfizer was aware that
sildenafil was the only effective compound for the treatment of
erectile dysfunction; however, the application did not disclose
which compound was effective. The Court noted that further testing
would have been required to determine which compound was
Teva's application was unsuccessful at both the Federal
Court and the Federal Court of Appeal. Both of those Courts
considered whether a single claim within an application that
contains several claims can be considered in isolation for the
purposes of preserving Pfizer's patent over the single valid
claim. The Federal Court held that the invalidity of claims 1
through 6, which were invalid on the basis that the compounds
claimed were ineffective, did not affect the validity of claim 7 of
Teva argued that the Federal Court and Federal Court of Appeal
erred by limiting the disclosure analysis to the only effective
claim, claim 7. The Supreme Court agreed with Teva on the basis
that Pfizer had not complied with the disclosure requirements of
the Patent Act (found within s. 27(3)). The requirements
state that specification of an invention (which specification
contained all claims for all seven compounds) must "set out
clearly the various steps in a process, or the method of
constructing, making, compounding or using a machine, manufacture
or composition of matter, in such full, clear, concise and
exact terms as to enable any person skilled in the art or science
to which it pertains, or with which it is most closely connected,
to make, construct, compound or use it".
In determining that Pfizer had not complied with s. 27(3), the
Court followed the reasoning from Pioneer Hi-Bred Ltd. v.
Canada (Commissioner of Patents),  1 S.C.R. 1623, at p.
1636. In that decision, the Court stated that: "(t)he
description must be such as to enable a person skilled in the art
or the field of the invention to produce it using only the
instructions contained in the disclosure". The Court found
that Pfizer had not complied with this requirement, as it was not
clear which of the claimed compounds was effective for the
treatment of erectile dysfunction. A skilled person would not have
been able to determine which compound was effective without further
testing. The lower Courts erred by limiting their consideration of
the disclosure requirements to each of the individual compounds
rather than to the specification as a whole.
The case notes that Teva had been able to reproduce the drug,
albeit with additional testing of the claimed compounds to
determine which was effective. Pfizer argued that disclosure
requirements had been met because of Teva's ability to
reproduce the drug. However, the need for additional testing simply
served to confirm that Pfizer's disclosure did not comply with
the requirements of the Patent Act.
The Supreme Court observed that "(t)he patent system
is based on a "bargain", or quid pro quo: the inventor is
granted exclusive rights in a new and useful invention for a
limited period in exchange for disclosure of the invention so that
society can benefit from this knowledge." The
Court's decision is consistent with this principle, and serves
to clarify that full disclosure is required for parties to enjoy
monopoly rights over their inventions. The decision limits a
party's ability to enjoy those monopoly rights if they attempt
to conceal their invention. Parties who attempt to "game"
the system by concealing an invention will risk losing their
exclusive rights to the invention on the basis that full disclosure
has not been made.
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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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