Summary – Bayer attempted to broaden the
scope of a product-by-process claim by arguing that the process
recited in the claim was a non-essential feature and should not be
considered as part of the claim. The Court disagreed and found the
process steps essential and not infringed by Cobalt, who wished to
produce the same product through a different method of
Analysis – Bayer holds
Canadian Patent No. 2,261,137, directed to processes for
producing drospirenone (an oral contraceptive marketed as
YasminTM) and drospirenone produced according to these
processes. As this was a decision under the Patented Medicines
(Notice of Compliance) (PM(NOC)) Regulations, the process
claims were not eligible to be asserted. Furthermore, Cobalt
indicated that the patented process would not be used. Therefore,
only product claim 13 was at issue. Claim 13 is specifically
directed to purified drospirenone, claimed in terms of its method
of manufacture and is as follows:
A product prepared according to the process of claim 12, wherein
the product comprises drospirenone and less than 0.2% contaminants
from the isolactone ... and the 6,7-ring opening product that is
produced by acidic attack on the 6,7-methylene group.
The process referred to in claim 13 involves three steps,
including ruthenium salts-mediated oxidation. In addition, two
named intermediates were recited as being produced prior to final
production of drospirenone.
Bayer argued that claim 13 should be interpreted broadly to be
directed only to the compound and not to include the recited method
steps. Alternatively, Bayer argued that the method steps should not
be construed to require ruthenium salts-mediated oxidation as
recited but, rather, oxidation by any appropriate metal salt. These
arguments were not well-grounded in either law or fact and, not
surprisingly, the Court disagreed with Bayer's interpretation.
It was found that the method steps and the use of ruthenium
salts-mediated oxidation, both features that were explicitly
recited in the claims, were essential elements of the claimed
Once the question of claim construction was decided, the
question of infringement was a simple one to deal with. Cobalt
stated that they would not infringe this claim because they would
produce drospirenone by another method, which did not use ruthenium
salts-mediated oxidation and did not result in production of the
two intermediates that were recited in the claims. The Court agreed
and found that Cobalt did not infringe the claim at issue.
Accordingly, the validity of claim 13 was not addressed.
Practice Point – Product-by-process
claims are claims directed to a product that is limited in terms of
its method of manufacture. In order for a product-by-process claim
to be patentable, the product itself must be both novel and
inventive, irrespective of the recited process steps. Therefore, in
most cases, it is possible to define the novel product
independently of its method of manufacture (for example, in terms
of a specific purity level unobtainable in the past). It is good
practice to include claims to the product itself, defined in terms
of features that are not process-limited, whenever possible so as
to avoid non-infringement by modifying a process step.
The content of this article is intended to provide a general
guide to the subject matter. Specialist advice should be sought
about your specific circumstances.
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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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