Subject Matter, Obviousness, Double Patenting and Sound Prediction all Issues in Recent FC Case

Subject Matter, Obviousness, Double Patenting and Sound Prediction all Issues in Recent FC Case

Bayer Inc. v Cobalt
Pharmaceuticals Company
FC 1061


This proceeding is an application under the NOC
regulations by Bayer seeking a prohibition order to prevent Cobalt from
manufacturing an oral contraceptive using the two patents at issue. The two
patents at issue: Canadian Patent Numbers 2,179,728 and 2,382,426.

The ‘728 patent is entitled “Composition for a Contraceptive Comprising an Estrogen and a Gestogen”.
The patent claims priority from a German application filed on December 22, 1993
and was filed in Canada under the Patent Co-Operation Treaty (PCT) on December
22, 1994 meaning it will expire December 22, 2014.

The ‘426 Patent is entitled “Pharmaceutical Combination of Ethinylestradiol and Diospirenone for
Use as a Contraceptive”.
The Application was filed under the PCT in Canada
on August 31, 2000. The patent will expire on August 31, 2020.

Several decisions of the UK and US Courts have dealt with
similar patents. Justice Hughes notes that not only are there differences in
law but that there may also be different evidence, different parties and
different patents themselves.


A patent is presumed to be valid in the absence of
evidence to the contrary.[31] The patent holder bears the burden of proving
that the allegations of the generic (second person) are not justified.[32]

A generic must raise all facts and legal arguments in its
Notice of Allegation that it intends to rely upon at trial.[34] Justice Hughes
notes that this may be seen as draconian since, in the period between filing
the NOA and the hearing the law can change. He also points out that it would be
unfair for the patent holder to face shifting allegations.[35] Ultimately the
process is in need of change.[35]

Person of Ordinary Skill in the Art – ‘426 Patent

The parties agree that the person is a pharmaceutical
formulator with a degree in pharmaceutical science or a similar field with a
few years of experience.

Claim Construction – ‘426 Patent

Bayer argues that the ‘426 patent is not restricted to
micronized drospirenone. Cobalt argues that the patent is.

Claim 1 specifies micronized drospirenone without stating
the form that ethinylestradiol is present in. Claim 3 allows the
ethinylestradiol to be micronized or sprayed. No claim in the ‘426 patent
claims that the drospirenone component may be sprayed.[52] This differentiates
this case from the UK case cited by the parties. Claim 30 defines the
drospirene component by particle size while claim 31 defines the drospirene
component by dissolution rate.

Cobalt argued that claims 30 and 31 only relate to the micronized
form of drospirenone while Bayer argues it is any form of drospirenone
(micronized or sprayed).[55] Bayer
argues that page 4 of the Description of the patent supports their argument
that the essential point of the patent is not micronized drospirenone but
rather the rapid dissolution. The Judge agreed that this was the appropriate
construction of the claims.

Non-Infringement– ‘426 Patent

Cobalt alleged non-infringement with respect to the ‘426
Patent. Their abbreviated new drug submission indicates that the process will
involve dissolving drospirenone and ethinylestradiol separately and then
spraying each into an inert carrier. Cobalt has refused to provide actual
tablets despite the contention that their tablets contain drospirenone in
micronized form. The patent has not been construed to restrict to micronized
tablets but instead be restricted only by the dissolution parameters. Cobalt
failed to provide sufficient evidence as to the dissolution parameters and so
their non-infringement claim is not justified. [68]

Obviousness – ‘426 Patent

The person of ordinary skill has already been identified.
The common general knowledge was that micronizing an acid labile substance
would make it even more prone to isomerization when it came in contact with
stomach acid. It was known as of August 1999 that a combination of drospirenone
and ethinylestradiol could be used as an oral contraceptive. However it was not
known that the dissolution of the drospirenone in the stomach could be enhanced
by having it dissolve rapidly. Isomerization in the stomach would be

The inventive concept is an oral contraceptive comprised of a
combination of drospirenone and ethinylestradiol where the drospirenone may be
micronized or in another rapidly dissolving form without enteric coating. The
difference between the prior art and the inventive concept is providing
drospirenone in a rapidly dissolving form to provide a successful oral
contraceptive. This difference was not more or less self-evident.[83] The prior
art pointed away from providing acid-labile drugs in a rapidly dissolving form.

Utility/Sound Prediction – ‘426 Patent

Cobalt sought to raise additional arguments by way of the
evidence of Dr. Pramar. These were not contained in the NoA and so were


The Judge then adopts the reasoning from Sanofi-Aventis dealing with the promise
of the patent.[94] Using this the judge determines that the promise is found at
page four of the ‘426 patent. The promise is for good bioavailability of the
compound provided in a form that promotes rapid dissolution. Cobalt fixates on
a particular paragraph on page four to argue inutility. The paragraph begins
“without wishing to be limited to any particular theory…” and then goes on to
attempt to explain how the high bioavailability is achieved. It is not a
promise but rather an effort to explain the rapid dissolution.[98]


Cobalt’s allegations regarding inutility and lack of
sound prediction are therefore not justified.[100]


Overbreadth and Insufficiency – ‘426 Patent

Cobalt allegations with respect to overbreadth and
insufficiency are dependent on the claims being restricted to drospirenone and
its micronized form. Since the claims were not construed that way they are not
overbroad or the patent lacking sufficiency.[102]


Ambiguity – ‘426 Patent

Cobalt argued ambiguity due to the use of the word
‘about’ in specifying the dosage ranges. The expert evidence indicated that the
term ‘about’ was not ambiguous but would rather lead the skilled person to
refer to the USP.[106]


Person of Ordinary Skill in the Art – ‘728 Patent

Cobalt and Bayer were essentially in agreement – the
person is someone versed in the field of oral contraceptives with a biological
science degree or an MD with several years experience in prescribing oral


Claim at Issue – ‘728 Patent

The claims call for a dosage of drospirenone where it
provides for a maximum dosage.


The Description – ‘728 Patent

The object of the invention is to provide an improved
single-phase combination preparation contraceptive. The description indicates
consumption for 23 or 24 days with a 4 or 5 day rest. The narrowest range given
for administration is between 0.25mg to a dose equivalent of 0.075 mg of
gestodene. Drospirenone is never individually mentioned.


Claim Construction – ‘728 Patent

All of the claims are ‘use’ claims directed at the use of
a combination of drugs for use as female contraceptives. Both parties agree
that the patent does not disclose what a “dose equivalent” of drospirenone
would be. The expert for Cobalt indicates that the person of ordinary skill
would read the dose equivalent and calculate an end dose of 2mg – a number
already found to inhibit ovulation in 1991.


Several papers were uncovered dating after the filing of
the original patent. It was not clear whether they were available prior to
filing of the Canadian patent. Based upon these papers Bayer’s expert contends
that the dose equivalent should be raised from 2mg to 3mg. There is no
certainty regarding what the equivalent dose would be. The claim at issue
therefore does not distinctly and in explicit terms define the subject matter
of the invention.[134]


Non-Infringement – ‘728 Patent

Cobalt’s product promises to contain 3mg of drospirenone.
Based on either construction (either 2mg or indeterminate amount) Cobalt’s
product will not infringe.[135]


Obviousness – ‘728 Patent

The Judge then considers European patent ‘607 in the
context of obviousness. There was no evidence that a person of ordinary skill
would have found the ‘607 patent sufficient to motivate an inquiry that would
lead to the claimed invention.


Double Patenting – ‘728 Patent

Double patenting arises where the further patent is
applied for at a time when the first patent cannot serve as prior art. Both
patents must be owned by the same patentee. The application for the ‘729 patent
was filed December 22, 1994. Given the expiry date of the two patents (August
31, 2020 and December 22, 2014) the ‘426 patent may be challenged for double
patenting but not the other way around.[144]


With respect to the ‘780 patent the question is whether
the monopoly claimed was improperly extended by the ‘728 patent.[145] The
expert of Cobalt makes statements of law that are beyond his expertise. The
expert for Bayer coherently distinguishes the claimed subject matter of the
‘728 patent and the ‘780 patents.[148] The double patenting allegations are
therefore not justified.


Utility and Sound Prediction – ‘728 Patent

The list of advantages should not be elevated to a
promise.[152] Alluding to a possibility should not be confused with the
inventor promising a result.[152] The use of gestodene and its extension to a
class of other gestagens could be soundly predicted based upon the evidence of
the experts.[154]


Method of Medical Treatment

In the present case all the claims are expressed in terms
of use for a contraceptive.[160] The claims provide for a range of doses. Testimony
reflected that these products are prescribed in the form of kits containing
tablets used in a daily regimen. Exceptional circumstances may result in a
different number of tablets or a different daily regime.[161]


The question is not whether a commercial product is
provided with fixed dosages and regimens but what the claims say.[162] All the
claims are use claims – not product claims. Some of the claims are not proper
subject matter since they do not claim a vendible product – they provide for a
choice to be made by those prescribing or providing contraceptive drugs. Claim
8 survives as it is directed to a single dosage of each of two compounds.



This case is the second case to deal with ‘use’ claims in
recent weeks. It would appear that there is resistance on the part of courts to
uphold claims that propose vague treatment uses for compounds. Where however a
claim is directed at a dosage of active ingredient(s) it is likely that the
claim will be held to be valid subject matter. This is consistent with another recent
that dealt with this same issue. The invalidated claims in this case required
too much discretion with respect to medical treatment of the practitioner for
them to be considered patentable subject matter.


Once again the Court chose not to grant a patent
that would limit a medical professional from exercising their expertise. The
Court reiterated that where a patent would limit the discretion of a
professional in some manner it is improper subject matter and therefore
non-statutory subject matter.