Failure to provide samples sinks YAZ non-infringement allegation

On October 22, 2013 Justice Hughes of the Federal Court of Canada released his Reasons for Judgment and Judgment in a prohibition application between Bayer and Cobalt involving the oral contraceptive YAZ (drosperinone + ethinyl estradiol) and Canadian Patent Nos. 2,382,426  and 2,179,728. The Court granted Bayer’s prohibition application in respect of the 426 Patent and dismissed it in respect of of the 728 Patent.

426 Patent

The 426 Patent is generally related to a pharmaceutical composition comprising drosperinone and ethinyl estradiol having certain dissolution characteristics. Claim 31 provides:

A pharmaceutical composition comprising:

from about 2 mg to about 4 mg of drospirenone particles, wherein the
drospirenone is in a form, which when provided in a tablet containing 3 mg of drospirenone, has a dissolution such that at least 70% of said drospirenone is dissolved in 900 ml of water at 37° C. (±0.5° C.) within 30 minutes, as determined by USP XXIII Paddle Method using a USP dissolution test apparatus 2 at a stirring rate of 50 rpm, including 6  covered glass vessels and 6 paddles;
about 0.01 mg to about 0.05 mg of 17αethinylestradiol; and
one or more pharmaceutically acceptable carriers;
the composition being in an oral dose form, and the composition being  effective for oral contraception in a human female.


An issue between the parties was whether claim 31 was limited to micronized drosperinone, as submitted by Cobalt, or encompassed all forms of drosperinone, whether micronized or sprayed, as submitted by Bayer. Justice Hughes, while indicating that the matter was not free of doubt, held that the claim was not limited to micronized drosperinone, but includes drosperinone in any form that satisfied the claimed dissolution profile.

Non infringement

Cobalt’s only allegation of non-infringement was that proposed tablets would not contain micronized active ingredients. During the prohibition application, Cobalt refused to provide tablets of its proposed product and provided no information on the dissolution parameters of its drosperinone. After reiterating Bayer has the burden of demonstrating that Cobalt’s allegation of non-infringement is not justified, Justice Hughes held:

[68] Given that Cobalt is obliged in its Notice of Allegation to provide sufficient information so that Bayer can come to grips with the allegations made; and, given that Cobalt has supplied no sample tablets nor any evidence as to the dissolution parameters of its tablets, I must conclude that Cobalt’s allegations as to non-infringement of claim 31, and dependent claims, of the ‘426 patent are not justified.


Justice Hughes characterized the inventive concept of the 426 Patent as an oral contraceptive comprised of a combination of drosperinone and ethinyl estradiol where the drosperinone may be provided in a rapidly dissolving form without an enteric coat. Justice Hughes preferred the evidence of Bayer’s experts that in the special case of an acid-labile drug such as drosperinone, micronization would be expected to increase degradation in the stomach, such that it was not self-evident to provide drosperinone in a rapidly dissolving form.

Utility and Promise of The Patent

Following the Court of Appeal in Clopidogrel ( see our previous post here) Justice Hughes held that the passage in the specification seeking to explain the why rapid dissolution of drosperinone works even in the acidic environment of the stomach cannot be construed as a promise.  Accordingly, Justice Hughes concluded that Cobalt’s allegations of lack of utility and lack of sound prediction were not justified.


Justice Hughes held that Cobalt’s allegation that the word “about” used in the claims was vague was not justified and accepted that a skilled person would look to the United States Pharmacopeia which defines “about” as referring to a quantity within 10 %.

 728 Patent

The 728 Patent is generally directed to the use of a low dose fixed combination of an estrogen and a gestagen in a reduced dosing regime. Claim 1 of the 728 Patent provides, in relevant part:

1. Use of an oral dosage form comprising an estrogen selected from

0.015 to 0.020 mg of ethinylestradiol;

and a gestagen selected from

0.1 mg of drospirenone to a drospirenone dose equivalent to 0.075 mg of gestodene, and

for contraception for a female of reproductive age who has not yet reached premenopause, by administration of the form of dosage for 23 or 24 days, beginning on day one of the menstrual cycle, followed by 5 or 4 pill-free or placebo pill days, for a total of 28 days in the  administration cycle.

The experts for both parties agreed that the term “dose equivalent to 0.075 mg of gestodene” was not defined. Justice Hughes accepted that “dose equivalent” would depend on how the activity of the compound is measured and the intended pharmacological effect/end point of the compound, and that the most likely answer  was 2 mg. Since Cobalt’s proposed product contained 3 mg of drosperinone, Justice Hughes concluded that Cobalt will not infringe any claim at issue.

Double Patenting

Justice Hughes rejected Cobalt’s allegation that earlier-expiring 728 Patent was invalid in in light of the later-expiring 426 Patent, holding that double patenting only works in one direction:

[144] Given the expiry date of each of the ‘426 patent (August 31, 2020) and the ‘728 patent (December 22, 2019), it is obvious that the ‘426 patent may be challenged for Double Patenting in light of the ‘728 patent, but not the other way around. Only the ‘728 patent has been challenged by Cobalt in light of the ‘426 patent. Thus, that challenge is not justified.

Justice Hughes also dismissed Cobalt’s second double patenting allegation based on another Canadian Patent No 2,016,780, holding that what is claimed in the 728 patent is clearly distinguishable from that claimed in the 780 Patent.

Utility and Sound Prediction

Justice Hughes, following the decision of the Court of Appeal in Clopidogrel, held that the list of advantages explicitly set out in the 728 Patent is a goal expected to be achieved and should not be elevated to a promise.

Method of Medical Treatment

All of the asserted claims are directed to the use of the claimed combination. Following his recent decision in ACLASTA (see our previous post here), Justice Hughes held that claims directed to the use of a range of active ingredients are not patentable subject matter in Canada, holding:

[162] The point is, what do the claims say? All claims at issue are use claims, not product claims. All but claim 8 claim the use as a contraceptive of a two-component drug with each component to be selected from a choice of components, and with each component to be furnished at a dosage within a range of dosages. Claims 1, 2, 6 and 7 are not proper subject matter for a Canadian patent, as they do not claim a vendible product; they provide for a choice to be made by those prescribing or providing contraceptive drugs to choose between a variety of components and a variety of dosage ranges. Only claim 8 survives, as it is directed to a single dosage of each of two compounds.

A copy of Justice Hughes’ Reasons for Judgment may be found here.