YAZ / drospirenone / 2,179,728 – 2,382,426
Cobalt sought an order of compliance allowing it to market a drospirenone + ethinylestradiol combination birth control product. Two patents were listed on the register. Hughes J granted the order of prohibition based on the ‘426 patent (which doesn’t expire until 2020), but dismissed it in respect of the earlier expiring ‘728 patent on the basis that the claims which were arguably infringed were unpatentable methods of medical treatment, as well as non-infringement. This decision is significant primarily as a development in the law relating to patentability of methods of medical treatment. Another point worth noting is that the promise of the patent respecting utility was modestly construed for both patents. The decision also raised an evidentiary point of interest. Other issues turned on the facts. This post discusses the evidentiary point and the promise of the patent.
Claim 31 of Bayer’s ‘426 patent was to a composition of drospirenone with a specified dissolution profile and the question of fact was whether Cobalt’s product fell within the specified parameters. The problem for Bayer was that Cobalt refused to provide samples to Bayer for testing: “Bayer complains that, despite a motion that it brought to compel Cobalt to produce samples, Cobalt refused to do so; and the Court would not compel it to do so”  (and see ). Despite this lack of direct evidence, Hughes J held in Bayer’s favour on the infringement issue:
 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.
In the absence of evidence, the answer must turn on the burden of proof. Hughes J summarized the rule as being that “with respect to the second person’s [generic’s] allegations of non-infringement, the first person [innovator] bears the burden of proving that such allegations are not justified” , which would seem to imply that Cobalt should prevail. But more precisely, the generic must present “sufficient evidence to give the allegations in its NOA an air of reality”: see eg 2013 FC 573 . Similarly, in 2011 FCA 215 , quoted by Hughes J, the FCA affirmed that “The determination must turn on whether there are allegations by the second person sufficiently substantiated to support a conclusion for administrative purposes (the issuance of a NOC) that an applicant's patent would not be infringed if the second person's product is put on the market” (FCA emphasis). So, Hughes J’s holding on this point illustrates that a mere statement that its product will not infringe does not amount to sufficient substantiation of the allegation of non-infringement to give the allegation an air of reality. However, it appears that if the generic does supply the product for testing, this is sufficient to substantiate the allegation of non-infringement, even if the innovator does not actually test it: see 2005 FC 1205 rev'd on related but distinct grounds 2007 FCA 209.
Promise of the Patent
While the obviousness issue in this case turned on the facts, a brief review is necessary to understand the utility issue. Drospirenone is acid-labile and would degrade (isomerize) in the presence of stomach acid, and micronization could be expected to exacerbate this problem. Consistently with this, degradation of micronized drospirenone was a serious problem in in vitro tests, and consequently Bayer initially worked on an enteric coated tablet. It turned out that micronized drospirenone nonetheless had good bioavailability in vivo. Hughes J held on the facts that the good bioavailability was non-obvious .
The ‘426 patent contained the following statement:
Without wishing to be limited to any particular theory, it appears that the in vitro dissolution rate of drospirenone is connected to the dissolution rate in vivo resulting in rapid absorption of drospirenone in vivo on oral administration of the compound. This is an advantage because isomerization of the compound in the gastric environment and/or hydrolysis in the intestine is substantially reduced, leading to a high bioavailability of the compound.
That is, the patent speculated that the reason for the good bioavailability was that fine particles of drospirenone were absorbed more quickly than they degraded. Hughes J indicated that Cobalt argued that this passage should be construed as a promise, so that the patent would lack utility unless this theory could be shown to be the correct explanation for the observed bioavailability . (I must say that the passage from Cobalt’s NOA set out at  seems to me to be making the more modest argument that the studies relied on were not sufficient to show that a composition with the claim dissolution profile would be an effective contraceptive, but of course I do not have the advantage of the full record.)
Hughes J declined to read this statement as a promise. He quoted at length from the FCA’s recent Clopidogrel decision 2013 FCA 186 (blogged here), emphasizing that the promise must be explicit  and that “Courts should not strive to defeat otherwise valid patents” . He concluded that the quoted passage from the patent was not a promise, but rather an effort to explain the mechanism of action .
Hughes J’s emphasis on the need to avoid being overly aggressive in construing the promise is, in my view, welcome, but his holding with respect to the ‘426 patent is not especially significant, as it seems to me that the passage in question would probably not have been construed as a promise even prior to Clopidogrel.
The promise analysis of the ‘728 patent is more interesting. The ‘728 patent claimed a low-dose contraceptive composition, with a 23-day dosage cycle. In effect, a lower dose is achieved by using a longer period of administration. The specification contained the statement that “The advantages of a combination preparation for oral contraception [with the claimed characteristics] can be characterized as follows” with four specific advantages listed . The passage concludes by noting that “In summary, an intake [of the claimed composition] can produce the above-mentioned advantages. . .” . This is very much the kind of statement that might be taken as a promise of utility. Hughes J did not construe this as a promise, finding that it was included in the patent to support non-obviousness, rather than as a promise of utility :
 That list should not be elevated to a “promise”; it is simply an observation as to advantages expected to be achieved. As expressed by Pelletier JA in Sanofi-Aventis v Apotex Inc, [Clopidogrel] 2013 FCA 186 at paragraph 67, in alluding to a possibility, an inventor is not promising a result to be achieved; a goal is not necessarily a promise.
Because the statement in the ‘728 patent might easily have been construed as a promise, Hughes J’s holding on this point is significant in indicating that Clopidogrel may mark a real shift in approach. Of course, it shouldn’t be surprising that an FCA decision would influence the Federal Court, but there is still a great deal of subjectivity involved in assessing the promise of the patent, so the enthusiasm with which the FC embraces Clopidogrel will strongly influence its real impact. With that said, one decision does not make a trend. Moreover, the significance of the decision on this point is diminished because it was not determinative. While Hughes J rejected the utility attack, he held the key claims invalid for lack of patentable subject matter. A more stringent test of the impact of Clopidogrel will come when validity turns on the construction of the promise.