Pfizer Canada Inc v Apotex Inc, 2017 FC 774

In AstraZeneca Canada Inc v Apotex Inc, 2017 SCC 36 [AstraZeneca], the Supreme Court of Canada (“SCC”) set out to abolish the so-called “promise doctrine,” not simply rename it to “overpromising.”

In this decision, the Federal Court (“FC”) granted Pfizer Canada Inc. (“Pfizer”) an order [5] pursuant to Section 6 of the Patented Medicines (Notice of Compliance) Regulations (“PM(NOC) Regulations”) prohibiting the Minister of Health from issuing a Notice of Compliance to Apotex Inc. (“Apotex”), with respect to Canadian Patent No. 2,436,668 (“the ‘668 Patent”). [1] The FC found, on a balance of probabilities, that Apotex’s allegations of obviousness, inutility, non-infringement, overpromising, anticipation and double patenting were not justified. [5]

Background

Entitled, “Novel Succinate Salt of O-Desmethyl-Venlafaxine,” the ‘668 Patent covers the drug PRISTIQ, which is used to treat depression. [1] O-desmethyl-venlafaxine (“ODV”) is a serotonin and norepinephrine reuptake inhibitor which works by simultaneously inhibiting reuptake of these chemicals, both neurotransmitters believed to play a role in depression and anxiety. [7] The main active pharmaceutical ingredient in this proceeding was Form I ODV succinate, a particular crystal form of ODV succinate, which is a particular salt of ODV. [7]

The claims at issue in this decision were Claims 8, 9, 33, 43 and 44. [2] The FC accepted that Form I ODV succinate was a novel composition of matter and is the subject of Claims 8 and 9, on which Claims 33, 43 and 44 depend. [7]

Claims 8, 9, 33, 43 and 44 are as follows:

8. A compound according to claim 6 which exhibits an X-ray powder diffraction pattern having characteristic peaks expressed in degrees 2.theta. (~ 0.2° 2.theta.) at 10.20, 14.91, 20.56, 22.13, 23.71, 24.60, and 25.79.
9. A compound according to claim 6 having an endotherm at about 131° C.
10. Use of an effective amount of O-desmethyl-venlafaxine succinate or a mixed salt thereof as claimed in any one of claims 1 to 20 for the treatment of depression.
11. Use of a therapeutically effective amount of a sustained release oral dosage form comprising O-desmethyl-venlafaxine succinate or a mixed salt thereof as claimed in any one of claims 1 to 20 prepared in a dosage to induce a blood plasma level of no more than 225 ng/ml to lower the incidence of nausea, vomiting, diarrhea, abdominal pain, headache, vaso-vagal malaise, or trismus resulting from the oral administration of O-desmethyl-venlafaxine succinate.
12. A sustained release formulation comprising O-desmethyl-venlafaxine succinate and a pharmaceutically acceptable carrier or excipient, wherein the sustained release formulation provides peak serum levels of up to 225 ng/ml.

While ODV and pharmaceutically acceptable salt forms of it were both known and claimed in claim 22 of US Patent No. 4,535,186 (“the ‘186 Patent”), issued in 1985, and in claim 21 of Canadian Patent No. 1,248,540 (“the ‘540 Patent”), issued in 1989, [11] there was nothing in either the two patents or elsewhere in the prior art which indicated that the salt of ODV succinate had even been known. [13]

Issues

The issues at the heart of this decision were whether Pfizer had demonstrated on a balance of probabilities that Apotex’s allegations of obviousness, inutility, non-infringement, overpromising in relation to subsection 27(3) of the Patent Act, anticipation and double patenting were not justified. [145]

Analysis

The FC dealt with each of the six issues in turn.

Allegation of Obviousness Not Justified

The FC first considered whether or not the invention in the ‘668 Patent was obvious. In identifying the notional person of skill in the art (“POSITA”), the FC preferred Pfizer’s position, [225] which stated that the POSITA should be skilled in solid-state chemistry, pharmaceutical formulation and development, pharmacology, and pharmacokinetics, but not necessarily be a medical doctor, as Apotex had put forth. [226] With regards to the general knowledge possessed by the POSITA, it was found that the POSITA would not have known, anticipated or predicted the properties of either ODV succinate generally or Form I ODV succinate, or whether those properties would be amenable to formulation as a sustained release drug. [235] In identifying the inventive concept the FC found that the most basic inventive concept was the novel crystal, Form I ODV succinate. [251] The FC also repeatedly disagreed with Apotex’s argument that the ODV succinate was the single inventive concept of the claims. [250-261] The invention in the ‘668 Patent was then found to be separate from what the state of the art would have been at the time of invention. [265, 269, 275] Thus, the view of the FC regarding obviousness generally was that the POSITA would not have come directly and without difficulty to the solution taught by the ‘668 Patent. [279]

Moving on to the obvious to try analysis, the FC assessed whether it was more or less self-evident to the POSITA that what was being tried ought to work, and whether there existed a finite number of identified predictable solutions known to the POSITA. The FC found considerations such as the state of the art in the early 2000s to point against a finding of obvious to try under this initial element. [304] It was similarly found that the extent, nature and amount of effort required to achieve the invention, and level of routineness in the trials also pointed away from a finding of obvious to try. [309] There was no motive found in the prior art for finding the solution the ‘668 Patent addressed and so this this aspect of the test also favoured Pfizer. [315] Pfizer was also favoured with regard to the course of conduct followed that culminated in the making of the invention. [323] Overall, the FC concluded that Form I ODV succinate was not obvious to try. [329]

The FC found that Pfizer had established on a balance of probabilities that Apotex’s allegations of obviousness and obvious to try were not justified. [330]

Allegations of Inutility Not Justified

In an inutility analysis, the first step is to identify the subject matter of the invention as claimed in the patent, after which the court must ask whether that subject matter is useful or, in other words, capable of a practical purpose. [336] Utility must be either demonstrated or soundly predicted. [336] Following a claim-by-claim analysis, the FC agreed with Pfizer that the utility of Claims 8 and 9 is the usefulness as a stable, solid-state form of ODV succinate. [340] The FC was also satisfied that the subject matter of Claims 8 and 9 was a subject matter that was useful and capable of a practical purpose in that it allowed the compound to be used as a pharmaceutical drug. [342] The FC also agreed with Pfizer’s argument that the practical usefulness of the drug as a stable solid form was by itself sufficient utility under the SCC decision in AstraZeneca, [344] and thus Claims 8 and 9 had demonstrated utility. [345] In terms of Claim 33, it was found that the inventors had demonstrated and soundly predicted that the ODV compound was capable of a practical purpose in the form of a treatment for depression, thus demonstrating its utility as well. [349] Similarly, Claims 43 and 44 were found to provide the practical result of a sustained release formulation, intended to release the drug more slowly so as to reduce blood concentrations and side effects. [353]

The FC was satisfied that on a balance of probabilities Apotex’s allegations of inutility were not justified. [354]

Allegation of Non-Infringement Not Justified

Pfizer asserted that both of Apotex’s products infringed Claim 8 of the ‘668 Patent, while Apotex only alleged that Claim 8 was invalid and therefore could not be infringed. [184] The FC found on a balance of probabilities that Apotex’s allegations relating to the invalidity of Claim 8 were not justified and, therefore, neither were Apotex’s allegations of non-infringement of Claim 8. [185] Pfizer asserted that both of Apotex’s products infringed Claim 9, with Apotex’s defence again being that the Claim was invalid and incapable of being infringed, as well as that Apotex’s products did not fall within the scope of Claim 9. [186] The FC rejected this argument as well, its reasoning turning on the way Claim 9 was construed, [187] especially the word “about,” wherein a margin of error of ±2°C in the melting point of the product [188] would put both of Apotex’s products within the scope of Claim 9. [190] With regards to Claim 33, Pfizer again asserted that both of Apotex’s products infringed it, while Apotex argued that the claim was invalid and could not be infringed. [191] As the allegations of invalidity could not be justified, the FC found that Apotex’s allegation of non-infringement was also not justified. [192] Claims 43 and 44 were assessed together, where Pfizer asserted that only one of Apotex’s products infringed them, and Apotex used the same invalidity argument for non-infringement that it had previously advanced. [193] The FC therefore found that on a balance of probabilities, Apotex’s allegation of non-infringement was justified for one of Apotex’s products, [195] but not the other. [194]

The FC concluded that on a balance of probabilities Pfizer had established that Apotex’s allegation of non-infringement was not justified. [197]

Allegation of Overpromising in relation to subsection 27(3) of Patent Act Not Justified

The FC noted that Apotex’s allegations of overpromising resembled the previously advanced promise of the patent arguments. [360] Apotex had argued that the ‘668 Patent should be invalidated as its overpromises violated subsection 27(3) of the Patent Act, based on the SCC decision in AstraZeneca. [356] Under subsection 27(3), the invention must be described correctly and fully by the inventor, something Apotex did not consider to be the case in the ‘668 Patent. [356] The FC did not agree with this, particularly because it thought the SCC would not likely have abolished the promise doctrine, which it did in the AstraZeneca decision, only to see it reinstated with a new name. [363]

In essence, the FC did not agree with Apotex’s allegations of overpromising and thus did not find them on a balance of probabilities to be justified. [366]

Allegation of Anticipation Not Justified

Apotex had raised the issue of anticipation in its NOA [370] and provided affidavit evidence from two of its witnesses to give its allegation an air of reality. [372] The FC refused to accept this evidence as neither of the witnesses were instructed on the law of anticipation, nor were either of them instructed on disclosure or enablement. [373] Furthermore, the evidence from both witnesses was provided with regard to the issues of obviousness and obvious to try, not anticipation. [374]

The FC did not find on a balance of probabilities that Apotex’s allegation of anticipation was justified. [390]

Allegation of Double Patenting Not Justified

A second patent for an invention will fail for double patenting if its claims are either coterminous with the claims of the first patent, or if its claims lack ingenuity over the claims of the first patent. [391] With regards to coterminity, the claims of the ‘668 Patent were not found to be coterminous with the claims of the ‘540 Patent. [397] It was also found that the ‘668 Patent did not lack ingenuity, in that the POSITA would not be able to arrive at the claims of ‘668 Patent without exercising some ingenuity of their own. [398]

The FC was therefore satisfied on a balance of probabilities that Apotex’s allegation of double patenting was not justified. [405]

Conclusion

On a balance of probabilities, Apotex’s allegations of obviousness, inutility, non-infringement, anticipation, overpromising and double patenting were found not to be justified. [406] Pfizer was granted its requested order, [406] and costs were payable by Apotex to Pfizer. [407]

Commentary

A matter of great interest in this decision is the FC’s reasoning surrounding overpromising. With the recent SCC ruling in AstraZeneca (PCK Reporter summary available Here), which abolished the so-called “promise doctrine” in Canada, the current decision appears to involve what may be considered by some as a revival. In AstraZeneca, the SCC stated:

Supporters of the doctrine assert that the consequences of the Promise Doctrine play a key role in ensuring patentees do not “overpromise” in their patent applications. That is, a patentee will be dissuaded from stating the invention can be used for things that are not sufficiently established at the time of filing if doing so would risk invalidating the entire patent. The utility requirement should not be interpreted, however, as the Federal Courts have done, to address such concerns. Nonetheless, overpromising is a mischief. [AstraZeneca, 45]

In the current decision, the FC exercised the above guidance from the SCC in that while overpromising may certainly be a mischief, using the utility requirement to remedy that problem may not be the correct response. In considering subsection 27(3), it may be possible that a different tool, such as insufficiency of disclosure, would be more fitting.