2,661,422 / abiraterone acetate & prednisone / ZYTIGA / old NOC
My last post outlined the unusual facts in this case, and discussed the overarching problem that arose. This post looks at a few points of legal interest that were raised, though none impacted the final decision. Briefly, Phelan J’s claim construction analysis reflects the ongoing debate as to whether it is always appropriate to look to the disclosure in construing the claims, or only if the claims are ambiguous; the obviousness analysis illustrates a problematic consequence of the holding in Ciba v SNF 2017 FCA 225 [51]-[63], that the state of the art for the purpose of an obviousness attack comprises all the prior art; the “patentable subject matter” analysis is, in my view, properly part of the obviousness analysis; and the utility analysis raises the question of what the SCC meant when it said in AstraZeneca 2017 SCC 36 [55] that the utility must be “related to the nature of the subject-matter.”
(As an aside, Phelan J uses the abbreviation “POS” to refer to a person skilled in the relevant art. I’m not sure I can endorse that abbreviation, given its slang meaning.)
Claim construction
Phelan J’s claim construction analysis reflects the ongoing debate over whether it is always appropriate to look to the disclosure in construing the claims, or whether recourse to the disclosure is permissible only if the claims are ambiguous when read on their own: see eg here, here and here.
Claim 3 is representative of the asserted claims [38]:
3. Use of a therapeutically effective amount of abiraterone acetate or a pharmaceutically
acceptable salt thereof and a therapeutically effective amount of prednisone, for the
treatment of a prostate cancer in a human
Janssen argued that the claim should be construed as requiring that the combination be effective for treating cancer [117], which would encompass a combination where prednisone was used only to address side effects. Phelan J rejected this argument, holding that on a plain reading of the claim, anti-cancer efficacy of the prednisone itself was required.
The point of interest arises because the construction ultimately adopted by Phelan J was express in the disclosure: “[T]he amount of the additional anti-cancer agent [prednisone]. . . is an amount that is sufficient to treat the cancer whether administered alone or in combination with [abiraterone]” [Disclosure ¶ 44]. Phelan J nonetheless came to his conclusion without recourse to the disclosure: “Even if there was some confusion or ambiguity, recourse to the Disclosure confirms as reference that the amount of inhibitors or of steroid is an amount sufficient to treat cancer, whether administered alone or in combination. However, there is no need to refer to the Disclosure” [125, my emphasis]. This implies that Phelan J is of the view that recourse to the disclosure is improper unless the claims are ambiguous when read on their own. This is even though Phelan J, at the same time, considered it “essential” to refer to the express definitions set out in the disclosure at [23]-[33]. My own view is that it is always appropriate, and I would suggest that referring to the statement in [44] of the disclosure is no more or less appropriate than referring to the definitions set out ten paragraphs earlier. The point would have been truly interesting if Phelan J had arrived at the contrary construction without relying on the disclosure; but since the express statement in the disclosure confirmed the construction he had arrived at for other reasons, the issue was moot.
Patentable subject matter
Under the heading “Patentable Subject Matter” [128] - [142], separate from obviousness and utility, Phelan J held that “[t]o be a patentable combination, the 422 Patent must claim a combination with effects different from the sum of the effects of the elements” [132, original emphasis], citing R v American Optical Co [1950] Ex CR 344, 13 CPR 87 at 98-99 and Eli Lilly Canada Inc v Apotex Inc 2018 FC 736 at paras 71-72.
I have two concerns. First, it appears that Phelan J may be saying that the synergistic effect must be specified in the claims: “[t]he issue regarding patentability of the subject matter is whether the 422 Patent reads from the perspective of the POS as claiming a combination with synergistic effect or effects beyond those of either component drug” [132]; “[f]or the claimed combination to be patentable, the Asserted Claims supported by the disclosure of the 422 Patent from the perspective of a POS must claim that the combination of AA [abiraterone] and PN [prednisone] has a greater effect than either component alone” [133]. If that is what he is saying, it is not supported by the cases cited, which merely say that is essential to validity that “the combination should lead to a unitary result, and that such result should be different from the sum of the results of the elements” Eli Lilly [72], citing American Optical which is to the same effect.
The second point is one I have already expressed in my post on Eli Lilly here, but I’ll be a bit more direct. There is no requirement of “patentable subject matter.” The requirement is a matter of obviousness: “The real and ultimate question is: Is the combination obvious or not?: Albert Wood & Amcolite Ltd v Gowshall Ltd (1937) 54 RPC 37 at 40 (CA), quoted with approval in Wandscheer [1948] SCR 1 at 12; Bridgeview 2010 FCA 188 [51]. In most cases the result will be the same either way. If I take ibuprofen for my sprained ankle and calcium carbonate for my heartburn, and all that happens is that the pain in my ankle subsides, exactly as it would have with ibuprofen and no calcium carbonate, and my heartburn goes away, exactly as it would have with calcium carbonate and no ibuprofen, then there is no inventive step in putting the two together; to claim the combination would be a matter of arbitrary selection. But the issue really should be treated as a matter of obviousness, because there is a large body of law addressed to obviousness, and re-creating that law under a different name to address combinations cannot help, and it has the potential to do harm if the so-called law of collocation diverges from the established law of obviousness.
State of the art for the purpose of an obviousness attack
Under the “old” Patent Act the body of prior art that may be set up against the patent in an obviousness attack — the “state of the art” — did not include all publicly available information that could be set up in a novelty attack, but only that which was generally known to a person skilled in the art or which would be discovered in a reasonably diligent search. As Hughes J noted in Merck v Pharmascience 2010 FC 510 at [37], there is a “quaere” as to whether codification of the obviousness requirement in s 28.3 of the new Act, which requires a person skilled in the art to have regard to information “available to the public” as of the claim date —the same language used in respect of novelty in s 28.2— has changed the law in this respect, so that all publicly available prior art may be used in an obviousness attack, regardless of whether it would have been discovered by a reasonably diligent search. In my article, ‘What is the State of the Art for the Purpose of an Obviousness Attack?’ (2012) 27 CIPR 385, I reviewed the debate. Subsequently, as discussed here, in Ciba v SNF 2017 FCA 225 [51]-[63], the FCA, per Pelletier JA and Rennie JA, with Woods JA expressing no opinion on this point, held that the new s 28.3 had indeed changed the law, so that the state of the art for the purpose of an obviousness attack does indeed encompass all prior art that is available in a novelty attack.
Janssen Inc v Apotex is one of the few cases so far to actually consider this point in the obviousness analysis, with Phelan J accepting that the FCA in Ciba “confirmed that Apotex can choose the prior art elements that make the 422 Patent obvious as long as they were publically available prior to [the filing date]” [164].
The application to the facts illustrates a significant shortcoming of the new rule. The general problem facing the inventors was that “the primary treatment for metastatic prostate cancer has been androgen deprivation therapy [ADT] through medical or surgical castration to suppress androgen production in the testes” [17]. Unfortunately, in some instances the cancer would become castration resistant and the cancer would continue to progress [18]. The invention, to combine abiraterone acetate, which is a CYP17 enzyme inhibitor, and prednisone, with a putative synergistic effect, was aimed at addressing this problem. It appears that Janssen wanted to argue that focusing on a CYP17 inhibitor was itself inventive, as the mechanism for castration resistance was not known at the time, and there were multiple theories where a large number of different experimental compounds, representing different approaches, were being tested at the time [73]-[74], [148]. As I read this decision, this line of argument was effectively foreclosed because Apotex was able to base its attack on the specific prior art documents that focused on CYP17 inhibitors and abiraterone, without ever having to establish that these were part of the common general knowledge [164].
This means that the obviousness question turned from something like ‘Was it obvious to focus on CYP17 inhibitors?’ to ‘Given a focus on CYP17 inhibitors, was it obvious to combine a CYP17 inhibitor, specifically abiraterone, with prednisone?’ These are very different questions and one might easily imagine that the answer to the former is “No” at the same time that the answer to the latter is “Yes.” In that case, a combination that would not in fact have been obvious to a person skilled in the art because it was not obvious to select one of the components, might nonetheless be found to be legally obvious, because the question of whether it was obvious to select that component never arises. That strikes me as wrong in principle.
With all that said, on these facts the difference in these questions didn’t matter, as Phelan J found that even starting with abiraterone, it would not have been obvious to combine it with prednisone [192]. (I would also note that on the facts, it is not clear that it would have been non-obvious to select abiraterone as a starting point; given his holding on the law, Phelan J did not have to make that determination.)
(As an aside, at [97] Phelan J says “[t]he relevant date for obviousness . . . is the common general knowledge as of the Filing Date, August 23, 2007," and at [164] he states that it is proper to consider all prior art available prior to August 23, 2007— again, the filing date—and then he does go on to consider prior art that does appear to post-date the claim date. This is even though s 28.3(b) provides that the relevant date is the claim date, the patent’s “priority filing date based on a US Patent was August 25, 2006" [7], and priority does appear to have been claimed. I’m clearly missing something.)
Utility
Finally, in assessing utility, Phelan J required that there be a scintilla of utility in the sense of a synergistic effect, such that the combination has a greater effect than either abiraterone or prednisone on its own: see eg [219]-[221]. The alternative would be to ask whether there was a scintilla of utility in the sense that if the combination is given to a person suffering from prostate cancer, it has a scintilla of utility in treating that cancer—without requiring any synergistic effect. The question is what the SCC in AstraZeneca 2017 SCC 36 meant when it said that the utility must be “related to the nature of the subject-matter” [55]. I won’t go on about this, given this is already a very long post, but I will say that I consider it very much an open question as to whether a synergistic effect is required in a case such as this one. I am inclined to think it is not, and the question of synergy or lack thereof is really a matter that should be confined to the non-obviousness inquiry. The SCC in AstraZeneca at [55] went on to explain that “a proposed invention cannot be saved by an entirely unrelated use. It is not sufficient for an inventor seeking a patent for a machine to assert it is useful as a paperweight.” Even without a synergistic effect, the use of the combination to treat prostate cancer is clearly related to a claim “for the treatment of a prostate cancer in a human”; it is far removed from claiming the use of the compound as a paperweight, or landfill. Requiring a scintilla of a synergistic effect links utility to the inventive concept; that may be problematic, given how tricky it can be to identify the inventive concept. It also strikes me as unnecessary, as the need to establish synergy can be adequately addressed in the context of non-obviousness. With that said, perhaps a different set of facts will shed a different light on the issue. In this case, the point didn’t make any difference, as Phelan J held that there was evidence of a scintilla of a synergistic effect [221].
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