Wednesday, July 8, 2015

Application of Distinction Between Overarching Promise and Claim-Specific Promise

Novartis Pharmaceuticals Canada Inc v Teva Canada Ltd (NOC) 2015 FC 770 O'Reilly J
            2,255,951 / deferasirox / EXJADE

As discussed in Monday’s post, the ‘951 patent relates to iron chelators, which are used to treat disorders caused by excess iron in the body [7]. As usual, the utility attack turned on the promise of the patent. O'Reilly J’s Deferasirox decision illustrates once again that under the promise doctrine the validity of the patent will turn on a meticulous reading of the disclosure. It is also interesting as applying the recently developed distinction between an “overarching” promise, which will affect all claims, and a promise that is directed at one claim only. One point I would quibble with is that there seems to have been an implicit assumption that the stated utility is the same as the inventive concept. Consequently, while O’Reilly J explicitly stated that (for the compound claims) he applied the low standard for utility that applies in the absence of an explicit promise, the standard he actually applied was higher than a mere scintilla.

The key sentence in the disclosure was that the compounds of the patent “have valuable pharmaceutical properties when used in the treatment of disorders” related to iron retention [15]. Teva argued that this was an explicit promise that the patented compounds had been tested in humans and had been found to be therapeutically valuable [16]. While O’Reilly J remarked that this statement was “infelicitous,” and Teva’s interpretation was a possible construction of the sentence, after reading it in context he concluded that the better reading was that this statement made no express promise. I will not review O’Reilly J’s reasoning in detail, except to say that while his careful analysis of the disclosure does strike me as reasonable, that the validity of the patent turns on such a meticulous analysis of the disclosure, which is intended to disclose the invention, not define it, is one of the major problems with the promise doctrine.

While he found there was no overarching promise, following the FCA decision in Celecoxib 2014 FCA 250 (blogged here), O’Reilly J distinguished between an overarching promise which applies to all claims, and a promise that applies to only some claims. In this case, the so-called Formula II compounds, including deferasirox, were novel compounds and consequently were claimed both as compounds and for the use in treatment of iron excess diseases [14]. The key statement discussed above would have been an overarching promise which would have applied to all claims, including the compound claims. Because O’Reilly J did not construe that statement to be a promise, there was no promise which applied to the compounds claims [35], which consequently survived the utility attack [39]. However, even Novartis’ experts acknowledged that the use claims contained an explicit promise of a specific result, and O’Reilly J held that that claim-specific promise had not been demonstrated or soundly predicted [41]. (Because the compound claims were held to be valid, Novartis’ application for an order of prohibition was granted.)

Because no explicit promise applied to the compound claims, O’Reilly J held that “the usual, relatively low, utility requirement applies to those claims” [35]. However, the utility actually applied was that compounds were useful “for their marked iron-binding characteristics as shown both in vitro and, in animal studies, in vivo” [33], [39]. While this stops short of therapeutic utility in humans, it is higher than the alternative suggested by Teva, which was simply that the compounds had the ability to bind iron [18]. Teva argued for that alternative construction of the promise in order to set up a utility / obviousness squeeze, on the basis that similar compounds with an affinity for iron were known in the prior art, and it was obvious that the claimed compounds would have similar characteristics [48]. O’Reilly J avoided this squeeze with a construction which came down the middle: “the inventive concept of the ‘951 patent [is] a class of compounds with a capacity to bind to iron, which are soluble in vivo and capable of inducing excretion of the iron complex” [49]. This, he held on the facts, was not obvious.

My only quibble with this analysis is that O’Reilly J apparently treated the stated utility and the inventive concept as being the same. So, he “would construe the compound claims of the patent as follows: Claims 5 to 37 relate to the novel formula II compounds, including DFS [deferasirox] (claim 32), which are useful for their marked iron-binding characteristics as shown both in vitro and, in animal studies, in vivo [and] are sufficiently soluble to induce excretion of the iron complex [33]. He then applied this same construction in assessing utility [39] and obviousness [49]. In my view, there is no reason in principle why the utility and the inventive concept should be the same, and indeed, generally, they are not. For example, if a compound is useful in treating cancer, the inventive step may lie in discovering a method of synthesizing it, as for example in the separation of enantiomers. Nor do the inventive concept and stated utility need to be part of the claim as construed. 

It is now normal to talk about “construing” the promise, but this is not the same as construing the claim. It is the invention as claimed which must have the promised utility, but the utility is not necessarily part of the claim itself. In this case, it seems to me that the compound claims should be construed simply as being the specified compounds, namely deferasirox in the case of Claim 32. The inventive concept was a compound which solved the problem at hand, so that would encompass the advantages over the prior art, which is to say in vivo iron binding with sufficient solubility, which is the concept O’Reilly J applied in the obviousness analysis. But a scintilla of utility could be less than that. So, iron binding alone might be sufficient, even without sufficient solubility to allow oral administration; after all, compounds in the prior art had been clinically used for treating humans even though they could not be orally admininistered, so surely that must be sufficient utility to support a patent. In other words, it strikes me that while O’Reillly J stated that he was applying the low standard of utility that applies in the absence of an explicit promise, he actually applied a higher degree of utility than the mere scintilla necessary to support a patent. I suspect he did this in order to avoid the utility / obviousness squeeze. But there is no need to do so; the squeeze is avoided simply because there is no reason why the stated utility and the inventive concept should be the same. With all that said, I may be parsing O’Reilly J’s decision too finely, as the unnecessarily elevated “scintilla” of utility did not make any difference in the final analysis.

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