2,226,784 / tadalafil / CIALIS / NOC
I’m back to blogging again after an end of term vacation—still catching up on the
backlog from my longer hiatus over the winter. In my last post on this case I discussed
the meaning of “or”. This post turns to validity. St-Louis J held the 784 patent to be
invalid for overbreadth [120] and insufficiency [149], while declining to address utility. I
have argued that overbreadth is almost always functionally duplicative of another
established ground of invalidity, and this case illustrates that point once again, as the
facts supporting the finding of overbreadth were the same as those supporting
insufficiency.
The facts are reasonably straightforward. The 784 patent relates to the use of tadalafil
for the treatment of ED. Claim 2, which is representative for present purposes, is to a
pharmaceutical composition for the treatment of ED in a male animal, comprising
“[tadalafil] or a physiologically acceptable salt or solvate thereof.” All asserted claims
include the phrase “or a physiologically acceptable salt.”
St-Louis J found on the facts that it is not possible to make a physiologically acceptable
salt of tadalafil [118]. Tadalafil does not have an ionisable functional group and
consequently it is very difficult to make a salt form [103]. It may be possible to make one
or two salts, but only under extreme conditions that would result in the degradation of the tadalafil such that the resultant salt would not be sufficiently pure and stable to be
considered physiologically acceptable [118]. As a result, St-Louis J held the 784 patent to
be invalid for overbreadth [120] and insufficiency [149], while declining to address
utility.
As discussed in my last post, St-Louis J concluded that a physiologically acceptable salt
is an essential element of the claim. While I have my doubts about that conclusion, once
we accept that, the claim is effectively to a physiologically acceptable salt of tadalafil, and
insufficiency then follows directly from the fact that it is not possible to make even one
physiologically acceptable salt. This is the classic “how to make” variety of sufficiency. If
you claim “Compound X” you have to tell a skilled person how to make Compound X, or
the claim is invalid for insufficiency. The traditional view is that the purpose of the
disclosure is to ensure that the public would have benefit of the invention after the term
expired: see eg Minerals Separation [1947] ExCR 306, 316. If a skilled person cannot
make the claimed compound with the guidance provided by the specification, the
patentee could get the benefit of patent protection during the term, while keeping its
monopoly through secrecy after the term expired. There is an extremely difficult
question as to whether the invention has to be enabled across the full scope of the claim.
But that doesn’t concern us here, as the specification did not provide sufficient
instruction to allow a skilled person to make any physiologically acceptable salt.
A standard statement of the sufficiency requirement is that the specification must enable
the skilled person to practice “the invention” [133]; citing s 27(3) and Teva 2012 SCC 60
[51]. But what is “the invention”? That term is notoriously ambiguous: “The word
‘invention’ has many meanings and nuances,” as Henderson pointed out in Patent Law
of Canada (1994) 7–8. It can mean the inventive concept, which is to say the
information disclosed in the patent which is the quid pro quo for the grant; it can means
the invention as claimed, which is the set of all existing or future embodiments of the
claimed invention; or it can mean a particular embodiment: see British United Shoe
Machinery Co Ltd v A Fussell & Sons Ltd (1908) 25 RPC 631 (CA) 649–51. This led to a
debate in this case in which Lilly argued that insufficiency was not available as an attack
because the Defendants had not established the nature of the invention [139]. Lilly’s
argument isn’t fleshed out in enough in St-Louis J’s decision for me to fully understand
it, but I suspect the point is that the inventive concept was the discovery that tadalafil is
an effective treatment for ED, and not the discovery of how to make a salt form of a
compound that was already known to be effective. If that is indeed what Lilly was
arguing, it is effectively another angle on the “or” argument, and one which, in my view,
is better framed in terms of claim construction (as discussed in my last post) rather than
sufficiency. So, given St-Louis J’s conclusion on the meaning of “or”, I would say she was
right to reject Lilly’s argument on this point [143], to focus on whether the specification
instructed how to make the salt [144]–[148]. And since the answer to that on the facts is
“no,” I agree with her conclusion that the patent is invalid for insufficiency [149] (given
her conclusion on the construction of “or”).
With all that said, the ambiguity as to the meaning of “the invention” made this part of
the decision more convoluted that it needed to be. Given the ambiguity of the phrase
“the invention,” I suggest it might be desirable for the courts to simply stop using it
altogether, in any context in which precision is necessary—which is to say, especially in
defining validity doctrine. Instead, the law should specify “the invention as claimed” or
“an embodiment of the invention,” or “the inventive concept,” as appropriate to the
particular doctrine. That is a clarification that would probably have to be done by the
FCA, since many authoritative statements of the law use the ambiguous term
“invention.”
On that note, I would also point out that the law of sufficient disclosure has several
threads that need to be disentangled, and the meaning of “the invention” isn’t
necessarily the same for each aspect of the disclosure requirement. The SCC in
Consolboard [1981] 1 SCR 504, 518, noted that the statutory provision, s 27(3) “gives the
impression of a mélange of ideas gathered at random rather than an attempt to
enunciate, clearly and concisely, a governing principle or principles.” While the Court in
Consolboard at 518 suggested that the haphazard nature of the statutory provision
might be the product of amendment over a period of many years, I think the truth is that
the case law gives a similar impression of a mélange of ideas. This is illustrated by
Thorson P’s well-known summary of the disclosure requirement established by the case
law in Minerals Separation [1947] ExCR 306, 316–17. I won’t repeat it here, but it is
plain on its face that it runs together several concepts that are sometimes only
tangentially related.
Moving on, St-Louis J also held the asserted claims to be invalid for overbreadth:
[120] As I conclude that it is more probable than not that physiologically
acceptable salts of tadalafil cannot be made I conclude, as the Defendants
argue, that such a salt was not invented. The Asserted Claims therefore
claim broader than what was invented and are thus invalid for
overbreadth.
In my article Overbreadth in Canadian Patent Law: Part I (2020) 33 IPJ 21 and Part II
(2021) 33 IPJ 147, I argued that a finding of invalidity for overbreath is almost always
redundant with another established ground of invalidity. And so it is here. All the
evidence St-Louis J reviewed in the context of overbreadth went to the question of
whether went to whether a physiologically acceptable salt could be made [114]–[119].
Exactly the same facts that results in a finding of insufficiency—that the claim
compound could not be made—was also the basis for the finding of overbreadth.
The problem with overbreadth is that it remains ill-defined. St-Louis J noted that “There
are two (2) ways that a patent claim can fail for overbreadth (or overclaiming): it can be
broader than the invention disclosed in the specification, or it can be broader than the
invention made by the inventor” [109]. It seems that in this case she was relying on the
second prong, as she noted that
Under the claims broader than invention made, it is a question of fact as to
what the inventor actually invented [112].
But
what does “actually invented” mean? As I argued in my Overbreadth
article, if the
patentee has sufficiency disclosed and claimed subject-matter that is
new, useful and
non-obvious, how could it be said that they had not “invented” the
claimed subject-matter? Overbreadth has an air of being something
distinct only because of the
ambiguity in the phrase “the invention.” It sound very reasonable to say
that the
patentee cannot claim more than it invented, but if we try to define
exactly what is
meant by “invention,” it is difficult to give this proposition any
content that is
independent of the standard grounds of invalidity.
In any event, as noted, this is another case in which overbreadth is redundant as turning
on the same analysis as another ground of invalidity, in this case insufficiency.
The third issue is as to utility. The utility argument turned entirely on the point that a
physiologically acceptable salt could not be made: the Defendants argued that “the
failure of the 784 Patent to indicate which of the many possible salts can be made as a
physiologically acceptable salt of tadalafil” renders the asserted claims invalid for a lack
of utility [154], while Lilly argued that “the Defendants have not met their burden to
establish that a physiologically acceptable salt of tadalafil cannot be made” [159]. That
is, the argument was that the invention lacked utility because a physiologically
acceptable salt could not be made; it really just recapitulated the sufficiency argument.
To my mind, this conflates utility and sufficiency. (This is not a criticism of St-Louis J,
as this is the way the case was argued.) I have to admit, this conflation is very common.
There was really no distinction between the two in early English practice, before the
development of claims; if the specification describes a device that is not operable, there
is no distinction to be made between a case where the patentee had devised a useful
invention but failed to disclose it and a case where the specification disclosed the
invention precisely, and the invention itself was useless, unless recourse is had to
extrinsic evidence.
But with the advent of claims, we can distinguish between the two. The utility
requirement asks whether the claimed invention works (or can be soundly predicted to
work). Sufficiency asks whether the claimed invention can be made. These are different.
Suppose, for example, that in the early days of genetic engineering, the patentee claims
“Pure human insulin.” The claimed subject-matter, pure human insulin, is undoubtedly
very useful. If the patentee cannot actually make it, the patent is invalid for
insufficiency, but not for lack of utility. On the other hand, it may be easy to make
something that lacks utility. If the patent claims “Oregano oil for the treatment of
cancer,” the claim is sufficient, because oregano oil can be made and administered with
the intent of treating cancer, but invalid for lack of utility because oregano oil does not
in fact treat cancer. Applications for impossible inventions, like a perpetual motion
machine, are traditionally rejected for both lack of utility and insufficiency; in my view,
they should be rejected for insufficiency alone. After all, a device with greater power
output than input would be extraordinarily useful—if it is could be built. With all that
said, I acknowledge that there is a lot of confusion in the caselaw on this issue,
stemming ultimately, in my view, from the fact that the distinction could not be drawn
prior to the introduction of claims.
Ultimately, St-Louis J, wisely, in my view, declined to address the utility argument. The
Defendants argued that”a claim must fail if, in addition to claiming something that is
useful, it also claims something that is useless” [173]. In other words, the question is
whether utility has to be established across the full scope of the claim. St-Louis J
reviewed the caselaw and noted the uncertainty on the question of whether a claim is
invalid if it claims a single inoperable species [175]–[178]. Given that she had already
held the asserted claims invalid on two other grounds, she refrained from deciding this
point of law, and so she declined to rule on the utility ground [178]. This is a difficult
question, which is better left to a case in which it is the focus of the argument.