Friday, April 29, 2022

Arbitrary Selection?

Merck Sharp & Dohme Corp v Pharmascience Inc 2022 FC 417 Furlanetto J

            2,529,400 / sitagliptin phosphate salt form / JANUVIA / NOC

The key claim at issue in Merck’s 400 patent, Claim 4, is to the crystalline monohydrate form of the dihydrogenphosphate [DHP] salt of sitagliptin, which is used to treat type 2 diabetes [1], [12]. The closest prior art is PCT application WO 03/004498, which disclosed a genus of compounds, specifically exemplifying sitagliptin, among other compounds, both as a free base and hydrochloride salt [11]. The crystalline monohydrate DHP salt was evidently not specifically disclosed.

Pharmascience argued that the 400 Patent is invalid for obviousness and/or insufficiency [3], [64]. The insufficiency attack was a straightforward “how to make” argument, alleging that the disclosed process details were not sufficient to allow a skilled person to make the crystalline monohydrate [255]. This attack failed on the facts: [277–78].

The more interesting attack was obviousness. Given that sitagliptin was specifically disclosed in WO498, the inventive step lay in selecting sitagliptin as the lead compound from the other compounds, or in selecting the salt form, or in the combination of those decisions. As I see it—and this is not the way Pharmascience expressed it—the basic case for obviousness is that Merck just chose sitagliptin arbitrarily from the compounds disclosed in WO498, then did more or less routine salt screening to come up with a salt form with reasonable stability and manufacturing properties.

Suppose a genus patent discloses a class of compounds as having certain useful properties, such as utility in treating diabetes. There is no invention in picking one compound at random from the genus and showing that it is useful in treating diabetes; the genus patent told of us that all members of the genus are useful for that purpose, and the compound is a member of the genus, so of course it is useful in treating diabetes. This is known in European law as an “arbitrary selection”: see Dr Reddy's [2009] EWCA Civ 1362 [44]–[52]; and see Actavis v ICOS [2019] UKSC 15 discussed here. While the term “arbitrary selection” is not as commonly used in Canadian law, the same principle has been recognized in Canadian law: see Teva v Janssen 2018 FC 754 [198], Locke J, expressly noting that arbitrariness is not inventive; Millennium v Teva 2019 FCA 273, applying the principle; Janssen v Teva 2015 FC 247, also applying the principle. This is why a selection must have some special property over what is already known about the genus: this is not a matter of special rules applicable to selection patents, but simply a reflection of the fact that if the selected compound has no advantage, then it is not inventive to select it. Supose I hand you a bag, saying “This is full of red rocks” and I pull out a handful of rust-coloured pebbles of various shapes and sizes to show you. If you reach into the bag yourself and pull out another rusty pebble, no one will be surprised. Now, I can’t predict in advance exactly which rusty pebble you will take from the 100s in the bag—precisely because the selection is arbitrary. An arbitrary selection is both uninventive and unpredictable at the same time.

I don’t see much in Furlanetto J’s decision to suggest that the selection of sitagliptin was anything other than arbitrary. She states:

[203] The evidence indicates that the [skilled person] would not have any specific motivation arising from WO498 to focus on the particular crystalline form of a salt of sitagliptin over the other compounds disclosed within WO498.

But an arbitrary selection is exactly one where there is no particular motivation to pick the compound over the other compounds of the genus, precisely because one is as good as the other.

Furlanetto J also noted that “In June 2003, the only publication on sitagliptin was WO498. There was no indication as to its activity, efficacy, toxicity or tolerability. Further, the general level of potency reported in WO498 indicated a level of potency that was 45 to 167 times less than [another compound known in the prior art]" [210]. This was generally in a support of a “teaching away” argument. But teaching away is evidence of non-obviousness when the compound that was disparaged is subsequently discovered to have exceptional properties. I don’t see anything to that effect in Furlanetto J’s discussion.

Furlanetto J concluded

[212] There is no evidence that the PSA would be drawn to sitagliptin as a starting point for further development. On the basis of the prior art, it cannot be concluded that there was motivation for anyone other than Merck to move forward with sitagliptin as a lead compound.

Again, this is consistent with saying that Merck selected sitagliptin arbitrarily.

I’m not saying that the selection was arbitrary; only that the decision doesn’t identify this possibility and explain why it’s not. I think part of the reason for this is the focus on the inventive concept. Of course, the Windsurfing / Polozzi framework invites us to identify the inventive concept, but it is now recognized that this can be treacherous, with the FCA having wrestled with the question of whether a focus on the inventive concept is unhelpful, helpful or necessary: see here, here and here. This is a context where it seems to have been unhelpful. Pharmascience argued that “the choice of sitagliptin as the starting point does not form part of the inventive concept” [207]. Once we decide that it is, the question becomes whether that was obvious, and that leads to the asking whether it was predictable, which, in my view, is the wrong question.

The question might have been addressed with an objective problem-and-solution approach, in which case the issue of arbitrary selection would have been addressed in identifying the objective problem. Or it might have been addressed simply by asking is whether there was an inventive step involved in choosing sitagliptin.

There is also the old IG Farbenindustrie (1930) 47 RPC 289 (Ch) in Sanofi 2008 SCC 61 [10]–[11] approach to selection patents. Furlanetto J had a fairly long discussion of whether the claimed invention was a “selection patent” over WO498 invention of [77]–[95]. While she recognized that the validity requirements are the same either way, she expressed the view that this assists the Court “in understanding ‘the nature of the beast’” and makes it “easier to compare the facts of the particular case before the court with other previous fact scenarios” [80]. Ultimately she decided that it was a selection, but this doesn’t seem to have played any important role in the obviousness analysis.

In particular, she didn’t mention the IG Farben factors. There is good reason for this omission. The IG Farben factors have fallen out of favour, for two main reasons. First, as Rennie JA pointed out in Apotex v Shire 2021 FCA 52 [32] “A selection patent is subject to the same requirements and vulnerable to the same attacks as any other patent, including attacks based on anticipation and obviousness.” The IG Farben factors must therefore either be duplicative of standard grounds of attack, or wrong. And, as discussed here, the second and third IG Farben factors are arguably wrong, or at least problematic—though these factors were rarely if ever actually used to strike down a patent.

So there are good reasons to avoid the IG Farben approach. With that said, there is a reason the IG Farben factors were used for so long. It is the first factor that was almost always the crux of the analysis:

1. There must be a substantial advantage to be secured or disadvantage to be avoided by the use of the selected members.

This factor is a convenient way of expressing the inventive step requirement in the context of selection patents. It directly addresses the problem of arbitrary selection. As just discussed, if an entire genus has certain properties, it is obvious that any member of the genus will also have those properties. There is no invention in reaching into the bag of rocks and pulling out a rusty pebble; but if you rummage around and pull out a ruby, to everyone’s astonishment, that deserves a reward. The “advantage to be secured or disadvantage to be avoided” is the extra ingredient ensures the patentee has extracted a ruby from the bag, and not another red rock.

So, while the first factor is strictly redundant, in the sense that it simply encapsulates the inventive step requirement, it nonetheless poses that requirement in the context of selection patents in a way that is perhaps more helpful than the Windsurfing / Pozzoli focus on the inventive concept.

There seems to be more of a case that the development of the crystalline monohydrate form of the DHP salt was inventive, as there was a significant amount of work involved. But it seems that it was routine to develop the DHP salt [226]–[229], which was suitable for tableting. Developing the particular crystalline monohydrate form was challenging, but it is not clear to me that it offered significant advantages over the DHP. What was the problem solved by the crystalline monohydrate? It was difficult to develop, but if it did not solve any problem, in what way was it inventive? I have to admit that I came away with the nagging feeling that the inventors developed the DHP salt, and its properties were just fine, but they kept on going to develop something more difficult, just because they knew that the routine work to develop the DHP salt would not support a patent. There’s nothing in the decision that I can point at to support that notion, but I don’t see anything to rule it out, either. If that’s right, this is different from arbitrary selection, since the crystalline monohydrate was difficult to develop, but it’s still not clear to me that it’s inventive. Arbitrary selection is reaching into the bag and extracting a random rock that has the same properties as the others that were already known; inventive selection is rummaging painstakingly through the bag to find the single ruby; developing the crystalline monohydrate seems to have been like rummaging painstakingly through the bag to find the rusty rock that is most nearly spherical, even though being spherical offers no practical advantage over any other shape. One may at least question whether that is deserving of a patent.

Ultimately, even accepting all of Furlanetto J’s factual findings, I am having difficulty putting my finger on the inventive step in this invention. Assuming I’m not just missing the something, this strikes me as problematic. We need a doctrinal framework to guide the analysis, but in the end, a good framework should do more than simply generate an answer—it should help us understand the nature of the contribution that deserves the reward of a patent. I don’t see anything specifically wrong doctrinally with Furlanetto J’s analysis, and I suspect that ultimately my difficulty lies with the way the problem has been framed, with the focus on identifying the inventive concept.

Wednesday, April 27, 2022

Brulotte is Not the Law in Canada

Ghali v Jordahl USA Inc 2022 ABQB 248 Labrenz J

In Brulotte v Thys Co 379 US 29 (1964) the US Supreme Court held that an agreement to pay postexpiration patent royalties is per se unenforceable. The Court then reaffirmed in Kimble v Marvel Entm't LLC 135 S Ct 2401 (2015). Ghali v Jordahl illustrates that this rule, thankfully, is not part of Canadian law.

The invention at issue related generally to a mechanically anchored reinforcement system for concrete slabs. One clause of the agreement defined the “Invention” to include “all mechanically anchored reinforcements for concrete structures, protected or not protected by patents,” [46] (my emphasis). Another clause expressly provided that royalties would be paid after the expiry of the last patent: “Following the expiry date of the last Patent, DECON agrees to pay a royalty of three percent (3%) of Sales Price receipts. . . for as long the as [sic] product is made. . .” Thus the agreement was express that the payment obligation survived the expiry of the patents.

The wrinkle, as a matter of contract law, was that the termination clause provided that the agreement was to be in effect “for the lifetime of the Patents issued based on Invention,” and also provided for termination on one year’s notice [51]. Applying standard principles of contractual interpretation, Labrenz J held that the only way to give effect to all the terms of the agreement was to interpret the payment obligations as not being captured by the termination clause [46], [58].

This would be an unremarkable matter of contractual interpretation, but for the US rule in Brulotte, which held that royalty provisions of a patent licensing agreement which provides for royalties for the use of machines incorporating certain patents are not enforceable for the period beyond the expiration of the last patent incorporated in the machine. This rule was widely criticized by commentators: see Herbert Hovenkamp Brulotte's Web (2015) 11 J of Comp Law & Econ 527. It was nonetheless reaffirmed by the Court in Kimble, largely on the basis that it was settled law. As Professor Cotter points out, even the majority in Kimble seemed to acknowledge that the rationale for the rule is unconvincing; and he notes that Landes & Posner referred to it as “one of the all-time economically dumb Supreme Court decisions.”

The main prior Canadian case on point is Culzean Inventions v Midwestern Broom Co (1984) 82 CPR(2d) 175 (SKQB), which also held that parties are able to contract for the payment of royalties beyond the term of the patent. The analysis in Culzean focused on competition law, in particular the argument that at common law monopolies were void as being against the public interest and contrary to public policy. The argument in Ghali v Jordahl focused on the contract law issue of whether such an agreement would be commercially unreasonable. These arguments were rejected in both cases, in favour of the basic policy in favour of enforcing the express terms of a contract between sophisticated parties. (For authority Culzean relied on cases such as Trubenizing Process [1943] SCR 422, which make the distinct but related point that payment obligations can survive the invalidity of the patent; Ghali relied on standard contract law doctrine and cases.)

While Culzean and Ghali are not high authority, but they are consistent in the result and in the reasoning. In light of this, and given the criticism that Brulotte and Kimble have received, it seems safe to say that the Brulotte doctrine is not, and will not become, part of the Canadian law.

Tuesday, April 19, 2022

Liability of the Parent Corporation / Implied Obligation of Confidence

Angelcare Canada Inc v Munchkin Inc 2022 FC 507 Roy J

2,640,384 / 2,855,159 / 2,936,415 / 2,936,421 / 2,937,312 / 2,686,128 / Diaper pail cassette

In this decision Roy J held many claims of Angelcare’s six patents to be valid and infringed by Munchkin. The holding turned largely on the facts, but there are a few points of interest relating to inducement, liability of the parent corporation, an implied obligation of confidence and overbreadth.


The invention at issue relates to diaper pail cassettes. A cassette is an insert filled with plastic film which fits into a diaper pail, forming a diaper pail assembly, that dispense plastic bags bags to contain soiled diapers that are put into the pail. The cassettes are replaced once the film is used up, just as the cartridge in an ink jet printer is replaced one the ink is dry.

Angelcare held six patents, consisting of the 128 patent, and a family of divisional patents with 384 patent being the parent [32], [42]. The 128 patent was originally owned by Playtex, and was transferred to Angelcare in 2019 [8]. The claims at issue mostly relate to the cassette, but some relate to the assembly of the cassette and pail. Angelcare or related companies sold diaper cassettes and pails under the Diaper Genie brand. Munchkin’s cassettes were designed with the aim of being compatible with the Diaper Genie pails [14]. Until Munchkin launched its own line of pails in 2016, the Munchkin cassettes were compatible only with Diaper Genie pails: [16], [18].

Claim construction turned almost entirely on the facts. Munchkin argued non-essentiality in respect of only one element of the 128 patent [110]. After noting the presumption of essentiality [109], Roy J found that this element was essential, on the basis that a variant would have a material effect on the way the invention worked: see [38]–[39], [112]–[115]. Infringement followed on the facts in light of claim construction: see eg [163], [191].

The anticipation argument largely failed on the facts. One twist is that four claims of the 384 patent were anticipated by Angelcare’s own 138 patent” [303], [326]. While the decision is not explicit on this point, it appears that it was a matter of anticipation rather than double patenting because the 138 patent was a co-pending application owned by Playtex at the claim date of the 138 patent. These were the only infringed claims that were held invalid on any ground.

The obviousness attack failed on the facts. There was generally no difficulty in identifying the inventive concept of the patents: [394], [396], [403], [404]. The claimed invention was an improvement on the original Captiva/Diaper Genie II system that had been developed by Playtex and Angelcare, and that original system was accordingly the closest prior art [50], [407]. There was some dispute as to whether this was part of the common general knowledge, but that issue made no real difference, as it was not contested that the Captiva/Diaper Genie II system was part of the prior art, and Munchkin was consequently entitled to rely on it as the basis for the obviousness attack [382]. Roy J found on the facts that the differences between that system and the claimed inventions were not obvious.

Roy J had no difficulty in disposing of very tenuous arguments relating to insufficiency, ambiguity, utility and double patenting.


Angelcare alleged that Munchkin’s sale of cassettes to end-users had induced infringement of certain assembly claims by those end-users [250]. The cassettes were suitable for use only in combination with patented assemblies (whether used with Angelcare or Munchkin pails) [256]. In the US, this would give rise to what is now usually called contributory infringement—sale of a component especially adapted for use in a patented invention contrary to 35 US § 271(c). However, as Roy J noted, in Canada, in MacLennan 2008 FCA 35 ¶ 33, the FCA stated that “the courts have consistently held that selling a component intended to be incorporated in a patented combination (or process) without anything further, does not constitute an inducement to infringement, even where this component cannot be used for any other purpose.” Consequently, in Canada, such situations are treated as turning on inducement, which requires some additional encouragement beyond mere sale of the part.

Now, it is true that the courts have often stated that contributory infringement in the US sense is not part of Canadian law, but as I pointed out in my article Contributory Infringement in Canadian Law (2020) 35 CIPR 10, there are very few cases which actually decline to impose liability in that scenario, with the most recent being Permacon [1988] 2 FC 179, decided over thirty years ago. Instead, whenever the part sold by the indirect party has no substantial non-infringing use, the courts have consistently found the necessary inducement, sometimes on a slender basis, such as rudimentary assembly instructions in Windsurfing (1985) 8 CPR(3d) 241 (FCA), or the equivalency table in MacLennan.

In this case, Roy J found influence sufficient to establish inducement primarily on the basis of the label affixed on the Munchkin cassettes which clearly directed the end-user to use the Munchkin cassettes with the Diaper Genie diaper pails [266]. [267]. As Roy J noted, this finding is entirely consistent with MacLennan, and the many pharma cases which have found inducement on the basis of the product monograph [268]–[270]. This confirms that, at least in the case of a product especially adapted to infringe, any indication by the indirect party that the product will be used in a patented combination will be sufficient to establish the necessary influence.

The third prong, knowing inducement, was easily established on the facts [272].

Liability of Parent Corporation

To this point I’ve omitted mention of the corporate structure of the defendants, who I have referred to as Munchkin. To be more precise, there are two defendants, Munchkin, Inc, a US company, and Munchkin Baby Canada Ltd, its Canadian subsidiary [11]–[12]. The infringing cassettes were designed by Munchkin Inc [14]–[22], but it was not established that Munchkin Inc had any role in the manufacture, use or sale of the Munchkin cassettes or diaper pails in Canada [281]. (Munchkin Canada distributed and sold the products in Canada; it’s not clear to me where the products were made or by whom [282].) Roy J held Munchkin Inc liable on the basis of its role in the design of the infringing products. The entirety of his analysis on the issue is as follows (my underlining):

[282] The Plaintiffs do not address this issue directly in their closing arguments. However, the evidentiary record they mounted contained information about design decisions that came directly from Munchkin, Inc. in California, which resulted in the infringing products sold in Canada. The Court heard testimony from Mr. Johnson and Mr. Dunn, two Munchkin Inc. Officials, about how Munchkin’s cassettes were designed to be compatible with Diaper Genie’s diaper pails. Mr. Johnson testified that, to his knowledge, there have never been designers at Munchkin Canada (Johnson, TT Vol. 21, p. 2:17-21). Mr. Carvelho testified that all of the Munchkin products distributed in Canada are designed at Munchkin, Inc.’s Los Angeles headquarters (Carvelho, TT Vol. 19, p.183:10-16). He also explained that there are only seven Munchkin Canada employees and that their roles are limited to sales, marketing, and warehousing (Carvelho, TT Vol, 19, p.183:22-28). Moreover, Munchkin Canada’s products are merely a subset of what is offered in the United States; there are no unique items in Canada (Carvelho, TT Vol. 19, p.184:18-25). The Court also heard testimony from Mr. Carvelho about Munchkin’s strategy to advertise that their cassettes are compatible with Diaper Genie pails, with labelling designed to this effect. There was no distinction made between the decisions undertaken for the American market and the Canadian market to this effect. As such, the Plaintiffs advanced evidence that the American parent company made design and marketing decisions that had a direct impact on the resulting infringing activities in Canada. As such, Munchkin, Inc. is liable for any proven infringing activities in Canada.

Roy J cited no authority, and I find this passage puzzling. The gist seems to be in the penultimate sentence, which is to the effect that Munchkin Inc, caused the infringement in Canada, specifically in by (1) designing the infringing cassettes and (2) making the decision to affix labels advertising compatibility with the Diaper Genie pails.

Taking the design issue first, I have difficulty seeing how this in itself can give rise to liability. Suppose a device is patented in Canada, but not in France. If I manufacture it in France I am not infringing the Canadian patent. If I then sell and deliver it, in France, to another party who imports it into Canada, I am still not infringing the Canadian patent, even though I have caused the infringement. This point is well-established in the context of the Saccharin doctrine, which establishes that if a process that is patented in Canada is used abroad to make a product which is itself unpatented, importation and use in Canada of the product is an infringement. At the same time, it is well established that the user of the invention abroad is not an infringer under the Saccharin doctrine, even though the product is ultimately imported by another party: see Hospira v Kennedy Trust / infliximab 2020 FCA 30 ¶ 33–37 rev’g on this point Hospira v Kennedy Trust / infliximab 2018 FC 259; Cefaclor liability 2009 FC 991 ¶ 281–84; Saccharin Corporation v Reitmeyer & Co (1900) 17 RPC 606 (Ch) 612. It is for this reason that the Saccharin doctrine does not violate the principle that patent rights are territorial: Hospira v Kennedy Trust / infliximab 2020 FCA 30 ¶ 36. Accordingly, it is clear that if Munchkin Inc manufactured the cassettes in the US, that would not in itself give rise to liability for infringement of the Canadian patent, even if the cassettes are ultimately imported. It’s difficult to see how design rather than manufacture could lead to a different result.

The second point concerns the labels instructing use in an infringing combination. It may be that a party can be found liable for inducing infringement in Canada by virtue of acts abroad, but it’s not clear that this can support Roy J’s conclusion either. First, Roy J did not undertake an inducement analysis, so it does not appear that this was the basis on which he imposed liability. Second, liability based on inducement would at most support liability for the assembly claims, which were found to be infringed by inducement. Further, liability based on inducement, even for the assembly claims, gives rise to significant issues of extraterritoriality. Suppose a drug is patented in Canada but not in the US, and a generic pharma company sells the drug in the US accompanied by instructions to use it in a way that would infringe the Canadian patent. It sells the same drug in Canada with a skinny label that excises the infringing instructions. A Canadian vacationing in the US reads the PM in the US, and, as a result, uses the drug in an infringing manner on returning home to Canada. Imposing inducement for liability in such circumstances would certainly raise serious issues of extraterritoriality. Munchkin’s decision to affix the labels in the US is perhaps distinguishable, on the basis that the decision was specifically aimed at Canada. But whether that is sufficient to overcome the extraterritoriality concerns would require a full analysis. Finally, the decision to affix labels, taken abroad, is similar to the design decision, also taken abroad. If the latter does not give rise to liability, it is not clear why the former should be any different.

Implied Obligation of Confidence

Roy J’s decision provides some guidance on the question of when an obligation of confidence can be implied so that a disclosure is not a disclosure to the public. While Roy J applied established law and his decision turned on the facts, it is nonetheless helpful, as there is relatively little caselaw on this point in the patent context.

The inventor, a Mr. Morand, had emailed a CAD file of a prototype of the patented cassette to Initial, a third party prototype manufacturing company located in France, more than a year before the earliest filing date [332]. Munchkin argued this disclosure was anticipatory, and Angelcare responded that it was not a disclosure to the public because it was subject to an obligation of confidentiality [336].* There was no express non-disclosure agreement, so the question was whether an obligation of confidentiality could be implied [342].

Relying on Corlac 2011 FCA 228 and Lac Minerals [1989] 2 SCR 574, Roy J held that there was an implied obligation of confidence. This was based in part on the view that “The manufacture of articles by a party for another would fall prima facie in that category carrying an obligation of confidentiality” [339], but he emphasized more specifically not just third party manufacturing, but manufacturing of prototypes:

Initial was in the business of making prototypes, which inherently suggests that an obligation of confidentiality is present” [348]

See similarly [351]. This is even though this was the first interaction between Morand and Intial, or at least very early in the relationship [340], [347].

Mr Morand also sent the same file to a different firm, Plasti-Lax, to create technical drawings for mould-making [333]. This was also found to be subject to a obligation of confidence, though the issue was easier because there was a “longstanding business relationship of trust and cooperation” between the parties.

Roy J also found that the Plaintiffs’ reliance on article 1434 of the CCQ was not helpful, because it added nothing to the test set out in Lac Minerals, and “The legal test set out in Lac Minerals, which is consistent with art. 1434 CCQ and the jurisprudence that Quebec’s courts have developed on it, should continue to guide the Court” [346].


Munchkin also argued that the claims of several of the patents at issue were overbroad. [445] Roy J began by noting at [445] that “in some quarters it was argued that overbreadth does not constitute a proper ground of invalidity.” This is perhaps an oblique reference to my article Overbreadth in Canadian Patent Law 33 IPJ 21, 33 IPJ 147, in which I showed that the overbreadth argument is almost always redundant, and argued that there is no clear justification for striking down a patent which is otherwise new, useful, non-obvious and properly disclosed. As Roy J went on to point out, this argument was rejected by the FCA in Seedlings 2021 FCA 154 (blogged here), in which Locke JA expressly affirmed that “overbreadth remains a proper ground of invalidity” [50]. But as Locke JA acknowledged “[o]verbreadth often overlaps with other grounds of invalidity,” and this “makes it difficult to define circumstances in which a patent claim would be invalid for overbreadth but not also invalid on other grounds” [50], [51]. With Seedlings having given new life to overbreadth, the law will have to wrestle with new questions: What exactly constitutes overbreadth? What is the test? How it is distinct from other invalidity attacks? What justification is there for invalidating a patent to an invention which is new, useful, non-obvious and fully disclosed?

Roy J’s decision in this case does not really advance the law on those points, simply because the more difficult questions were not engaged on the facts. Roy J did begin with a general analysis, saying that “To determine whether a patent is overbroad, the Court assesses whether the claims, read fairly on what the patent discloses in the disclosure and the figures, are too wide and claim more than was invented. . . . As discussed recently by Justice Grammond, findings of overbreadth will usually occur when the patent fails to claim an essential element of the invention” [452]. This does not explain how overbreadth is different from other grounds of invalidity; in particular, if the patent fails to claim an esssential element of the invention, it will normally—dare I say inevitably?—be invalid for anticipation or obviousness.

Munchkin’s arguments on the facts were difficult to understand: so, Roy J started his analysis by saying “It is unclear how it can be said that more than this invention is claimed” given the facts acknowledged by Munchkin itself [454], and Roy J dismissed the overbreadth attack on other patents by noting that “Munchkin has not shown how these two Patents are overbroad in that the claims are broader than the invention disclosed in the specification or broader than the invention” [456]. Without going into the details reviewed by Roy J, I will say that I agree with his analysis, and his conclusion that Munchkin failed to make out any real case for overbreadth.

My sense is that what is going on is that parties seeking to attack the validity of a patent recognize that they have a new weapon in the overbreadth attack, but no one is really sure what that new weapon is, or how it should be used. I expect we will continue to see a series of futile overbreadth attacks until one day something sticks, and the law begins to develop more systematically; or nothing ever sticks, and defendants simply give up on the overbreadth attack. Time will tell, but this particular decision does not provide any signposts.

*In my initial post, this sentence reversed the names of the parties. Corrected as of 17 Feb 2023