Multiple dependent claims, blaze marks, and ipsis verbis support

By Chris Holman

University of Minnesota v. Gilead

This is a follow-up to Dennis’s post discussing a recent Federal Circuit decision, University of Minnesota v. Gilead, wherein the university was essentially precluded from claiming priority to a provisional patent application because the provisional failed to provide adequate written description support for a later claimed invention.

Note that a provisional patent application is not required to include any patent claims, since a provisional can never mature into an actual patent, but only serves to provide an earlier effective filing date for a later-filed non-provisional patent application, assuming certain requirements are satisfied. In this case, however, the university’s provisional application included 63 claims, 49 of which are directed toward “[a] compound of Formula I:

wherein: . . . .”

The bodies of the claims defines various possible substituents at the seven “R” positions.  Here are the claims filed in the provisional application.

Claim 1 is the only independent claim, defining a genus of astronomical proportions. As Judge Lourie puts it, “the listings of possibilities are so long, and so interwoven, that it is quite unclear how many compounds actually fall within the described genera and subgenera.”  Claim 49 is the only claim that recites a single chemical “species,” presumably the molecule that the university thought was the most promising at the time the provisional was drafted.

Claims 2-48 lie between these two extremes, defining a huge number of subgenuses of the genus of compounds defined by Claim 1 – by my count over 500,000. (Note that the terms genus, subgenus, and species are relative terms when used in this context.)  How, one might ask, can 47 patent claims define over half a million subgenuses? The answer is through the use of multiple dependent claims that depend upon other multiple dependent claims, a practice that is not permitted under U. S. law.

The Manual of Patent Examiner Procedure (MPEP) defines a multiple dependent claim as “a dependent claim which refers back in the alternative to more than one preceding independent or dependent claim.”  It also cites 37 C.F.R. 1.75 for the proposition that “[a] multiple dependent claim shall not serve as a basis for any other multiple dependent claim.”

37 C.F.R. 1.75 further provides that for fee calculation purposes, a multiple dependent claim will be considered to be that number of claims to which direct reference is made therein. For fee calculation purposes also, any claim depending from a multiple dependent claim will be considered to be that number of claims to which direct reference is made in that multiple dependent claim.

This fee calculation policy reflects the reality that a multiple dependent claim is simply a shorthand means of reciting multiple discrete patent claims.  For example, the provisional’s claim 12 recites “[t]he compound of any one of claims 1-11 wherein R2 is hydroxy.”  That is simply shorthand for and the functional equivalent of 11 discrete dependent claims, i.e., the compound of claim 1 wherein R2 is hydroxy, the compound of claim 2 wherein R2 is hydroxy, the compound of claim 3 wherein R2 is hydroxy, the compound of claim 4 wherein R2 is hydroxy, etc..

When you start going down the path of multiple dependent claims that depend upon other multiple dependent claims, which in turn depend on other multiple dependent claims, etc., the number of discrete dependent claims can become immense. In this case, the provisional’s claim 47 is a multiple dependent claim that, inter alia, refers back to another multiple dependent claim (claim 45), which in turn refers back to a third multiple dependent claim (claim 33), which refers back to a fourth multiple dependent claim (claim 21), which refers back to a fifth multiple dependent claim (claim 13), which refers back to dependent claim 2. If you follow this path, you arrive at a subgenus that the University asserts is the same subgenus claimed in the later issued patent.  Assuming this to be correct, then, as Dennis pointed out in his post, claim 47 does appear to encompass a claim that specifically defines the later claimed subgenus.

The problem is, claim 47 also encompasses 250,880 other unique claims, each of which defines its own subgenus. The huge number results from the multiplicative effect of five iterations of multiple dependent claims. One can readily understand why the PTO does not allow multiple dependent claims that depend on other multiple dependent claims. But since this was only a provisional application, the claims were never examined, and are simply serving as a vehicle for disclosing a huge number of subgenuses.  By my count, the provisional includes a total of 584,431 subgenus claims.

The Board concluded that the claims in the provisional did not provide ipsis verbis support for the later claimed subgenus, albeit without providing much in the way of explanation, and the Federal Circuit affirmed. Black’s Law dictionary defines ipsis verbis as “in the identical words, as opposed to substantially.” In my view, claim 47 does literally describe the later claimed subgenus, the problem is that it is buried in astronomical number of other subgenuses.

The courts have long used the terminology of “blaze marks” when assessing written description support for a later claimed chemical compound or genus.  The term refers to the practice of marking a trail through the forest by slashing the bark of trees. Expanding upon that metaphor, imagine a vast forest wherein there lies hidden a beautiful waterfall.  One could employ blaze marks to chart out a trail leading to the waterfall.  But if all of the trees in the forest have a blaze mark, the explorer would have no idea which marks to follow, regardless of the fact that one could go back retrospectively and point out specific blaze marks that would define a trail leading to the waterfall.  The point is, even if there are blaze marks defining a trail to the waterfall, as a practical matter it would be very difficult to find the correct trail if there are too many other blaze marks defining a huge number of trails that do not lead to the waterfall.

Returning to the case at hand, I do not think the result would have changed if somehow the university could have, perhaps with the help of AI, drafted 584,331 discrete dependent claims that would have been the functional equivalent of the multiple dependent claims that it did file in its provisional application.  At some point, the disclosure of too many alternative possibilities can, as a practical matter, negate the disclosure of one specific subgenus. I would suggest that this is the basis for the Board’s determination that there was not ipsis verbis support for the later claimed subgenus, nor were there sufficient blaze marks pointing the way.

And given the standard of review, it is not surprising to me that the Federal Circuit affirmed.  As stated in its opinion, “the primary considerations in a written description analysis are factual and must be assessed on a case-by-case basis. We thus review the Board’s decision regarding written description for substantial evidence.”

18 thoughts on “Multiple dependent claims, blaze marks, and ipsis verbis support

  1. 8

    Thanks for the Tracking information you put up on the USPS site inorder to get the skinny. . I hope it was worth it to find out why I had to leave TN. Personally I don’t think the Court will.

  2. 7

    heads up, some stable coins in crypto are starting to depeg from a dollar, this could spell disaster for crypto and larger markets, keep your eyes peeled for ez pickings in such case, any fiat you have may be worth quite a bit in a couple days. The bank crash in silicon valley is what is causing this, they held many VC’s money and also held some stablecoin reserves (enough to spook people into doing a mini bank run on the stablecoins right now).

    1. 7.1

      Who needs “pickings” when you can just sit back and laugh at a bunch of greedy s c u m b a g s losing tons of money? It’s a laugh riot watching these lizard-brained VCs and their bank implode and the bonus laughs will come when all the Richie Rich’s demand to be bailed out because they are sooooooo important and clever.

      Just flush Sand Hill Road down the sewer and the world is instantly a better place.

  3. 6

    In a first mechanical provisional application that will eventually be converted and filed outside the US, multiple dependent claims are highly recommended to show possession of each claim element combination. Since the US is harmonizing with the rest of the world, instead of the other way around, the Federal Circuit decision seems to be out of place. If a patent attorney routinely files multiple dependent claims in first filed Europe or Asia priority applications, does US FC decision create a new trap?

    1. 6.1

      There is nothing new about this decision or it’s implications and competent attorneys planning to file applications around the world do what is necessary to protect the most important items in any so-called “laundry” list, whether it’s presented as a massive sequence table or as a multiply dependent series of claims/sentences/paragraphs.

      It’s also ALWAYS been important to advise naive clients of how the law works in all relevant jurisdictions.

  4. 5

    Inventor makes a breakthrough and discovers a general principle that that has wide application. From her discovery, the inventor quickly conceives of a large genus of components, including their structures. The Federal Circuit (and soon, the Supreme Court) wants her to include a description of all of these structures in the application; otherwise they may conclude that producing all of those components would require undue experimentation. So the inventor includes a combinatorial description of all of the structures in her patent application.

    During prosecution, the inventor discovers that one subgenus of her components is of commercial interest and directs the pending claims to that subgenus. Ah, but the application does not have blaze marks pointing to that subgenus. So the Federal Circuit strikes again: no sufficient written description for the claimed subgenus.

    But why should it matter if an inventor invents one embodiment or two million embodiments? I suppose one could file 100,000 applications so that each of the subgenera a “adequately described,” but that just elevates form over substance.

    Is there a limit to the number of embodiments that can be invented and protect? If so, why?

    1. 5.1

      Bob, may I ask: was your use of the word “general principle” unwitting or was it deliberate, because you are aware of the WD case law of Europe, which recognises the distinction betweeen the invention of a “general principle” and the discovery that one specific molecule has some degree of effectiveness against a medical indication?

    2. 5.2

      To invent any embodiment you have to show its utility. Imagining families of chemical compounds that can be made using a general synthetic scheme doesn’t enable their use.

      1. 5.2.1


        Perhaps you are confusing “to invent” with the (mere) ability to generate novelty destroying prior art.

        Well beyond mere “imagining,” use of an AI to print out reams and reams of ‘actual objective structure’ simply need not be enabled of that structure to serve as prior art.

        To simply “be” is enough to destroy the chance of others to obtain patents (your use of the word ‘invent’ may apply to those who are blocked, but does not apply to that which does the blocking).

  5. 4

    >The courts have long used the terminology of “blaze marks” when assessing written description support for a later claimed chemical compound or genus.

    So, is the patentee limited to blazed embodiments i.e., all of the other text is worthless?

    Out of curiosity, would this claim w. this priority document (including the multiple dependent claims) have worked in Europe?

    1. 4.1

      “ Out of curiosity, would this claim w. this priority document (including the multiple dependent claims) have worked in Europe?”

      Out of curiosity, how much would that claim set cost to be examined in Europe?

      1. 4.1.1

        I’m not sure how that’s relevant… particularly if everyone does the normal trick of cutting-and-pasting the full/original claim set into the detailed description.

  6. 3

    The idea of “blaze marks” has been familiar to me since childhood. Same with just about everybody, I suppose. But, until now I was not aware of the use of the idea to navigate a way through the legal maze of the WD requirement. Excellent fit, I think. Bravo! Who should get the credit for being, long ago I gather, the first to liken the task of tracking WD back to a particular PTO filing date with the notion of blaze marks? By now lost in the mists of time, I suppose.

    Reading the piece, another thought occurs: a corollary, perhaps. I once, long ago, heard a mischievous old English patents judge, musing on the subject of what any particular document reveals to its reader, pointing out that the best place, by far, to hide a particular leaf is of course in the middle of a forest. Key word there is of course “hide”.

    Oh and BTW, it is a misconception that under the EPC anything less than ipsis verbis text support is not good enough. Trouble is, most EPO Examiners, egged on by ever more oppressive EPO managers, ever-increasingly take the easy route of refusing anything that falls short of strict 1:1 text support.

  7. 2

    “Claim 49 is the only claim that recites a single chemical “species,” presumably the molecule that the university thought was the most promising at the time the provisional was drafted.”

    Classic! Did they manage to get a handful or two of other “promising” molecules characterized before the utility application was filed? Or was it still about this beauty in claim 49 a year later?

    1. 2.1

      Nice post, by the way.

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