“Consisting Of” Creates Closed Group and Provides Avenue to Avoid Infringement

Shire Development v. Watson Pharma (Fed. Cir. 2017) [16-1785-opinion-2-8-2017-11]

In a short opinion, the Federal Circuit has reversed a lower court infringement claim — holding instead that Watson’s generic product does not infringe.

In U.S. Patent law, it is an act of infringement to file an Abbreviated New Drug Application (ANDA) with the Food and Drug Administration (FDA) seeking to market a generic version of a patented drug listed in the FDA Orange Book.  That is just what Watson did here and Shire sued on its U.S. Patent No. 6,773,720.  The drug at issue is LIALDA, a mesalamine drug used to treat ulcerative colitis.  The claimed compound includes the following limitation:

said outer hydrophilic matrix consists of compounds selected from the group consisting of polymers or copolymers of acrylic or methacrylic acid, alkylvinyl polymers, hydroxyalkyl celluloses, carboxyalkyl celluloses, polysaccharides, dextrins, pectins, starches and derivatives, alginic acid, and natural or synthetic gums;

The basic question on appeal the scope of the claimed Markush group and whether it is a “closed group.”   In other words: is the hydrophilic matrix limited only to substances in the list.  This issue is a deciding factor in the case because Watson’s proposed generic version includes an inner hydrophilic matrix with additional substances not listed.

Consisting Of: In its analysis, the Federal Circuit began by recognizing that the phrase “consisting of” and “consists of” are terms of art in patent claims and “creates a very strong presumption that that claim element is ‘closed’ and therefore ‘exclude[s] any elements, steps, or ingredients not specified in the claim.'” quoting Multilayer Stretch Cling Film Holdings, 831 F.3d 1350, 1358 and AFG Indus., Inc. v. Cardinal IG Co., 239 F.3d 1239, 1245 (Fed. Cir. 2001). Although the presumption of standard meaning can be overcome, it requires that the patentee have documented the redefinition during prosecution in ways ““unmistakably manifest.”  However, as an exception to the standard meaning, the court may still find infringement when elements are added to the group that are “unrelated to the invention.” Norian Corp. v. Stryker Corp., 363 F.3d 1321, 1331 (Fed Cir. 2004).

Here, the generic proposal includes magnesium stearate within the matrix.  Citing Noriam, the district court still found infringement – noting that magnesium stearate is lipophilic and therefore including it within the hydrophilic outer matrix was “unrelated to the invention.”

On appeal, the Federal Circuit has reversed – noting that the “unrelated” exception is a “rare exception” to the general rule that “consisting of” closes the group.  The court explained here that the existence of magnesium stearate would certainly impact the invention by placing a lipophilic compound in an area designed to be hydrophilic.

When the outer, hydrophilic matrix interacts with a person’s digestive fluids, the matrix creates a swollen barrier preventing aqueous solution from reaching the inner, lipophilic matrix. This delay permits the product to proceed through the digestive system until the water breaks apart the outer matrix, releasing the lipophilic granules.

The court here found that the adding mag stearate to the outer layer has the potential of changing this process.  As such, the Norian exception does not apply, and Shire’s Markush claim is closed.  No infringement.

Question: Tell me why did Shire use “consisting of” instead of “comprising” or “consisting essentially of”?

Answer: In response to this inquiry, a reader correctly pointed us to MPEP 2173.05(h), which states” “It is improper to use the term ‘comprising’ instead of ‘consisting of’ [in a Markush group.]”  Citing Ex parte Dotter, 12 USPQ 382 (Bd. App. 1931).  In Dotter, the patentee sought a patent on an air purifier apparatus that relied upon a “mass of loose granules of a natural material of the group comprising wood and grains.”  Although the Board objected to the use of “comprising”, it did not explain the legal basis for its objection. Board wrote:

The word “comprising” does not exclude other materials besides wood and grains. It is considered that the word “consisting” would be more appropriate in this relation in confining the material strictly to these materials –wood and grains. If this formal change is made in claim 17 it may be allowed.

The word “comprising” does not exclude other materials besides wood and grains. It is considered that the word “consisting” would be more appropriate in this relation in confining the material strictly to these materials –wood and grains. If this formal change is made in claim 17 it may be allowed.

It turns out that the MPEP’s quote is from a case, just not Dotter.  It comes from In the precedential case In re Harnish, 631 F.2d 716, 723 (C.C.P.A. 1980)(“It is improper to use the term ‘comprising’ instead of ‘consisting of.'”)  Again, however, the court fails to justify its reasoning or basis for that objection. However, there is a slight suggestion elsewhere in the decision that the objection might be based on lack of unity of invention.

An interesting bit of the claim at issue here is that they make double-use of the consist/consisting of language.

said outer hydrophilic matrix consists of compounds selected from the group consisting of

I wonder whether the PTO would object to a reformulation claiming the “matrix comprising compounds selected from the group consisting of …” Thoughts?

18 thoughts on ““Consisting Of” Creates Closed Group and Provides Avenue to Avoid Infringement

  1. The fact that this was a Markush situation shouldn’t be a determinative factor. DC district court upheld ability to use “consisting of” to close one step of a method claim having a “comprising” preamble in our Sec 145 appeal. This was many years ago but I don’t think the law has changed. Berenter v. Quigg, 737 F. Supp. 5 (D.D.C. 1988), link to law.justia.com.

  2. I understand that we are looking at a patent that is at least a partial translation, but claims 1 and 4 (the most independent of the claims) are quite hideous. Ceteris paribus I prefer claims to be written as much in the singular as possible. The antecedent basis should precede and not follow the reference. I’m not sure melt granulation is a legitimate step in a process.

    1. Controlled-release oral pharmaceutical compositions containing as an active ingredient 5-amino-salicylic acid, comprising:

    a) an inner lipophilic matrix consisting of substances selected from the group consisting of unsaturated and/or hydrogenated fatty acid, salts, esters or amides thereof, fatty acid mono-, di- or triglycerids, waxes, ceramides, and cholesterol derivatives with melting points below 90° C., and wherein the active ingredient is dispersed both in said the lipophilic matrix and in the hydrophilic matrix;

    b) an outer hydrophilic matrix wherein the lipophilic matrix is dispersed, and said outer hydrophilic matrix consists of compounds selected from the group consisting of polymers or copolymers of acrylic or methacrylic acid, alkylvinyl polymers, hydroxyalkyl celluloses, carboxyalkyl celluloses, polysaccharides, dextrins, pectins, starches and derivatives, alginic acid, and natural or synthetic gums;

    c) optionally other excipients;

    wherein the active ingredient is present in an amount of 80 to 95% by weight of the total composition, and wherein the active ingredient is dispersed both in the lipophilic matrix and in the hydrophilic matrix.

    4. A process for the preparation of the compositions of claim 1, which comprises:

    a) melt granulation of at least one portion of the active ingredient with the lipophilic excipients with melting point lower than 90° C.;
    b) mixing the granules from step a) with the hydrophilic excipients and subsequent tabletting or compression.

  3. In my practice (biotech) it is not unusual to have a case where it is helpful to claim a composition “comprising an element selected from the group consisting of” x, y, and z. It simply makes it mandatory that at least one of x, y and/or z is present, while additional elements may be added. The above example with starches listed as one of the choices might not work if you must have one of the other members of the group present (often necessary for distinguishing over prior art). One deals with that by making the starches optional.
    Sometimes the above approach is not enough to distinguish over prior published patents that listed everything under the sun as a potential element. Then we try claiming it in a way that limits the universe of options for the “open” part of the claim. Maybe we claim “up to” X number of potential elements, or recite a limiting characteristic that must be shared to qualify as a member of the open part. Perhaps in the case under discussion here, those options were not available.
    Some examiners understand/accept the hybrid open/closed language, some do not.

  4. I wonder whether the PTO would object to a reformulation claiming the “matrix comprising compounds selected from the group consisting of …” Thoughts?

    The double-use approach is clever in terms of patent linguistics. But, in practice, it carries very little patentable weight in the face of an obviousness rejection.

    I’ve actually encountered a similar scenario during prosecution. The examiner asserted that the double-use language was effectively non-limiting. That is, the open-ended “the matrix comprising” allowed for other compounds/elements to be in the matrix, so as to render a closed-ended “the compounds consisting of” ineffectual for purposes of arguing against a reference offered on obviousness grounds.

    Think of it this way: A is disclosed in the art, and a skilled person recognizes A as an obvious variation of B, C, and D. If a claim recites “a compound comprising B, C, or D,” it’s fairly easy to assert its open-ended nature makes it obvious/easy to add A. However, a closed-ended limitation that excludes A (i.e., “a compound consisting of B, C, or D”) forces the examiner to explain a rejection under 103 in more detail and, in doing so, provides an opporunity to dissect/distinguish the reference in light of that explanation.

    I won’t go so far as to side with the examiner’s point of view or suggest closed-ended limitations safeguard against obviousness rejections from being properly maintained. But, at a minimum, I suspect it might explain why Shire–and a good number of other patent prosecution professionals–would feel compelled to use a closed-ended limitation like this. If obviousness wasn’t at issue, perhaps the better presentation of this claim from the outset would have been “an outer matrix including B, C, or D…”

  5. I am with Dennis on this one. Shire’s mistake was not in limiting the Markush group, but in defining the matrix as “consisting of.” The use of “comprising” or “consisting essentially of” in that instance would have allowed for other than the specified members of the Markush group.

    I have not read the opinion, but the comment above the Shire complained that the narrow reading eliminated other preferred embodiments further evidences Shire’s poor drafting and/or prosecution. Quite simply, a good Markush group should, at a minimum (unless there is art to be avoided) list all of the elements specifically embodied in the specification, if not all the elements merely suggested in the specification.

    If there was art that was being avoided, then the claim could have used “consisting essentially or” or, if more appropriate, “consisting of” while listing the other optional components.

  6. Surely it would’ve been ok to say the “matrix comprising compounds selected from the group consisting of …”

    First, it makes total sense that the word comprising can’t follow the word “group” in a Markush group, because then the Markush group wouldn’t limit the claim. If I say a material selected from “the group comprising wood or plastic,” any material at all would fit the bill.

    The same is not true for “the matrix.” The matrix can comprise an element of the Markush group, as well as other things, which allows the Markush group to limit the scope of the matrix.

  7. I don’t usually consult on patent applications in the chemical or pharma area. I would have recommended the Markush group part of the limitation to be written as follows:

    said outer hydrophilic matrix consists of compounds selected from the group consisting of:

    polymers of acrylic acid,
    copolymers of acrylic acid,
    polymers of methacrylic acid,
    copolymers of methacrylic acid,
    alkylvinyl polymers,
    hydroxyalkyl celluloses,
    carboxyalkyl celluloses,
    polysaccharides,
    dextrins,
    pectins,
    starches,
    derivatives of starches,
    alginic acid,
    natural gums, and
    synthetic gums;

    The claim as actually written is difficult to parse to the point of indefiniteness, and I could suggest very different interpretations.

    I believe my version is more precise and captures the intension, but I’m not sure because correct interpretation of the “starches and derivatives” list element is unclear to me.

  8. There are a myriad of reasons to use consisting of.

    The real question is why was this case filed if the accused infringing product didn’t meet the comprising of limitation.

  9. MPEP 803.02 mandates that Markush groups are written as “selected from the group consisting of.” I doubt practitioners will ever use these again.

  10. Next step. Convince the PTO that consisting of and comprising are not to be interpreted the same way. Most examiners are ignorant of the difference or choose to ignore it.

  11. Tell me why did Shire use “consisting of” instead of “comprising” or “consisting essentially of”?

    The usual answer is that it was either a mistake, or there was some art they were trying to avoid. Maybe they were hoping that if they needed to expand the claim a bit, they could rely on the doctrine of equivalents.

    It would be a bit of gamble to rely on Norian at the prosecution stage. Also, Norian must cut in both directions, no? Has anyone ever encountered an Examiner who applied Norian “offensively” to expand the breadth of a closed Markush group?

  12. Tell me why did Shire use “consisting of” instead of “comprising” or “consisting essentially of”?

    At a guess, because the Examiner would not allow the claim otherwise. Possibly the claim really is not patentable unless it is so limited? At least by getting some claim listed on the Orange Book, Shire bought itself a 30-month stay, if nothing else. Two & ½ years exclusivity is not nothing.

    I agree with the court’s reasoning via-à-vis the Norian exception. I do rather wonder, however, whether Shire was not cheated in this decision. Claim 1 clause (c) makes allowance for “optionally other excipients…” The CAFC disposes of this clause (fn 2) by saying “Claim 1(c) plainly falls under the preamble’s ‘comprising’ transitional phrase and outside of claim 1’s (a) and (b) Markush groups.” I guess that this is not so “plain” to my eye. Meanwhile, as Shire pointed out, to read (c) as the CAFC does excludes preferred embodiments disclosed in the spec from the claim’s scope. All other things being equal, a construction that excludes preferred embodiments is probably the wrong construction.

    I think that (c) can bear the meaning that Shire proposes, and given the presumption against constructions that exclude preferred embodiments, clause (c) should be read to excuse the presence of the Mg sterate in the hydrophilic layer.

    1. I do not believe that it is cheating to say that in a claim like:
      Compositions containing a compound, comprising:
      a. an inner lipophilic matrix consisting of…
      b. an outer hydrophilic matrix consisting of… and
      c. optionally, other excipients.

      the language of (c) does not open up the closed “consisting of…” language of (b). If you choose to categorize the structure in that manner than there is an inner lipophilic matrix, and outer hydrohilic matrix, and optionally “other” excipients that are not the inner and outer matrices, not optionally an inner lipophilic matrix including other materials and/or optionally an outer lipophilic matrix including other materials. A red ball, a blue ball, and optionally other balls does not ordinarily mean that a green ball (made using blue and yellow pigments) is a blue ball.

      1. Why not write two claims: one with excipients and one without excipients?

        If the relationship between the excipients and the inner lipophilic matix or the outer hydrophilic matrix needs more description, I would add one or more “wherein” relative adverbial clauses.

        BTW, in Japanese a ball of color green (ao=hiragana あお; kanji 青) would be a ball of color blue (ao=hiragana あお; kanji 青).

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