United States: Fed. Circ. Provides Cautionary Tale On Markush Claiming

Use of the transitional phrase "consisting of" [in a Markush claim] to set off a patent claim element 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." AFG Indus., Inc. v. Cardinal IG Co., Inc., 239 F.3d 1239, 1245 (Fed. Cir. 2001). "'Consisting of' is a term of patent convention meaning that the claimed invention contains only what is expressly set forth in the claim." Norian Corp. v. Stryker Corp., 363 F.3d 1321, 1331 (Fed. Cir. 2004). Thus, if a patent claim recites "a member selected from the group consisting of A, B, and C," the "member" is presumed to be closed to alternative ingredients D, E, and F. . . .

The presumption that a claim term set off by the transitional phrase "consisting of" is closed to unrecited elements is at least a century old and has been reaffirmed many times by our court and other courts. . . . [T]o overcome the exceptionally strong presumption that a claim term set off with "consisting of" is closed to unrecited elements, the specification and prosecution history must unmistakably manifest an alternative meaning.

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

1. 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 [sic], waxes, ceramides, and cholesterol derivatives with melting points below 90°C., and wherein the active ingredient is dispersed both in said [sic] the lipophilic matrix and in the hydrophilic matrix;
2. 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;
3. optionally other excipients ... .

In an earlier appeal in this case, the Federal Circuit had determined that "the correct construction requires that the inner volume contain substances from the group described for the inner lipophilic matrix (which are all lipophilic substances), and that the outer volume separately contain substances from the group described for the outer hydrophilic matrix (which are all hydrophilic)." Shire, 2017 WL 541013 at *2.

On remand, the district court concluded that Watson's ANDA product infringed the asserted claims. According to the district court, "the excipients [in Watson's ANDA product] falling outside the respective Markush groups were 'unrelated' to the invention since they did not drive the water-affinity property of their respective matrices," and therefore, "the lipophilic component in the outer hydrophilic matrix [claim limitation 1(b)] fell within the exception announced in Norian." Id. at *2-3.

The Federal Circuit, however, explained that there was no infringement because Watson's allegedly infringing product did not meet claim limitation 1(b). Watson's product included lipophilic magnesium stearate, a chemical not within the hydrophilic closed Markush group recited in claim limitation 1(b), which was limited to: "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."

Id. at *2.

The Federal Circuit acknowledged that under Norian Corp. v. Stryker Corp., 363 F.3d 1321, 1331 (Fed Cir. 2004), there is an exception to the strong presumption triggered by Markush language for "aspects unrelated to the invention." In Norian, the exception applied because a spatula present in the accused infringing kit was unrelated to the chemicals recited in the claim, i.e., the spatula had "no interaction with the chemicals, and is irrelevant to the invention." Shire, 2017 WL 541013 at *3.

The Federal Circuit, however, "disagree[d] with the district court's interpretation of Norian and what constitutes a component unrelated to the invention." Id. at *3. The Federal Circuit explained why the Norian exception did not apply in the Watson case:

Id. at *3-4.

The Federal Circuit applied this "closed" interpretation to the Markush language in Shire's claims even though the patent examples apparently disclosed magnesium stearate in the outer matrix:

Id. at *4.

The Federal Circuit also rejected the district court's determination that the claim was saved by limitation 1(c), which recites "optionally other excipients." According to the Federal Circuit, "Claim 1(c) plainly falls under the preamble's 'comprising' transitional phrase and outside of claim 1's (a) and (b) Markush groups. Claim 1(c) therefore does not present a permissive catchall to those closed Markush groups." Id. at FN 2.³

As a result, the patent owner was defeated in the Hatch-Waxman litigation, and the ANDA generic was effectively granted a royalty-free license for simply adding an extra component to its product that was not included in the Markush groupings recited in the claims.

A lesson for practitioners from the Federal Circuit's Shire decision is to use Markush language with caution, such as only when truly necessary, for example, to avoid prior art. Restrictive, i.e., closed, Markush language utilizing "selected from the group consisting of" may be better filed in a practitioner's toolbox along with strategies like provisos.

In looking through that toolbox to select the appropriate tools for constructing particular claims, a practitioner may conclude that if a proviso would not be necessary or appropriate for a given claim to overcome the prior art, a "closed" Markush phrase also may not be necessary or appropriate. In other words, if there is no reason to close the scope of the claim with respect to particular embodiments to overcome prior art, then practitioners may want to consider claiming such embodiments in the alternative without "closed" language, or with an open-ended transitional term such as "comprising," rather than using Markush "consisting of" language to close the group.

Alternatively, or in addition, practitioners may want to avoid using closed "consisting of" language altogether, instead using phrasing such as "X selected from A, B, and C" or "X chosen from A, B, and C." See Manual of Patent Examining Procedure §2173.05(h). For example, perhaps a claim like the following, avoiding any use of "selected from the group consisting of," would have, assuming it is valid, been infringed by Watson's
ANDA product:

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

1. an inner lipophilic matrix chosen from at least one unsaturated and/or hydrogenated fatty acid, salts, esters or amides thereof, fatty acid mono-, di- or triglycerides, waxes, ceramides, and cholesterol derivatives with melting points below 90° C., and wherein the active ingredient is dispersed in the lipophilic matrix and in the hydrophilic matrix;
2. an outer hydrophilic matrix wherein the lipophilic matrix is dispersed, and wherein the outer hydrophilic matrix is chosen from at least one polymer or copolymer of acrylic or methacrylic acid, alkylvinyl polymer, hydroxyalkyl cellulose, carboxyalkyl cellulose, polysaccharide, dextrin, pectin, starch and derivatives, alginic acid, and natural or synthetic gum;
3. optionally other excipients ... .

And even if Markush "consisting of" language is desired to overcome prior art, practitioners may want to consider reciting such Markush language in dependent claims rather than in an independent claim.

Perhaps, in addition, pursuit of a functionally defined genus in accord with 35 U.S.C. § 112(f) in an independent claim would provide adequate
protection divorced from any need for "consisting of" Markush language. As an example to illustrate this point, consider the following claim:

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

1. inner lipophilic matrix means, wherein the active ingredient is dispersed in the lipophilic matrix and in the hydrophilic matrix;
2. outer hydrophilic matrix means wherein the lipophilic matrix means are dispersed, and
3. optionally other excipients ... .

But, as a final caution, in eschewing traditional "closed" Markush language, one should make sure not to swing too widely and fall into the trap of Superguide Corp. v. DirecTV Enterprises Inc., 358 F.3d 870 (Fed. Cir. 2004).

In Superguide, the drafter avoided use of the closed "consisting of" Markush phrasing, instead employing the following format in an attempt to include alternative embodiments: "at least one of a W, a X, a Y, and a Z." However, this phrasing raised the question of whether the claim required at least one of each of W, X, Y, and Z to be present. Because the drafter did not include a noun in front of the "at least one of a W, a X,
a Y, and a Z" language, the Federal Circuit found that the list was indeed conjunctive and required at least one of all of W, X, Y, and Z to be present, resulting in a finding of noninfringement.

Such a royalty-free license of patented technology might have been avoided, had the drafter written "at least one material chosen from W, X, Y, and Z." That language likely would have preserved alternative elements to be covered by the claim, rather than only the combination of W, X, Y, and Z.

Footnotes

1 MPEP § 2173.05(h).

2 Some may have a preference for "chosen from" because it sounds less like traditional Markush language.

3 Interestingly, it appears the Federal Circuit is suggesting that the following alternative claim, assuming it is valid, may have been infringed, despite the presence of magnesium stearate in the outer hydrophilic matrix of Watson's ANDA product:

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

1. 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 triglycerides, waxes, ceramides, magnesium stearate, and cholesterol derivatives with melting points below 90° C., and wherein the active ingredient is dispersed both in said [sic] the lipophilic matrix and in the hydrophilic matrix;
2. 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, magnesium stearate, and natural or synthetic gums;
3. optionally other excipients ... .