Sadao Kinashi | March 3, 2017
Shire Development v. Watson Pharma
February 10, 2017
Before: Prost, Taranto and Hughes. Opinion by Hughes.
Shire sued Watson for infringing USP 6,773,720 by filing Abbreviated New Drug Application (ANDA) with the FDA seeking to market a generic version of Shire’s brand drug. The Patent claim recited “outer hydrophilic matrix consisting of . . . .” Watson’s ANDA product included a small amount of Mg stearate (which is lipophilic). The district court found infringement, but CAFC reversed and held that Watson’s ANDA Product does not satisfy claim 1(b), and remanded with instructions to enter judgment of non-infringement.
Shire社は、Watson社の新薬簡略承認申請(ANDA)が米国特許USP 6,773,720を侵害するとして提訴した。特許クレームは「外部親水性基質は、～なる群から選ばれた物質のみからなる(consisting of)」と限定していた。Watson社の申請新薬の外部親水性基質は、クレームにある群に含まれないステア燐酸Mg（しかも親油性）を少量含んでいた。CAFCは、Watson社の申請新薬を非侵害とした地裁判決を覆し、該新薬はクレーム1の限定(b)を満たさないとして、非侵害とした。
A. Patent Claims
The patent is directed to a controlled-release oral pharmaceutical composition of mesalamine used to treat inflammatory bowel diseases. The composition includes (a)the mesalamine active ingredient; (b) an inner, lipophilic matrix; (c) an outer, hydrophilic matrix; and (d) other optional excipients. In relevant part, claim 1 reads:
- Controlled-release oral pharmaceutical compositionscontaining 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 [sic] 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 . . . .
When the outer hydrophilic matrix interacts with a person’s digestive fluids, the matrix creates a swollen barrier to prevent 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.
B. District Decision
The district court concluded that Watson’s ANDA Product satisfied the “inner lipophilic matrix” and “outer hydrophilic matrix” limitations and that Watson’s ANDA Product satisfied the Markush limitations because the excipients falling outside the Markush groups were “unrelated” to the invention since they did not drive the water-affinity property of their respective matrices. Watson appealed.
I. CAFC DECISION
CAFC noted that (a) and (b) in claim 1 use the phrase “consisting of,” to characterize the matrix, and “consisting of” to define the groups, which creates a very strong presumption that the claim element is closed and excludes any elements or ingredients not specified in the claim. CAFC also noted that overcoming this presumption requires “the specification and prosecution history” to “unmistakably manifest an alternative meaning,” such as when the patentee acts as its own lexicographer.
Although the presumption is very strong, there can be rare exception for “aspects unrelated to the invention.” Norian Corp. v. Stryker Corp., 363 F.3d 1321, 1331 (Fed Cir. 2004). In Norian, CAFC considered whether adding a spatula to a calcium phosphate chemical kit designed to repair teeth and bones took the accused product outside the scope of the asserted patent. The claim recited only aspects of the chemicals, and CAFC concluded that “infringement is not avoided by the presence of a spatula, for the spatula has no interaction with the chemicals, and is irrelevant to the invention.”
Here, Watson’s ANDA Product does not facially satisfy the claim 1(b) Markush limitation. The Product’s extragranular space (which correspond to the outer hydrophilic matrix) contained Mg stearate, an excipient not within the claim 1(b) Markush group within the extragranular space. Nonetheless, the district court found that Watson infringed because the component outside of the Markush group (i.e., the lipophilic Mg stearate in the hydrophilic outer matrix) is unrelated to the invention and falls within the exception (like spatula in Norian).
However, CAFC disagreed with the district court conclusion.
The district court concluded that the “Mg stearate in the extragranular space is overwhelmed by the hydrophilic properties of the sodium starch glycolate in the extragranular space” and credited expert testimony that the hydrophilic “sodium starch glycolate is more potent than the Mg stearate” when “outside” the granules.
The district court thereby found that the Mg stearate exerted lipophilic influence in the outer matrix, and that finding is well supported: Shire’s expert acknowledged that “the Mg stearate in the spaces between the granules is no less lipophilic than the Mg stearate in the granules,” and the court found that Mg stearate is so strongly lipophilic that it may “impart lipophilic characteristics to a composition even in low concentrations.”
CAFC noted that no one has suggested that Mg stearate is neither lipophilic nor hydrophilic when in the outer matrix, and CAFC concluded that, based on the district court’s findings, the Mg stearate retains its lipophilic character in the extragranular space, and that the Mg stearate structurally and functionally relates to the invention, and its presence in the outer matrix violates the “consisting of” requirement in claim 1(b).
Regarding Shire argument that the Mg stearate in Watson’s product—which Watson includes as a lubricant rather than for its lipophilic properties—is unrelated to the invention because it is not sufficiently lipophilic to render the outer matrix lipophilic. But CAFC ruled that Norian did not restrict “related” components to only those that advance or are intended to advance a Markush group’s allegedly inventive elements.
CAFC also distinguished “consisting of” from “consisting essentially of”, which does not exclude unspecified element unless it materially affect to the novel properties of the invention.
Thus, CAFC reversed the district court’s judgment and remanded for entry of judgment of non-infringement and other proceedings consistent with this opinion.
The phrase “consisting of” creates a very strong presumption that the claim element is closed and excludes any elements or ingredients not specified in the claim.
Even if an unspecified element is overwhelmed by the properties of the specified element, Norian exception is not applied as long as the unspecified element has some effect.
The phrase “consisting essentially of” is preferable to “consisting of”, but Examiners often reject to “consisting essentially of” and we have problem of support to effectively rebut the rejection.
How about the case where the unspecified element is detectable but too little to have recognizable effect?