Last Month at the Federal Circuit
Last Month at the Federal Circuit

June 2012

A Reference May Anticipate Even If It Requires a Person of Ordinary Skill to Pick Items from Lists of Components to Assemble the Invention


Judges:  Newman (concurring-in-part and dissenting-in-part), Bryson (author), Fogel (district judge sitting by designation)
[Appealed from N.D. Ill., Judge Dow, Jr.]

In Wm. Wrigley Jr. Co. v. Cadbury Adams USA LLC, Nos. 11-1140, -1150 (Fed. Cir. June 22, 2012), the Federal Circuit affirmed the district court’s determination on SJ that a patent owned by Wm. Wrigley Jr. Co. (“Wrigley”) was invalid and that Wrigley’s product did not infringe a patent owned by Cadbury Adams USA LLC (“Cadbury”).

Wrigley and Cadbury compete in the market for chewing gum.  This case involved gum that provided a cooling sensation when chewed.  Menthol, historically known to provide a cooling sensation, has drawbacks that newer products, such as coolants “WS-3” and “WS-23,” do not have.  Cadbury owns U.S. Patent No. 5,009,893 (“the ’893 patent”), directed to a chewing gum that combines menthol with WS-3.  Meanwhile, Wrigley owns U.S. Patent No. 6,627,233 (“the ’233 patent”), claiming a chewing gum combining menthol with WS-23. 

Cadbury’s products embodying the ’893 patent went on the market before Wrigley’s products embodying the ’233 patent.  After Wrigley introduced its menthol/WS-23 chewing gum, Cadbury reformulated some of its products to contain both menthol and WS-23.  Wrigley sued Cadbury for infringing the ’233 patent.  Cadbury counterclaimed that Wrigley’s menthol/WS-23 chewing gum products infringed the ’893 patent and that the ’233 patent was invalid for obviousness and anticipation.  The district court granted SJ of invalidity of the ’233 patent and noninfringement of the ’893 patent. 

On appeal, the Court affirmed that U.S. Patent No. 5,688,491 (“Shahidi”) anticipated claim 34 of the ’233 patent.  Shahidi discloses various oral compositions, including chewing gum.  Shahidi also lists categories of components that can be included in the compositions, including “essential” and
“non-essential,” and certain “non-essential” components are noted as “preferred.”  Within the category of “cooling agents,” Shahidi discloses WS-3 and WS-23 as two of the three “particularly preferred cooling agents.”  Slip op. at 8.


“The question for purposes of anticipation is therefore whether the number of categories and components in [the prior art reference] was so large that the combination [of items from various categories] would not be immediately apparent to one of ordinary skill in the art.”  Slip op. at 8-9.

In finding that Shahidi “envision[ed] using WS-23 and menthol in a single product,” the Court rejected Wrigley’s argument that Shahidi did not disclose all the elements in the combination as recited in claim 34.  Id.  It also rejected the proposition that a prior art reference was not enabling simply because it required one of ordinary skill in the art to pick items from two lists of components to assemble the invention.  Instead, the key inquiry was “whether the number of categories and components in Shahidi was so large that the combination of WS-23 and menthol would not be immediately apparent to one of ordinary skill in the art.”  Id. at 8-9.  Accordingly, the Court found that Shahidi anticipated claim 34 because it specifically disclosed the use of both WS-23 and menthol in chewing gum and included component amounts within the range as claimed in the ’233 patent.  Id. at 9.

Next, the Court affirmed that claim 34 of the ’233 patent was obvious in view of U.S. Patent No. 5,698,181 (“Luo”) over an article by Dr. M. A. Parrish (“Parrish”).  Luo discloses chewing gum that achieves a cooling effect by combining WS-3 and menthol.  Parrish describes WS-3 and WS-23 as potential replacements for menthol in applications like chewing gum.  Wrigley argued that combining menthol and WS-23 was not obvious because it produced an unexpected cooling effect beyond what one of ordinary skill in the art would predict.  Emphasizing that the synergistic effect of combining coolants had already been discovered, the Court found obviousness because Wrigley failed to demonstrate that “the results were unexpected to a significant degree beyond what was already known about the effect of combining WS-3 and menthol.”  Id. at 11.

In particular, the Court pointed out that Wrigley’s products differed from Cadbury’s products in “a number of other ways” besides replacing WS-3 with WS-23 and that Wrigley failed to show “any nexus between the success of Wrigley’s chewing gums covered by Claim 34 and the specific combination of menthol and WS-23.”  Id. at 12.  Therefore, the superior flavor and cooling features of Wrigley’s products, as well as their commercial success, could not serve as probative evidence of the nonobviousness of claim 34.  Id. at 12-13.  Wrigley further argued that Cadbury’s copying of Wrigley’s products supported the nonobviousness of claim 34.  The Federal Circuit again found this argument unpersuasive for lacking a nexus between Cadbury’s copying and the novel aspects of claim 34.  Id. at 13.  According to the Court, the fact that chewing gum market participants typically copied each other’s development provided evidence to the contrary.  Id. at 14.

Finally, the Court affirmed that Wrigley’s products did not infringe the ’893 patent, either literally or under the DOE.  The claims-at-issue in the ’893 patent used the term “N-substituted-p-menthane carboxamide of [a specific formula],” which covered WS-3 but not WS-23.  Id. at 3 (alteration in original).  On appeal, both parties agreed that WS-23 did not literally infringe the ’893 patent, but Cadbury maintained that it infringed under the DOE.  The Court rejected Cadbury’s argument, reasoning that both the disclosure and the claims of the ’893 patent suggested that WS-23 was not an equivalent of WS-3.  On one hand, the disclosure of the ’893 patent narrowly focused on N-substituted-p-menthane carboxamide and emphasized its structural similarity with menthol, which arguably was not shared by WS-23.  On the other hand, the Court noted that the “claims themselves [were] narrow,” covering only a subset of the N-substituted-p-menthane carboxamide.  Id. at 17.

To support its argument that Wrigley infringed the ’893 patent under the DOE, Cadbury relied on Abraxis Bioscience, Inc. v. Mayne Pharma Inc., 467 F.3d 1370 (Fed. Cir. 2006), which held that diethylenetriaminepentaacetic acid (“DTPA”) was an equivalent of edetate and therefore was covered by the patent-at-issue under the DOE.  The Court distinguished Abraxis by highlighting that the patentee in Abraxis had no reason to claim DTPA because it was not known to be interchangeable with edetate.  Here, however, the inventors of the ’893 patent were “on notice of the potential interchangeability of WS-23 and WS-3, yet they drafted the claims of the ’893 patent narrowly” without including WS-23.  Slip op. at 17-18.  As a result, Abraxis did not compel a finding of infringement under the DOE.  Thus, the Court affirmed the district court’s determinations of SJ of invalidity of the ’233 patent and noninfringement of the ’893 patent.

Judge Newman, while concurring on the noninfringement of the ’893 patent, dissented-in-part.  In her view, the ’233 patent was valid.  On the obviousness issue, she emphasized that the evidence of commercial success and copying by the infringer should be considered in determining whether a prima facie case of obviousness had been presented.  Judge Newman would have reversed the district court’s holding that a prima facie case was established on the prior art alone, which then shifted the burden of proof to the patentee to rebut the finding of obviousness.  On the anticipation issue, Judge Newman explained that Shahidi did not anticipate claim 43 because it did not show the specific combination of menthol and WS-23, or present “so short and selective a list of these ingredients as to warrant an inference that their combination was already known.”  Newman Dissent at 9.

*Wanli Tang is a Summer Associate at Finnegan.