Wrigley v. Cadbury: Pushing Back Against Impax

By Jason Rantanen

WM. Wrigley Jr. Co. v. Cadbury Adams USA LLC (Fed. Cir. 2012) Download 11-1140-1150
Panel: Bryson (author), Newman (dissenting-in-part), Fogel

Chewing gum is a big business, with billions of dollars of sales each year.  Wrigley and Cadbury are the two dominant players and compete closely in the "cooling sensation" gum market.  This lawsuit involved patent assertions by each company: Cadbury contended that Wrigley infringed its Patent No. 5,009,893, which claims chewing gum containing a combination of menthol and a coolant known as WS-3, while Wrigley contended that Cadbury infringed its Patent No. 6,627,233, which claims chewing gum containing a combination of menthol and a coolant known as WS-23.

The district court proceedings were essentially a wash: Cadbury obtained summary judgment of anticipation and obviousness of the '233 patent, while Wrigley obtained summmary judgment of noninfringement of the '893 patent.  Both parties appealed. 

Anticipation: Anticipation of the '893 was based on a prior art patent referred to as "Shahidi."  Shahidi discloses a variety of oral compositions such as toothpaste and chewing gum, containing several categories of components, including those that are "essential," "optional," and "preferred."  Included in the preferred nonessential categories were WS-3 and WS-23, with menthol being listed as one of 23 flavoring agents that can be used in the claimed composition.

Relying on Impax Laboratories v. Aventis Pharmaceuticals, 545 F.3d 1312 (Fed. Cir. 2008), Wrigley argued that Shahidi could not anticipate because it would require a PHOSITA to pick items from two lists of components in order to assemble the invention, and thus did not disclose all of the limitations of the claim arranged or combined in the same way as in the claim.  Rejecting the extension of Impax to this case, the CAFC concluded that the disclosure in Shahidi was sufficient.  The ultimate question instead 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."  Slip Op. at 8-9. The majority concluded that it was not.

Judge Newman disagreed with the holding of anticipation.  "The purported anticipatory reference does not show this combination, and does not present so short and selective a list of these ingredients as to warrant an inference that their combination was already known."  Slip Op. at 28.  Rather, the contents of Shahidi's lists "can be combined in over a million possible combinations."  Id. at 29. 

  • For those who are interested in looking at the disclosure, a copy of Shahidi is available here: Download US5688491

Obviousness: The CAFC also affirmed the district court's grant of summary judgment of obviousness, a determination that largely turned on whether combining menthol and WS-23 produced an unexpected effect.  The court concluded that there was not: the prior art had already revealed an "enhanced breath-freshening effect" between menthol and WS-3, and pointed to characteristics shared by the WS-3 and WS-23 that suggested that they would likely have similar effects when ingested.  Given these disclosures, the court concluded that effects above and beyond those of the combination of menthol and WS-3 needed to be shown:

to show that the cooling effect of the combination of WS-23 and menthol was unexpected, Wrigley needed 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.

Slip Op. at 11 (emphasis added).  The court concluded that such evidence was not present.  The Cadbury study that Wrigley presented, while touting the superior cooling features of Wrigley's products, involved tested products that differed in ways other than just the coolant.  Likewise, the court concluded that no nexus was demonstrated between the commercial success of Wrigley's products containing menthol and WS-23 and the specific combination of menthol and WS-23.

Judge Newman again disagreed, concluding that "[t]he record is rife with" evidence of nexus between the success of Wrigley's chewing gums covered by the claim and the specific combination of menthol and WS-23.  Slip Op. at 24.  Judge Newman further criticized the majority and district court for concluding that Cadbury had established a prima facie case of obviousness, then shifting the burden to the patent holder.  

Infringement by Equivalents: The court unanimously affirmed the district court's ruling of noninfringement, concluding that the claims were narrowly drafted to WS-3 and the interchangeability with WS-23 was forseeable. 

Practice Convention: In the majority opinion, Judge Bryson consistently refers to the patents-in-suit by their abbreviated numbers and the prior art patents, such as Shahidi, by the first inventor's name.  Providing an easy way for the reader to distinguish between the two types of patents in this way adds clarity to his writing.  As far as I am aware this is not currently a generally accepted convention but it seems like a good stylistic practice for attorneys writing briefs. 

Addendum: One commentator pointed out that Judge Bryson is not the only Federal Circuit judge to apply this convention.  Judge Moore also consistently refers to prior art references by name rather than number, although in my small sample of three I noted that a third judge does not.