Wm. Wrigley Jr. Co. v. Cadbury Adams USA LLC (Fed. Cir., June 22, 2012) 

Chewing gum has come a long way since, as a youth, I opened a pack of Juicy Fruit® gum just to inhale its marvelous aroma.  As a law student, I felt unprepared for class without a stick or two of Doublemint® gum to calm the nerves and sharpen the brain.  Then came the rivals to challenge Wrigley with creatively packaged products iced with the latest physiological coolants.  The chewing gum wars began in earnest.  This battle pits heavyweight Wrigley against upstart Cadbury Adams.

The Federal Circuit agreed with the District Court for the Northern District of Illinois that neither Cadbury Adams (“Cadbury”) nor Wm. Wrigley Jr. Co. (“Wrigley”) can prevail against the other over certain patent rights related to the use of chewing gums that contain physiological coolants.  In a decision announced on June 22nd, the court ruled that Wrigley’s gums that combine menthol and WS-23, an acyclic carboxamide, do not infringe Cadbury’s U.S. Pat. No. 5,009,893, which claims combinations of menthol and p-menthane carboxamides such as WS-3.  The court also affirmed the district court’s decision that claim 34 of Wrigley’s U.S. Pat. No. 6,627,233, which is drawn to chewing gums that combine menthol and WS-23, is anticipated by prior art and therefore invalid.

The holdings, which stick it to both contestants, are on target.  Cadbury’s ‘893 patent is limited to p-menthane carboxamides, which have, by definition, a cyclohexane ring that is para-substituted with methyl and isopropyl groups in addition to having a carboxamide functionality.  Wrigley’s use of menthol and WS-23 does not infringe that claim because WS-23 (N-2,3-trimethyl-2-isopropyl butanamide) is an acyclic carboxamide.  The Federal Circuit correctly declined to find infringement under the doctrine of equivalents because acyclic and p-menthane carboxamides are distinct classes of coolants.

The district court found that claim 34 of Wrigley’s ‘233 patent lacked novelty and was obvious from prior art.  In particular, the court ruled that a Procter & Gamble patent to Shahidi (U.S. Pat. No. 5,688,181) anticipated claim 34 by disclosing chewing gums that could contain WS-3 or WS-23 as a “particularly preferred” cooling agent and menthol as one of twenty-three listed flavoring agents.  As Judge Bryson wrote for the Federal Circuit majority, this is “not a case in which the prior art reference merely discloses a genus and the claim at issue recites a species of that genus . . . .  Shahidi specifically discloses WS-23 as a coolant and menthol as a flavoring agent.  The question . . . is therefore 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.”  With relatively few lists, and few members identified as “most suitable” or “particularly preferred,” the district court had little trouble finding anticipation, and the Federal Circuit agreed.

Not surprisingly given its conclusions about Shahidi, the Federal Circuit also affirmed the district court’s holding that claim 34 was obvious from prior art.  Although Wrigley maintained that the combination of WS-23 and menthol is synergistic, the Federal Circuit explained that it was already known in the art WS-3 and menthol exhibited synergy.  Additionally, WS-3 and WS-23 had been singled out as especially favored cooling agents from over 1200 tested compounds.  Thus, there was a reasonable expectation of synergy in the WS-23/menthol combination.  “Therefore, 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 with menthol.”

The Federal Circuit also dismissed Wrigley’s arguments related to secondary considerations as evidence of nonobviousness, such as commercial success from the WS-23/menthol combination and copying of the formulation by Cadbury.  The district court had identified other factors that could also have contributed to commercial success, including Wrigley’s use of three times more sweetener, encapsulation to prolong flavor, other coolants in addition to menthol and WS-23, and more expensive ingredients.  The Federal Circuit agreed that Wrigley failed to show that its commercial success was directly attributable to the use of WS-23 rather than WS-3 with menthol.  The Federal Circuit was also unpersuaded by the evidence of copying.  The “evidence shows that in the market for chewing gum the parties have a practice of marketing very similar products.”  Moreover, internal documents from Cadbury demonstrated numerous adjustments made by Cadbury in addition to the use of WS-23, such as the use of similar sweeteners and a higher sweetener level.

In discussing obviousness of Wrigley’s claim 34, the Federal Circuit referred to another Procter & Gamble patent, U.S. Pat. No. 5,451,404, which “specifically refers to the combination of menthol and WS-23, along with other components, in a composition designed to produce physiological cooling.”  After a quick study of the reference, one reasonably concludes that it could have been Exhibit A in the anticipation case.  The abstract of the ‘404 patent describes “coolant compositions comprising a ketal and a secondary coolant which may be menthol, carboxamides, or mixtures thereof.”   (Note that in claim 34 of the ‘233 patent, the flavoring agent “comprises” WS-23 and menthol, so the claim does not exclude ketals.)  The ‘404 patent clearly discloses acyclic carboxamides such as WS-23 (col. 5, ll. 20-47), and chewing gums are among the first uses identified (col. 6).  What’s not to like about this reference?  Perhaps Cadbury’s lawyers chose to deemphasize the ‘404 patent because it was “considered” by the USPTO examiner.  However, Wrigley did not need to argue that claim 34 was somehow distinguishable over the ‘404 patent because that issue did not arise during prosecution.

Bottom line: the district court and the Federal Circuit got it right.  We gum chewers can rejoice in knowing that Wrigley, Cadbury Adams, and other purveyors can continue to satisfy our cravings and freshen our breath with gum that contains menthol and WS-23.  Physiologically speaking, what a cool world!

–Jon Schuchardt

This article is for informational purposes, is not intended to constitute legal advice, and may be considered advertising under applicable state laws.  The opinions expressed in this article are those of the author only and are not necessarily shared by Dilworth IP, its other attorneys, agents, or staff, or its clients.