Docket No. 2011-1325
REYNA, BRYSON, WALLACH
February 14, 2013
Brief summary: Watson’s ANDA fentanyl product was found not to infringe Cephalon’s patents because it did not contain a “saliva activated effervescent agent” (affirmed). The DC decision that Cephalon’s patents were not enabled was reversed because Watson did not provide evidence of undue experimentation (“the mere potential need for clinical work, without more, is not dispositive in this case”).
Summary: Watson’s generic version of FENTORA® (fentanyl for treatment of breakthrough cancer pain) was found not to infringe Cephalon’s US 6,200,604 and 6,974,590 (the Khankari patents), and the patents were held invalid for lack of enablement. The FC panel affirmed the non-infringement decision but reversed on enablement because “Watson failed as a matter of law to show with clear and convincing evidence that Cephalon’s patents require undue experimentation to practice the invention.” The Khankari patents relate to drug delivery via the mucous membrane lining or mucosa in the oral cavity to avoid the “first pass effect” (percentage of drug lost to metabolism in the liver). The claims require a solid oral dosage form that includes “at least one [saliva activated] effervescent agent in an amount sufficient to increase absorption of said orally administerable medicament across the oral mucosa”. The patents explain that an effervescent agent includes a soluble acid source (e.g., citric acid) and a “mostly basic” source of carbon dioxide (e.g., sodium bicarbonate) that react to release a gas to effect pH level of the saliva. The DC construed the term “at least one effervescent agent” to include at least one compound but Watson argued that the term was synonymous with “effervescent couple” (e.g., “a combination of two or more compounds that evolve gas”). A singular “agent” would require the soluble acid source to be in a separate tablet or dosage form from the effervescent agent. The parties agreed that the claims were enabled as to the “couple”. This was an important point because the potassium bicarbonate and mannitol in Watson’s products were found not to react to generate an effervescent reaction in saliva (e.g., no “saliva activated effervescent agent”) and, therefore, not to infringe literally or under the DOE. Cephalon argued the enablement determination was incorrect because “a skilled artisan could easily calculate the required amount of acid and co- administer a soluble acid source, which may be a separate tablet, a film, or a liquid [e.g., orange juice], with the tablet containing the effervescent agent” (expert testimony). Watson’s expert disagreed and testified that “co-administration would be ‘difficult’ and ‘complicated'” but the FC panel noted that his testimony was “largely unsupported, and therefore, carries little weight in this analysis.” Watson was required to show the amount of experimentation needed to calculate a suitable formulation in order to demonstrate it was undue (citing Moba, B.V. (FC 2003) and United States v. Telectronics, Inc. (FC 1988), and White Consolid. Indus., Inc. (FC 1983)) and did not do so (“the mere potential need for clinical work, without more, is not dispositive in this case” (citing AK Steel, FC 2003). Thus, the enablement conclusion was reversed. The conclusion of non-infringement was, however, affirmed.