Cephalon, Inc. v. Watson Pharmaceuticals, Inc.

Enablement can be found when one skilled in the art can practice the invention without “undue experimentation.”

Opinion (Wallach): Watson Pharmaceuticals (“Watson”) filed an Abbreviated New Drug Application (“ANDA”), which involved the use of mannitol as an effervescent agent. Cephalon sued Watson, claiming infringement of its #604 and #590 patents (“Khankari patents”). The district court found that the Khankari patents lacked enablement, and Watson’s ANDA did not infringe it. Cephalon appealed. At the bench trial, Cephalon’s expert witness showed that a skilled artisan, through routine experimentation, could calculate a single compound effervescent agent from the Khankari disclosures of coupled effervescent formulations. Watson’s expert witness failed to show why the Khankari disclosures did not guide one skilled in the art to calculate a single compound effervescent agent. On the issue of infringement, the record showed Cephalon’s expert only proved that mannitol was acidic in water, and did not prove it to be an acidic effervescent agent in saliva. Therefore, Cephalon failed to prove that Watson’s ANDA product practiced their Khankari claim limitation of “at least one [saliva activated] effervescent agent.” Because the court found that Watson failed to prove by clear and convincing evidence that the Khankari patents lacked enablement, that portion was REVERSED, and because Cephalon failed to prove infringement, the non-infringement finding was AFFIRMED.