Novartis’ Entresto Patent Claims Revived by CAFC

The U.S. Court of Appeals for the Federal Circuit (CAFC) today issued a precedential decision reversing a district court’s determination that certain claims of a patent for Novartis’ heart failure drug Entresto were invalid for lack of written description, and affirming a finding that the claims were not shown to be invalid for obviousness, lack of enablement, or indefiniteness. Judge Lourie authored the opinion.

MSN Pharmaceuticals, Inc. and other generic companies submitted an Abbreviated New Drug Application (ANDA) seeking approval to market a generic version of Entresto. Entresto includes the active ingredients valsartan and sacubitril “in a specific form known as a ‘complex,’ which combines the two drugs into a single unit-dose-form through weak, non- covalent bonds,” according to the CAFC opinion.

Novartis sued, alleging the ANDA directly infringed claims 1–4 of Novartis’ U.S. Patent 8,101,659. The U.S. District Court for the District of Delaware agreed with Novartis that the single term of the ‘659 patent under dispute—i.e., “wherein said [valsartan and sacubitril] are administered in combination” —should be given its plain and ordinary meaning. While MSN attempted to argue that the plain and ordinary meaning “would render the claims invalid for lack of written description and enablement because the specification nowhere describes such complexes,” the district court found that there was “no basis to believe that the construction [the court] adopt[ed was] necessarily consigning the asserted claims to a judgment of invalidity.” MSN stipulated to infringement of the asserted claims based on the court’s claim construction and the case proceeded to a three-day bench trial.

At trial, the court was unpersuaded by MSN’s obviousness arguments and ultimately said the claims were not proven invalid by clear and convincing evidence. But on the subjects of written description and enablement, the district court agreed with MSN that the claims lacked written description and with Novartis that the claims were enabled. MSN’s argument was that the patent must enable and describe the relevant complexes “since a patent must enable and describe the full scope of the claims,” while Novartis said that “a complex of valsartan and sacubitril was an after-arising invention that need not have been enabled or described.” Novartis specifically noted that its “later, nonobvious discovery of valsartan and sacubitril in the form of a complex should not invalidate the ’659 patent claims to Novartis’s earlier invention: the novel combination of valsartan and sacubitril.”