Holding: For the purpose of analysis of adequate written description and enablement, the analysis should focus on what is claimed. Later-existing state of the art cannot be used to invalidate a patent that was enabled for what was claimed at the time of filing.
Novartis markets the drug Entresto® to treat heart failure. Entresto includes valsartan and sacubitril in the form of a complex, which combines the drugs into a single unit dose using weak, non-covalent bonds. Valsartan is an angiotensin receptor blocker (“ARB”) that reduces the blood-vessel constricting effects of angiotensin II, and sacubitril is a neutral endopeptidase (“NEP”) inhibitor that also reduces blood vessel constriction. Entresto is covered by several patents, including US Patent No. 8,101,659, which is directed to a pharmaceutical composition comprising valsartan and sacubitril “administered in combination in about a 1:1 ratio.”
Torrent and several other generic drug manufacturers, including MSN Pharmaceuticals, submitted an Abbreviated New Drug Application (ANDA) seeking FDA approval to market and sell a generic version of Entresto. Novartis sued the generic drug manufacturers alleging direct infringement of the ‘659 Patent. At the district court, the “in combination” language from the claims of the ‘659 Patent was construed to have its plain and ordinary meaning rather than being restricted to requiring valsartan and sacubitril as separate components. However, due to this claim construction, the district court found the claims to be enabled, but to lack written description. Since complexes were unknown to a person of ordinary skill in the art as of the priority date of the ‘659 Patent, the district court held that Novartis could not satisfy the written description requirement for a complex of valsartan and sacubitril.
The Federal Circuit overturned the ruling of invalidity based on lack of written description. The district court erred in its analysis by focusing on whether complexes were described in the ‘659 Patent when the claims are instead directed to a combination of valsartan and sacubitril, and not a complex. For the purpose of the written description inquiry, the invention is whatever is claimed. The ‘659 Patent plainly describes pharmaceutical combinations comprising valsartan and sacubitril and therefore has adequate written description. Whether the ‘659 Patent describes a complexed form of valsartan and sacubitril is not relevant to the validity of the patent, since complexes are not claimed in the ‘659 Patent.
The Federal Circuit affirmed the district court’s decision that the ‘659 Patent is enabled for similar reasons as to why it found the ‘659 Patent to have adequate written description. Since the ‘659 Patent does not claim valsartan-sacubitril complexes, the ‘659 Patent does not need to enable valsartan-sacubitril complexes. The complexes are part of a later-existing state of the art and should not be considered in enablement analysis. A later-existing state of the art cannot be used to invalidate a patent that was enabled for what it claimed at the time of filing.
The Federal Circuit also affirmed the district court’s finding of nonobviousness. Even if a person of ordinary skill in the art had been motivated to try an ARB-NEP inhibitor, there was no motivation in the prior art to combine valsartan and sacubitril. There were over 100 known NEP inhibitors and sacubitril had never been administered to humans or animals. Additionally, multiple ARBs were known and there was no clear indication that the valsartan would be the preferred ARB to combine with a NEP.
Federal Circuit Precedential 
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