In a precedential opinion issued on January 10, 2025, the United States Court of Appeals for the Federal Circuit reversed a district court's ruling that had invalidated claims 1-4 of U.S. Patent No. 8,101,659 ("the '659 patent") for lack of written description.
Owned by Novartis Pharmaceuticals Corporation, the '659 patent relates to a heart failure medicine comprising valsartan and sacubitril, marketed under the brand name Entresto®. Claim 1 of the patent recites a pharmaceutical composition, comprising:
"(i) the AT 1-antagonist valsartan or a pharmaceutically acceptable salt thereof;
(ii) the NEP inhibitor N-(3-carboxy-1-oxopropyl)-(4S)-(p-phenylphenylmethyl)-4-amino-2R-methylbutanoic acid ethyl ester or (2R,4S)-5-biphenyl-4-yl-4(3-carboxy-propionyl amino)-2-methyl-pentanoic acid or a pharmaceutically acceptable salt thereof; and
(iii) a pharmaceutically acceptable carrier;
wherein said (i) AT 1-antagonist valsartan or pharmaceutically acceptable salt thereof and said (ii) NEP inhibitor N-(3-carboxy-1-oxopropyl)-(4S)-(p-phenylphenylmethyl)-4-amino-2R-methylbutanoic acid ethyl ester or (2R,4S)-5-biphenyl-4-yl-4(3-carboxy-propionyl amino)-2-methyl-pentanoic acid or pharmaceutically acceptable salt thereof, are administered in combination in about a 1:1 ratio."
The district court had ruled that claim 1-4 were invalid due to an insufficient written description. Upon review, the Federal Circuit found that the district court erred in its assessment of the written description requirement, concluding that the '659 patent adequately describes the claimed invention.
In the analysis, the Federal Circuit emphasized that the written description requirement mandates that a patent's specification must reasonably convey "to those skilled in the art that the inventor had possession of the claimed subject matter as of the filing date." The court noted that the claims are directed to a pharmaceutical composition comprising valsartan and sacubitril administered "in combination," and not to a specific complex of these two compounds. Therefore, the specification needed to describe the combination therapy, not necessarily the complexed form.
The Federal Circuit found that the specification of the'659 patent sufficiently described the combination of valsartan and sacubitril. For example, the opening sentence of the detailed description provides that "the present invention relates to pharmaceutical combinations comprising valsartan . . . and a NEP inhibitor . . . and pharmaceutical compositions comprising them." The specification further specifies that the NEP inhibitor used in combination with valsartan can be sacubitril, stating that "it can be shown that combination therapy with valsartan and a NEP inhibitor results in a more effective anti-hypertensive therapy." The specification explains that "[a] therapeutically effective amount of each of the component[s] of the combination of the present invention may be administered simultaneously or sequentially in any order." According to the court, these disclosures demonstrate that the inventors had possession of the claimed combination therapy at the time of filing.
The '659 patent does not describe a complexed form of valsartan and sacubitril. In fact, the first on-covalently bound complex of these two compounds, LCZ696, was synthesized in January 2006, four years after the '659 patent's priority date in January 2002. However, this does not affect the validity of the '659 patent. The court reasoned that because the claims were directed to the combination of valsartan and sacubitril rather than a specific complex, the specification did not need to enable the formation of such a complex.
This case is Novartis Pharmaceuticals Corporation v. Torrent Pharma Inc., Appeal No. 23-2218. Opinion available HERE.
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