Docket No. 2017-1909, -1910
REYNA, CLEVENGER, WALLACH
May 21, 2018
Brief summary: DC decision of no invalidity of UCB’s OB claims covering the anti-epileptic Vimpat® affirmed.
Summary: Accord appealed DC decision that UCB’s RE38,551 covering the anti-epileptic functionalized amino acid (FAA) drug lacosamide (Vimpat®; the ‘551 patent currently being the sole patent listed on the FDA Orange Book) not invalid for obviousness-type double patenting, obviousness, or anticipation. The FC panel opinion explains that lacosamide is the R-enantiomer of N-benzyl-2-acetamido-3-methoxypropionamide, “prior to the ‘551 patent, there was no public disclosure of pharmacological efficacy or safety data to support the use of any FAA as an anti-epileptic or anti-convulsant drug”, “Vimpat® remains the only approved FAA for the treatment of epilepsy”, and that proof-of-concept studies were published for a related anticonvulsant compound (“AAB”) beginning in 1985, resulting in US 5,378,729 (prior art) and CIP US 5,654,301 (not prior art), and lacosamide is “a species of the genus disclosed in the ‘729 and ‘301 patents” (e.g., ‘301 claim 39 found to cover “thousands, if not millions, of possible group combinations”). The DC “concluded that it would not have been obvious to make lacosamide by placing an unsubstituted benzyl at R or an unsubstituted methyl at R1 in combination with methoxymethyl at R3” (methoxymethyl not being listed by the ‘729 patent), and that a prior art thesis does not anticipate because “while it discloses the racemic mixture compound 107e, it does not explicitly disclose the R-enantiomer or its characteristics” (Sanofi-Synthelabo, FC 2008). The FC panel first explained that the DC “did not err by focusing its double patenting analysis on the claims’ differences, as well as the claims as a whole” (Otsuka, FC 2012; AbbVie, FC 2014; Eli Lilly, FC 2012; Gen. Foods, FC 1992). The FC panel also found no clear error in the obviousness portion of the DC double-patenting analysis based on “the prior art and expert evidence” and finding “no reasonable expectation of success” in making the substitutions resulting in lacosamide (Eli Lilly, FC 2012 (must identify “some reason that would have led a chemist to modify the earlier compound to make the later compound with a reasonable expectation of success”); Amgen, FC 2009; Par Pharm., FC 2014) (“complex compounds like FAAs…provide for many opportunities for modification”). The FC panel noted in FN3 that the USPTO similarly found no obviousness in an ex parte reexamination and following IPR2016-00204. On obviousness, the DC applied the “lead compound analysis” and “concluded that a person of ordinary skill in the art would not have selected any FAA, let alone” the AAB compounds, “as lead compounds in the lead compound analysis.” Accord argued the DC “erred by using a lead compound analysis because this case merely involves purification (not structural modification) of a known compound”, citing Aventis Pharma (FC 2007). The FC panel agreed on this point with Accord, explaining that “Aventis simply required proving that a person of ordinary skill in the art would have been motivated to purify a mixture of compounds based on some known desirable property” (“if it is known that some desirable property of a mixture derives in whole or in part from a particular one of its components, or if the prior art would provide a person of ordinary skill in the art with reason to believe this is so, the purified compound is prima facie obvious over the mixture”). However, the FC panel nonetheless found that the DC did not clearly err in finding of no obviousness based on its “fact finding that a person of ordinary skill in the art would not have selected” the alleged lead compound “as a lead compound”, which was supported by expert testimony. The FC panel also found no error with the DC’s decision that the claimed R-enantiomer was not anticipated by a disclosure of the racemate (In re May, CCPA 1978 (“the novelty of an optical isomer is not negated by the prior art disclosure of its racemate”)). Judge Prost dissented, arguing that the DC erred in not finding a reasonable expectation of success in selecting the chemical substitutions because as the DC found, e.g., “there were many tests conducted on FAAs with benzyl at R and methyl at R1” and erred in dismissing the associated data (“the prior art showed, without question, that those substituents would work at those positions”).