The US Court of Appeals for the Federal Circuit affirmed the district court's finding that a skilled artisan would have had no reasonable expectation of success in making the claimed invention. UCB, Inc., et al., v. Accord Healthcare, Inc., et al., Case Nos. 16-2610; -2683; -2685; -2698; -2710; 17-1001 (Fed. Cir., May 23, 2018) (Stoll, J) (Prost, CJ, dissenting). 

UCB owns a patent that covers lacosamide, an anti-epileptic drug, which treats epilepsy and other central nervous system disorders. UCB holds new drug applications that cover its lacosamide anti-epileptic drug approved by the US Food and Drug Administration and marketed under the tradename Vimpat®. Several generic drug manufactures filed abbreviated new drug applications seeking approval to market generic versions of Vimpat®. UCB sued the generic drug manufacturers under the Hatch-Waxman Act. The generic drug manufacturers stipulated to infringement but argued that the patent claims were invalid for obviousness type double patenting, obviousness and anticipation. Following a bench trial, the district court found the claims not invalid. The generic drug manufacturers appealed.

The Federal Circuit affirmed the district court's finding. On the issue of obviousness type double patenting, the Court explained that the inquiry in chemical cases "is not whether a person of ordinary skill in the art would select the earlier compound as a lead compound, but rather whether the later compound would have been an obvious or anticipated modification of the earlier compound."

Turning to the facts of the case, the Court explained the inquiry as whether a skilled artisan "would have been motivated to place an unsubstituted benzyl at R and an unsubstituted methyl at R1 in combination with the methoxymethyl group at R3 with a reasonable expectation of success." Acknowledging that this was a "close case," the Court explained that it "discern[ed] no clear error in the district's underlying fact finding" of no reasonable expectation of success, finding that "not a single reference disclosed any anticonvulsant data for any compound comprising a methoxymethyl group at R3 let alone lacosamide." The Court noted that the prior art did not provide sufficient insight into the effectiveness of placing benzyl at R and methyl at R1 relative to other substituents that could be placed at R and R1. Further, compounds with benzyl at R and methyl at R1 with different R3 groups had a varying degree of effectiveness.

Chief judge Prost dissented. According to Judge Prost, the district court clearly erred when it dismissed the results of the many tests conducted on compounds with benzyl at R and methyl at R1. Judge Prost noted that "[a]lthough the experiments may have been designed to assess changes made at the R3 position . . . the prior art showed without question, that those substituents would work at these positions" and demonstrated anticonvulsant activity. She stated that it was clear error for the district court to require testing to provide insight into the effectiveness of benzyl and methyl relative to other structures that could be placed at R and R1, noting that an "inability to predict how one substituent will work in a composition and a need for testing will not render that selection nonobvious" where the prior art teaches that the selected substituent will work albeit selected from thousands of compounds. 

Judge Prost also took issue with what she believed to be the district court's failure to consider the LeGall thesis prior art. She noted that the thesis discloses compound 107e with benzyl, methyl and methoxymethyl groups except that it is a mixture of R and S enantiomers, rather than just the claimed R enantiomer. The thesis further discloses that the compound "may have good anticonvulsant activity," and thus, according to Judge Prost, the district court clearly erred to the extent it found that benzyl and methyl together with methoxymethyl groups would have been successful.

The majority disagreed with Judge Prost's characterization of the district court's opinion on the LeGall thesis. Noting that the district court had made extensive fact findings regarding the LeGall thesis, the majority explained that it "cannot reweigh the evidence, make credibility findings, or find facts," and the evidence shows that "LeGall discloses no data whatsoever for compound 107e or any compound with a methoxymethyl group at the R3 position." Ultimately, the majority refused to disturb the district court crediting expert testimony that a skilled artisan looking at LeGall would have had no interest in pursuing the compound or had reasonable expectation of success.

Practice Note: Prior art disclosure may be insufficient without expert testimony articulating why a later compound would have been an obvious or anticipated variation of the earlier compound.

Lower Court's Factual Finding Given Deference In "Close Case"

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