Federal Circuit Looks For A Different Kind Of Unexpected Results In BMS v. Teva

In Bristol-Myers Squibb Co. v. Teva Pharmaceuticals USA, Inc., the Federal Circuit affirmed the district court's finding that BMS's Baraclude® patent is invalid as obvious. In so doing, the court gave little weight to unexpected results characterized as reflecting a difference in "degree" rather than a difference in "kind." This decision joins other recent Federal Circuit decisions that have found unexpected results to be not unexpected enough to prevail against a strong showing of prima facie obviousness.

The Patent at Issue

The patent at issue was BMS's U.S. 5,206,244. The Federal Circuit decision focuses on claim 8, which recites the following compound:

[1S-(1α,3 α,4β)]-2-amino-1,9-dihydro-9-[4-hydroxy-3-(hydroxymethyl)-2-methylene-cyclopentyl]-6H-purin-6-one.

The ANDA Litigation

BMS markets the claimed compound as the hepatitis B drug Baraclude® (entecavir) for the treatment of hepatitis B. Teva filed an Abbreviated New Drug Application (ANDA) seeking to market a generic version of entecavir. In the ensuing Hatch-Waxman litigation, Teva asserted that the '244 patent was invalid as obvious and unenforceable due to inequitable conduct.

After a bench trial, the district court found that the patent was invalid as obvious. The court conducted a "lead compound" analysis, determined that 2'-CDG was a lead compound for the development of antiviral drugs at the filing date of the '244 patent, and found that the modification required to arrive at entecavir would have been obvious. Although the court found that BMS had presented objective evidence of nonobviousness (commercial success, long-felt need, and unexpected results), it "ultimately concluded that Teva proved by clear and convincing evidence that claim 8 would have been obvious."

The Federal Circuit Decision

The Federal Circuit decision was authored by Judge Chen and joined by Chief Judge Prost and Judge Plager.

Much of the Federal Circuit opinion focuses on the "lead compound" analysis. Because that analysis is so fact-specific, I will not review it here. The section of the Federal Circuit decision that I find more interesting—and more troubling—is its treatment of BMS's evidence of unexpected results. In particular, the opinion seems to set a high hurdle for establishing nonobviousness based on unexpected results unless the kind of results were unexpected.

The Federal Circuit transitions to this issue with this paragraph:

BMS also argues that a new chemical entity, as a matter of law...