U.S. Supreme Court Will Not Review Lead Compound Test for Obviousness Analysis

On Monday, the Supreme Court denied the petition for writ of certiorari filed by Apotex seeking review of the Federal Circuit’s May 7, 2012, ruling that affirmed the District Court of New Jersey’s judgment that Otsuka’s patents covering its blockbuster drug Abilify© are valid and not obvious.

In that ruling, the Federal Circuit found no error in the District Court’s application of the so-called lead compound test; an analytical framework in chemical art cases that seeks — in an obviousness inquiry under 35 U.S.C. § 103 — to determine whether a POSA (“person of ordinary skill in the art”) would select the proffered prior art as a “lead compound.” Specifically, in a lead compound analysis, the Court will consider:

the hypothetical person of skill in the art’s identification of a lead compound, structural differences between the proposed lead compound and the claimed invention, motivation or teachings in the prior art to make the necessary changes to arrive at the claimed invention, and whether the person of skill in the art would have a reasonable expectation of success in making such structural changes.

Otsuka Pharm. Co., Ltd. v. Apotex Inc. et al., (citing Otsuka Pharm. Co., Ltd. v. Sandoz, Inc., No. 3:07-cv-1000, 2010 U.S. Dist. LEXIS 132595, at *52-53 (D.N.J. Dec. 15, 2010)). In its decision, the Federal Circuit agreed that the POSA would have considered the only marketed antipsychotic compounds at the time – clozapine and risperidone – as viable lead compounds and not the carbostyril compound developed by Otsuka.

Furthermore, the Federal Circuit concluded that the District Court properly rejected the defendants’ proposed lead compounds. It held that a POSA would not have understood that each of a “laundry list” of carbostyril derivative compounds disclosed in a prior art reference to possess the reported central nervous system controlling effects. Nor would a POSA select a compound that was inferior to other test compounds or shown not to be an acceptable therapeutic candidate.