Law360, New York (August 5, 2016, 11:26 AM EDT) -- The U.S. Supreme Court's recent rejection of the Federal Circuit's use of a rigid test instead of a flexible approach that provides more discretion to district courts,[1] raises the question of why the court has not accepted any challenge to the two-step analytical approach to the prima facie structural obviousness of new pharmaceutical compound claims. Under that approach, patent challengers must show, as a threshold step, that a person of ordinary skill ("POSA") would have been motivated by the prior art to use a known compound(s) as the starting point.[2] The second step requires that there be motivation in the prior art for the modification(s) of that lead compound needed to arrive at the claimed new compound.[3] This article outlines the development and use of that approach, the arguments whether the approach is consistent with the Supreme Court's opinion in KSR encouraging flexibility in the obviousness inquiry, and the unsuccessful efforts to obtain Supreme Court review of that approach post-KSR. Why Supreme Court review of the approach has yet to occur and the type of record needed before review is likely to be obtained are then addressed....