By Joseph O'Malley, Young Park and Aaron Selikson (November 13, 2017, 4:33 PM EST) -- On Nov. 1, 2017, the Federal Circuit reversed Judge Gregory Sleet's (District of Delaware) decision that Bayer's asserted patent was not invalid for obviousness. Bayer Pharma AG et al. v. Watson Labs. Inc., et al., No. 2016-2169 (Fed. Cir. Nov. 1, 2017). According to the Federal Circuit, Judge Sleet failed to address several prior art references relied upon by defendants to argue motivation to combine prior art teachings. The court also applied a stringent standard for proving a "teaching away" of a formulation i.e., it is insufficient to demonstrate a preference for one type of formulation design over another; the design of the claimed formulation must have been considered "unproductive" for the intended result. This opinion also joins a growing list of opinions from the Federal Circuit that have minimized the objective indicia of nonobviousness, even though they "may often be the most probative and cogent evidence in the record," in cases where a prima facie showing of obviousness was made. See Merck Sharp & Dohme Corp. v. Hospira Inc., No. 2017-1115 (Fed. Cir. Oct. 26, 2017) (Newman, J., dissenting) (quoting Stratoflex Inc. v. Aeroquip Corp., 713 F.2d 1530, 1538-39 (Fed. Cir. 1983))....