In a recent inter partes review (IPR), the Patent and Trial Appeals Board (PTAB), in addressing two important concepts in construing and validating patent claims, found that only some of the grounds of patentability were sufficient to meet the “preponderance of the evidence standard” for determining claims unpatentable. Specifically, the PTAB held that claim terms in an IPR are construed in a broad but reasonable manner and that secondary considerations, without any nexus between the evidence of the secondary considerations and the claimed invention, are not enough to save claims from a prima facie case of obviousness.¹