In the chemical and biological arts, it is common for patent challengers to allege obviousness based upon prior art disclosures of ranges combined with “routine optimization” by one skilled in the art. In E.I. du Pont de Nemours & Co. v. Synvina C.V., No. 17-1977 (Fed. Cir. Sept. 17, 2018), the Federal Circuit reversed the PTAB’s (“Board”) final written decision upholding Synvina’s U.S. Patent No. 8,865,921 (“’921 patent”) as non-obvious, in response to du Pont’s inter partes review (“IPR”) challenge on such grounds. In particular, in E.I. du Pont, the Court found that the patentee failed to demonstrate that 1) the claimed range produced a new and unexpected result, different in kind and not merely in degree from the prior art, 2) the optimized parameter was not recognized as a result-effective variable, 3) the disclosure of broad ranges did not invite more than routine optimization, or 4) that the prior art taught away from the range.
The claims of the ’921 patent are generally directed to methods of preparing 2,5-furan dicarboxylic acid (“FDCA”), a compound useful in certain “green” chemicals. Claim 1 requires that a substrate is “contact[ed] … in the presence of an oxidation catalyst . . . at a temperature between 140°C and 200°C[, and] an oxygen partial pressure of 1 to 10 bar.” While methods for preparing FDCA were already well-known, the prior art disclosed methods using at least different temperatures and pressures from those recited in the ’921 patent claims.
In its final written decision, the Board found that the ’921 patent claims were not obvious despite prior art references disclosing oxidation of substrates using overlapping conditions to create FDCA. The Board reasoned that none of the applied references expressly taught the claimed combination of conditions recited in the ’921 patent’s methods and rejected DuPont’s argument that the burden-shifting framework applies to overlapping prior art ranges.
According to the Federal Circuit, the Board misconstrued In re Magnum Oil Tools Int’l, Ltd., 829 F.3d 1364, 1375 (Fed. Cir. 2016), and Dynamic Drinkware, LLC v. Nat’l Graphics, Inc. 800 F.3d 1375, 1378 (Fed. Cir. 2015), as prohibiting application of burden-shifting framework to IPRs and further erred by applying the wrong legal standards for obviousness. In overruling the Board’s final written decision, the Federal Circuit explained that the burden-shifting framework applies to IPRs in the same manner as it applies in the district courts and at the USPTO. The Federal Circuit cited In re Aller, 220 F.2d 454, 456 (CCPA 1955), and others, to support the asserted rationale for obviousness: “For decades, this Federal Circuit and its predecessor have recognized that where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” (Internal quotation marks omitted.) Because the claimed ranges recited in the ’921 patent’s methods are within those ranges described in the prior art, the Federal Circuit also found that a presumption of obviousness applies. The presumption of obviousness provides that a prima facie case of obviousness has been met when prior art ranges overlap with those recited in the claims. In re Peterson, 315 F.3d 1325 (Fed. Cir. 2003). When such a presumption is proper, as it was here, the burden shifts to the patentee to rebut the presumption by demonstrating that (1) the claimed process parameter “produce[s] a new and unexpected result which is different in kind and not merely in degree from the results of the prior art,” (2) the prior art taught away from the claimed range, (3) the parameter was not recognized as “result-effective,” and/or (4) the prior art disclosed “very broad ranges” which “may not invite routine optimization.” See In re Aller, 220 F.2d 454, 456 (CCPA 1955); In re Applied Materials, Inc., 692 F.3d 1289 (Fed. Cir. 2012); Genetics Inst., LLC v. Novartis Vaccines & Diagnostics, Inc., 655 F.3d 1291 (Fed. Cir. 2011). Synvina failed to rebut the presumption using any of these four approaches. As such, the Federal Circuit held that the Board erred in its analysis and should have held that the ’921 patent is obvious.