Whose Burden Is It?
| September 19, 2018
DuPont, Archer Daniels v. Synvina
September 17, 2018
Before Lourie, O’Malley and Chen. Opinion by Lourie, joined by O’Malley and Chen.
Summary:
DuPont and ADM filed an inter partes review petition against Synvina’s ‘921 patent that claims a method for making 2,5-furan dicarboxylic acid (FDCA), which is useful as bio-mass. The Board ultimately held that DuPont had failed to prove that the ‘921 patent was obvious over the prior art. On appeal, the CAFC reversed, finding that the Board had incorrectly failed to shift the burden of production, from DuPont to the patentee Synvina and had misapplied the standard for finding whether variables are result-effective.
Details:
Synvina’s claim 1 recites:
A method for the preparation of 2,5-furan dicarboxylic acid comprising
the step of contacting a feed comprising a compound selected from the group consisting of 5-hydroxymethylfurfural (“HMF”), an ester of 5-hydroxymethylfurfural, 5-methylfurfural, 5-(chloromethyl)furfural, 5-methylfuroic acid, 5-(chloromethyl)furoic acid, 2,5-dimethylfuran and a mixture of two or more of these compounds
with an oxygen-containing gas,
in the presence of an oxidation catalyst comprising both Co and Mn, and
further a source of bromine,
at a temperature between 140° C. and 200° C.
at an oxygen partial pressure of 1 to 10 bar,
wherein a solvent or solvent mixture comprising acetic acid or acetic acid and water mixtures is present.
The ‘921 specification asserts that the claimed oxidation reaction, according to the claimed process conditions, results in unexpectedly high yields of FDCA. Temperature, reaction pressure, and presence of acetic acid are highlighted as result-effective process conditions.
DuPont cited three primary references that disclosed the following process conditions:
The Board found that there was evidence of unexpectedly superior yields, as touted in the specification, but that the data was not commensurate in scope with the claims and that the results for some of the experimental samples were not unexpectedly good. Still, the Board found that none of the references disclosed the claimed combination of temperature, pressure, solvent, and catalyst, and that the references failed to recognize temperature and pressure as result effective variables.
DuPont made two arguments on appeal: first, that the Board misinterpreted precedent by erroneously refusing to apply a burden-shifting framework in the context of overlapping prior-art ranges, and second, that the Board had invoked a “result-effective variable” requirement that was inconsistent with precedent. The CAFC agreed on both counts.
The Court began its analysis by repeating certain legal principles for determining obviousness:
- it is not inventive to discover optimum or workable ranges by routine experimentation,
- changes in temperature and reactant concentration are usually unpatentable, and
- overlap between a claimed range and a range in the prior art establishes a prima facie case of obviousness.
An applicant may rebut such a prima facie case of obviousness where:
- modification of a process parameter to obtain a new and unexpectedly superior result, different in kind and not degree,
- the prior art teaches away from the claimed invention,
- the prior art fails to recognize a claimed process parameter as result-effective, and
- the prior art ranges are so broad that they do not invite routine optimization.
The CAFC then addressed DuPont’s first argument, finding that the Board had erred in not shifting the burden of production to Synvina, in view of the overlapping ranges in claim 1 and the prior art. “Where there is a range disclosed in the prior art, and the claimed invention falls within that range, the burden of production falls upon the patentee to come forward with evidence” of teaching away, unexpected results, etc. (emphasis added). If the patentee meets that burden, the court or and the examiner must weigh all the evidence to determine whether the challenger to the patent has met its burden of proof.
The Board had relied upon two earlier CAFC decisions – Dynamic Drinkware and Magnum Oil – for not shifting the burden of production to the patentee Synvina. But Dynamic Drinkware held that the burden of persuasion regarding the priority date does not shift to the patentee, and Magnum Oil held that the burden of persuasion regarding obviousness does not shift to the patentee as a result of institution of an IPR.
Similarly, with DuPont’s second argument, the CAFC found that the Board had erred in its analysis of whether the prior art recognized temperature and pressure as result-effective variables. “In cases in which the disclosure in the prior art was insufficient to find a variable result-effective, there was essentially no disclosure of the relationship between the variable and the result in the prior art.” In other words, a finding of “no recognition” is very, very much the exception rather than the rule.
Here, the Board erred in requiring DuPont to prove that the disclosure in the prior art “necessarily required” the variable to be within the claimed range, or that the variable “predictably affected FDCA yields.” In fact, each of the three primary references indicated that the reaction was affected by temperature and pressure.
The CAFC concluded by analyzing the ‘732 and RU ‘177 references, finding that the only difference between those disclosures and the claims were the temperature and pressure ranges. And yet these would be understood as result-effective variables, in view of the overlap and the explanations in the references.
Takeaway:
Who bears the burdens of production and persuasion is a critical question. The answer depends upon the particular issue in dispute.
