Post-Issuance Experimentation As Evidence of Unexpected Results

To rebut a prima facie case of obviousness, aside from an analysis of the prior art, secondary considerations, such as evidence of commercial success or of unexpected functions and results of the invention may be considered. For example, a prima facie case of obviousness based on structural similarity is rebuttable by proof that the claimed compound possesses unexpectedly advantageous or superior properties. In re Papesch, 315 F.2d 381 (CCPA 1963). The utility of considering such secondary considerations is that they “focus attention on economic and motivational rather than technical issues and are, therefore, more susceptible of judicial treatment than are the highly technical facts often present in patent litigation,” Graham v. John Deere Co., 383 U.S. 1, 35-36 (1966), and they guard against the improper use of hindsight reasoning based on knowledge gleaned from the inventor's own work. Glaros v. H.H. Robertson Co., 600 F. Supp. 342, 344 (N.D. Ill. 1984), aff'd, 797 F.2d 1564 (Fed. Cir. 1986) (“The Federal Circuit has … repeatedly emphasized the importance of the inquiry into secondary considerations, such as the commercial success of the invention and the prior failure of others, as the strongest precaution against judging an invention from the perspective of 20/20 hindsight.”).

At least with respect to commercial success, courts often rely on secondary consideration evidence obtained even after issuance of a patent. Furthermore, reliance on evidence of commercial success obtained after issuance of the patent is typical, “because the inventor usually waits until his patent issues before he swings production into full gear.” In re Sernaker, 702 F.2d 989 (Fed. Cir. 1983). Even where commercial success is achieved after some delay, the Federal Circuit in Windsurfing International, Inc. v. AMF Inc., 782 F.2d 995, 100 (Fed. Cir. 1986) noted that “[a]bsent some intervening event to which success must be attributed, the delay in achieving the great commercial success of the claimed invention in this case does not detract from the probative value of the evidence of that success.” This does not clash with the rule that obviousness of an invention is determined according to the state of the art at the time the invention was made, because such evidence, even though obtained after patent issuance, tends to indicate the nature of the state of the prior art before issuance of the patent. See E. Kitch, “Graham v. John Deere Co.: New Standards for Patents,” 1966 Sup. Ct. Rev. 293, 330-35 (1966). For example, commercial success tends to indicate that attempts had been previously made to find a solution to the problem solved by the patented invention. In a similar vein, where individuals other than the patentee developed a solution to the problem solved by the patented structure at approximately the same time as the development by the patentee of the patented structure, the Fifth Circuit in Graham v. Jeoffroy Mfg. Co., 206 F.2d 769 (5th Cir. 1953) ruled that such development tends to refute any claim that the patent involved any invention, even though the patented structure probably antedated the individuals' development, such that the development does not qualify as prior art. That is, such later development tends to indicate that the state of the art at the time the invention was made was such as to render obvious the patented structure.