MPEP § 716.02 — Allegations of Unexpected Results

Ninth Edition, Revision 01.2024 · last revised R-01.2024

Any differences between the claimed invention and the prior art may be expected to result in some differences in properties. The issue is whether the properties differ to such an extent that the difference is really unexpected. In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986) (differences in sedative and anticholinergic effects between prior art and claimed antidepressants were not unexpected). In In re Waymouth, 499 F.2d 1273, 1276, 182 USPQ 290, 293 (CCPA 1974), the court held that unexpected results for a claimed range as compared with the range disclosed in the prior art had been shown by a demonstration of “a marked improvement, over the results achieved under other ratios, as to be classified as a difference in kind, rather than one of degree.” Compare In re Wagner, 371 F.2d 877, 884, 152 USPQ 552, 560 (CCPA 1967) (differences in properties cannot be disregarded on the ground they are differences in degree rather than in kind); Ex parte Gelles, 22 USPQ2d 1318, 1319 (Bd. Pat. App. & Inter. 1992) (“we generally consider a discussion of results in terms of ‘differences in degree’ as compared to ‘differences in kind’ . . . to have very little meaning in a relevant legal sense”). See also UCB, Inc. v. Actavis Labs, UT, Inc., 65 F.4th 679, 693, 2023 USPQ2d 448 (Fed. Cir. 2023) (“A difference of degree is not as persuasive as a difference in kind – i.e., if the range produces ‘“a new property dissimilar to the known property,’” rather than producing a predictable result but to an unexpected extent.”).