Practical Prosecution Advice After KSR

© 2007 Michael Kondoudis ( and Christopher Paul Mitchell (Chris)

KSR In A Nutshell

The Supreme Court’s decision in KSR Int’l. Co. v. Teleflex, Inc., et al., 550 U.S.___(2007) modified an established test for obviousness under 35 U.S.C. §103. Prior to KSR, Federal Circuit jurisprudence generally required a teaching, suggestion, or motivation to support a combination or modification of cited art (the TSM test) in an obviousness determination. After KSR, the TSM test is still insightful, but because it is too rigid, a broader, more flexible standard is proper. KSR did not alter the fundamental principles of obviousness.

In KSR, the Supreme Court identifies four specific Federal Circuit errors in applying the TSM test. Extrapolating from these errors, KSR provides the following guidance:

1. In searching for a reason to combine/modify elements of cited art, it is permissible for an Examiner to look not only to the problem to be solved by the inventor, but also at any known problem or need for the combination/modification.

2. One of ordinary skill in the art may be led by art other than that which solves the problem at hand.

3. A claim can be obvious merely because the combination/modification was obvious to try.

4. Common sense, whether guided by hindsight or not, properly plays a role in an obviousness analysis. KSR mentions common sense five times.

The Analytical Framework After KSR

KSR leaves a lot of open questions the answers to which are not immediately clear. That being said, the following observations appear most noteworthy:

1. There has been a further shift, however slight, against patentability. In practice, KSR makes it easier for an Examiner to make obviousness rejections by replacing the “rigid” TSM test with a more expansive, flexible standard.

2. Graham v. John Deere still controls. KSR emphasizes that “the [Graham] factors continue to define the inquiry that controls. If a court, or a patent Examiner, conducts this analysis and concludes the claimed subject matter was obvious, the claim is invalid under §103.” (KSR Opinion at p. 2).

3. An Examiner must establish “an apparent reason to combine … known elements.” (KSR Opinion at page 4).

4. An Examiner must expressly articulate the underlying analysis supporting a proffered “apparent reason.”

Patent Prosecution After KSR

After KSR, it would appear that a strategic shift in emphasis in responding to rejections under 35 U.S.C. §103 may be prudent. When appropriate, at least the following strategies for challenging the sufficiency and/or propriety of an asserted combination may be more promising, depending on the unique circumstances of a case.

Strategy #1 – Focus on the Interdependency of Features in a Claim

KSR expressly instructs that it remains legally insufficient to conclude that a claim is obvious just because each feature of a claim can be independently shown in the cited art. (KSR Opinion at p. 14). Thus, establishing that a claimed combination is not a “predictable use of prior art elements according to their established functions” (KSR Opinion at p. 13) may be particularly effective in traversing an obviousness rejection.

Strategy #2 – Emphasize Teachings Away

KSR discussed in some detail United States v. Adams, 383 U.S. 39 (1966), stating in part that in that case, “[t]he Court relied upon the corollary principle that when the prior art teaches away from combining certain known elements, discovery of a successful means of combining them is more likely to be nonobvious.” (KSR Opinion at p. 12). Accordingly, if such teachings are present and are significant, there may be no reason to make the asserted combination/modification.

Strategy #3 – Ensure that an Office Action Provides a Sufficient Rationale for an Asserted Combination

KSR requires that an Examiner provide “some articulated reasoning with some rationale underpinning to support the legal conclusion of obviousness.” (KSR Opinion at p. 14). Remember, an Examiner must “identify a reason that would have prompted a person of ordinary skill in the relevant field to combine the elements in the way the claimed new invention does,” (KSR Opinion at p. 15). And, the Examiner must make “explicit” this rationale of “the apparent reason to combine the known elements in the fashion claimed,” including a detailed explanation of “the effects of demands known to the design community or present in the marketplace” and “the background knowledge possessed by a person having ordinary skill in the art.” (KSR Opinion at p. 14). Anything less than such an explicit analysis may not be sufficient to support a prima facie case of obviousness.

Strategy #4 – Focus/Present Unexpected Results or Commercial Success

These secondary considerations under Graham v. Deere remain relevant. Accordingly, presenting evidence of unexpected results or commercial success remains a possible strategy for rebutting an obviousness rejection.


KSR did not change the fundamental principles of obvious under U.S. Patent Law. Instead, KSR increased the challenge an applicant faces to obtain allowance. This increased challenge, however, can be met by including non-obviousness arguments that were either emphasized by or unaffected by KSR instead of arguments: (1) based on a failure to meet the TSM test; (2) that the examiner is relying on an “obvious to try” rationale; and/or (3) that cited art is too far afield because it is not directed to the problem at hand.

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