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Federal Circuit’s Recent Application of KSR

The Supreme Court’s KSR decision leaves the Court of Appeals for the Federal Circuit (CAFC) with the task of interpreting the parameters of the obviousness test. Some issues affecting those parameters were recently addressed:

  1. The extent to which prior art references cited in combination to establish obviousness must expressly provide the motivation for the particular claimed invention;
  2. Whether a prior art reference addressing a problem unrelated to that solved by the invention could be considered “non-analogous art”; and
  3. Whether the principle of “obvious to try” is applicable in determining whether a claimed invention is obvious.


The CAFC applied KSR in ruling that cited prior art references need not themselves express the motivation for the combination of elements recited in the claim that was deemed obvious. Leapfrog Enterprises, Inc. v. Fisher-Price, Inc.. and Mattel, Inc., No. 06-1402 (Fed. Cir. May 9, 2007). In that case, a patent for a child’s learning device was ruled obvious in view of the combination of two prior art references which collectively disclosed all of the claimed elements except for the inclusion of electronic means, as opposed to mechanical means, for operating the patented device. The CAFC ruled that it was commonplace to apply modern electronics to older mechanical devices, and that it was not necessary for the motivation to apply electronics in such a manner to be provided by the cited prior art references. Rather, common sense and ordinary skill in the art were the linch pins for finding the device to be obvious.


The CAFC also took the opportunity to re-characterize the concept of “analogous art”. In the past, if a cited prior art reference was applied in an obviousness rejection as showing a particular claimed element, but that prior art reference addressed a situation unrelated to the problem that the claimed invention addressed, the obviousness rejection could sometimes be overcome by arguing that the cited prior art reference involved non-analogous art.

In In re Icon Health and Fitness, Inc. No. 06-1573 (Fed. Cir. August 1, 2007), claims for a treadmill having a folding mechanism were found obvious by a combination of prior art references that included a foldaway bed. The CAFC cited a quote from KSR that “familiar items may have obvious uses beyond their primary purposes” in discounting the inventor’s arguments that a fold-away bed addressed a different problem than that relating to the exercise treadmill. The court determined that both devices employed the folding mechanism for the same purpose of supporting relatively moving elements, thus rendering the folding mechanism as analogous art.


While patent law earlier recognized that obviousness could be established by demonstrating that it would be obvious for a person having skill in the art to try a particular claimed embodiment in view of the existence of similarly-performing elements, such as chemical compounds, the CAFC had disfavored that approach. However, the KSR decision suggests that the “obvious to try” test is applicable.

In Takeda Chemical Industries Ltd. v. Alphapharm Pty. Ltd., No. 06-1329 (Fed. Cir. June 28, 2007), the CAFC upheld a patent claiming a drug for treating diabetes. The claimed compound was attacked as being obvious because a prior art reference disclosed a compound having a similar chemical structure (pyridal ring with similar attached substituent group, although at a different location on the ring). In alleging obviousness, it was argued that the chemical substituent groups (ethyl vs. methyl) were relatively interchangeable, and that the location of the group on the ring could be simply moved, thus, making it obvious to try such modification of the prior art compound to derive the inventive compound.

The CAFC explained that in cases involving new chemicals, it is necessary to explain the reason why it would be obvious to modify a known compound to derive the new compound. In the Takeda case, the prior art compound did not exhibit comparable effectiveness to the patented compound, and the prior art compound caused certain side effects. Furthermore, there existed a large number of other compounds that similarly presented themselves as candidates for modification for an alleged “obvious to try” rationale, thereby making the prior art compound no better suited than any of those.


The CAFC will hopefully continue to place the obviousness test in a predictable framework, which may take several years. What seems clear, however, is that mechanical inventions will be subject to a more rigorous examination, as that technology generally involves a finite number of identified and predictable solutions known to a person having ordinary skill in the art. Chemical inventions may fare better in certain circumstances where the requirements for articulating the reasons for obviousness are followed.