Obvious to Try: Notes on In re Kubin

Since the Supreme Court held that “obvious to try” is a proper test for obviousness (see KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398 (2007)), examiners have not missed an opportunity to apply this test in rejecting claims under 35 USC 103. But applicants must not automatically accept that the examiners are applying this test correctly.

The Supreme Court in KSR gave conditions under which “obvious to try” can be equated with obviousness. Now the Federal Circuit, reaching back to In re O’Farrell, 853 F.2d 894, 895-99 (Fed. Cir. 1988), has identified two “obvious to try” pitfalls, i.e., when it would be wrong to equate “obvious to try” with obviousness (see In re Kubin, Appeal No. 2008-1184, decided April 3, 2009).

The first pitfall arises when:

what would have been “obvious to try” would have been to vary all parameters or try each of numerous possible choices until one possibly arrived at a successful result, where the prior art gave either no indication of which parameters were critical or no direction as to which of many possible choices is likely to be successful.

The second pitfall arises when:

what was “obvious to try” was to explore a new technology or general approach that seemed to be a promising field of experimentation, where the prior art gave only general guidance as to the particular form of the claimed invention or how to achieve it.

In re Kubin does not show how the examiner or the Board of Patent Appeals and Interferences (BPAI) inappropriately applied the "obvious to try" test, but it allowed the Federal Circuit to discredit a previous charge made in In re Deuel, 51 F.3d 1552 (Fed. Cir. 1995), that "obvious to try" does not constitute obviousness while providing insight on how "obvious to try" can be misapplied.

In Kubin, the question of “obvious to try” came up because of the method used in DNA cloning or isolation in the patent application under appeal. The appellants had alleged that the record does not support that the method used by the appellants in isolating the NAIL (Natural Killer Cell Activation Inducing Ligand) DNA is the same as that taught in Valiente and Sambrook (prior art). In response the Federal Circuit asserted that it was blatant that the method was the same as in the prior art because the appellants’ disclosure mentioned cloning or isolating using standard biochemical methods such as disclosed in Sambrook.