Ex Parte Kubin (BPAI 2007) (Precedential)
Kubin’s patent claims are directed to a cDNA molecule (NAIL) that serves as an NK cell surface marker. During examination, the examiner found them obvious. On appeal to the Board of Patent Appeals and Interferences (BPAI or Board), the applicant constructed an argument based on In re Deuel (Fed. Cir. 1995), that its cDNA claims cannot be “made obvious by mere knowledge of a desired protein sequence and methods for generating the DNA that encodes that protein.” (Quoting Deuel).
The Board, however, affirmed the rejection, finding the claims invalid because the cDNA structure would have been “obvious to try.” This case likely eviscerates any strength still remaining in Deuel.
[T]he Supreme Court recently cast doubt on the viability of Deuel to the extent the Federal Circuit rejected an “obvious to try” test. Under KSR, it’s now apparent “obvious to try” may be an appropriate test in more situations than we previously contemplated. . . .
Thus, isolating NAIL cDNA was “the product not of innovation but of ordinary skill and common sense,” leading us to conclude NAIL cDNA is not patentable as it would have been obvious to isolate it.
Kubin’s claims were also challenged on enablement and written description because they claimed only 80% identity with the described DNA sequence.
On enablement, the Board noted a parallel from its obvious to try analysis. Although there are certainly caveats, the Board appears to have held that a compound that is obvious to try is necessarily enabled because it would not require undue experimentation to make and use the invention.
The amount of experimentation to practice the full scope of the claimed invention might have been extensive, but it would have been routine. The techniques necessary to do so were well known to those skilled in the art.
Written Description: On the other hand, the Board found that “appellants did not describe the invention [] sufficiently to show they had possession of the claimed genus of nucleic acids.”
Rejections affirmed on obviousness and written description.
Notes:
- This is one of two precedential BPAI opinions for 2007.
- The application appears to be owned by Immunex, a company now owned by Amgen after a $17B purchase.



