In re Kubin: Extending “Obvious to Try” to cDNA Sequence Patents

The Federal Circuit court applied the “obvious to try” test from KSR International v. Teleflex Inc. to biotechnology patent applications, and essentially eviscerated the obviousness standard once applied to biotech patents by the Federal Circuit in In re Deuel. While the decision in In re Kubin, 561 F.3d 1351 (Fed. Cir. 2009), will likely make it more difficult for some biotech inventors to secure patents, it does acknowledge that advances in technology and the field of biotechnology knowledge make more inventions “obvious” in light of those advances.

Background

Inventors Kubin and Goodwin, scientists for Amgen, a leading biotechnology company, applied for a patent on DNA molecules encoding a protein known as natural killer (NK) cell activation inducing ligand (NAIL). At the time of their invention, the prior art disclosed the existence of a protein (later found to be the NAIL protein) on the surface of NK cells, as well as the creation of a monoclonal antibody capable of recognizing that protein. The prior art did not describe the purification or isolation of the NAIL protein, and it did not teach the NAIL protein’s amino acid sequence.

Kubin and Goodwin cloned and sequenced the cDNA sequence encoding the NAIL protein, enabling them to determine the protein’s chemical structure. They also found that the NAIL protein binds to CD48, another protein found on the surface of several cells involved in the immune process. Kubin and Goodwin claimed that the interaction between NAIL and CD48 can have important biological and therapeutic benefits. Amgen sought to patent the specific cDNA sequence encoding NAIL, as well as the entire genus of polynucleotides substantially related to their findings – this broad type of claim is standard in biotechnology claims.

The patent examiner rejected the claim for failure to comply with the nonobviousness, enablement, and written description requirements. On appeal, the Board of Patent Appeals and Interferences (BPAI) reversed on enablement, but affirmed the rejection on the issues of obviousness and written description. Amgen appealed to the U.S. Circuit Court for the Federal Circuit. In re Kubin, 561 F.3d 1351 (Fed. Cir. 2009).

Applying KSR to reject In re Deuel’s obviousness standard

On appeal, Amgen made its argument for patentability based on the Federal Circuit’s 1995 holding in In re Deuel, 51 F.3d 1552 (Fed. Cir. 1995). In many ways, the facts of Deuel were analogous to the facts of Kubin:

In Deuel, the BPAI found that a partial amino acid sequence for a protein, when combined with standard cDNA cloning methodology, rendered obvious both the methodology for cloning the specific resulting cDNA as well as the resulting cDNA itself. The Federal Circuit reversed the BPAI, stating that in assessing the obviousness of a biomolecule, it is not enough that the methodology for generating the biomolecule would have been obvious. Rather, the prior art should render the biomolecule itself – its nucleotide sequence—obvious. Amgen argued that, under Deuel, 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. See Deuel, 51 F.3d at 1558.

But the BPAI affirmed the patent examiner’s rejection, holding that the U.S. Supreme Court’s recent ruling in KSR International Co. v. Teleflex Inc., 550 U.S. 398 (2007)  “cast doubt on the viability of Deuel… under KSR, it’s now apparent ‘obvious to try’ may be an appropriate test in more situations than we previously contemplated…” In re Kubin, 561 F.3d 1351, 1358 (citing the BPAI decision, p. 8). Thus, Amgen’s claim 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.” 561 F.3d at 1355 (citing the BPAI decision, p. 9 (citing KSR, 550 U.S. at 421)).

The Federal Circuit agreed with the BPAI that Amgen’s methodology of isolating NAIL cDNA was essentially the same as the prior art and was “obvious to try” based on the known properties of the proteins at issue and the known methodologies. The Federal Circuit stated that “the Supreme Court expressly invoked Deuel as a source of the discredited ‘obvious to try’ doctrine. The KSR Court reviewed this court’s rejection, based on Deuel, of evidence showing that a particular combination of prior art elements was obvious because it would have been obvious to one of ordinary skill in the art to attempt such a combination.” 561 F.3d at 1358.

Amgen argued that there was no reasonable expectation that one of skill in the art would have been able to carry out the prophetic example in the prior art because Amgen’s invention was far more difficult and complicated than suggested in the prior art. The Court pointed out that differences in the processes are irrelevant, as the inventors were claiming a genus of polynucleotides, not a process or method. Id. at 1356.

KSR instructed against subjective consideration of how difficult the invention was for the inventor – instead an objective test should apply considering only how difficult the invention would have been for a person having ordinary skill in the art. Here, the prior art purported to teach conventional techniques used by the inventors. Amgen could not overcome the presumption that any person with skill in the art could use those techniques to arrive at the claimed biomolecule with a reasonable expectation of success. Id. at 1357.

The Federal Circuit left open the possibility that an “obvious to try” invention may still be nonobvious. For example, where the inventor “merely throws metaphorical darts at a board filled with combinatorial prior art possibilities,” the invention may be nonobvious, despite prior art. Id. at 1359. Also, if it was “obvious to try” a new technology or promising area of experimentation that was only hinted at in the prior art, the invention might not be obvious. Id.

CONCLUSION

In Kubin, the Federal Circuit has signaled that the significant advances in technology since Deuel similarly raise the level of what will be considered obvious to one of ordinary skill in the art. If the prior art identifies a problem and suggests methods for pursuing the solution, subsequent inventions that solve the problem may be considered obvious. Accordingly, “obvious to try” rejections may become more frequent.

If nothing else, Kubin certainly indicates that it will be harder to obtain patents for DNA sequences encoding a protein that was previously identified if standard cloning methods are relied upon to discover the sequence. However, if a patent applicant can overcome the presumption of enablement in the prior art by showing a technical challenge that made the chance of success unpredictable, he may avoid a finding of obviousness.

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Yuri Mikulka

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