Print PDF

The “Obvious to Try” Rationale May Provide the Basis for an Obviousness Rejection After KSR

April 03, 2009

Decision icon Decision

Last Month at the Federal Circuit - May 2009

Judges: Rader (author), Friedman, Linn

[Appealed from: Board]

In In re Kubin, No. 08-1184 (Fed. Cir. Apr. 3, 2009), the Federal Circuit affirmed the Board’s rejection of the claims of U.S. Patent Application Serial No. 09/667,859 (“the ’859 application”) to Marek Kubin and Raymond Goodwin (collectively “appellants”) as obvious under 35 U.S.C. § 103(a).

The ’859 application related to the isolation and sequencing of a human gene that encodes a particular domain of a protein. Specifically, the ’859 application claimed DNA molecules that encode the protein known as the Natural Killer Cell Activation Inducing Ligand (“NAIL”). Natural Killer (“NK”) cells are a class of cytotoxic lymphocytes that play a major role in fighting tumors and viruses. NAIL is a specific receptor protein that plays a role in activating NK cells.

The specification recited an amino acid sequence and a polynucleotide sequence of a NAIL polypeptide. The appellants also contended that they had discovered a binding relationship between NAIL and a CD48 protein. The NAIL-CD48 interaction has important biological consequences for NK cells, including an increase in cell cytotoxicity and in production of interferon. Representative claim 73 recited a genus of isolated polynucleotides encoding a protein that binds CD48 and is at least 80% identical to the disclosed amino acid sequence for the CD48-binding region of NAIL.

The Board rejected the claims under § 112 for inadequate written description. The Board also rejected the claims as obvious over the combined teachings of U.S. Patent No. 5,688,690 (“Valiante”) in view of 2 Joseph Sambrook et al., Molecular Cloning: A Laboratory Manual 43-84 (2d ed. 1989) (“Sambrook”). The Board also considered another reference (“Mathew”) that it found to be cumulative to Valiante and Sambrook. The appellants appealed the Board’s decision.

On appeal, the appellants argued the record does not contain substantial evidence to support the Board’s conclusion that the appellants’ methodology of isolating NAIL DNA was essentially the same as the methodologies and teachings of Valiante and Sambrook. The Federal Circuit noted that any putative difference in the prior art’s and appellants’ processes does not directly address the obviousness of representative claim 73, which claims a genus of polynucleotides. Nevertheless, the Federal Circuit held that the Board had substantial evidence to conclude that the appellants used conventional methods, as taught by Valiante and Sambrook, to isolate a gene sequence for NAIL. The Court also found substantial evidence supports the Board’s finding that the Mathew reference reinforces the relative ease of deriving the claimed sequence following the teachings of the prior art. The Court further noted that Mathew did not ”teach away” from combining its teachings with Valiante.

The Federal Circuit then addressed the Board’s application of an “obvious to try” rationale in its obviousness rejection. The Court held that such an inquiry was now proper in view of KSR International Co. v. Teleflex Inc., 550 U.S. 398 (2007). The Federal Circuit then revisited its findings regarding the “obvious to try” doctrine set forth in In re Deuel, 51 F.3d 1552 (Fed. Cir. 1995). In Deuel, the Court indicated that “obvious to try” was not an appropriate test for obviousness. The Federal Circuit stated that the Supreme Court in KSR had “unambiguously discredited” the holding in Deuel with respect to the “obvious to try” doctrine. Slip op. at 12-13. Given the Supreme Court’s admonition against a “formalistic approach to obviousness in this context,” the Federal Circuit resurrected its holding in In re O’Farrell, 853 F.2d 894, 903 (Fed. Cir. 1988). Slip op. at 14.

To differentiate between proper and improper applications of “obvious to try,” O’Farrell set out two classes of situations where “obvious to try” would be erroneously equated with obviousness. In Kubin, the Court stated that the first situation where a finding of obviousness would not be established is where an inventor merely throws “metaphorical darts at a board filled with combinatorial prior art possibilities” without providing any guidance or direction as to which of many possible choices is likely to be successful. Id. According to the Kubin decision, the Supreme Court encapsulated the inverse of this proposition, stating that “where a skilled artisan merely pursues ‘known options’ from a ‘finite number of identified, predictable solutions,’ obviousness under § 103 arises.” Id. (citing KSR, 550 U.S. at 421). The second situation occurs where what was “obvious to try” was to explore a promising new technology, where the prior art gave only general guidance as to the particular form of the claimed invention or how to achieve it. The Federal Circuit reasoned that the Supreme Court affirmed the logical inverse of this statement as well, stating that § 103 bars patentability unless “the improvement is more than the predictable use of prior art elements according to their established functions.” Id. at 15 (quoting KSR, 550 U.S. at 417).

The Federal Circuit then found that the prior art disclosed the protein of interest, a motivation to isolate the gene coding for that protein, and illustrative instructions to use a monoclonal antibody specific to the protein for cloning the gene. The Court held that the record showed that a skilled artisan would have had reasonable expectation of success in deriving the claimed invention in light of the teachings of the prior art.

The Court then noted that it declined to limit KSR to the “predictable arts” (as opposed to the “unpredictable art” of biotechnology). It held that, at any rate, the record showed that one of skill in that advanced art would find the claimed results predictable. Therefore, the Court held that it cannot, “in the face of KSR, cling to formalistic rules for obviousness, customize its legal tests for specific scientific fields in ways that deem entire classes of prior art teachings irrelevant, or discount the significant abilities of artisans of ordinary skill in an advanced area of art.” Id. at 16-17.

Here, the Court noted that because the prior art did not explicitly disclose the amino acid sequence for the NAIL protein or a DNA sequence for the NAIL gene, the invention represented some minor advance in the art. But the Federal Circuit stated that allowing such minor advances to be patentable might stifle further innovation in this field. Thus, the Federal Circuit concluded that the claimed invention was reasonably expected in light of the prior art and was obvious to try.

Having reached its decision on these grounds, the Court did not address the issue of invalidity under 35 U.S.C. § 112, ¶ 1 for lack of written description.

Summary authored by Jeffery P. Langer, Ph.D., Esq.