Facts: The inventors filed a patent application directed to DNA and cDNA molecules that encoded heparin binding growth factor (HBGF). The examiner rejected the claims as obvious and the Board of Patent Appeals and Interferences affirmed. The examiner cited two prior art references. The Bohlen references provided a partial amino acid sequence of HBGF and did not address the DNA coding of the enzyme. The Maniatis reference disclosed the method of gene cloning that the applicants had used.

Issue: Whether the combination of a prior art reference teaching a method of gene cloning, together with a reference disclosing a partial amino acid sequence of a protein, may render DNA and cDNA molecules encoding the protein prima facie obvious under 35 USC § 103.

Holding: No. In order to establish that a structurally novel chemical compound is prima facie obvious, the teachings of the prior art must suggest the claimed compounds to a PHOSITA (person having ordinary skill in the art).

Reasoning: Obviousness is normally based on structural similarity between the claimed and prior art compounds. Structural similarities may provide a motivation or suggestion to prepare new analogs of known compounds. Such similarities can include geometric or positional isomers or homologs.

In such cases, “the question becomes whether the prior art would have suggested making the specific molecular modifications necessary to achieve the claimed invention.” See In re Dillon. Only then does the burden shift to the inventor to rebut the prima facie case of obviousness.

The court held that the prior art did not disclose any relevant DNA molecules or close relatives of the claimed compounds. While the protein sequence was known, the redundancy of the genetic code provided too many alternatives for one to have contemplated or focus on the claimed compounds. One could not have conceived of the sequence until it was isolated and purified and what cannot be contemplated or conceived cannot be obvious. A motivation to search for a gene with a known property does not make the specific gene that is found obvious.

Brief Summary of Holding:

(1) Combination of prior art reference teaching method of gene cloning, together with reference disclosing partial amino acid sequence for a protein that stimulated cell division did not render claims prima facie obvious;

(2) Conceived method of preparing some unidentified DNA does not define it with precision necessary to render it obvious over protein it encodes; and

(3) Patent claims generically encompassing all DNA sequences encoding human and bovine proteins to stimulate cell division were not invalid as obvious.

Disposition: Reversed.

In re Thomas F. DEUEL, Yue-Sheng Li, Ned R. Siegel and Peter G. Milner.

In re Deuel, 51 F.3d 1552, 1558-59, 34 USPQ2d 1210, 1215 (Fed. Cir. 1995).

Tags: 35 USC 103, Biotech, case, Cases, DNA, law, obviousness, Patent