Biotech Claims Found to Be Over Combinations of Prior Art References

The U.S. Court of Appeals for the Federal Circuit affirmed the decision by the U.S. Patent and Trademark Office (USPTO) Board of Patent Appeals, rejecting the appellants’ application for "Mutated Recombinant Collagens" as obvious. In re Berg, Case Nos. 02-1120, -1160 (Fed. Cir. February 20, 2003). Uncharacteristically, the Court appears to have applied the substantial evidence standard with some care and given a high degree of deference in this complicated art to the "persons of scientific competence" at the USPTO.

Collagen is a natural protein found in humans that can be produced as a recombinant protein. In order to synthesize collagen, one typically starts with a precursor known as procollagen. Procollagen consists of collagen with additional peptide extensions at either end of the collagen chain, i.e., the N-terminus or the C-terminus. The extensions are then removed by enzymes that cleave, or "cut off," the extensions at specific sites to produce collagen that can successfully be used in humans. The appellants’ patent claimed a procollagen chain, which included a non-natural "cut-off" site between the collagen chain and the natural C-terminal extension, allowing the extension to be removed by using a specific enzyme that reacts with the non-natural site, leaving just the collagen.

The decision in In re Berg came down to a question of how broadly the teachings of a prior art "suggestion to combine" would be read. The examiner and the board viewed the prior art reference broadly, as disclosing that two proteins can be fused together for a variety for reasons, and once those proteins are expressed they can be chemically or enzymatically separated at specific sites on the protein chain. The appellant urged a narrower reading and was rebuffed, by the examiner, the board and now the Federal Circuit. Based on the record before it, and giving considerable deference to the examiner and the board, the Federal Circuit affirmed the finding of obviousness and the denial of the patent, holding that "it would have been obvious to a person of ordinary skill in the art to create a recombinant DNA system for the production of procollagen in which the recombinant procollagen chain consisted of a natural collagen polypeptide and a first natural propeptide, with a first non-natural site-specific proteolytic agent recognition site located between them."

Practice Note: In areas of complicated technology, such as biotechnology, the Federal Circuit tends to rely more heavily on the expertise of the Board of Patent Appeals and the "substantial evidence" rule can have some bite.