October 1, 2005 (Vol. 25, No. 17)

The Capon Case Reveals the Reasonable Artisan

An August 12, 2005, decision by the Federal Circuit (the federal court that hears patent-related appeals) bodes well for those who wish to patent biotech inventions.

The decision concerns a dispute that started as a priority contest (called an interference in patent law) between two sets of inventors as to who invented first: Capon et al., or Eshhar et al. In a curious twist, the priority contest was short-circuited and morphed into a dispute that made allies of the original adversaries.

The interference concerned claims of Capon and Eshhar that generally were directed to novel chimeric DNA molecules encoding a fusion protein composed of a single-chain antibody and a membrane-bound lymphocyte signaling protein.

Some claims included limitations to specific antibody targets and/or specific lymphocyte signaling proteins. The Board of Patent Appeals and Interferences (the Board), which resolves interferences within the Patent Office, declared that neither partys specification satisfied the patent statutes written description requirement as it relates to a sequence-based biological invention.

The Patent Office has taken a stricter approach to written description requirements generally in recent years, and especially in the biotechnical arts. The stricter approach, building over a number of years in various cases, was fully articulated in a 1997 Federal Circuit decision invalidating claims directed at an undisclosed DNA sequence where only a protein sequence was known.

Bright Line Rule

Citing Lilly and other cases2, the Board held that the references to prior art and disclosure of specific examples provided in each partys specification, in the absence of any sequence information within the specification, did not provide adequate written descriptive support for the invention. The Board, having pronounced this bright line rule, rejected all the claims without considering the support for each claim individually.

Both parties appealed the Boards decision, and the director of the U.S. Patent and Trademark Office intervened3, thereby setting the stage for the Federal Circuit to clarify important aspects of the written description requirement of the patent statute as it relates to biotech inventions.

In an opinion authored by Judge Pauline Newman, the Federal Circuit now states plainly that a sequence need not appear in a patent specification to support a DNA-based invention provided that the state of the scientific knowledge includes such structural information.

Moreover, the Court noted that application of the written description law necessarily will vary [over time] with differences in the state of knowledge in the field and differences in the predictability of the science. This last note of varying application of the law is a key issue for biotech patenting as it may impact the allowable breadth in claims of sequence-based patents.

The Federal Circuit rejected the Boards per se sequence requirement for biotechnical inventions. Such a requirement was characterized as an inappropriate generalization that ignores the state of the scientific knowledge, as explained by both parties.

Indeed, the Boards bright line rule places form unreasonably over substance, as Judge Newman noted in writing that requiring reanalysis of the chimeric molecules detailed structure where the prior art includes the nucleotide information simply lacks descriptive substance.

Moreover, the requirement to describe ones invention for the patent right, says the Federal Circuit, does not state that every invention must be described in the same way.

Breadth of Claims

The Federal Circuit also took this opportunity to comment on the issue of breadth of claims to sequence-based inventions. A common rejection by the Patent Office to a sequence-based generic claim is that the claim is overly broad and, especially in the absence of identifying particular sub-structures to include or exclude as being required or necessarily avoided, may include inoperative species.

Indeed, the director argued that it cannot be known whether all permutations and combinations of components included in the claims would be effective. The parties argued that their respective specifications describe how to produce chimeric combinations using known techniques, reagents, and components, and how to evaluate a given chimeric combinations effectiveness. These two positions have been played out repeatedly in prosecuting biotech applications in recent years.

The Federal Circuit found the Board erred in its failure to address the scope of each of the parties claims in view of existing precedent. The Federal Circuit repeats other precedential cases that held that generic claims are not invalid because success is not assured.

These cases distinguished adequately supported generic inventions where the effect is sufficiently demonstrated versus those that are merely a desired outcome, more a research proposal than a recital of a new invention.

In remanding the issue, the Federal Circuit suggested that the Board consider instruction provided by its predecessor court: [T]he certainty required of the disclosure is not greater than that which is reasonable, having due regard to the subject matter involved.4

The ability to rely on the teachings of the prior art for written descriptive support of an invention in appropriate circumstances is good news, and mirrors the conduct of science itself: The contribution of a discovery into the general knowledge of a field provides the grounding for the next discovery, and so on.

General Knowledge

In the Capon case, the Federal Circuit acknowledges that general knowledge in a field underlies advances and accepts general knowledge as a possible source of support for a claim. The holding in the Capon case is in line with the long-held understanding that a specification preferably does not describe information available in the prior art to one who works in the relevant field.5

The Capon case presents a good start in the direction of finding a more reasonable position for the Patent Office to define the scope of a patent claim for purposes of examination. It serves as a reminder to the Patent Office that examination of the written support for a new thing or method in an application should be accomplished using a reasonable standard based on both general and art-specific knowledge as of the filing date of the application.

Using hard and fast rules to measure the adequacy of a writing may be convenient for courts or the Patent Office, but such inflexible rules become stale in view of the inexorable march of technological progress.

Indeed, the past 30 years of advances in our knowledge of molecular biology and genetics should warrant increased claim breadth in sequence-based biological inventions. By taking shortcuts in examining patents, the Patent Office unfairly burdens parties who then face a difficult choice: undertake the cost of an appeal or accept the cost of no patent coverage.

The focus for determining possession of an invention should be based more on the description of the general concept along with presentation of sufficient detail understandable in the context of the general and art-specific knowledge as of the filing date, so that one skilled in the art apprehends the invention.

In other words, the written description requirement should be deemed satisfied as long as a reasonable artisan of the relevant field, having read the specification, then knows what the invention is.6

There is no place for per se or bright-line rules where the adequacy of written description and the understandings of the reasonable artisan of a particular field necessarily varies in response to inevitable technological advances.

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