The federal Appeals Court in Washington has ruled that the specificstructure of a DNA sequence, not the manner in which it was cloned,should be a determining factor in deciding whether a gene can bepatented.

The unanimous decision, issued this week, reversed a U.S. Patent andTrademark Office (PTO) rejection of a 1990 application by St. LouisJewish Hospital researchers seeking to patent a DNA sequence(cDNA) encoding a heparin-binding growth factor.

The PTO said in 1993 the patent claim did not meet the requirementof non-obviousness because the method of cloning the sequence wasconsidered routine and a related protein sequence, heparin-bindingbrain mitogen, already was known. Non-obviousness is one of threemajor requirements in getting a patent.

St. Louis lawyer G. Harley Blosser, who argued on behalf of theJewish Hospital scientists, said the court's ruling, issued Tuesday,strengthens a 1993 Appeals Court decision in a similar case involvingEmeryville, Calif.-based Chiron Corp.

Chiron successfully challenged a PTO denial for DNA sequencesencoding human insulin-like growth factors I and II. The PTO'sfinding of obviousness in that case was based on a specific cloningmethod.

The Jewish Hospital appeal, Blosser said, expands the court'sinterpretation, saying that the cloning method, in general, is not asimportant as the actual structure of the DNA sequence in determiningobviousness, even if a partial protein sequence is known.

The court said, "We reaffirm the principle, stated [in the Chiron case]that the existence of a general method of isolating cDNA or DNAmolecules is essentially irrelevant to the question whether the specificmolecules themselves would have been obvious."

And the three-judge panel also stated, "The disclosure of the aminoacid sequence of a protein does not necessarily render particularDNA molecules encoding the protein obvious because theredundancy of the genetic code permits one to hypothesize anenormous number of DNA sequences coding for the protein. Noparticular one of these DNAs can be obvious unless there issomething in the prior art to lead to the particular DNA and indicatethat it should be prepared."

Debra Shetka, of Palo Alto, Calif., who filed an amicus brief in theJewish Hospital case for the Biotechnology Industry Organizationand Bay Area Science Center, said the ruling should make it easier toget gene patents and should clarify obviousness standards.

She said the Appeals Court judges used a "long-standing precedent ofobviousness in the context of chemical compounds," which is basedon a compound's structure.

"The court held the cDNA would not have been obvious because theprior art only taught proteins," she observed.

Blosser said the court's decision sends the patent application back tothe PTO for reconsideration.

Jeff Kushan, of the PTO's Office of Legislative and InternationalAffairs, said PTO officials had not yet read the ruling and could notcomment on it.

However, Blosser said the Jewish Hospital decision compares inimportance to the PTO's new utility guidelines, which allow evidencefrom in vitro and animal studies, not just human clinical trials, tosupport patent claims. (See BioWorld Today, Dec. 22, 1994, p. 1.)

"These two should be a tremendous boost to the biotechnologyindustry," Blosser said. "[The Jewish Hospital ruling] tellsbiotechnology companies if they develop structurally non-obviousproducts, even if using routine methods, they will get patentprotection."n

-- Charles Craig

(c) 1997 American Health Consultants. All rights reserved.