Ex Parte Wigler et al

Board of Patent Appeals and Interferences

Sep 19, 2001

08471884 (B.P.A.I. Sep. 19, 2001)

The opinion in support of the decision being entered today was not written for
publication and is not binding precedent of the Board.

Paper No. 24

UNITED STATES PATENT AND TRADEMARK OFFICE

__________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
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Ex parte MICHAEL H. WIGLER and JOHN J. COLICELLI
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Appeal No. 1999-1351
Application 08/471,884
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HEARD:
August 9, 2001
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Before WINTERS, MILLS, and GRIMES, Administrative Patent Judges.

WINTERS, Administrative Patent Judge.

DECISION ON APPEAL

In Paper No. 10 received September 17, 1997, applicants filed a notice of appeal
from the examiner’s decision finally rejecting claims 22 through 31, which are all of the
claims remaining in the application. Subsequently, in Paper No. 22 received August 1,
2001, applicants proffered an amendment canceling claims 22 through 30. According to
applicants, “claims 22-30 are cancelled in favor of the claims in US Patent No.
6,080,540 which issued on June 27, 2000 subsequent to briefing of the present appeal.”
We shall construe the proffered amendment as a withdrawal of the appeal of claims 22
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Application 08/471,884

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through 30. Accordingly, the appeal with respect to those claims is dismissed. This
leaves claim 31 before us.1

THE APPEALED CLAIM
Claim 31 reads as follows:
31. (Amended) A method of identifying a chemical agent which alters activity
of a protein encoded by a mammalian gene which, when expressed in genetically
altered [yeast] host cells, modifies a phenotypic alteration associated with a genetic
alteration in the [yeast] host cells, comprising the steps of :
(a) expressing the protein encoded by the mammalian gene in genetically
altered [yeast] host cells in which the protein encoded by the mammalian
gene is not expressed, thereby modifying the phenotypic alteration
associated with the genetic alteration;
(b) obtaining from genetically altered [yeast] host cells produced in step (a)
protein encoded by the mammalian gene;
(c) combining protein encoded by the mammalian gene with a chemical agent
to be assayed for its ability to alter activity of the protein encoded by the
mammalian gene; and
(d) determining activity of the protein encoded by the mammalian gene in
combination with the chemical agent.

THE REFERENCES
The prior art references relied on by the examiner are:
Goddard et al. (Goddard), “Cloning of human purine-nucleoside phosphorylase cDNA
sequences by complementation in Escherichia coli.” Proceedings of the National
Academy of Sciences, USA, Vol. 80, pp. 4281-4285, July 1983

Kataoka et al. (Kataoka), “Functional cloning of mammalian and yeast RAS genes.”
Cell, Vol. 40 pp. 19-26, January 1985

Lee et al. (Lee), “Complementation used to clone a human homologue of the fission
yeast cell cycle control gene cdc2,” Nature, Vol. 327 pp. 31-35, May 1987

Chang et al. (Chang), “Phenotypic expression in E. Coli of a DNA sequence coding for
mouse dihydrofolate reductase,” Nature, Vol. 275 pp. 617-624, October 1978

1 On return of this application to the examining corps, we recommend that the examiner approve entry of
the proffered amendment canceling claims 22 through 30.
Appeal No. 1999-1351
Application 08/471,884

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THE ISSUE
The sole issue on appeal is whether the examiner erred in rejecting claim 31
under 35 U.S.C. § 103 as unpatentable over the combined disclosures of Goddard,
Kataoka, Lee, and Chang.

DELIBERATIONS
Our deliberations in this matter have included evaluation and review of the
following materials:
(1) the instant specification, including Figures 1 through 8 and claim 31 on
appeal;
(2) applicants’ Appeal Brief (Paper No. 12) and the Reply Brief (Paper No. 17);
(3) the Examiner’s Answer (Paper No. 13);
(4) the above-cited prior art references; and
(5) US Patent No. 6,080,540 issued June 27, 2000 to Wigler et al.
On consideration of the record, including the above-listed materials, we reverse
the examiner’s rejection under 35 U.S.C. § 103.

DISCUSSION
The pivotal reference in this case is Chang. Applicants argue, and the examiner
does not deny, that the E. coli strain disclosed by Chang expresses bacterial
dihydrofolate reductase (DHFR). See Chang, page 617, second paragraph. That is
why Chang carries out the assay described at length in the Chang reference. The
assay is needed to distinguish between bacterial DHFR and cloned mammalian DHFR.
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Application 08/471,884

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In other words, for Chang, the expression of mammalian DHFR by a bacterial host (E.
coli) and the assay are inextricably linked. If Chang’s E. coli strain did not express
DHFR, there would have been no need for Chang to carry out the disclosed assay. In
view of the foregoing, we believe that the examiner’s rejection under 35 U.S.C. § 103 is
predicated on the impermissible use of hindsight. The examiner relies on Chang’s
disclosure to reach the assay steps recited in claim 31. Note, however, that the
appealed claim also calls for “host cells in which the protein encoded by the mammalian
gene is not expressed” (emphasis added). See claim 31, step (a). In our judgment, a
fair interpretation of the Chang reference would not have led a person having ordinary
skill in the art to the assay steps recited in claim 31 in combination with “host cells in
which the protein encoded by the mammalian gene is not expressed” (emphasis
added). Again, Chang’s E. coli strain expresses bacterial DHFR and, for Chang, the
expression of mammalian DHFR by a bacterial host and the assay are inextricably
linked. Furthermore, the disclosures of Goddard, Kataoka, and Lee do not cure the
above-noted deficiency in the disclosure of Chang. For this reason, we reverse the
rejection of claim 31 under 35 U.S.C. § 103 as unpatentable over the combined
disclosures of Goddard, Kataoka, Lee, and Chang.
One further matter warrants attention. At the oral hearing on August 9, 2001,
counsel acknowledged that claim 31 on appeal and claim 10 in US Patent No.
6,080,540, issued June 27, 2000, are not patentably distinct.2 Counsel further
expressed a willingness to file a terminal disclaimer in this application. Accordingly, on
return of this application to the examining corps, we recommend that the examiner:

2 At the oral hearing, Greta E. Noland (Registration No. 35,302) argued on behalf of the applicants.
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Application 08/471,884

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(1) enter an obviousness type double patenting rejection of claim 31 over
claim 10 of US Patent No. 6,080,540; and
(2) require that applicants file a terminal disclaimer in this application in light
of claim 10 of the ‘540 patent.
The examiner’s decision is reversed.
REVERSED

)
Sherman D. Winters )
Administrative Patent Judge )
)
)
) BOARD OF PATENT
Demetra J. Mills )
Administrative Patent Judge ) APPEALS AND
)
) INTERFERENCES
)
Eric Grimes )
Administrative Patent Judge )
Appeal No. 1999-1351
Application 08/471,884

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