Ex parte Gibson et al.

Board of Patent Appeals and Interferences

Mar 31, 1998

08035546 (B.P.A.I. Mar. 31, 1998)

Application for patent filed March 23, 1993. According to1
applicants, this application is a continuation of Application
07/786,691, filed November 1, 1991, now abandoned; which is a
continuation of Application 07/142,888, filed January 11, 1988, now
U.S. Patent 5,089,480, patented February 18, 1992; which is a
continuation-in-part of Application 06/886,867, filed July 16, 1986,
now abandoned. Applicants claim the benefit under 35 U.S.C. § 119 of
the July 27, 1985, August 9, 1985, April 24, 1986, and May 2, 1986,
filing dates of United Kingdom Applications 8,518,999, 8,520,069,
8,610,063, and 8,610,862, respectively.
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THIS OPINION WAS NOT WRITTEN FOR PUBLICATION
The opinion in support of the decision being entered today
(1) was not written for publication in a law journal and
(2) is not binding precedent of the Board.
Paper No. 24
UNITED STATES PATENT AND TRADEMARK OFFICE
____________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________
Ex parte STEPHEN P. GIBSON, ALEXANDER GOUDIE,
KELVIN S. HOLDOM and JOHN D. BU’LOCK
____________
Appeal No. 95-0576
Application 08/035,5461
____________
ON BRIEF
____________
Before WINTERS, WILLIAM F. SMITH, and GRON, Administrative Patent
Judges.
Appeal No. 95-0576
Application 08/035,546
We presume for purposes of this appeal that the subject matter2
presently claimed is entitled to the benefit only of the January 11,
1988, filing date of grandparent Application 07/142,888. However,
the effective filing date of the subject matter claimed has not been
established.
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GRON, Administrative Patent Judge.
DECISION ON APPEAL UNDER 35 U.S.C. § 134
1. Introduction
This is an appeal from an examiner’s rejection of
Claims 1-3, 17, 28, 33-35, and 40, all claims pending in this
application. Claims 1-3, 17, 28, 33-35, and 40, stand finally
rejected under 35 U.S.C. § 103 as being unpatentable in view of
the teaching of Mrozik, U.S. 4,423,209, patented December 27,
1983. Claims 1-3, 17, 28, 33-35, and 40, stand finally rejected
under 35 U.S.C. § 103 as being unpatentable in view of the
combined teachings of United Kingdom Patent Application
GB 2,166,436, published May 8, 1986, and Mrozik.
All claims on appeal stand or fall together with
representative Claim 1 which is reproduced in the attached
Appendix. We have considered the claimed subject matter and the
supporting specification, the prior art teachings of Mrozik and
GB 2,166,436 , the Declaration Under 37 CFR § 1.132 of David A.2
Perry, dated October 2, 1992, the Brief For Appellants and
Examiner’s Answer. We also note the subject matter claimed in
Appeal No. 95-0576
Application 08/035,546
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commonly assigned U.S. 5,089,480 and the terminal disclaimer
entered in this application on December 20, 1993.
2. Findings
A. The claimed invention
The claims on appeal are directed to novel
antiparasitic “compounds related to the avermectins and
milbemycins but having a novel substituent group at the 25-
position. . .” (Specification, page 1, lines 8-12). The
specification acknowledges that avermectins are antiparasitic
agents which are produced by “fermenting a strain of the
microorganism Streptomyces avermitilis ATCC 31267, 31271 or 31272
under aerobic conditions in an aqueous nutrient medium containing
inorganic salts and assimilable sources of carbon and nitrogen”
(Specification, page 1, lines 13-19). Applicants “discovered
that by adding certain specified carboxylic acids, or derivatives
thereof, to the fermentation of an avermectin producing organism
it is possible to obtain novel compounds, related to the
avermectins but having an unnatural substituent group at the 25-
position in place of the isopropyl or sec-butyl group which is
normally present” (Specification, page 1, line 32, to page 2,
line 3). The examiner does not dispute the Description of the
Prior Art on page 1 or the Summary of the Invention on pages 1-4
of the specification.
Appeal No. 95-0576
Application 08/035,546
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B. Mrozik
Mrozik describes a series of avermectin compounds which are
naturally produced by, and isolated from the fermentation broth
of, Streptomyces avermitilis (Mrozik, column 1, lines 6-8). The
examiner finds that the compounds Mrozik describes are identical
to compounds appellants claim but for the substituent groups
at the 25-position (Examiner’s Answer, pages 2-3, bridging
sentence). Mrozik’s compounds have a methyl, ethyl, isopropyl
or sec-butyl group at the 25-position (Mrozik, column 1, line 63,
and column 2, lines 10-19). Mrozik’s compounds with an isopropyl
or sec-butyl group at the 25-position are homologues of the
compounds appellants claim with an “alpha-branched C -C alkyl 5 8
. . . group” at the corresponding 25-position.
C. GB 2,166,436
GB 2,166,436 (GB) describes a series of antibiotic compounds
which “may be prepared by culturing certain Streptomyces strains,
in particular Streptomyces thermoarchaensis NC1B 12015" (GB,
Abstract). The examiner finds that GB describes compounds which
are “closely analogous” to compounds described by Mrozik and
certain compounds provisionally excluded from appellants’ claims
(Examiner’s Answer, page 4, lines 1-5). The significant
difference between the compounds which are not expressly excluded
from appellants’ claims and the “closely analogous” compounds GB
Appeal No. 95-0576
Application 08/035,546
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broadly describes, for purposes of resolving the merits of this
case, appears to be the difference between homologous
substituents at the 25-position. GB’s compounds have an
“isopropylene group substituted by methyl, ethyl, or isopropyl”
at the 25-position (GB, Abstract, last sentence). We understand
the examiner to find that GB’s compounds with an isopropylene
group substituted by methyl, ethyl, or isopropyl at the 25-
position are “closely analogous” to the compounds provisionally
excluded from appellants’ claims and both “closely analogous” and
homologous to the compounds appellants otherwise claim which have
an “alpha-branched . . . C -C alkenyl group” at the3 8
corresponding 25-position.
3. Discussion
The examiner portrays the prima facie case of obviousness of
the compounds appellants claim in view of Mrozik’s teaching as
follows (Examiner’s Answer, page 3):
Since an alpha-branched group having 5 carbon atoms
is a next higher homologue of a sec-butyl group, it
would have been obvious to a person having ordinary
skill in the art at the time the instant invention
was made to substitute alpha-branched alkyl group
having 5 carbon atoms for the sec-butyl group on the
compounds disclosed by Mrozik because the results
obtained therefrom would have been expected i.e. a
person having ordinary skill in the art at the time
the instant invention was made would have been motivated
to substitute a 5-carbon alkyl for a 4-carbon alkyl on
a compound disclosed by Mrozik with the expectation of
getting a compound possessing antiparasitic activity.
Appeal No. 95-0576
Application 08/035,546
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With regard to the prima facie case of obviousness of the
compounds appellants claim in view of the combined teachings of
GB and Mrozik, the examiner states (Examiner’s Answer, page 4,
first full sentence):
[S]ince Mrozik discloses interchangeability of a
hydrogen atom and a sugar moiety at the 13-position
of a closely analogous milbemycin derivative having
antiparasitic activity and since propylene is a next
lower homologue of 2-buten-2-yl, a person having
ordinary skill in the art at the time the instant
invention was made would have been motivated to
modify the compounds disclosed by the British
patent in accordance with the teaching of Mrozik
and to substitute an alkenyl group having 4-carbon
atoms with a lower homologue having 3 carbon atoms
because such a person would have expected the
resulting compounds to possess antiparasitic activity.
Even if the examiner’s findings are supported by the
evidence of record, the examiner still has not sustained the
initial burden of the Patent Office to establish the prima facie
obviousness of the invention appellants claim under 35 U.S.C.
§ 103 in view of the cited prior art. Close structural
similarity between claimed and prior art compounds may provide
all the necessary motivation a person skilled in the art may
require to make the claimed compounds with reasonable expectation
that compounds similar in structure will have similar properties.
In re Payne, 606 F.2d 303, 313-14, 203 USPQ 245, 254-55 (CCPA
1979). However, to sustain a rejection of compounds over prior
Appeal No. 95-0576
Application 08/035,546
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art describing compounds having close structural similarity, In
re Payne, 606 F.2d at 314-15, 203 USPQ at 255, states:
References relied upon to support a rejection under
35 USC § 103 must provide an enabling disclosure, i.e.,
they must place the claimed invention in the possession
of the public. In re Brown, 329 F.2d 1006, 1011, 51 CCPA
1254, 1259, 141 USPQ 245, 249 (1964). An invention is not
“possessed” absent some known or obvious way to make it.
In re Hoeksema, 399 F.2d 269, 274, 55 CCPA 1493, 1500,
158 USPQ 596, 601 (1968). Hence, the presumption of
obviousness based on close structural similarity is overcome
where the prior art does not disclose or render obvious a
method for making the claimed compound.
Whether or not the references cited in this case describe
compounds with sufficiently close structural similarity to
motivate persons skilled in the art to make the compounds
presently claimed with reasonable expectation of antiparasitic
activity, they would not have enabled persons skilled in the art
to make the claimed compounds. Both Mrozik and GB prepared the
compounds each describes by culturing certain Streptomyces
strains. The compounds isolated by Mrozik have isopropyl and
sec-butyl groups at the 25-position and those isolated by GB have
an isopropylene group substituted by methyl, ethyl, or isopropyl
at the 25-position. There is no indication in either of the
references that the same or similar strains might be cultured to
prepare structurally similar compounds with homologous
substituent groups at the 25-position. Moreover, there is not a
shred of evidence of record that the compounds prepared by the
Appeal No. 95-0576
Application 08/035,546
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natural methods described in Mrozik and GB may be used as
starting compounds for synthesizing compounds structurally
similar at the 25-position by conventional chemical methods with
reasonable expectation of retaining, or producing new compounds
which also exhibit, antiparasitic utility. Put simply, the
record is devoid of any evidence in support of the proposition
that persons skilled in the art would have been enabled by the
prior art cited of record to make the compounds appellants claim
without undue experimentation. Absent evidence which would
indicate that the claimed compounds might be synthesized from
their prior art homologues without undue experimentation with
reasonable expectation of antiparasitic utility, the prior art of
record would not have placed the compounds appellants claim in
the possession of the public. Based on the evidence in this
case, we cannot assume that the natural prior art methods for
making the compounds indicated also can be used to naturally
produce structurally similar compounds. The references
themselves refute the proposition.
Having determined that the examiner has not established a
prima facie case of obviousness of Claims 1-3, 17, 28, 33-35, and
40 under 35 U.S.C. § 103 in view of the teaching of Mrozik alone,
or in view of the combined teachings of GB and Mrozik, we need
not consider the evidentiary weight to be accorded the
Appeal No. 95-0576
Application 08/035,546
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Declaration Under 35 CFR § 1.132 by David A. Perry. However,
even if Perry’s opinions are entitled to little weight, they are
at least consistent with our present conclusion.
4. Conclusion
We reverse the examiner’s rejections of Claims 1-3, 17, 28,
33-35, and 40 under 35 U.S.C. § 103 as being unpatentable in view
of Mrozik alone and/or the combined teachings of GB 2,166,436 and
Mrozik.
REVERSED
Sherman D. Winters
Administrative Patent Judge )
)
)
)
William F. Smith ) BOARD OF PATENT
Administrative Patent Judge ) APPEALS AND
) INTERFERENCES
)
)
Teddy S. Gron )
Administrative Patent Judge )

Appeal No. 95-0576
Application 08/035,546
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Gregg C. Benson
Pfizer Inc.
Eastern Point Road
Groton, CT 06340
Appeal No. 95-0576
Application 08/035,546
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APPENDIX