Ex Parte Zhao et al

Patent Trial and Appeal Board

Dec 15, 2015

10335056 (P.T.A.B. Dec. 15, 2015)

UNITED STATES PATENT AND TRADEMARK OFFICE
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
10/335,056 12/31/2002 Ming Zhao 3939
7590 12/16/2015
ANTICANCER, INC
7917 OSTROW STREET
SAN DIEGO, CA 92111
EXAMINER
BRISTOL, LYNN ANNE
ART UNIT PAPER NUMBER
1643
MAIL DATE DELIVERY MODE
12/16/2015 PAPER
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
____________________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________________

Ex parte MING ZHAO, XIAO-MING LI, MENG YANG,
MINGXU XU, PING JIANG, and LINGNA LI1
____________________

Appeal 2013-003208
Application 10/335,056
Technology Center 1600
____________________

Before DONALD E. ADAMS, ULRIKE W. JENKS, and
JACQUELINE T. HARLOW, Administrative Patent Judges.

HARLOW, Administrative Patent Judge.

DECISION ON APPEAL2
This is an appeal under 35 U.S.C. § 134(a) involving claims to a
system for monitoring bacterial tumor treatment. The Examiner rejected the
claims as obvious. We have jurisdiction under 35 U.S.C. § 6(b).
We AFFIRM.

1 According to Appellants, the Real Party in Interest is AntiCancer, Inc.
(App. Br. 1).
2 This Appeal is related to Appeal No. 2013-003491, Application No.
12/422,863, which is a divisional of the present Application and is currently
pending at the Board.
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Application 10/335,056
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STATEMENT OF THE CASE
The Specification describes “the use of fluorescent proteins delivered
in bacteria to monitor the delivery and efficacy of antitumor drugs”
(Spec. ¶ 2).
Claims 12, 15, 16, and 22–29 are on appeal. Claim 12, the sole
independent claim on appeal, reads as follows:
12. A method to evaluate an experimental protocol for
delivery of a therapeutic protein to treat a tumor in a laboratory
animal tumor model which method comprises
imaging over time facultative anaerobic or anaerobic
bacteria that have been modified to express a first fluorescent
protein of a first color fused to a therapeutic protein wherein
said bacteria have been modified to disable any toxic effects
and have been administered to said animal model;
wherein said tumor has been labeled with a second
fluorescent protein of a second color different from the first
color,
whereby the presence of said image confirms the
therapeutic protein is present to treat the tumor,
wherein said imaging is by whole body fluorescence
optical imaging in the laboratory animal tumor model.

Appeal 2013-003208
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The Examiner has rejected claims 12, 15, 16, and 22–29 under
35 U.S.C. § 103(a) as being unpatentable over Tjuvajev,3 Rainov, 4 Yang, 5
King, 6 Bermudes, 7 and Köhler. 8
ISSUE
Does the preponderance of evidence on this record support the
Examiner’s conclusion that the combination of Tjuvajev, Tainov, Yang,
King, Bermudes, and Köhler renders Appellants’ claimed invention
obvious?
FINDINGS OF FACT
We adopt the Examiner’s findings concerning the scope and content
of the prior art (Ans. 3–15), and repeat the following findings for emphasis.
FF 1. Yang discloses whole-body, real-time optical imaging, via
trans-illuminated epifluorescence microscopy or a fluorescence light box
and thermoelectrically cooled color charge-coupled device camera, of green

3 Tjuvajev et al., Salmonella-based tumor-targeted cancer therapy: tumor
amplified protein expression therapy (TAPETTM) for diagnostic Imaging,
J. Controlled Release, 74, 313–315 (2001).
4 Rainov et al., A chimeric fusion protein of cytochrome CYP4B1 and green
fluorescent protein for detection of pro-drug activating gene delivery and for
gene therapy in malignant glioma, in Gene Therapy of Cancer, 393–403
(Walden et al. eds., 1998).
5 Yang et al., Whole-body optical imaging of green fluorescent protein-
expressing tumors and metastases, Proc. Nat’l. Acad. Sci., 97(3), 1206–1210
(2000).
6 King et al., Tumor-selective delivery of therapeutic proteins by Salmonella
typhimurium in murine tumor models, Proc. Am. Assoc. Cancer Res., 41,
732 (2000).
7 Bermudes et al., WO 01/25399 A2, published April 12, 2001.
8 Köhler et al., Expression and use of the green fluorescent protein as a
reporter system in Legionella pneumophila, Molecular & General Genetics,
262, 1060–1069 (2000).
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fluorescent protein-labeled (“GFP-labeled”) tumor cells in the brain, liver,
bone, colon, and lymph nodes of live mice (Yang 1206).
FF 2. Yang discloses that “GFP-expressing primary and metastatic
lesions were considered to be externally measurable if the average
fluorescence of the GFP-expressing tumor was at least 20% above the
average fluorescence of the surrounding skin” (id. at 1210).
FF 3. Yang discloses that
external labeling is not a necessary limitation on the technique.
Recent findings in our laboratory suggest that in situ labeling,
with the GFP gene, of tumors growing in vivo is feasible, as
shown by the labeling of AC3488 colon tumor in this study
(S.H., M.Y., and R.M.H., unpublished data). A wide variety of
tumors now can be followed for subsequent tumor growth,
spread, and metastases, all reported by inherited GFP
expression.
(Id. at 1210.)
FF 4. Tjuvajev discloses that tumor amplified protein expression
therapy (“TAPET”) has “potential for diagnostic imaging directly coupled
with antitumor therapy” (Tjuvajev 315), and states that “Second generation
TAPET vectors will be developed to include transgenes that will express
therapeutic agents and reporter transgenes for non-invasive imaging” (id. at
314).
FF 5. Rainov discloses successful in vivo treatment of tumor cells
with herpes simplex mediated delivery of a cytochrome CYP4B1-green
fluorescent protein (“GFP”) fusion protein (Rainov 394). Rainov states “If
an operating microscope with an UV source is used, transgene-mediated
intratumoral fluorescence may be discovered even in situ, as this was
previously demonstrated by other investigators with other systems” (id. at
401–402).
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FF 6. King discloses the delivery, via a modified strain of Salmonella
typhimurium, of “cytosine deaminase and green fluorescent protein into
tumors selectively. These proteins were functional and could be detected in
tumors.” (King Abstract). King states “[o]ur results suggest that VNP20009
can be used to express therapeutic proteins in situ, which could enhance its
anti-tumor efficacy” (id.).
FF 7. Bermudes discloses administering tumor-targeted, labeled
bacteria, including fluorescently labeled bacteria, to a subject, and “scanning
the subject to detect the labeled compound, thereby detecting the tumor-
targeted bacteria and imaging the tumor in the subject” (Bermudes 7:26–30),
or “scanning to image an infection caused by the bacteria, thereby detecting
and imaging the tumor in the subject” (id. at 7:34–8:3). Bermudes describes
numerous embodiments whereby labeled tumor-targeted bacteria are directly
imaged, and that those images are used to infer the size, location, condition,
or other characteristics of a tumor (id. at 7:10–8:22, claim 1).
FF 8. Bermudes discloses
[M]ethods of simultaneously imaging and treating a tumor in a
subject. In one embodiment, simultaneous imaging and
treatment comprises administering tumor-targeted bacteria
expressing a marker gene and a suicide gene capable of
converting a prodrug into a cytotoxic drug, together with a
labeled marker substrate. A single tumor-targeted bacterial
vector may contain more than one bacterial expression
construct, wherein at least one construct is used for imaging the
tumor, as above, and at least one construct is used for treating
the tumor. Alternatively, a population of at least two tumor-
targeted bacterial vectors is administered, wherein one vector is
for imaging as above, and another vector is for therapeutic
treatment.
(Id. at 8:11–19.)
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FF 9. Bermudes discloses the use of marker genes encoding
fluorescent molecules having a variety of wavelengths and intensities, such
as GFP mutants, and “yellow or red-orange emitter[s] recently discovered in
reef corals” (id. at 18:26–19:6). Bermudes further discloses that “[w]hole-
body imaging of GFP-expressing tumors and metastases has been reported
by Yang et al. (2000, Proc. Nat’l Acad. Sci. U S A 97:1206–11)” (id. at
19:6–7).
FF 10. Köhler discloses using GFP-labeled Legionella pneumophila
to monitor, in real-time, the infection of Acanthamoeba castellanii, as well
as the survival of, and incidence of host-cell killing by GFP-labeled
Legionella (Köhler 1060, 1061). Köhler states that “[t]he availability of new
versions of the GFP, for example, the mutant analogue that emits blue
fluorescence . . . will significantly extend the usefulness of GFPs in
Legionella in [the] future” (id. at 1068).
FF 11. The Examiner finds that
One of ordinary skill in the art would have been
motivated and been reasonably assured of success in having
created a fluorescence method for monitoring localization of a
fluorescent-therapeutic fusion protein in a solid tumor via
bacterial delivery of the fusion protein in view of Tjuvajev,
Rainov and Yang and further in view of King, Bermudes, and
Kohler. Tjuvajev and Yang and further in view of King,
Bermudes, and Kohler in combination teach administering a
recombinant bacterium to a laboratory animal tumor model to
assess the presence and fluorescence intensity of a
therapeutic/fluorescent fusion protein expressed by the
bacterium being localized in the tumor in a method for
evaluating a protocol for treating the animal, where the
monitoring of the fluorescence occurs by whole body
fluorescence optical tumor imaging in the intact animal.
Rainov teaches a viral vector based system for tumor targeting
in order to deliver a fluorescent protein for targeted delivery.
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Rainov, Bermudes and Yang teach the need to develop
fluorescence detection methods for visualizing fluorescence
markers in vivo in tumor therapies and visualizing bacteria per
se. Yang teaches labeling the tumors themselves with
fluorescence proteins to observe tumor regression or
metastases.
(Ans. 7–8.)
FF 12. The Examiner finds that “Rainov, Yang, Bermudes and
Kohler specifically teach and support visualization of fluorescent labels in a
tumor, in situ or in vivo, by optical methods well recognized in the field at
the time of the invention. Bermudes and Kohler teach tracking fluorescent
labeled bacterium in a tumor in vivo” (Ans. 13).
ANALYSIS
We agree with the Examiner that the claims are rendered obvious by
Tjuvajev, Rainov, Yang, King, Bermudes, and Köhler (FF 1–13). Because
the claims are not separately argued, we focus our discussion on independent
claim 12, which is representative.9 We address Appellants’ arguments
below.
Appellants acknowledge that “King and Bermudes both teach that
Salmonella that express the gene for a fluorescent protein can selectively be
delivered to tumors and Yang demonstrates that tumors can be imaged by
whole body fluorescent imaging,” but nevertheless contend that Bermudes
teaches away from the claimed invention (App. Br. 4). In particular,
Appellants argue that Bermudes “teaches away from using two different

9 We note that although Appellants “request that claims 15-16 and 23 be
considered separately from claim 12 as they contain the additional feature
that the tumor must also be imaged as a measure of the effectiveness of
administering the bacteria” (App. Br. 3), Appellants’ do not separately argue
those or any other of the claims presented on appeal.
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fluorescent proteins, one for the tumor and one for the bacteria by suggesting
that the bacteria be used simply to label the tumor” (App. Br. 5). Appellants
assert that “adapt[ing] the approach of Bermudes to an animal whose tumor
is already labeled does not make any sense” (App. Br. 3.). Appellants also
argue that King does not disclose real-time whole body imaging of that GFP
(App. Br. 3), and that the Tjuvajev, Rainov, and Köhler references are
“peripheral” to the Examiner’s rejection (App. Br. 5).
Appellants further contend that, as set forth in the Hoffman
Declaration,10 the cited combination of prior art does not support a
conclusion of obviousness because, at the time of invention, a skilled artisan
would not have had a reasonable expectation of success in combining the
cited references (App. Br. 4). Appellants cite the statement by Cronin11 that
“high background levels and poor tissue penetration of both excitation and
emission light restricts the application of fluorescence in vivo to
predominantly subcutaneous, shallow depth models” (Cronin 1) as
indicating “doubt[] in the field that the demonstrable success of the presently
claimed method is expected” (Reply Br. 7). Appellants assert that the
Examiner’s reliance on Yang, Bermudes, Rainov, and Köhler, as
establishing a reasonable likelihood of success, either individually or in
combination, is misplaced, and improperly extrapolates success in whole
body imaging of tumors to success in whole body imaging of bacterial cells
(Reply Br. 7–8).
We do not find Appellants’ arguments persuasive. As an initial
matter, we note that Appellants’ arguments attacking the Bermudes, King,

10 Declaration of Dr. Robert Hoffman, executed June 13, 2012.
11 Cronin et al., High resolution in vivo bioluminescent imaging for the study
of bacterial tumor targeting, PLoS ONE, 7:1, 1–11 (2012).
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Yang, Tjuvajev, Rainov, and Köhler references individually (see, e.g., App.
Br. 3, 5), where the rejection is based on their combination, is improper. In
re Keller, 642 F.2d 413, 426 (CCPA 1981).
Furthermore, we find that Bermudes discloses real-time, whole body
imaging of tumor-targeted bacteria that express fluorescently labeled,
therapeutic fusion proteins (FF 8, 9). Bermudes describes administering
tumor-targeted bacteria expressing fluorescently labeled therapeutic fusion
proteins to a subject, and then scanning for and detecting the fusion protein
expressing bacteria in that subject (FF 8, 9). Although Bermudes teaches the
indirect visualization of tumors via detection of the fusion protein
incorporated into the tumor-targeted bacteria, contrary to Appellants’
assertion, it is the fusion protein, and fusion protein expressing bacteria, not
the tumor itself, that are imaged in the cited embodiments of Bermudes
(FF 8, 9). Accordingly, we are not persuaded by Appellants’ assertion that
“[t]he tumor is the only thing imaged according to Bermudes using whole
body fluorescence imagining” (App. Br. 5), or that a skilled artisan would
not have been motivated, with a reasonable expectation of success to modify
the method of Bermudes for use in combination with the method of Yang, to
image labeled, tumor-targeted bacteria (Reply Br. 7–8).
We are likewise unpersuaded by Appellants’ arguments that a skilled
artisan would not have been motivated to adapt the method of Bermudes for
use in a model where the tumor is already fluorescently labeled (App. Br. 3
(Bermudes teaches away from combination); Reply Br. 3 (combination
defeats the purpose of Bermudes and Tjuvajev)). We agree with the
Examiner that a skilled artisan would have been motivated to combine the
cited references, with a reasonable expectation of success, to “create[] a
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fluorescence method for monitoring localization of a fluorescent-therapeutic
fusion protein in a solid tumor via bacterial delivery of the fusion protein”
(FF 12). We also agree with the Examiner that a skilled artisan would have
been motivated to adapt the methods of Bermudes for use with the
fluorescently labeled tumors of Yang because “Rainov, Bermudes and Yang
teach the need to develop fluorescence detection methods for visualizing
fluorescence markers in vivo in tumor therapies and visualizing bacteria per
se,” and “Yang teaches labeling the tumors themselves with fluorescence
proteins to observe tumor regression or metastases” (FF 12). Moreover, in
view of Bermudes teachings that fluorescently labeled, tumor targeted
bacteria can be visualized using real-time, whole body imaging, we find
Appellants’ argument that Yang “does not lead to a prediction that
individual bacteria could be followed in vivo using whole body
fluorescence” (Reply Br. 7–8) unpersuasive (FF 8, 9).
Appellants’ contention that the claimed invention was unexpectedly
successful, including the Hoffman Declaration and exhibits attached thereto,
is insufficient to establish the nonobviousness of the claims on appeal. Dr.
Hoffman declares that “[d]espite our many publications, practitioners in the
field are skeptical that it would be possible to employ whole body imaging
to detect bacteria in the interior of tumors which are themselves interior to
laboratory animals to be imaged” (Hoffman Decl. 1–2). Dr. Hoffman points
to the statement in Cronin that the application of fluorescence in vivo is
predominantly limited to “subcutaneous, shallow depth models” (Cronin 1)
as evidence of such skepticism (Hoffman Decl. 2). We find, however, that
neither Dr. Hoffman’s statement, nor Cronin is indicative of unexpected
success, because claim 12 encompasses the subcutaneous and shallow depth
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tumor models Cronin identifies as appropriate candidates for whole body
fluorescence applications.
Moreover, we agree with the Examiner that a skilled artisan would
have a reasonable expectation of success in making the cited combination
because those references disclose “visualization of fluorescent labels in a
tumor, in situ or in vivo, by optical methods well recognized in the field at
the time of the invention,” and further because “Bermudes and Kohler teach
tracking fluorescent labeled bacterium in a tumor in vivo” (FF 13).

SUMMARY
We affirm the rejection of claim 12 under 35 U.S.C. § 103(a) based on
Tjuvajev, Rainov, Yang, King, Bermudes, and Köhler. Claims 15, 16, and
22–29 fall with claim 12.
TIME PERIOD FOR RESPONSE
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a)(1)(iv).

AFFIRMED

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