Ex Parte Wei et al

Board of Patent Appeals and Interferences

Sep 17, 2010

10718997 (B.P.A.I. Sep. 17, 2010)

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.
10/718,997 11/21/2003 Ning Wei KCX-691 (18379) 9089
22827 7590 09/17/2010
DORITY & MANNING, P.A.
POST OFFICE BOX 1449
GREENVILLE, SC 29602-1449
EXAMINER
SHIBUYA, MARK LANCE
ART UNIT PAPER NUMBER
1641
MAIL DATE DELIVERY MODE
09/17/2010 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 BOARD OF PATENT APPEALS
AND INTERFERENCES
__________

Ex parte NING WEI and RAMESHBABU BOGA
__________

Appeal 2010-005244
Application 10/718,997
Technology Center 1600
__________

Before LORA M. GREEN, MELANIE L. McCOLLUM, and
JEFFREY N. FREDMAN, Administrative Patent Judges.

McCOLLUM, Administrative Patent Judge.

DECISION ON APPEAL1
This is an appeal under 35 U.S.C. § 134 involving claims to a flow-
through assay device. The Examiner has rejected the claims as obvious. We
have jurisdiction under 35 U.S.C. § 6(b). We reverse.

1 The two-month time period for filing an appeal or commencing a civil
action, as recited in 37 C.F.R. § 1.304, or for filing a request for rehearing,
as recited in 37 C.F.R. § 41.52, begins to run from the “MAIL DATE”
(paper delivery mode) or the “NOTIFICATION DATE” (electronic delivery
mode) shown on the PTOL-90A cover letter attached to this decision.
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STATEMENT OF THE CASE
Claims 14-19 and 29-31 are on appeal. Claims 20-28 are also pending
but have been withdrawn from consideration by the Examiner. (App. Br. 2.)
We will focus on claim 14, the only independent claim on appeal, which
reads as follows:
14. A flow-through assay device for detecting the presence or
quantity of an analyte residing in a test sample, said flow-through assay
device comprising a porous membrane in communication with optical
detection probes conjugated with a first antibody specific for the analyte,
said porous membrane defining:
a competitive zone that contains a second antibody immobilized on
said porous membrane that is complexed to an antigen containing an
optically detectable substance prior to the application of a test sample to the
device, said antigen being identical to or an analog of the analyte and said
optically detectable substance being capable of producing a competitive
signal when contained within said competitive zone; and
a detection zone within which a third antibody is immobilized that is
configured to bind to complexes formed between the analyte and said
conjugated optical detection probes to produce a first detection signal, said
third antibody also being configured to bind to said antigen from said
competitive zone to produce a second detection signal, wherein the amount
of the analyte within the test sample is determined from said competitive
signal, and at least one of said first detection signal and said second
detection signal.
Claims 14-16 and 29-31 stand rejected under 35 U.S.C. § 103(a) as
obvious over Boehringer et al. (US 7,144,742 B2, Dec. 5, 2006) in view of
Behnke et al. (US 5,573,921, Nov. 12, 1996) (Ans. 4).
Claim 17 stands rejected under 35 U.S.C. § 103(a) as obvious over
Boehringer in view of Behnke and Polito et al. (US 2004/0018637 A1,
Jan. 29, 2004) (Ans. 7).
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Claim 18 stands rejected under 35 U.S.C. § 103(a) as obvious over
Boehringer in view of Behnke and Harris et al. (US 2003/0162236 A1,
Aug. 28, 2003) (Ans. 8).
Claim 19 stands rejected under 35 U.S.C. § 103(a) as obvious over
Boehringer in view of Behnke and Blatt et al. (US 2005/0196875 A1, Sep. 8,
2005) (Ans. 9).
The Examiner relies on Boehringer for teaching:
a lateral flow (flow-through) assay device for detecting the
presence or quantity of an analyte residing in a test sample, said
lateral flow assay device comprising a porous membrane in
communication with a labeled reagent (optical detection
probes) conjugated with a specific binding member, such as a
first antibody, specific for the analyte, said porous membrane
defining:
a barrier (competitive) zone 16a that can contain either
(i) a second antibody immobilized on said porous membrane
that can be complexed to an antigen containing a label
(optically detectable substance) during use, said antigen being
identical to or an analog of the analyte and said label being
capable of producing a signal; or (ii) an immobilized analyte
analog; and
a detection zone 16b and 16c within which a third
antibody is immobilized that is configured to bind to complexes
formed between the analyte and said conjugated labeled reagent
to produce a first detection signal, said third antibody can also
be configured to bind to said antigen or analyte analog from
said barrier zone to produce a second detection signal, wherein
the amount of analyte within the test sample is determined from
said detection signals.
(Ans. 4.) The Examiner refers to the embodiment in which “the barrier zone
comprises an immobilized analyte analog” as “a secondary or sandwich
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format” and indicates that it “is the closest comparable embodiment to
Appellant[s’] independent claim 14” (id. at 13-14).
The Examiner relies on Behnke for teaching “a test strip device for
determining the amount of analyte in a sample using immunochemical
displacement” (id. at 5). The Examiner finds:
The test strip device contains at least one immobilized
antibody, wherein the antibody is bound to an analyte analog
(tracer) prior to application of test sample to the device. The
bound analyte analog (tracer) can also include an attached dye
(molecule or particle), such that the area of the test strip
comprising the immobilized antibody and tracer can be directly
visualized even before beginning the test.
(Id.)
The Examiner concludes that it would have been obvious
to include with the device of Boehringer et al. the binding of the
antigen or analyte analog containing an optically detectable
substance to an immobilized antibody in the barrier zone prior
to application of the test sample as taught by Behnke . . .
because the bound analyte analog attached to the dye allows for
directly visualizing the area of the test strip comprising the
immobilized antibody (i.e. barrier zone) even before beginning
the test, and also allows for utilizing the reduction in the dye
from the area of immobilized antibody after applying the test
sample in determining the amount of analyte in the sample.
(Id. at 5-6.)
The Examiner relies on Polito, Harris, and Blatt for teaching features
of dependent claims 17-19 (id. at 7-10).
Appellants contend that the proposed combination fails to teach all of
the limitations of claim 14, it would not have been obvious to combine the
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references in the manner suggested, and the modification is based on
impermissible hindsight analysis (App. Br. 8-11).
ISSUE
Has the Examiner set forth a prima facie case that Boehringer and
Behnke suggest an assay device for detecting an analyte comprising: (a) a
porous membrane in communication with optical detection probes
conjugated with a first antibody specific for the analyte and (b) a second
antibody immobilized on the porous membrane that is complexed to an
antigen containing an optically detectable substance prior to the application
of a test sample to the device?
FINDINGS OF FACT
1. Boehringer discloses “a method of determining an amount of an
analyte in a sample, wherein the analyte is a member of a specific binding
pair (sbp member),” comprising “providing a lateral flow matrix which
defines a flow path and which comprises in series, a sample receiving zone,
a labeling zone, and one or more serially oriented capture zones”
(Boehringer, col. 3, ll. 11-16).
2. Boehringer also discloses that the “labeling zone comprises a
diffusively bound labeled first sbp member that is complementary to or
analogous to the analyte” (id. at col. 3, ll. 17-19).
3. In addition, Boehringer discloses “a lateral flow matrix which
defines a flow path and which comprises in series, a sample receiving zone,
a labeling zone, a barrier zone and one or more serially oriented capture
zones” (id. at col. 3, ll. 35-39).
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4. Boehringer also discloses that the “barrier zone, whether a
labelled analyte analog, or a labelled sbp member complementary to the
analyte, serves as a means of preventing a labelled species from migrating
further along the matrix unless the analyte concentration exceeds a certain
threshold level” (id. at col. 10, ll. 55-60).
5. In one embodiment, Boehringer discloses:
the labeling zone comprises a diffusively bound labeled first
sbp member that is complementary to the analyte, the barrier
zone comprises a second sbp member analogous to the analyte
immobilized in the barrier zone, and each of the one or more
capture zones comprises at least a third sbp member
immobilized in the one or more capture zones.
(Id. at col. 3, ll. 38-45.)
6. To use this embodiment, Boehringer discloses:
[A]nalyte in the sample is first allowed to bind to labelled sbp
member complementary to the analyte to form an analyte-
labelled sbp member complex. The amount of unbound
labelled sbp member remaining is inversely proportional to the
amount of analyte in the sample. . . . Analyte analog on the
barrier zone is able to bind free labelled sbp member.
Generally, there is sufficient analyte analog on the barrier zone
to bind all the labelled sbp member in the absence of analyte.
Bound labelled sbp member flows through the barrier zone in
the form of an analyte-labelled sbp member complex which is
unable to bind to the immobilized analyte analog. The
detection zone contains an immobilized sbp member that is
capable of binding the analyte-labelled sbp member complex.
(Id. at col. 11. l. 67, to col. 12, l. 61.)
7. In another embodiment, Boehringer discloses:
the labeling zone comprises a diffusively bound labeled first
specific binding pair member that is analogous to the analyte,
the barrier zone comprises a second specific binding pair
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member that is complementary to the analyte, and each of the
one or more capture zones comprises at least a third specific
binding pair member immobilized in the one or more capture
zones, the third specific binding pair member being
complementary to the analyte.
(Id. at col. 3, ll. 47-55.)
8. To use this embodiment, Boehringer discloses:
Sample mixes with labelled antigen and passes first through the
barrier zone. When no antigen is present in the sample, all the
labelled antigen will bind to the barrier zone. The amount of
antibody on the barrier zone must be sufficient to bind all the
labelled antigen when antigen is not present in the sample.
Usually, this zone will be masked off from view and will not be
visible in the test device. If antigen is present in the sample,
labelled antigen competes with sample antigen for the antibody
immobilized in the barrier zone. If the sample contains antigen
above a threshold level, the barrier zone antibody is unable to
capture all of the labelled antigen. This level is controlled by
the relative ratios of antigen and labelled antigen as well as the
concentration and affinity of the barrier zone antibody.
(Id. at col. 11, ll. 8-22.)
9. Behnke discloses an immunological process for determining an
analyte in a sample using a test strip “on which an antibody is immobilized
in at least one partial area” (Behnke, col. 5, ll. 19-23).
10. In particular, Behnke discloses:
The process includes bringing into contact a test solution
containing the sample with one end of the test strip. The test
solution is allowed to pass over at least one part of the test strip,
including the partial area containing the antibody, by capillary
migration. . . . The antibody is provided to be specific for the
analyte. An analyte analog (tracer) is bound to the antibody and
the affinity of the antibody for the analyte is higher than for the
tracer. A dye or dye generating or dye providing system that is
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able to bind to the tracer is present and the tracer is displaceable
by the analyte during the capillary migration of the test
solution.
(Id. at col. 5, l. 61, to col. 6, l. 6.)
11. Behnke also discloses that, if “the tracer is visualized directly
with an attached dye (molecule or particle), the area of the test strip
containing the antibody is visible as a dyed area even before the beginning
of the test” (id. at col. 7, ll. 15-18).
PRINCIPLES OF LAW
“In rejecting claims under 35 U.S.C. § 103, the examiner bears the
initial burden of presenting a prima facie case of obviousness. Only if that
burden is met, does the burden of coming forward with evidence or
argument shift to the applicant.” In re Rijckaert, 9 F.3d 1531, 1532 (Fed.
Cir. 1993) (citation omitted).
ANALYSIS
Boehringer discloses “a lateral flow matrix which defines a flow path
and which comprises in series, a sample receiving zone, a labeling zone, a
barrier zone and one or more serially oriented capture zones” (Finding of
Fact (FF) 3). The Examiner relies on Boehringer’s labeling zone, barrier
zone, and capture zone for suggesting, respectively, the first antibody, the
competitive zone, and the detection zone of claim 14 (Ans. 4).
In one embodiment, Boehringer discloses that “the labeling zone
comprises a diffusively bound labeled first sbp member that is
complementary to the analyte [and] the barrier zone comprises a second sbp
member analogous to the analyte” (FF 5 (emphasis added)). Boehringer
discloses that this device can be used in a process that we will refer to as the
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non-competitive process (FF 6). In another embodiment, Boehringer
discloses that “the labeling zone comprises a diffusively bound labeled first
specific binding pair member that is analogous to the analyte [and] the
barrier zone comprises a second specific binding pair member that is
complementary to the analyte” (FF 7 (emphasis added)). Boehringer
discloses that this device can be used in a competitive process (FF 8). The
Examiner does not point to a teaching or suggestion in Boehringer in which
both the labeling zone and the barrier zone comprise an sbp member that is
complementary to the analyte.
The Examiner argues, however, that it would have been obvious to
modify the device used in the non-competitive process, that is, the device
including a barrier zone comprising a second sbp member analogous to the
analyte, to use “an antibody to immobilize the analyte analog within the
barrier zone” and to include “a label or optically detectable substance to the
analyte analog within the barrier zone prior to the application of the test
sample” based on the teachings in Behnke (Ans. 14-15). We do not agree.
In the non-competitive process, the purpose of the analyte analog in
barrier zone is to bind free labelled sbp member from the labeling zone to
keep it from migrating further along the matrix (FF 6 & 4). Given its
purpose, we do not agree that it would have been obvious to immobilize the
analyte analog in the barrier zone by an antibody, as described in Behnke,
because Behnke teaches that the analyte analog would be displaced by the
analyte (FF 10) and therefore would no longer be present in the barrier zone
to keep the free labeled sbp from moving on to the capture zone.
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With regard to the device used in Boehringer’s competitive process,
Appellants argue that “the ‘probes’ are conjugated with an antigen. In this
manner, the antigen of the probes compete – but do not bind – with the
analyte for binding sites at the barrier zone” (App. Br. 9). We agree. Even
if we found that it would have been obvious, based on the disclosures in
Behnke, to attach Boehringer’s labeled first sbp member, which is analogous
to the analyte, to the second sbp member, which is complementary to the
analyte, in the barrier zone prior to application of the test sample, the
Examiner has not explained why it would have been obvious to additionally
include a labeled antibody that is specific for the analyte.
CONCLUSION
The Examiner has not set forth a prima facie case that Boehringer and
Behnke suggest an assay device for detecting an analyte comprising: (a) a
porous membrane in communication with optical detection probes
conjugated with a first antibody specific for the analyte and (b) a second
antibody immobilized on the porous membrane that is complexed to an
antigen containing an optically detectable substance prior to the application
of a test sample to the device. We are therefore compelled to reverse the
obviousness rejections.

REVERSED

cdc
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