Ex Parte Liljedahl et al

Patent Trial and Appeal Board

Mar 2, 2016

10395816 (P.T.A.B. Mar. 2, 2016)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE
10/395,816 0312012003
20855 7590 03/02/2016
PASTERNAK PATENT LAW
1900 EMBARCADERO ROAD
SUITE 211
PALO ALTO, CA 94303
FIRST NAMED INVENTOR
Monika Liljedahl
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
ATTORNEY DOCKET NO. CONFIRMATION NO.
8325-3003 3642
EXAMINER
WILSON, MICHAEL C
ART UNIT PAPER NUMBER
1632
MAILDATE DELIVERY MODE
03/02/2016 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 MONIKA LILJEDAHL, SIMON ERIC ASPLAND, and
DAVID J. SEGAL 1
Appeal2013-005228
Application 10/395,816
Technology Center 1600
Before TONI R. SCHEINER, ERIC B. GRIMES, and LORA M. GREEN,
Administrative Patent Judges.
GRIMES, Administrative Patent Judge.
DECISION ON APPEAL
This is an appeal under 35 U.S.C. § 134 involving claims to a method
of generating a genetically modified cell. The Examiner has rejected the
claims for obviousness. We have jurisdiction under 35 U.S.C. § 6(b ).
We affirm.
STATEMENT OF THE CASE
This application was the subject of a previous appeal (2010-001206,
decided Sept. 21, 2010), in which the Examiner's rejection was affirmed.
1 Appellants identify the Real Party in Interest as Sangamo BioSciences, Inc.
(Appeal Br. 2.)
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Application 10/395,816
After prosecution was resumed, Appellants amended the claims and
introduced new evidence, the Examiner rejected the amended claims, and
this appeal followed. The opinion in Appeal 2010-001206 summarizes the
background of the invention.
Claims 1, 7-9, 11, 12, 15, 37, and 38 are on appeal. Claim 1 is
illustrative and reads as follows:
1. A method of generating an isolated genetically modified plant or
mammalian cell, comprising:
providing an isolated cell containing an endogenous chromosomal
target DNA sequence in which it is desired to have homologous
recombination occur;
providing at least one expression vector that expresses first and
second zinc finger endonucleases, each zinc finger endonuclease comprising
a Fok! cleavage domain that cuts DNA, and a non-naturally-occurring zinc
finger domain comprising a plurality of zinc fingers that bind to a specific
nucleotide sequence within said endogenous chromosomal target DNA in
said cell
wherein the first and second zinc finger endonuclease form a dimer
which cuts both strands of a nucleotide sequence within said endogenous
chromosomal target DNA sequence in said cell, thereby enhancing the
frequency of homologous recombination in said endogenous chromosomal
target DNA sequence; and
providing a nucleic acid comprising a sequence homologous to at least
a portion of said endogenous chromosomal target DNA such that
homologous recombination occurs between said endogenous chromosomal
target DNA sequence and said nucleic acid.
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DISCUSSION
Issue
The Examiner has rejected all of the claims on appeal under 35 U.S.C.
§ 103(a) as obvious based on Bibikova, 2 Pabo, 3 and Choulika. 4 (Ans. 2.)
The Examiner finds that Bibikova discloses a method of modifying a target
DNA sequence in a cell using a zinc finger endonuclease (ZFE) meeting the
limitations of claim 1, and discloses that two endonucleases must dimerize
to cut the target DNA. (Id.) The Examiner also finds that Bibikova's target
DNA is a model of an inactivated chromosomal target (id.) and that
Bibikova discloses how to target endogenous chromosomal DNA (id. at 3).
The Examiner finds that Pabo discloses zinc finger domains
comprising five or more zinc fingers and discloses that "'designer' zinc
finger domains had increased affinity and binding." (Id. at 4.) The
Examiner finds that Choulika discloses cleaving a chromosomal target DNA
using ZFEs in plant or mammalian cells. (Id. at 6.) The Examiner
concludes that
it would have been obvious to those of ordinary skill in the art to
use a ZFE with 5 zinc fingers to target endogenous chromosomal
DNA as described by the combined teachings of Bibikova and
Pabo wherein the ZFE is introduced into a plant or mammalian
cell using a vector encoding the ZFE as described by Choulika.
2 Bibikova et al., Stimulation of Homologous Recombination through
Targeted Cleavage by Chimeric Nucleases, 21 MOLECULAR AND CELLULAR
BIOLOGY 289--297 (2001 ).
3 Carl 0. Pabo et al., Design and Selection of Novel Cys2His2 Zinc Finger
Proteins, 70 ANNU. REV. BIOCHEM. 313-340 (2001).
4 Choulika et al., US 2002/0107214 Al, published Aug. 8, 2002.
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(Id.) The Examiner also concludes that it would have been obvious "to
replace the ZFE protein with a vector encoding the ZFE because Choulika
taught the two were interchangeable." (Id.)
Appellants contend that the references do not teach or suggest
targeting an endogenous gene in a plant or mammalian cell. (Appeal Br. 6-
15, 18-20.) Appellants also contend that the references do not teach or
suggest introducing dimerizing ZFEs in polynucleotide form. (Id. at 15-17.)
Finally, Appellants contend that the Examiner has improperly dismissed
their declaratory evidence. (Id. at 20-23.)
The issue presented is whether a preponderance of the evidence of
record supports the Examiner's conclusion that the method of claim 1 would
have been obvious to a person of ordinary skill in the art based on Bibikova,
Pabo, and Choulika.
Findings of Fact
1. Bibikova discloses "chimeric nucleases for DNA cleavage and
initiation of recombination in living cells. These enzymes are hybrids
between the nonspecific cleavage domain of the type IIs restriction
endonuclease Fokl and a DNA-binding domain made up of three Cys2His2
zinc fingers." (Bibikova 289, right col.)
2. Bibikova discloses that "DNA substrates and the nucleases were
injected into Xenopus laevis oocyte nuclei, in which DNA cleavage and
subsequent homologous recombination were observed." (Id. at 289,
abstract.)
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3. Bibikova states that "[ s ]pecific cleavage required two inverted
copies of the zinc finger recognition site in close proximity, reflecting the
need for dimerization of the cleavage domain." (Id.)
4. Bibikova discloses that the "[i]njected circular DNAs are
assembled into apparently normal chromatin and are inert for recombination,
but they can be induced to interact with a homologous partner, if they are
cleaved. A circular DNA thus serves as an effective model for an inactive
chromosomal target." (Id. at 290, right col.; reference citation omitted.)
5. Bibikova discloses that"[ c ]leaved DNA molecules were activated
for homologous recombination; in optimum conditions, essentially 100% of
the substrate recombined, even though the DNA was assembled into
chromatin." (Id. at 289, abstract.)
6. Bibikova states that its results
show[] that these chimeras are capable of locating their target
sequences in chromatin, cleaving \~1ith good efficiency, and
thereby stimulating homologous recombination. Although the
substrates we used were engineered plasmid DNAs and the
cellular milieu was that of the Xenopus oocyte, our findings
should be applicable to mammalian somatic cells and to many
other cells and organisms.
(Id. at 295, left col.)
7. Bibikova states that "[ t ]he method of delivery [of the chimeric
nucleases and DNA] would depend on the organism, cell type, and other
experimental conditions." (Id. at 296, left col.)
8. Bibikova states that "[ s ]ince each set of three fingers binds nine
consecutive base pairs, two chimeric nucleases effectively demand an 18-bp
target if each zinc finger domain has perfect specificity. Any given sequence
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of this length is predicted to be unique in a DNA as complex as the human
genome." (Id.)
9. Bibikova states that
[ s ]everal additional issues remain to be addressed to confirm the
utility of chimeric nucleases as tools for gene targeting. Among
these are demonstrating discrimination against related
sequences; proving the efficacy of zinc fingers designed to bind
arbitrarily chosen sequences; and testing the cleavage of genuine
chromosomal targets. The question of discrimination among
potential binding sites is a particularly critical one.
(Id. at 296, right col.)
10. Bibikova states that its results "show[] that two chimeric enzymes
with different binding specificities could collaborate to stimulate
recombination when their individual sites were appropriately placed.
Because the recognition specificity of zinc fingers can be altered
experimentally, this approach holds great promise for inducing targeted
recombination in a variety of organisms.'' (Id. at 289, abstract.)
11. Pabo discloses that "Cys2His2 zinc finger proteins offer a stable
and versatile framework for the design of proteins that recognize desired
target sites on double-stranded DNA." (Pabo 313, abstract.)
12. Pabo discloses that "selection strategies have been developed that
allow these proteins to be targeted to almost any desired site on double-
stranded DNA." (Id.)
13. Pabo discloses that "[t]hese new proteins can then be modified by
adding other domains-for activation or repression of transcription, for
DNA cleavage, or for other activities." (Id.)
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14. Choulika discloses
a method of repairing a specific sequence of interest in
chromosomal DNA of a cell comprising (a) inducing in the cell
a double stranded break at a site of interest, and (b) introducing
into the cell targeting DNA, wherein the targeting DNA
comprises (1) DNA homologous to the region surrounding the
site of interest and (2) DNA which repairs the specific sequence
of interest upon recombination between the targeting DNA and
the chromosomal DNA.
(Choulika 3 ii 26.)
15. Choulika states that "[ d]ouble stranded breaks at a site of interest
can also be achieved by the chimeric restriction endonucleases ... described
herein." (Id. at 2 ii 21.)
16. Choulika states that "[ fJor application of the method to the
manipulation of any chromosomal DNA locus, chimeric restriction
endonucleases generated by the juxtaposition of specific DNA binding
sequences (in some cases generated by the linking of specific zinc finger
binding domains) and DNA cleavage domains can be used to elicit
cleavage." (Id. at 3 ii 25.)
17. Choulika states that a "model chromosomal loc[ us] was generated
in which a site for the meganuclease I-Seel was introduced within the target
region for recombination, and double stranded DNA cleavage via
introduction of a vector encoding the restriction endonuclease was induced."
(Id.)
18. Choulika states that "DNA binding sequences include zinc finger
binding domains and meganuclease recognition sites. . . . In [one]
embodiment, the chimeric restriction endonuclease is produced by joining a
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I-Seel meganuclease recognition site and the FokI cleavage domain." (Id. at
5 ii 42.)
19. Choulika states that "[t]argeting DNA and/or restriction
endonucleases introduced into a cell or individual as described above can be
inserted in a vector." (Id. at 5 if 44.) "A vector comprising targeting DNA
and/or nucleic acid encoding a restriction endonuclease can also be
introduced into a cell." (Id. at 6 if 49.)
20. Choulika provides a working example that describes
cotransfecting NIH 3 T3 Gap 1 and NIH 3 T3 Gap2 cell lines with two vectors
("Expression Plasmid" and "Repair Matrix"). (Id. at 8 iii! 75, 76; Table 1.)
21. The NIH 3 T3 Gap 1 and NIH 3 T3 Gap2 cells had been modified
to include a plasmid (pPytknBWSacZ) integrated into their genomic DNA.
(Id. at 8, if 74: "[A]nalysis of the mRNA expressed by the integrated
pPytknBWSacZ construct showed no expression for one of the clones and
signals for the other two clones. These two cell lines, NIH 3T3 Gap 1 and
NIH 3T3 Gap2, were selected to be the targets to the gap repair.")
22. Choulika states that "[t]ransfection ofNIH 3T3 Gapl cells with
the mix number 1 (pCMV I-Seel(+), 9 µg; pSlacB, 1 µg) gave a 12 to 28%
of B-galactosidase positive clones (out of the three experiments) as the
higher rate of gap repair recombination of the pPytknBWSacZ deleted
plasmid." (Id. at 8 if 79.)
Analysis
We agree with the Examiner that the cited references would have
made obvious a method meeting the limitations of claim 1. Bibikova
discloses "chimeric nucleases for DNA cleavage and initiation of
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recombination in living cells" (FF 1 ). Bibikova states that its chimeric
nucleases are made up of a Fokl cleavage domain and a zinc finger DNA-
binding domain (FF 1 ). Bibikova discloses that specific cleavage required
dimerization of the cleavage domain (FF3). Bibikova states that "these
chimeras are capable of locating their target sequences in chromatin,
cleaving with good efficiency, and thereby stimulating homologous
recombination" (FF6).
Bibikova states that "[a ]lthough the substrates we used were
engineered plasmid DNAs and the cellular milieu was that of the Xenopus
oocyte, our findings should be applicable to mammalian somatic cells and to
many other cells and organisms" (FF6). Bibikova also states that its results
"show[] that two chimeric enzymes with different binding specificities could
collaborate to stimulate recombination when their individual sites were
appropriately placed. . . . [T]his approach holds great promise for inducing
targeted recombination in a variety of organisms" (FF 10).
Bibikova states that zinc finger domains like the one it used bind to 9-
bp recognition sites, so two such DNA-binding domains require an 18-bp
target, which is expected to be unique in the human genome (FF8).
Similarly, Pabo states that zinc finger proteins can be designed to target a
desired site in double-stranded DNA (FFl 1) and that they can be modified
by adding a DNA cleavage domain (FF13).
Choulika discloses a vector (FF 17) comprising a chimeric restriction
endonuclease comprising the DNA-binding domain of a I-Seel mega-
nuclease and the Fokl cleavage domain (FF18). Choulika suggests that the
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DNA-binding domain of its chimeric nuclease can be a zinc finger DNA-
binding domain (FF 18).
Choulika discloses inducing a double-strand break in the
chromosomal DNA of a cell (FF14) using its chimeric nuclease to cleave the
DNA at the nuclease's recognition site (FF15), and repairing a specific
sequence of interest via recombination of the chromosomal DNA with a
targeting DNA that "comprises (1) DNA homologous to the region
surrounding the site of interest and (2) DNA which repairs the specific
sequence of interest upon recombination between the targeting DNA and the
chromosomal DNA" (FF14). Choulika provides a working example of gap
repair recombination of a target site on a chromosomally integrated plasmid
by cotransfection of NIH 3T3 cells with an expression plasmid and a repair
matrix (FF20-FF22).
These teachings would have made obvious the method of claim 1.
Specifically, it would have been obvious to modify Choulika's vector to
include a chimeric nuclease with a zinc finger DNA-binding domain because
Choulika expressly suggests doing so. It would have been obvious to
include DNA encoding two of the resulting nucleases on Choulika's vector
because Bibikova teaches that chimeric nucleases require dimerization in
order to produce specific cleavage, and teaches that combining two chimeric
nucleases with different binding specificities will produce a dimer having a
target site that is expected to be unique in the human genome.
Choulika provides a working example of gap repair using its vectors in
NIH 3T3 cells, and states that it provides "a method of repairing a specific
sequence of interest in chromosomal DNA of a cell" (FF 14). Bibikova states
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that its results in Xenopus oocytes "should be applicable to mammalian
somatic cells and to many other cells and organisms" (FF6). These
disclosures would have provided a person of ordinary skill in the art with a
reasonable expectation of successfully using the vector made obvious by the
cited references to target a site in an endogenous mammalian gene, and
therefore would have provided a reason to introduce a targeting DNA into a
mammalian cell having the sequence to be repaired.
Appellants argue that "the combination of references fails to teach or
suggest cleavage of an endogenous mammalian or plant gene." (Appeal Br.
6.) Appellants argue that "Bibikova's teachings relate solely to extra-
chromosomal targets in frog (Xenopus) oocytes" and Bibikova "states that
homologous recombination in Xenopus oocytes occurs via single-stranded
annealing of exogenous DNA targets." (Id. at 7 .) Similarly, Appellants
argue that Bibikova "teaches that the cleaved (nonendogenous) substrate also
acts as the exogenous sequence for recombination with itself." (Id. at 18.)
Appellants also argue that the other references do not make up for Bibikova's
deficiency, because "Pabo includes only one sentence relating to ZFEs" (id.
at 10) and "Choulika uses the homing endonuclease Seel to cleave a single
Seel target site that is either episomal or artificially integrated into the
genome" (id. at 12).
These arguments are unpersuasive. Bibikova states that its injected
circular DNAs are assembled into apparently normal chromatin, in which
form they are inert to recombination but can be induced to recombine if
cleaved (FF4). Bibikova states that, therefore, its circular DNAs serve as
effective models for inactive chromosomal targets (FF4). Bibikova also
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states that its chimeric nucleases "are capable of locating their target
sequences in chromatin, cleaving with good efficiency, and thereby
stimulating homologous recombination" (FF6), and that its findings "should
be applicable to mammalian somatic cells and to many other cells and
organisms" (FF6).
Choulika states that a "model chromosomal loc[us] was generated in
which a site for the meganuclease I-Seel was introduced within the target
region for recombination" (FF 17, emphasis added). Choulika thus
characterizes its own work as modelling recombination with a chromosomal
target. In addition, Choulika repeatedly characterizes its disclosure as
allowing targeted recombination with "chromosomal DNA" (FF 14, FF 16),
and its Example 3 is carried out in mouse (NIH 3T3) cells (FF20).
Appellants' argument that the cited references would not have suggested
targeting an endogenous mammalian gene is therefore not persuasive.
Appellants cite the 2nd Umov Declaration5 (Appeal Br. 8-9) as
evidence that "Xenopus oocytes containing extrachromosomal, injected
substrates are not models for endogenous mammalian or plant genomes" (id.
at 9). Appellants also cite the 2nd Umov Declaration as evidence that
"Bibikova does not in any teach or suggest ZFE cleavage of endogenous
mammalian or plant genes." (Id. at 10.)
We have considered the cited declaratory evidence but are not
persuaded that it supports Appellants' position. Appellants cite i-fi-1 5-7 of
the declaration as showing that Bibikova's Xenopus system is not a model
5 Declaration under 37 C.F.R. § 1.132 of Fyodor Umov, dated Dec. 7, 2011.
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for mammalian or plant genomes. (Appeal Br. 8-9.) Dr. Umov states that
Xenopus oocytes differ from mammalian or plant cells in various ways and
that they have "completely different nucleoplasm dynamics." (2nd Umov
Deel. i-f 5.) Dr. Umov states that "Bibikova's 'chromatinized' substrates are
not normal, endogenous chromatin." (Id.)
Dr. Umov does not, however, explain what characteristics are implied
by the term "nucleoplasm dynamic," nor does Dr. Umov explain why the
cited differences between Xenopus oocytes and mammalian cells support his
conclusion that Xenopus oocytes are inadequate models for the interaction of
DNA binding proteins and their templates. Bibikova acknowledges that its
injected DNA is not endogenous chromatin, but concludes that it "serves as
an effective model for an inactive chromosomal target" that undergoes
homologous recombination if cleaved (FF4). Bibikova also states that,
contrary to Dr. Umov's opinion, its findings inXenopus oocyte experiments
"should be applicable to mammalian somatic cells and to many other cells
and organisms" (FF6). Choulika supports this conclusion because it teaches
that causing a double-stranded break in the chromosomal DNA, of a
mammalian cell, with a chimeric nuclease allows homologous recombination
of the cleaved site with a repair DNA introduced into the cell (FF14, FF15,
FF20-FF22).
Bibikova also states that homologous recombination "in Xenopus
laevis oocytes ... proceeds by the same single-strand annealing mechanism
that is the principal pathway available to exogenous DNAs in cultured
mammalian cells." (Bibikova 290, bridging para.) Dr. Umov questions the
applicability of this mechanism to the claimed method, stating that "this
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pathway is irrelevant to the homologous recombination process involving
endogenous genes that is claimed." (2nd Umov Deel. i-f 5.) Dr. Umov also
states that "every scientist working in this field knew (and knows) that extra
chromosomal substrates injected into Xenopus oocytes do not undergo
homologous recombination in the same way as endogenous targets in
mammalian and plant cells." (Id. at i-f 6.) Similarly, Dr. Umov states that
Bibikova's statement that "[s]everal additional issues remain to be
addressed" (see FF9) "clearly indicates that Bibikova' s Xenopus system is
not relevant to endogenous mammalian or plant genes." (2nd Umov Deel.
,-r 8.)
We are not persuaded that the cited evidence demonstrates lack of a
reasonable expectation of success based on the prior art. The claimed
method involves recombination between a nucleic acid provided to the cell of
interest and an endogenous chromosomal target. Dr. Umov does not provide
any technical explanation of why the pathway described by Bibikova would
be irrelevant to the recombination contemplated in the claimed method.
In addition, Choulika demonstrates that a method similar to that of
Bibikova, in which a chimeric nuclease cleaves a chromosomally integrated
target site and induces homologous recombination with an exogenously
introduced DNA, can be carried out in mammalian cells (FF20-FF22). The
evidence of record therefore does not support Dr. Umov's conclusion that
those skilled in the art would have considered Bibikova's experiments to be
irrelevant to recombination in mammalian cells.
We are also not persuaded that Bibikova's reference to "issues [that]
remain to be addressed" shows the irrelevance of its results to mammalian
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cells. Bibikova states that "[ s ]everal additional issues remain to be
addressed to confirm the utility of chimeric nucleases as tools for gene
targeting" (FF9, emphasis added). The acknowledgement that additional
work remains to be done to confirm a technique's utility does not mean that
previous work is irrelevant to that utility. In addition, the quoted statement
must be considered in combination with Bibikova's statement that its
"findings should be applicable to mammalian somatic cells and to many
other cells and organisms" (FF6) and Choulika's disclosure that its similar
method is applicable to chromosomal targets in mammalian cells, among
others. A preponderance of the evidence therefore supports a conclusion
that those skilled in the art would have considered Bibikova to be relevant to
the claimed method.
Dr. Umov also states that "Bibikova teaches explicitly that the ZFEs
must be delivered in protein form via microinjection" rather than via a
nucleic acid encoding the ZFE, as claimed. (2nct Umov Deel. i-f 7 .)
Appellants argue that the declaration shows that Bibikova does not suggest
an expression vector encoding a ZFE. (Appeal Br. 17 .)
This argument is also unsupported by the evidence, because Bibikova
expressly states that "[t ]he method of delivery [of the chimeric nucleases and
DNA] would depend on the organism, cell type, and other experimental
conditions" (FF7). Bibikova therefore does not limit the delivery of its
chimeric nuclease to microinjection of the nuclease itself. In addition,
Choulika expressly suggests delivering a chimeric nuclease to a cell via a
vector encoding the nuclease (FF 1 7, FF 19). Thus, the cited references
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would have made obvious a vector encoding a chimeric nuclease, as recited
in claim 1 .
Appellants argue that "Choulika clearly teaches away from cleaving
an endogenous mammalian or plant gene, as claimed, in that it clearly states
that cleavage of an endogenous gene may lead to death of the cells."
(Appeal Br. 13.) Appellants cite Dr. Umov's statement that "[t]he entire
purpose of Choulika is to insert a single restriction endonuclease target site
that is non-endogenous so the resulting cleavage by the single restriction
endonuclease is not toxic to the cell." (2nd Umov Deel. i-f 12.)
This argument is also unpersuasive. In support of their position,
Appellants cite the following statement in Choulika:
A restriction endonuclease used in the present invention
recognizes a target DNA sequence (e.g., a restriction
endonuclease site) which would not lead to death of the cells
upon cleavage of the DNA sequence by the restriction
endonuclease. i~\~ meganuclease enzyme, \~1hich recognizes a
very large DNA sequence, is an example of a restriction
endonuclease which can be used in the present invention. An
example of a meganuclease enzyme is I-Seel, which recognizes
an 18-bp site (DNA sequence) that does not appear to be
represented in murine or human DNA.
( Choulika 3 i-f 24.)
This statement does not support Appellants' position that "cleavage of
an endogenous gene may lead to death of the cells." (Appeal Br. 13.)
Rather, the above statement means that the restriction endonuclease target
site used in Choulika's method must be one that is unique in the target
genome (as the I-Seel site would be in the human or murine genome, after it
is introduced), because cleavage of the genome at additional sites could lead
to cell death. This reading of the above statement is consistent with
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Choulika's description of the inserted I-Seel recognition site as a "model
chromosomal loc[ us]" (FF 17) and its references to repairing a specific
sequence in chromosomal DNA (FF14) or manipulating a chromosomal
DNA locus (FF16).
Choulika also makes clear that an inserted meganuclease site is not the
only way to target a unique site in a genome. "[C]himeric restriction
endonucleases capable of recognizing specific DNA sequences unique to a
disease allele can be generated through juxtaposition of zinc finger DNA
binding domains and restriction endonuclease cleavage domains." (Choulika
5 i-f 41.) Similarly, Bibikova states that two chimeric enzymes, each with
three zinc fingers, demand an 18-bp target sequence that should be unique in
the human genome (FF8). Thus, whether Choulika is considered by itself or
together with the other cited references, it does not teach away from cleaving
an endogenous mammalian gene, as Appellants argue.
Appellants also argue that "the claims clearly require cleavage of an
endogenous mammalian or plant gene by dimerizing ZFEs expressed within
the cells from at least one expression vector. There is no combination of the
references that teaches such methods." (Appeal Br. 15.)
This argument is unpersuasive. For the reasons previously discussed,
the cited references would have made obvious the claimed method, even
though none of them identically disclose it. See In re Young, 927 F.2d 588,
591 (Fed. Cir. 1991) ("The test for obviousness is what the combined
teachings of the references would have suggested to one of ordinary skill in
the art.").
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Appellants argue that the Examiner improperly dismissed the
declaratory evidence submitted to show lack of predictability. (Appeal Br.
20-23.)
Appellants' arguments, however, focus on the Examiner's recitation of
fact-finding from the previous Board decision in this application. Appellants
do not address the Examiner's response to the declaratory evidence set out on
pages 12-18 of the Office Action mailed Feb. 21, 2012, or on pages 11-17 of
the Answer. Because the Examiner directly addressed Appellants'
declaratory evidence, we do not find Appellants' argument persuasive.
Finally, Appellants present additional arguments regarding the
dependent claims (Appeal Br. 23-24). In each case, however, Appellants
argue only that Bibikova does not teach cleaving an endogenous plant or
mammalian gene using a ZFE expressed from a polynucleotide, and also
does not teach the limitations of the dependent claims. (See id.) Appellants,
however, provide no reasoned basis for concluding that the limitations of the
dependent claims would not have been obvious based on the combined
teachings of the references. See Young, 927 F.2d at 591 ("The test for
obviousness is what the combined teachings of the references would have
suggested to one of ordinary skill in the art.") The arguments regarding the
dependent claims are therefore unpersuasive.
Conclusion of Law
A preponderance of the evidence of record supports the Examiner's
conclusion that the method of claim 1 would have been obvious to a person
of ordinary skill in the art based on Bibikova, Pabo, and Choulika.
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SUMMARY
We affinn the rejection of claims 1, 7-9, 11, 12, 15, 37, and 38 under
35 U.S.C. § 103(a) based on Bibikova, Pabo, and Choulika.
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).
AFFIRMED
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