Ex Parte Hung et al

Patent Trial and Appeal Board

Oct 9, 2014

09761893 (P.T.A.B. Oct. 9, 2014)

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.
09/761,893 01/17/2001 Shih-Chieh Hung 11709-003001 6011
7590 10/09/2014
Shih-Chieh Hung
Dept. of Orthop. and Traumetology, Vet. General
201, Sec. 2, Shih-pai Road
Hospital-Taipei
Taipei, 11217
TAIWAN
EXAMINER
DUNSTON, JENNIFER ANN
ART UNIT PAPER NUMBER
1636
MAIL DATE DELIVERY MODE
10/09/2014 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 SHIH-CHIEH HUNG and WAI-HEE LO
____________

Appeal 2014-006270
Application 09/761,893
Technology Center 2014-006270
____________

Before DONALD E. ADAMS, MELANIE L. McCOLLUM, and
JEFFREY N. FREDMAN, Administrative Patent Judges.

ADAMS, Administrative Patent Judge.

DECISION ON APPEAL1
This appeal under 35 U.S.C. § 134 involves claims 1, 4, 6, 9–11, 34,
35, and 38 (App. Br. 2).2 Examiner entered rejections under 35 U.S.C.
§ 103(a). We have jurisdiction under 35 U.S.C. § 6(b).
We affirm.

1 The Real Party in Interest is Shih-chieh Hung and Wai-hee Lo (App. Br.
2).
2 Pending claims 12–20, 43, and 45 stand withdrawn from consideration
(September 5, 2013 Advisory Action 1).
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Application 09/761,893

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STATEMENT OF THE CASE
The claims are directed to a method for isolating mesenchymal stem
cells from bone marrow aspirate. Claim 1 is representative and is
reproduced in the Claims Appendix of Appellants’ Brief.
Claims 1, 4, 6, 9, 11, 34, 35, and 38 stand rejected under 35 U.S.C.
§ 103(a) as unpatentable over the combination of Caplan,3 Reinart,4
Champion,5 and Prockop.6
Claim 10 stands rejected under 35 U.S.C. § 103(a) as unpatentable
over the combination of Caplan, Reinart, Champion, Prockop, and
Pittenger.7
ISSUE
Does the preponderance of evidence relied upon by Examiner support
a conclusion of obviousness?
FACTUAL FINDINGS (FF)
FF 1. Caplan suggests “a method for isolating, purifying, and culturally
expanding human mesenchymal stem cells (. . . or ‘MSCs’)” from bone
marrow aspirate (Caplan, col. 1, ll. 20–22; id. at col. 2, ll. 27–43; id. at col.
8, ll. 20–27; Ans. 3).
FF 2. Caplan’s method comprises: (a) obtaining a cell mixture comprising
mesenchymal stem cells and other cells from a bone marrow aspirate

3 Caplan et al., US 5,811,094, Sept. 22, 1998.
4 W.H. Reinhart et al., Roles of cell geometry and cellular viscosity in red
cell passage through narrow pores, 248 Am. J. Physiol. (Cell Physiol.)
C473-C479 (1985).
5 Champion et al., US 4,734,192, issuedMar. 29, 1988
6 Prockop et al., US 7,374,937 B1, issued May 20, 2008.
7 Mark F. Pittenger et al., Multilineage Potential of Adult Human
Mesenchymal Stem Cells, 284 Science 143-147 (1999).
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(Caplan, col. 2, ll. 27–43; id. at col. 8, ll. 20–27 and 33–44; Ans. 3), (b)
seeding the cell mixture onto a culture device and culturing the cell mixture
in a culture “medium containing factors that [(i)] stimulate mesenchymal
stem cell growth without differentiation” and (ii) allow “for the selective
adherence of only the mesenchymal stem cells to [the] substrate surface” of
the culture device (Caplan, col. 2, ll. 27–43; id. at col. 8, ll. 20–27 and 33–
44; id. at col. 9, ll. 48–54; Ans. 3), (c) “removing the non-adherent matter
from the substrate surface by replacing the medium with a fresh medium of
the same composition” and “allowing the isolated adherent mesenchymal
stem cells to culture expand” (Caplan, col. 2, ll. 27–43; id. at col. 8, ll. 20–
27; Ans. 3), and (d) recovering the mesenchymal stem cells from “culture
dishes utilizing a releasing agent such as trypsin with EDTA” (Caplan, col.
12, ll. 25–26; see also id. at col. 20, ll. 8–10 and col. 40, l. 67–col. 41, l. 2;
Ans. 3).
FF 3. Caplan suggests the use of a porous filter to remove, inter alia, red
blood cells from the bone marrow aspirate derived cell mixture comprising
mesenchymal stem cells (Caplan, col. 46, ll. 11–22; Ans. 4).
FF 4. Caplan fails to suggest (1) “a culture device comprising an upper
plate with pores and a lower plate base, where small cells pass through the
pores in the upper plate and adhere to the lower plate” or (2) “that the
isolated mesenchymal stem cells are able to proliferate without
differentiation and reach confluence after twelve passages” (Ans. 4 and 10).
FF 5. Examiner finds that Reinhart suggests that “red blood cells (RBCs)
pass through polycarbonate filters containing pores of 2.6 µm, 4.5 µm, and
6.9 µm)” whereas “larger white blood cells (WBCs) do not pass through the
pores” (Ans. 4).
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FF 6. Champion suggests
A filtration apparatus for the assay of microliter quantities of
biological and biochemical reactants . . . comprising a plate
having a plurality of apertures open at each end, filtration
means disposed across and sealed about one end of each
aperture thereby forming a well with a discrete filtering area
and a hydrophobic fabric disposed across and bonded adjacent
to the filtering area bounded by each well. The hydrophobic
fabric prevents a loss of fluid by capillary action and gravity
flow from within the well in the absence of an applied
differential pressure.
(Champion, col. 1, l. 62–col. 2, l. 4; see generally Ans. 4-5).
FF 7. Champion suggests that the “[p]revention of fluid loss by capillary
action and gravity flow becomes especially important when living cells or
tissues are being maintained or grown with the reaction wells” (Champion,
col. 1, ll. 39-42; see Ans. 4).
FF 8. Champion suggests that “[t]he porosity of the membrane will be
selected with a view to the chosen application. Although 0.025 to 10.0
micrometer porosity membranes of 150 micrometers thickness are favored”
(Champion, col. 3, ll. 14-17; Ans. 5).
FF 9. Champion suggests that microporous membranes selected from,
inter alia, polycarbonate have “proven characteristics in aqueous solutions
and tissue culture media” (Champion, col. 3, ll. 10-14; Ans. 5).
FF 10. Prockop suggests that “although MSCs obtained from bone marrow
aspirates from normal volunteers vary widely in their expandability in
culture, the expandability of those MSCs can be predicted by a simple assay
which detects colony-forming units (CFUs)” (Prockop, col. 21, ll. 34-38; id.
at col. 26, ll. 28-30 (“A CFU assay can . . . be used to select samples that
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have the greatest potential to expand in culture from among a number of
MSC samples”); Ans. 17).
FF 11. Prockop’s Fig. 3A is reproduced below:

“FIG. 3A is a bar graph depicting the decrease in CFUs of MSCs of passages
4 and 12” (Prockop, col. 7, ll. 18-19; see also id. at col. 24, ll. 16-19 (“The
number of CFUs declined as the MSC cell samples were expanded in
culture. The decline of CFUs with passage number was apparent from
assays of a single sample (i.e., as shown in FIG. 3A”)).
FF 12. Prockop’s FIG. 6G is reproduced below:

“FIG. 6G is an image depicting differentiation into osteoblasts of cells
obtained from passage 12 . . . after the cells were grown to confluence and
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incubated in osteogenic medium for 18 days” (Prockop, col. 7, ll. 54-57
(emphasis added)).
FF 13. Prockop exemplifies
[D]ifferentiation assays . . . carried out with late passage MSCs
(e.g., passage 12). Because the MSCs no longer generated
colonies following sparse plating, the assays were performed in
nearly confluent cultures after plating the cells at about a 1:3
dilution. MSCs of late passage cultures retained the ability to
differentiate into osteoblasts, as indicated in FIG. 6G.
(Prockop, col. 24, ll. 56-63; see Ans. 5 and 17.)
FF 14. Examiner finds that the combination of Caplan, Reinhart, Champion,
and Prockop fails to suggest “mesenchymal stem cells are CD34-” and relies
on Pittenger to make up for this deficiency in the combination of Caplan,
Reinhart, Champion, and Prockop.
ANALYSIS
The combination of Caplan, Reinart, Champion, and Prockop:
Based on the combination of Caplan, Reinart, Champion, and
Prockop, Examiner concludes that, at the time Appellants’ invention was
made, it would have been prima facie obvious to modify Caplan’s method of
isolating mesenchymal stem cells “to include the introduction of the mixed
composition of cells comprising mesenchymal stem cells in medium into the
device of Champion,” wherein the polycarbonate membrane has a pore size
suggested by Reinhart, “for the purpose of filtering out red blood cells”
(Ans. 6–7 and 11–12; FF 1–9). According to Examiner,
One would have been motivated to make such a
modification in order to provide an enriched population of
mesenchymal stem cells without the extra steps of using a
column containing a filter, or other separation method, as taught
by Caplan . . . since red blood cell removal and mesenchymal
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stem cell culture could be performed simultaneously using the
filtration apparatus of Champion.
(Ans. 7 and 12.) In addition, Examiner concludes that “it would have been
obvious to one of ordinary skill in the art that the isolated MSCs would be
capable of proliferating to confluence without differentiation for twelve
passages” as suggested by Prockop (Ans. 7; FF 10–13). We find no error in
Examiner’s rationale. Therefore, we are not persuaded by Appellants’
unsupported assertions that “a person of ordinary skill in the relevant field
would not have the motivation to combine the teachings of Caplan, Reinhart,
Champion and Prockop in the manner claimed” and “there was . . . no
reasonable expectation of success to combine the[] prior art elements” (App.
Br. 7). “Examiner has explained why a person of ordinary skill in the
relevant field would have combined the prior art elements in the manner
claimed, and Appellant[s] ha[ve] not provided any specific argument as to
why the rationale might be flawed” (Ans. 12).
Appellants contend that their device allows “smaller-sized cells and
the other small-sized non-adhering cells . . . [to] pass through the pores of
the upper plate due to . . . gravity,” while Champion’s device “prevent[s] the
fluid from passing through the pores” in the absence of a pressure
differential (App. Br. 6; see also Reply Br. 5–6; see FF 6). Therefore,
Appellants contend that “one of ordinary skill in the art could be taught
away . . . from combin[ing] the teaching of Champion . . . with those of
Caplan, Reinhart, and Prockop” to arrive at Appellants’ claimed method
(App. Br. 6; Reply Br. 6–8). We are not persuaded. As Examiner explains,
Appellants’ claim 1 does “not limit the flow of the cells through the pores to
gravity flow, and the claims do not exclude the use of an applied pressure
differential to promote the passage of small-sized cells through the pores”
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(Ans. 15). See In re Self, 671 F.2d 1344, 1348 (CCPA 1982) (“[A]ppellant's
arguments fail from the outset because . . . they are not based on limitations
appearing in the claims.”).
We recognize, but are not persuaded by, Appellants’ contention that
Prockop “clearly demonstrated an increasing loss of multipotentiality of
MSCs at high initial cell density” (App. Br. 7). Appellants’ claim 1 does not
require the maintenance of multipotentiality, but instead requires
proliferation of MSCs without differentiation and that the cultured MSCs
reach confluence after twelve passages (see Appellants’ claim 1). The
combination of prior art relied upon by Examiner suggests the foregoing
requirements of Appellants’ claim 1 (FF 1–4 and 10–13).
We recognize, but are not persuaded by, Appellants’ contentions
regarding expansion efficiency (App. Br. 8). Appellants’ claim 1 requires
that the MSCs reach confluence after twelve passages (see Appellants’ claim
1). Prockop suggests an assay to select MSCs for culture expansion and the
culture of MSCs to confluence after twelve passages (FF 10-13). Therefore,
we are not persuaded by, Appellants’ contention that the requirement of their
claim 1 that MSCs “proliferate without differentiation and reach confluence
even after 12 passages” represents an unexpected result, which is supported
by the “post-filing art (Kato et al US Patent Application 20050013804, filing
date: 09/12/2001), which mentioned that ‘. . . conventional culture methods
. . . cannot produce sufficient amounts of mesenchymal stem cells because
the proliferation of said stem cells stops or becomes extremely slow around
[the] 15th generation’” (App. Br. 8; Reply Br. 7; Cf. FF 11–13). See In re
Skoner, 517 F.2d 947, 950 (CCPA 1975) (“Expected beneficial results are
evidence of obviousness of a claimed invention. Just as unexpected
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beneficial results are evidence of unobviousness”). For the same reason, we
are not persuaded by Appellants’ contentions regarding particular cell
densities used to seed a culture device (Reply Br. 4 and 6–9).
We recognize, but are not persuaded by Appellants’ contention that
“[a]fter reading the Prockop et al’s teaching, a person[] skill[ed] in the art
would hardly . . . culture MSCs up to 12 passages” (Reply Br. 3 and 5).
Appellants’ claim 1 is drawn to a method of isolating mesenchymal stem
cells from bone marrow aspirate (see Appellants’ claim 1). There is no
requirement in Appellants’ claim 1 that any particular amount of cells be
obtained. For the same reason we are not persuaded by Appellants’ reliance
on “Lange et al (US Patent Application 20070160583, filing date:
08/6/2004);” “Lin et al (US Patent Application 20070128722, filing date:
12/5/205);” “Kato et al (US Patent Application 20050013804, filing date:
09/12/2001); or Prockop’s discussion of the prior art, to support Appellants’
additional contentions relating to an amount of MSCs (App. Br. 8–9; Reply
Br. 6–7). For the same reason, we are not persuaded by Appellants’
contention that Prockop suggests “not more than 10 cycles” or passages,
because Prockop discloses that “as few as 1, 2, 3, or 4 cycles will be
sufficient for many applications” (App. Br. 8).
Appellants fail to provide an evidentiary basis on this record to
support a conclusion that the pore size of the filter suggested by Reinhart
would be insufficient to remove “small adhering cells, such as hematopoietic
stem cells” from bone marrow aspirate (see Reply Br. 5; Cf. FF 5).
Accordingly, we are not persuaded by Appellants’ intimation to the contrary
(Reply Br. 5). See In re Pearson, 494 F.2d 1399, 1405 (CCPA 1974)
(“Attorney’s argument in a brief cannot take the place of evidence”).
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The combination of Caplan, Reinart, Champion, Prockop, and Pittenger:
Based on the combination of Caplan, Reinart, Champion, Prockop,
and Pittenger, Examiner concludes that, at the time Appellants’ invention
was made, it would have been prima facie obvious to recover CD34-
mesenchymal stem cells (Ans. 9). Appellants fail to address the rejection of
claim 10. Therefore, we are compelled to affirm the rejection for the reasons
set forth by Examiner (see Ans. 8-9; see also FF 14).
CONCLUSION OF LAW
The preponderance of evidence relied upon by Examiner supports a
conclusion of obviousness.
The rejection of claim 1 under 35 U.S.C. § 103(a) as unpatentable
over the combination of Caplan, Reinart, Champion, and Prockop is
affirmed. Claims 4, 6, 9, 11, 34, 35, and 38 are not separately argued and
fall with claim 1.
The rejection of claim 10 under 35 U.S.C. § 103(a) as unpatentable
over the combination of Caplan, Reinart, Champion, Prockop, and Pittenger
is affirmed.
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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