Ex Parte Pain et al

Patent Trial and Appeal Board

Nov 29, 2018

13206056 (P.T.A.B. Nov. 29, 2018)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE
13/206,056 08/09/2011
23628 7590 12/03/2018
WOLF GREENFIELD & SACKS, P.C.
600 ATLANTIC A VENUE
BOSTON, MA 02210-2206
FIRST NAMED INVENTOR
Bertrand Pain
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.
I0422.70112US01 3072
EXAMINER
WILSON, MICHAEL C
ART UNIT PAPER NUMBER
1632
NOTIFICATION DATE DELIVERY MODE
12/03/2018 ELECTRONIC
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.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address(es):
Patents_eOfficeAction@WolfGreenfield.com
WGS_eOfficeAction@WolfGreenfield.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte BERTRAND PAIN and F ABIENNE GUEHENNEUX 1
Appeal2017-002728
Application 13/206,056
Technology Center 1600
Before FRANCISCO C. PRATS, ULRIKE W. JENKS, and JOHN G. NEW,
Administrative Patent Judges.
Opinion for the Board filed by Administrative Patent Judge NEW.
Opinion Dissenting-in-Part filed by Administrative Patent Judge PRATS.
NEW, Administrative Patent Judge.
DECISION ON APPEAL
1 Appellants identify Valneva, a French corporation, as the real party-in-interest.
App. Br. 3.
Appeal2017-002728
Application 13/206,056
SUMMARY
Appellants file this appeal under 35 U.S.C. § 134(a) from the Examiner's
Final Rejection of claims 13-19 and 28-34 as unpatentable under 35 U.S.C.
§ 101 as being directed to nonstatutory subject matter,
Claims 28 and 32-34 also stand rejected under 35 U.S.C. § 112, first
paragraph, as failing to provide written descriptive support. 2
Claims 13-19 and 28-34 also stand rejected under 35 U.S.C. § 112, first
paragraph, for lack of enablement.
Claims 13-19 and 28-34 also stand rejected under 35 U.S.C. § 102(b) as
being anticipated by B. Pain et al., Long-term In Vitro Culture and
Characterisation of Avian Embryonic Stem Cells with Multiple Morphogenetic
Potentialities, 122 DEVELOPMENT 2339--48 (1996).
We have jurisdiction under 35 U.S.C. § 6(b).
We AFFIRM.
NATURE OF THE CLAIMED INVENTION
Appellants' invention is directed to a method for producing avian cell lines,
comprising gradual or complete withdrawal of growth factors, serum, and/or feeder
layer so that the established lines are adherent or non-adherent cells capable of
proliferating indefinitely in a basic culture medium. Abstract.
REPRESENTATIVE CLAIM
Claim 13 is representative of the claims on appeal and recites:
2 The Examiner also rejected claim 14 (based upon another limitation) and claims
15-18 as failing to meet the written description requirement. Final Act. 10-11.
The Examiner has withdrawn these rejections. Ans. 28.
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13. An avian cell line obtained by a process comprising the steps:
(1) isolating cells from a blastodermal disk of a fertilized
avian egg;
(2) culturing said isolated cells in a basal culture medium
supplemented with:
(i) trophic factors and cytokines, wherein said trophic
factors are at least one of stem cell factor (SCP), basic
fibroblast growth factor (bPGP), and insulin-like
growth factor 1 (IGP-1 ); and wherein said cytokines
are at least one of ciliary neurotrophic factor (CNTP),
leukemia inhibitory factor (LIP), interleukin 6 (IL-6),
soluble IL-6 receptor (sIL-6r) interleukin 11 (IL-11)
and oncostatin;
(ii) an inactivated feeder layer compnsmg mouse
fibroblast STO cells3; and
(iii) fetal calf serum at a concentration of 8 to 12 %;
(3) after at least 20 passages modifying the culture
medium by progressive withdrawal of said trophic factors and
cytokines;
( 4) further culturing cells of step (3) in basal medium in
the absence of said trophic factors and cytokines;
wherein cells of said cell line are capable of proliferating in a
basal culture medium in the absence of trophic factors and cytokines
for at least 50 days.
App. Br. 29.
3 STO cells are mouse embryo-derived fibroblast cells (ATCC CRL-1503).
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ISSUES AND ANALYSES
We agree with, or adopt, the Examiner's findings, reasoning, and conclusion
that the cells are directed to nonstatutory subject matter. We decline to adopt the
Examiner's conclusion that the claims: (1) lack written descriptive support; and (2)
lack enablement; and (3) are anticipated by Pain. We address Appellants'
arguments below.
A. Rejection of claims 13-19 and 28-34 under 35 U.S.C. § 101
Issue
Appellants argue that the Examiner erred in concluding that the claims are
impermissibly drawn to a product of nature. App. Br. 6.
Analysis
Appellants argue that the cells obtained by their claimed process exhibit
biological properties that are distinguishable from natural cells by their exhibition
of a different phenotype. App. Br. 6. Appellants assert that the claimed cells are
capable of proliferating as undifferentiated stem cells indefinitely (i.e., more than
600 days) in culture without trophic factors and cytokines, whereas cells isolated
from embryos and not subjected to the claimed steps (i.e., "primary cells")
differentiate into specialized tissue cells after a limited number of divisions. Id. at
6-7 ( citing Spec. Table 1 ). Appellants note that primary cells can proliferate only
for a certain number of passages, a property known as replicative senescence,
which is connected to the length of telomerase expression. Id. According to
Appellants, high telomerase activity is associated with rapid proliferation and the
capacity of cells to be immortal. App. Br. 7. Appellants argue that the cells of the
claimed invention have high telomerase activity. Id. ( citing Spec. Table 6).
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Appellants also contend that the cells of the claimed invention express
epitopes typical for non-differentiated embryonic stem cells ("ES cells"), which
react with specific monoclonal antibodies for SSEA-1 and EMA-I. App. Br. 7.
According to Appellants, strong alkaline phosphatase activity is a marker of non-
differentiated cells, which is also exhibited by their claimed avian stem cell line.
Id. ( citing Spec. Fig. 5).
Appellants point to the USPTO's Nature-Based Products, December 16,
2014, available at: https://www.uspto.gov/sites/default/files/documents
/mdc_examples_nature-based_products.pdf (last visited October 31, 2018). App.
Br. 7. Appellants specifically cite Example 9 ("Cells"), which, Appellants argue,
stands for the proposition that when there is a difference in biological properties
between a claimed cell population and naturally-occurring cells that rises to the
level of a marked difference, the claimed cell population is not a "product of
nature" exception to Section 101. Id.
The Examiner responds that Claim 13 is a product-by-process claim and is
directed to an avian cell line capable of proliferating without trophic factors and/or
cytokines for at least 50 days. Ans. 28. The Examiner notes that claim 13 does not
require the cells have any structural features, that the cells be "undifferentiated," or
that the cells have any functional feature other than being capable of proliferating
without trophic factors/cytokines for 50 days. Id. The Examiner finds the
functional limitation reciting "capable of proliferating in a basal culture medium in
the absence of trophic factors and cytokines for at least 50 days" in claim 13 does
not distinguish the cells from a natural product, because the structure and essential
functions of the [non-specific] cell type are the same. Id. Moreover, the method
steps do not alter the structure or function of the cells obtained in any way that
distinguishes them from natural products. Id. at 28-29. Rather, the Examiner
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finds, avian stem cells capable of proliferating without trophic factors/cytokines for
50 days have the same essential structures and functions as naturally occurring
stem cells. Id. at 29. By way of example, the Examiner finds that pluripotent
avian cells capable of proliferating without trophic factors/cytokines for 50 days
have the same essential structures and functions of pluripotent avian cells that
occur in nature. Id. The Examiner therefore concludes that the avian stem cells
obtained in the product-by-process of claim 13 do not constitute "significantly
more" than naturally occurring avian cells. Id.
The Examiner acknowledges Appellants' assertion that Table 6 and Figure 5
of Appellants' Specification discloses different telomerase levels, SSEA-1 and
EMA- I levels, and AP activity. Ans. 29. However, the Examiner finds that claim
13 does not require the avian cells have any specific structure associated with any
specific level of pluripotency. Id. The Examiner finds that claim 14 requires the
avian stem cells capable of proliferating without trophic factors/cytokines for 50
days have AP activity, telomerase activity, and/or reactivity with specific
antibodies that bind to SSEA-1, SSEA-3, or EMA-I. Id. However, the Examiner
finds, these structural limitations are associated with pluripotent cells that occur in
nature, and the combination with the functional limitation in claim 13 ( cap ab le of
proliferating without trophic factors/cytokines for 50 days) does not distinguish the
cell line from those in nature. Id.
We are not persuaded by Appellants' arguments. As an initial matter, we
note that Appellants' claims are directed to a composition of matter, i.e., avian
stem cells, and not to the method of preparing cells that are capable of proliferating
in a basal culture medium in the absence of trophic factors and cytokines for at
least 50 days. We further observe that Appellants' claims are "product-by-
process" claims. As such, the method of treating the stem cells so that they retain
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their proliferative capacity in the absence of trophic factors and cytokines for at
least 50 days are not limiting upon the claim, insofar as they do not impart a
different structural dimension on the composition. See In re Thorpe, 777 F.2d 695,
697 (Fed. Cir. 1985). Consequently, we find that claim 13 is structurally limited
to: "An avian cell line ... wherein cells of said cell line are capable of proliferating
in a basal culture medium in the absence of trophic factors and cytokines for at
least 50 days." We consequently tum to the issue of whether such an avian cell
line, so defined, is a product of nature and, therefore, a judicially created exception
to Section 101.
In performing such a patentability analysis under 35 U.S.C. § 101, we follow
the framework set forth by the Supreme Court in Mayo Collaborative Serves. v.
Prometheus Labs., Inc., 566 U.S. 66 (2012). As a first step, we determine whether
the claims at issue are directed to a patent-ineligible concept, i.e., a law of nature, a
phenomenon of nature, or an abstract idea. Mayo, 566 U.S. at 70-71. If the claims
are so directed, we next consider the elements of each claim both individually and
"as an ordered combination" to determine whether additional elements "transform
the nature of the claim" into a patent-eligible application. Id. at 78-79; see also
Ariosa Diagnostics, Inc. v. Sequenom, Inc., 788 F.3d 1371, 1375 (Fed. Cir. 2015).
Specifically, the Supreme Court considered this second step as determining
whether the claims recite an element or combination of elements that is "sufficient
to ensure that the patent in practice amounts to significantly more than a patent
upon the [ineligible concept] itself." Mayo, 566 U.S. at 72-73.
Appellants' claims are directed to avian stem cells, which as Appellants'
claims and the Specification recite: are "isolate[ ed] cells from a blastodermal disk
of a fertilized avian egg." Claim 13; see also Spec. 1 ("Stem cells are cells
identified by their culture in vitro from an embryo, from part of an embryo or even
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from an adult tissue"). It is therefore undisputed that the avian stem cells, as
initially isolated from the blastodermal disk and recited in the claims, are products
of nature, i.e., the undifferentiated blastodermal cells are present, in situ, in
embryonic birds. We therefore advance to the second step of the Mayo analysis,
and inquire as to whether the claims add "significantly more" than the claimed
natural product itself.
The Supreme Court has described this second step of the analysis as a search
for an "inventive concept"-i.e., an element or combination of elements that is
"sufficient to ensure that the patent in practice amounts to significantly more than a
patent upon the [ineligible concept] itself." Ariosa, 788 F.3d at 1375 (quoting
Mayo, 566 U.S. at 72-73). In the claims before us, the only limitation on the
claimed avian stem cells is that they are "capable of proliferating in a basal culture
medium in the absence of trophic factors and cytokines for at least 50 days."
The Examiner finds, and Appellants do not dispute, that the claimed cultured
cells possess the same properties, i.e., epitope expression, telomerase activity, etc.,
as the embryonic cells in situ. Ans. 29; App. Br. 6-7. Appellants argue in
response that the stem cells are "significantly more" than the product of nature
exception to Section 101, because stem cells normally cultivated in a basal culture
medium in the absence of trophic factors and cytokines quickly lose their
proliferative capacity and differentiate into specialized tissue cells after a limited
number of divisions. See App. Br. 6-7; see also Spec. 2 ("The in vitro culture of a
primary cell under satisfactory medium and growth factor conditions allows it to
proliferate only for a certain number of passages").
We are not persuaded. Appellants' claims merely provide a regime by
which the avian embryonic cells may be maintained in an undifferentiated state in
vitro for a period of at least 50 days in the absence of growth factors and cytokines.
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Appellants argue that the use of their culture technique provides cells that do not
differentiate and which retain their proliferative capacity compared to blastodermal
cells which, when cultured by alternative methods, and in the absence of cytokines
and growth factors, differentiate. We see this argument as largely irrelevant: the
question at hand is whether the cells cultured by Appellants' technique are
patentably distinct from the cells as they exist, in situ, in the embryo. In other
words, Appellants are contrasting the developmental trajectory of stem cells in one
artificial environment, with the behavior of those same cells in another artificial
environment. Appellants provide no argument, or adduce any evidence, to
demonstrate that their cultured cells are structurally or genomically distinct from
the embryonic blastodermal cells as they exist in the embryo. Indeed, Appellants
acknowledge that the cells subjected to their claimed steps exhibit properties
exhibited by undifferentiated stem cells in situ. Therefore, because Appellants do
not provide evidence rebutting the Examiner's prima facie findings, they cannot
prevail.
We can distinguish these claims from those in Diamond v. Chakrabarty, 447
U.S. 303 (1980). In Chakrabarty, the Supreme Court held that claims directed to a
genetically altered Pseudomonas bacterium, which was thereby rendered capable
of digesting crude oil, were directed to patentable subject matter. 447 U.S. at 305.
The Court held that genetically modifying the bacterium rendered it: "a non-
naturally occurring manufacture or composition of matter-a product of human
ingenuity 'having a distinctive name, character [and] use."' Id. at 310 ( quoting
Hartranftv. Wiegmann, 121 U.S. 609,615 (1887).
In this instance, the cells are not genetically altered, but merely subjected to
a regime that causes them to respond in a manner that is consonant with no more
than their natural capabilities, i.e., maintaining a proliferative capacity beyond 50
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days in the absence of cytokines and/or growth factors. In other words, the cells
are doing what they would do under the circumstances to which they are subjected
to by Appellants. We do not see in Appellants' claims, any significant addition or
alteration to the cells qua cells as they exist in situ, particularly since the
methodological steps in the claims are, as we have explained, are not themselves
limiting upon the claims. We consequently conclude that the limiting portions of
Appellants' claims add nothing significantly more to the claims than the
phenomenon of nature itself. We consequently affirm the Examiner's rejection on
this ground.
B. Rejection of claims 28 and 32-34 under 35 U.S.C. § 112, first paragraph, for
lack of written description
Issue
Appellants argue that the Examiner erred in concluding that the limitation of
claim 28 reciting: "wherein said cell line is capable of proliferating ... with serum
at low concentration" constitutes new matter not supported by Appellants'
Specification. App. Br. 30.
Analysis
The Examiner finds that claim 28 recites new matter because the boundary
of "low concentration" of serum cannot be found in Appellants' Specification.
Final Act. 11. The Examiner acknowledges that Appellants' Specification
discloses serum levels passing from 10% to 7.5%, and then 3.75% and 2%, and
then tending toward 0%. Id. ( citing Spec. 15). However, the Examiner concludes,
the genus of serum being "low" being defined as 2% is not readily apparent and
cannot be inferred from the original disclosures of the Specification. Id.
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Appellants point to Example 5 of the Specification, which provides a
process of establishing avian cell lines involving decreasing the concentration of
fetal calf serum, and refers to 2% fetal calf serum as an example of a low
percentage of serum. App. Br. 10-11 (citing Spec. 27). According to Appellants,
person of ordinary skill in the art, upon understanding the disclosures of
Appellants' Specification, would understand that the inventor had possession of the
claimed invention. Id. at 11.
We are not persuaded by the Examiner's reasoning. Example 5 of
Appellants' Specification discloses that:
The curves presented relative reduction of in figure 2 illustrates the
relative reduction of serum for a given cell type: S86N16 cells[.] The
doubling time and the mean division times were also calculated and
presented in table 3. It will be noted that the mean division time
increases as a function of the relative reduction in serum. A recovery
phase is nevertheless observed after some time in culture under the
conditions mentioned. This time remains nevertheless less than 24 h
( d> 1) which already represents a very advantageous proliferation in
industrial terms even at serum concentrations of 2%, which is already
relatively low.
Spec. 27 ( emphasis added). Figure 2 of the Specification plots the cumulative
coefficient of cell division against time for serum concentrations of 10%, 7%,
3.75%, and 2%. The Specification thus discloses that it is recognized in the art that
a concentration of 2% serum is "relatively low." Appellants' Specification further
discloses that: "In this regard, the withdrawal [ of serum] may be progressive, by
reducing the serum concentration during each passage, for example on passing
from 10% to 7.5% and then 3.75% and 2%, tending toward 0% (serum-free
medium). Alternatively, a drastic withdrawal may be carried out." Spec. 15.
We agree with Appellants that a person of ordinary skill in the art of cell
culture would understand from these disclosures of Appellants' Specification that
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serum concentrations of 2% or less (tending towards 0%) would represent a "low
concentration" of serum. We therefore reverse the Examiner's rejection upon this
ground.
C.
Issue
Rejection of claims 13-19 and 28-34 under 35 U.S.C. § 112, first paragraph,
for lack of enablement
Appellants argue that the Examiner erred in finding that the claims are not
enabled by the disclosures of Appellants' Specification. App. Br. 11.
Analysis
In the Final Office Action, the Examiner makes findings of fact relating to
some of the factors set forth by or reviewing court in In re Wands, 858 F.2d 731,
737 (Fed. Cir. 1988).
With respect to the breadth of the claims, the Examiner finds that
independent claim 13 encompasses any avian cell line having any structure or
function including ES cells or ES-like cells. Final Act. 13. The Examiner finds
dependent claim 14 encompasses making avian ES or non-ES cells that are: 1)
capable of proliferating basal medium in the absence of trophic factors and
cytokines for 50 days in culture; and 2) exhibit alkaline phosphatase activity,
telomerase activity, and/or reactivity with specific antibodies that bind to SSEA-1,
SSEA-3, or EMA-I. Id. The Examiner finds Appellants' Specification defines
embryonic stem cells ("ES cells") as cells that exhibit all the characteristics of a
stem cell in-vitro and, in-vivo, the unique capacity of contributing to the
morphogenesis of an embryo and of participating in germline colonization when
they are re-implanted in a recipient embryo. Id. (citing Spec. 1).
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With respect to the predictability of the state of the art, the Examiner finds
that conditions were known in the art that allowed for the long-term culture of
pluripotent embryonic stem cells. Final Act. 14 ( citing Pain 2339-48; JN Petitte et
al., Avian Pluripotent Stem Cells, 121(9) MECH. DEV. 1159, 1161---62 (2004)
("Petitte"); Samarut et al. (US 6,998,266 B2, February 14, 2006) ("Samarut")).
The Examiner finds that it was also known in the art that, using alkaline
phosphatase as a marker of pluripotency, cultured blastodermal cells from stage
IX-XI chick and stage X-XI quail embryos showed best results when cultured with
a combination of human leukemia inhibitory factor ("LIP"), FGF-2, avian or
murine SCP, and IL-11 on a feeder layer of inactivated STO fibroblasts. Id.
The Examiner further finds that it was known in the art that LIP appears to
be critical to the long-term proliferation and survival of the cultures and is required
to maintain the expression of several markers associated with an embryonic stem
cell phenotype, viz., SSEA-1, EMA-I, and EMA-7. Final Act. 14 (citing Pain,
Petitte, Samarut, id.). The Examiner finds that the prior art also teaches that
telomerase activity was maintained in the avian ES cell cultures after multiple
passages, but was down-regulated after a pulse of retinoic acid. Id. The Examiner
also finds that it was known that using heterologous and homologous feeder layers
and conditioned media containing variety of factors often produce variable results
affecting the long term survival of avian embryonic stem cells. Id. The Examiner
finds that the prior art thus teaches that the presence of LIP and retinoic acid were
known to critically affect the outcome of any culture conditions in order to produce
the chicken embryonic stem cells. Id.
The Examiner next finds that it was suspected that that mammalian
cytokines are not fully effective on chicken ES cells given the low identity between
chicken and mammalian cytokines. Final Act. 14 ( citing H. Horiuchi et al.,
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Chicken Leukemia Inhibitory Factor Maintains Chicken Embryonic Stem Cells in
the Undifferentiated State, 279(23) J. BIOL. CHEM. 24514--20, (2004)
("Horiuchi")). The Examiner finds that it was therefore considered probable that
chicken LIP ("chLIF") would be more effective in maintaining chicken ES cells in
the undifferentiated state than its mammalian homologue. Id. The Examiner finds
that it was known in the art that chLIF is "indispensable" for maintaining the
undifferentiated state of chicken blastodermal cells in culture. Id. Thus, the
Examiner finds that the use of a particular set of growth factors and cytokines in
the presence of an STO feeder layer, especially in context of the claimed invention,
would have been considered germane to maintain the viable chicken embryonic
stem cells. Id.
The Examiner therefore concludes that, considering that the state of the art is
highly unpredictable, and the limited amount of guidance provided in Appellants'
Specification, a person of ordinary skill in the art would not have been able to
practice Appellants' claimed invention without undue experimentation. Final Act.
15.
With respect to the disclosures of Appellants' Specification, the Examiner
finds that the Specification discloses isolating cells from blastodermal disks of
fertilized avian eggs. Final Act. 16 ( citing Spec. 21 ). The Examiner also finds that
Example 2 of the Specification discloses:
The growth factors and the cytokines added to the culture
medium are preferably factors and cytokines which are recombinant,
including mouse SCP at a final concentration of 1 ng/ml, IGF-1 at a
final concentration of 1 to 5 ng/ml, CNTF at a final concentration of 1
ng/ml, IL-6 at a final concentration of 1 ng/ml, and the soluble IL-6
receptor at a final concentration of 0.5 ng/ml to 1 ng/ml. In some
experiments, some other factors may be added during the first passages.
For example up to passage 3 or 10, it is possible to add bFGF to the
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medium at a final concentration of 1 ng/ml and IL-11 at a final
concentration of 1 ng/ml.
Id. (quoting Spec. 22). However, the Examiner finds, neither this passage, nor the
rest of the Specification, discloses the specific combination of growth factors and
cytokines used to obtain any specific adherent cell. Id.
Furthermore, the Examiner finds, Example 2 of Appellants' Specification
discloses culturing the cells with inactivated feeder STO cells, and removing
growth factors from the culture a variety of ways, including gradual or drastic or
one factor at a time. Final Act. 16-17 (citing Spec. 23). The Examiner finds that
the Specification further discloses that cell lines may be cultured for at least 50
days, and that the cell lines may exhibit characteristics of ES cells. Id. at 17 ( citing
Spec. 23-24 ). However, the Examiner finds that Example 2 does not disclose the
specific combination of growth factors used in the initial phase of culture, or the
specific factors withdrawn. Id. Moreover, the Examiner finds that the
Specification also fails to disclose the means required to obtain an adherent avian
non-ES cell line exhibiting telomerase activity, or that the adherent cells have any
of the ES cell characteristics described on page 24. Id.
The Examiner finds Example 3 of Appellants' Specification generally states
that stem cells proliferate in vitro by changing and replacing culture medium.
Final Act. 17 ( citing Spec. 25). Example 5, the Examiner finds, describes
gradually removing serum from cells, but fails to teach the cells have any of the
claimed features, that the cells are true ES cells, or that the medium is "free" of
serum ( or growth factors, cytokines, feeder layer), as recited in the claims. Id.
( citing Spec. 25-26).
The Examiner finds that the Specification's Example 6 describes gradually
removing the feeder cells from the culture, but fails to disclose that the S86N16
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cells are free of feeder cells, have any of the features claimed, that the cells are true
ES cells, or that the medium is free of serum, growth factors or cytokines as
claimed. Final Act. 17 ( citing Spec, 27-28).
The Examiner finds that Example 7 of the Specification discloses culturing
the cells in the initial phase using growth factors and cytokines, i.e. LIP, IL-11, IL-
6, CNTF, oncostatin and cardiotrophin. Final Act. 17 (citing Spec. 29). The
Examiner finds that the Specification discloses that the combination of IL-6 and
CNTF makes it possible to increase the proliferative effect observed, and that that
the trophic factors are SCP, IGF-1 and bFGF are also used at the start of the
culture. Id. The Examiner finds Example 7 also discloses removing growth
factors and/or cytokines; however, the Example fails to describe the specific
combination of growth factors and cytokines used in the initial phase of culture or
whether the growth factors and cytokines were removed one by one or all at once.
Id. ( citing Spec. 30).
With respect to Example 9, the Examiner finds that although Table 5
discloses various cell lines, and how many passages and generations the cell lines
had gone through, Example 9 does not teach the specific combination of growth
factors used in the initial phase of culture or the specific factors withdrawn or the
means required to obtain an avian non-ES cell line exhibiting telomerase activity.
Final Act. 18 (citing Spec. 30).
The Examiner finds that Example 13 teaches infecting nonadherent EB 1
and EB 14 cell lines with virus. Final Act. 19 (citing 34--36).
In concluding, the Examiner finds that, whereas claim 13 does not require
that the claimed cell line has any particular structure, function or potency or that it
is an avian ES cell or ES cell-like cell line, the claim still encompasses making an
avian ES cell line. Final Act. 19. The Examiner concludes that claim 13 is not
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enabled for making a true avian embryonic stem (ES) cell line that is pluripotent
because the specification fails to teach those of skill the specific combination of
trophic factors and cytokines required in the first culture phase or the trophic
factors and cytokines withdrawn, or the method by which this might be performed.
Id. ( citing Spec. 19-20, 25). The Examiner further concludes that, given
unpredictability of obtaining the desired cells from avian embryonic cells, as
established by Petitte, Pain, and Horiuchi, a person of ordinary skill in the art could
not reasonably determine how to make an avian non-ES cell line, exhibiting
telomerase activity, that can be cultured for at least 50 days in the absence of
trophic factors and cytokines, without losing its proliferative capabilities, as
required by claim 13. Id. (citing Spec. 25).
Appellants respond that a detailed description of the process by which the
claimed avian cell lines are established is provided in Example 2. App. Br. 13
(citing Spec. 21-24). According to Appellants, Example 9 of the Specification
further discloses a method for establishing a cell line which has the ability to
proliferate in the absence of trophic factors and cytokines and in the absence of a
layer of STO cells. Id. ( citing Spec. 30).
Appellants also contend that the Specification provides guidance on how to
determine the properties of the obtained cell line. App. Br. 13. By way of
example, Appellants point to Example 10 of the Specification, which discloses that
the telomerase activity can be determined by a PCR-ELISA assay, and that the
established cell lines, both adherent and non-adherent, presented telomerase
activity. Id. ( citing Spec. 32, Table 6).
Furthermore, Appellants argue, in addition, the non-adherent cell line EB 1
and the adherent cell line S86N45 in Examples 13 and 14 are shown to proliferate
in a culture medium in the absence of added exogenous growth factors and a layer
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of feeder cells, and that the cells of these cell lines can be infected by, and
replicate, a virus. App. Br. 13.
Appellants next point to the Declaration of Dr. James N. Petitte, filed July
25, 2014 (the "Petitte Declaration). App. Br. 14. Appellants point out that Dr.
Petitte contradicts the Examiner's findings regarding Petitte; specifically, that
Petitte teaches that that LIP is "critical to the long-term proliferation and survival"
of cultures ofblastodermal cells and required for maintenance of expression of the
several markers recited in the claims (i.e., telomerase activity, alkaline
phosphatase, SSEA-1, SSEA-3, or EMA-I expression). Id. Appellants note that
Dr. Petitte opines that that LIP is not required for long-term proliferation and
culture of the cells created using the claimed methods, or for maintenance of
expression of the markers recited in the claims. Id. (citing Petitte Deel. ,r 10a).
Appellants also assert that Dr. Petitte states that whether retinoic acid down
regulates telomerase activity is irrelevant, because the claims do not mention the
use of retinoic acid and telomerase activity is a required feature of the cells
produced by the claimed method. Id. ( citing Petitte Deel. ,r 1 Ob).
Next, Appellants point out that Dr. Petitte also avers that the inactivated
feeder layer of mouse fibroblast STO cells that is recited in the claims was
demonstrated in the application, e.g., in Example 6. App. Br. 15 ( citing Petitte
Deel. ,r 1 Oc ). Therefore, Appellants assert, Dr. Petitte testifies that he did not
consider use of the recited feeder layer of mouse fibroblast STO cells to be
unpredictable. Id. Appellants argue that Dr. Petitte further testifies that the use of
conditioned media from LMH cells referred to by the Examiner is not recited in the
claims, and is therefore is irrelevant. Id. Appellants further note that Dr. Petitte
observes that the Petitte reference is not relevant to the claimed methods of
establishing an avian cell line because the article describes the state of the art of
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making pluripotent stem cell lines and efforts to culture avian embryonic stem
cells, but does not describe a general method of creating an avian cell line. Id.
( citing Petitte Deel. ,r 1 Od). Appellants also argue that Dr. Petitte testifies that the
use of mammalian cytokines in the establishment and culture of avian cells was
well-known in the art at the time of filing. Id. (citing Petitte Deel. ,r lOe).
Appellants next note that Prof. Petitte states that the Examiner's finding that
mammalian cytokines are not fully effective on chicken embryonic cells is not
correct, as is demonstrated by the use of such cytokines in the Examples of the
Specification and as testified to in the Declarations of Dr. Majid Mehtali, filed June
20, 2016 (the "Mehtali Declaration") and Dr. Fabienne Guehenneux, filed June 20,
2016 (the "Guehenneux Declaration"). App. Br. 15 (citing Petitte Deel. lOe).
Appellants also assert that Dr. Petitte testifies that there are many examples of
mammalian cytokines being used for culturing avian cells, including chicken
embryonic cells, as mammalian cytokines are much more readily available; Dr.
Petitte further states that scientists in his own laboratory routinely use mammalian
cytokines in the establishment and culture of avian cells. Id.
Appellants next dispute the Examiner's finding that "the specification fails
to teach the specific combination of growth factors and cytokines used to obtain
any specific adherent cell." App. Br. 16 (citing Spec. 18-21). Appellants contend
that the Examiner failed to take into consideration the testimony of declarants
regarding the guidance provided in Appellants' Specification. Id. Furthermore,
Appellants argue, a person of ordinary skill in the art could readily have
reproduced the invention using the guidance provided in Example 2 by culturing
cells in the trophic factors and cytokines recited in claim 13 to supplement the
culture medium. Id. at 17. Appellants assert that there is a limited number of
combinations of the trophic factors and cytokines recited in the claims for the
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skilled person to try, and this would require only routine experimentation to
perform. Id.
Appellants note that Dr. Petitte testifies that Examples 2, 7, and 9 of
Appellants' Specification provide guidance that would have been amply sufficient
for a person of ordinary skill in the art to practice the claimed invention. App. Br.
17 ( citing Petitte Deel. ,r 12a). Appellants state that Prof. Petitte testifies that the
Specification does not need to teach a specific combination of growth factors used
in the initial phase of the cell culture, but that the teaching is more than sufficient
guidance for a person of ordinary skill in the art. Id. Appellants further point out
that Dr. Petitte states that, whereas the trophic factors and cytokines required to
make chicken EBx cells may be different than those required to make duck EBx
cell lines, the guidance in the application would be considered sufficient for a
person of ordinary skill in the art. Id. ( citing Petitte Deel. ,r 12b ).
Appellants summarize Dr. Petitte' testimony that the claims are enabled as
follows:
1. Isolating cells from a blastodermal disk of a fertilized avian egg was well
known in the art. (Petitte Deel. ,r 15).
2. Culturing the isolated cells in a basal culture medium supplemented with
trophic factors and cytokines was well known in the. (Id. at ,r 16).
3. The set of trophic factors and cytokines was well-described in the
specification and these trophic factors and cytokines were known to the
skilled person. (Id.).
4. A skilled person would have been familiar with supplementing culture
medium with trophic factors and cytokines, and as such the guidance
provided by the application is more than sufficient for such a skilled
person to carry out this step of the claimed method. (Id.).
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5. Culturing the cells in basal medium with reduced amounts of the trophic
factors and cytokines, or free of the trophic factors and cytokines, was
well-described in the application. (Id. at ,r 17).
6. In the art of cell culture it was routine experimentation to culture cells in
parallel cultures in which different combinations of trophic factors and
cytokines were added to the culture medium. (Id.).
7. A skilled artisan would know, based on the guidance in the Specification,
that factors could be withdrawn gradually (i.e., progressive reduction in
number and/or concentration), or all at once. (Id.).
8. A skilled person would make such changes and observe the cultures in
order to select the cultures surviving the withdrawal of one or more
factors. (Id.).
9. Telomerase activity is found in about 90% of all established cell lines.
(Id. at ,I 18).
10. Testing avian cell lines for telomerase activity, and for infection by and
replication of viruses was well-described in the Specification; for
example, Example 10 describes testing of cells for telomerase activity,
with Table 6 showing the results. (Id.).
11. Examples 13 and 14 of the Specification describe protocols for infecting
nonadherent and adherent avian cell lines with a virus. (Id.).
12. Examples 15 and 16 of the Specification describe infection of
nonadherent and adherent avian cell lines with avipox and modified
vaccinia virus Ankara, and that such testing also was routinely done by
those of ordinary skill in the art. (Id.).
App. Br. 18-19. Appellants emphasize that Dr. Petitte disagrees with the
Examiner's conclusion that it would have required undue experimentation to
practice Appellants' claimed invention. Id. at 19 (citing Petitte Deel. ,r 21).
Appellants argue further that the routine nature of the experimentation was
also shown in the previously-filed declarations of Dr. Mehtali and Dr.
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Guehenneux, as testified to by Dr. Petitte. App. Br. 21 ( citing Petitte Deel. ,r,r 24--
29). According to Appellants, the Mehtali and Guehenneux Declarations provide
evidence that different combinations of those trophic factors and cytokines enable
a skilled person to obtain avian cell lines that exhibit telomerase activity and have
the ability of being cultured in the absence of said trophic factors and cytokines,
and which are capable of being infected by and replicating viruses. Id. Appellants
contest the Examiner's finding that Declarations of Dr. Mehtali and Dr.
Guehenneux are not persuasive, because it is not clear from the Declarations that
the cell lines described therein were obtained using only the methods described in
Appellants' Specification. Id. at 22. Appellants point to Dr. Petitte's testimony to
the contrary that the Declarations of Dr. Mehtali and Dr. Guehenneux obtain the
described cell lines using the claimed methods, as described in Appellants'
Specification. Id. ( citing Petitte Deel. ,r 24).
The Examiner responds that the cells of the claimed invention, and in the
teachings of Petitte are derived from avian embryonic cells ( citing claim 13), that
they exhibit AP and telomerase activity, and react with antibodies that bind SSEA
1, SSEA3, or EMA 1 (citing claim 14). Ans. 30. The Examiner finds that Petitte
establishes the unpredictability of the specific combination of growth
factors/cytokines required to obtain the desired cells from embryonic avian cells
used with feeder cells, specifically, STO cells. Therefore, the Examiner finds, the
teachings of Petitte are relevant to the cells claimed by Appellants.
The Examiner finds that Petitte establishes the unpredictability of the
specific combination of growth factors/cytokines required to obtain the desired
cells from embryonic avian cells used with feeder, specifically STO, cells. Ans.
31. The Examiner finds that Appellants have not provided any evidence that
Petitte' s teachings are incorrect, or that use of mammalian cytokines in making a
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desired cell line from embryonic avian cells was predictable at the time of filing.
Id. The Examiner notes that the use of mammalian cytokines disclosed by the
Declarations by Mehtali and Guehenneux Declarations do not pertain to the art as
it was "at the time of filing," and that the protocols, reagents, and combination of
growth factors and/ or cytokines described in the Declarations are not disclosed in
Appellants' Specification and cannot, therefore, be used to determine what was
known in the art at the time of filing. Id.
The Examiner also finds, more importantly, that Appellants' Specification
fails to adequately provide the specific combination of trophic factors and
cytokines used in the initial culture phase (with inactivated STO cells and 8-12%
PCS), or the specific trophic factors and cytokines that are withdrawn, and by what
means they are withdrawn, in the second culture phase, such that an avian cell line,
specifically one having AP or telomerase activity ,or expressing SSEA-1, SSEA-3,
or EMA- I as in claim 14, is obtained. Ans. 31.
The Examiner finds that Example 2 of the Specification discloses that
preferred growth factors include mouse SCP, IGF-1, CNTF, and soluble IL-6.
Ans. 31 ( citing Spec. 22). The Examiner finds that Example 2 of the Specification
further discloses that: "In some experiments, some other factors may be added
during the first passages. For example up to passage 3 or 10, it is possible to add
bFGF to the medium at a final concentration of 1 ng/ml and IL-11 at a final
concentration of 1 ng/ml." Id. at 31-32. However, the Examiner finds, this
Example fails to teach the specific combination of growth factors and cytokines
used to obtain the pluripotent, ES-like, differentiated or multipotent cells
encompassed by claim 13, or cells that have AP activity, telomerase activity,
and/or reactivity with specific antibodies that bind to SSEA-1, SSEA-3, or EMA-I
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as required in claim 14, or the adherent or non-adherent cells recited in claims 30,
33 and 31, 34. Id. at 32.
Similarly, the Examiner finds that the Specification discloses culturing the
cells with inactivated feeder STO cells, and removing growth factors from the
culture in any of a number of ways including gradual or drastic or one factor at a
time. Ans. 32 ( citing Spec. 22, 23). The Examiner finds that the Specification
further discloses that cell lines may be cultured for at least 50 days, and that the
cell lines may exhibit characteristics of ES cells. Id. ( citing Spec. 23, 24 ). The
Examiner finds, however, that Example 2 fails to teach the specific combination of
growth factors and/or cytokines used to obtain a specific type of cells recited in
claims 13, 14, 30, 33, and 31, 34. Id.
The Examiner finds that paragraphs 6, 7, and 12-30 of the Petitte
Declaration, relied upon by Appellants, are not persuasive because they do not
negate the unpredictability established by Petitte, Pain, and Horiuchi by providing
protocols and combinations of growth factors/cytokines/feeder cells and the
specific processes of their withdrawal that were known in the contemporary art and
that would have allowed a person of ordinary skill in the art to obtain the desired
cells from embryonic avian cells. Ans. 33. The Examiner notes that the
Declaration merely declares that each step was well-known in the art; however, the
Examiner points out that the rejections are based on the method as a whole and the
ability to obtain ES or ES-like cell lines exhibiting telomerase or AP activity, or
expressing SSEA-1, SSEA-3, or EMA-I. Id.
The Examiner also finds that the specific combination of method steps,
growth factors, cytokines, withdrawal procedures used in combination with STO
feeder cells to obtain, either a cell line as recited in claim 13, or specifically one
exhibiting AP or telomerase activity and expressing SSEA-1, SSEA-3, or EMA-I
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as in recited claim 14, was unpredictable and the number of possible of the various
combinations of procedures and factors is so great that it would require undue
experimentation by a person of ordinary skill in the art to determine which provide
the cells recited in the claims. Ans. 33. The Examiner concludes that, for this
reason, the Specification does not enable the claims. Id.
With respect to Examples 6, 7, 9, 10, and 13-16, the Examiner finds that
none of the Examples teaches a protocol to obtain any specific cell as broadly
required by claim 13, such as pluripotent, differentiated, or multipotent cells. Id.
Nor, the Examiner finds, do they teach a protocol required to obtain a cell having
the properties recited in claim 14, or that are adherent or non-adherent as required
in claim 30, 31, 33, and 34. Ans. at 33-34.
With respect to the Declarations, the Examiner finds that none expressly
discloses the specific combination of growth factors in the initial phase recited in
the claims, or any specific protocol for withdrawal, as required in the second phase
of the claims. Id.
We are not persuaded by the Examiner's reasoning. Claim 13 recites the
following procedural limitations:
( 1) isolating cells from a blastodermal disk of a fertilized avian egg;
(2) culturing said isolated cells in a basal culture medium supplemented
with:
(i) trophic factors and cytokines, wherein said trophic factors are
at least one of stem cell factor (SCP), basic fibroblast growth
factor (bPGP), and insulin-like growth factor 1 (IGP-1); and
wherein said cytokines are at least one of ciliary neurotrophic
factor (CNTP), leukemia inhibitory factor (LIP), interleukin 6
(IL-6), soluble IL-6 receptor ( sIL-6r ), interleukin 11 (IL-11)
and oncostatin;
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(ii) an inactivated feeder layer comprising mouse fibroblast STO
cells; and
(iii) fetal calf serum at a concentration of 8 to 12 %;
(3) after at least 20 passages modifying the culture medium by
progressive withdrawal of said trophic factors and cytokines;
(4) further culturing cells of step (3) in basal medium in the absence of
said trophic factors and cytokines.
Example 2 of Appellants' Specification teaches isolating cells from the
blastodermal disk of an embryo (Spec. 21 ), and these cells are then:
[I]noculated on a "feeder" into defined culture medium. Among the
preferred conditions used for the culturing, preference is given to the
culture medium composed of MacCoy medium as basal medium
supplemented with fetal calf serum at an initial concentration of 12 to
8%, with nonessential amino acids at 1 %, with a mixture of vitamins of
commercial origin at 1 %, with sodium pyruvate at a final concentration
of 1 mM, with beta-mercaptoethanol at a final concentration of 0.2 mM,
glutamine at a final concentration of 2.9 mM, with an initial mixture of
antibiotics concentration containing gentamycin at a final concentration
of 10 ng/ml, penicillin at a final concentration of 100 U/ml and
streptomycin at a final concentration of 100 µg/ml. Rapidly after the
first passages of the cells, the mixture of antibiotics is no longer added
to the medium. The expression rapidly is understood to mean after the
first 3 to 5 passages in general. A mixture of nucleosides may also be
added, this mixture being prepared as described above (Pain et al.,
1996). Among the basal media tested under these same conditions and
which give similar results are the HamF12, Glasgow MEM and DMEM
media, the latter supplemented with biotin at a final concentration of 8
mg/1. By way of comparison, the biotin concentration is 0. 2 mg/1 in the
MacCoy medium, 0.0073 mg/1 in the HaniF12 and O in the commercial.
DMEM and GMEM media.
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The growth factors and the cytokines added to the culture
medium are preferably factors and cytokines which are recombinant,
including mouse SCP at a final concentration of 1 ng/ml, IGF-1 at a
final concentration of 1 to 5 ng/ml, CNTF at a final concentration of 1
ng/ml, IL-6 at a final concentration of 1 ng /ml, and the soluble IL-6
receptor at a final concentration of 0. 5 ng/ml to 1 ng/ml. In some
experiments, some other factors may be added during the first passages.
For example up to passage 3 or 10, it is possible to add bFGF to the
medium at a final concentration of 1 ng/ml and IL-11 at a final
concentration of 1 ng/ml.
The inoculation is carried out into this medium on the inactivated
"feeder" composed of mouse fibroblasts established as lines, the STO
cells. In some cases,
Spec. 21-22 ( emphasis added). We quote this section at length because it
expressly teaches not only the steps recited in the claim, but also explicitly
provides concentrations for the recited growth factors and cytokines recited in the
claim. The cytokine LIP (leukemia inhibitory factor), recited in claim 13 is not
mentioned in this passage, but it is disclosed elsewhere in the Specification, e.g.:
"The medium used in step a) may comprise at least one factor selected from
cytokines, in particular LIP, IL-11, IL-6, IL-6R, CNTF, Oncostatin and other
factors such as SCP, IGF-1 and bFGF." Spec. 14; see also 29:
The cytokines are mainly cytokines whose action is through a
receptor which is associated with the gp130 protein. Thus, LIP,
interleukin 11, interleukin 6, CNTF, oncostatin and cardiotrophin have
a similar mode of action with the recruitment at the level of the receptor
of a specific chain and the combination of the latter with the gp130
protein in monomeric or sometimes heterodimeric form.
We further note that, although specific concentrations of LIP are not
disclosed by Appellant's Specification, the use of LIP as a cytokine in avian
embryonic stem cell culture was well known in the art. Pain, for example, teaches:
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"long-term LIP-dependent growth of [embryonic stem cells derived from culture of
chicken and quail embryos] with histochemical and antigenic markers and
morphogenetic potentialities similar to those described for murine ES cells." Pain
2339. 4 We conclude that a person of ordinary skill would thus understand, from
the disclosures of Appellants' Specification and the teachings of the prior art, the
appropriate concentrations of the growth factors and cytokines to employ in the
recited steps of claim 13.
Appellants' Specification further discloses:
After about twenty passages, the cells are progressively deprived
of growth factors and cytokines. The expression gradual withdrawal is
understood to mean a removal factor by factor from the culture
medium. Thus, at one passage, SCP is first of all removed, and then,
two or three passages later, IGP-1. If the cells do not exhibit
morphological alterations or a variation in their average rate of
proliferation, the other factors, such as CNTP and IL-6, are then
removed. This withdrawal may also be drastic. All the factors are in this
case removed all at once. The cells are then observed and are only
passaged several days later if their rate of proliferation is modified. The
latter solution is generally that which is practiced.
Spec. 23. We interpret this passage to mean that, when the medium is changed at
successive passages, the various factors are removed from (i.e., not included in) the
new medium, either individually or all at once. In making this finding, we have
the support of the Petitte Declaration. 5 See Petitte Deel. ,r,r 13, 17, 20. We
4 Pain also teaches the use of other growth factors and ctyokines in avian
embryonic stem cell culture, including, e.g., bPGP, IGP-1, m-SCP, CNTP and
OSM, IL-6, and IL-11, further demonstrating that the use of such cytokines and
growth factors were know in the art prior to Appellants' filing date. See, e.g.,
Pain 2340.
5 Dr. James N. Petitte is presently Professor at the North Carolina State University,
in the College of Agriculture and Life Sciences. Petitte Deel. ,r 1. He is the
author of numerous publications (including prior art cited by the Examiner), and
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consequently conclude that a person of ordinary skill would understand, and be
able to practice the step of: "after at least 20 passages modifying the culture
medium by progressive withdrawal of said trophic factors and cytokines," as
recited in claim 13.
Finally, we find that Example 9 of the Specification discloses that:
During the successive passages of the stem cells, a high-density
inoculation directly into the bacteriological dish makes it possible to
obtain, after a few passages, embryonic cells which become detached
from their substrate and which proliferate in suspension in the form of
small regular aggregates. This proliferation is encouraged over several
passages by mere dilution, mechanical dissociation and nonuse of
proteolytic enzyme. The stirring of the cultures is generally carried out
but does not represent a distinguishing factor for obtaining nonadherent
cells.
Spec. 30. Appellants thus provide an explanation of how a nonadherent
suspension of cells may be made, as recited in claims 30 and 33.
We accord substantial evidentiary weight to the Petitte Declaration in this
appeal, particularly with respect to the teachings of the Petitte reference, of which
Dr. Petitte is the principal author. Dr. Petitte is not a party-in-interest to this
appeal, and has extensive experience as an expert in this field. 6 Indeed, one of Dr.
Petitte' s publications is expressly relied upon by the Examiner. See, e.g., Final
Act. 14. At the very least, we are inclined to accord Dr. Petitte's interpretation of
the meaning of his own publication more probative weight than that of the
contradictory findings of the Examiner. Dr. Petitte disagrees with the Examiner's
a named inventor on at least 13 US patents. Id. We find Dr. Petitte sufficiently
qualified to render an expert opinion in this appeal.
6 See fn.5.
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finding that the prior art, including Petitte, teaches that there was considerable
uncertainty in the art at the time of Appellants' invention:
I disagree with the Examiner's conclusion that undue
experimentation would have been required. Persons skilled in the art in
the 2002-2003 time frame routinely performed the types of
experiments described in the application for performing the claimed
methods. Further, the claimed methods were demonstrated in the
specification to work to produce avian cell lines.
Thus even though some experimentation would be required to
practice the claimed methods, such experimentation would be routine
for the person of ordinary skill in the art, and the skilled person would
have considered the success of the methods to be likely given the
demonstration in the specification of production of avian cell lines
using the claimed methods.
Petitte Deel. ,r,r 21-22. Importantly, and directly contradicting the Examiner's
findings, Dr. Petitte emphasizes that:
[T]he use of mammalian cytokines in the establishment and culture of
avian cells is well-known in the art and was at the time of filing of the
above-identified application. The Examiner's contention that
mammalian cytokines are not fully effective on chicken embryonic
cells is not correct, as is clearly demonstrated by the use of such
cytokines in the experiments described in the application, and in the
Declarations of Dr. Mehtali and Dr. Guehenneux. In addition, there are
many examples of mammalian cytokines being used for culturing avian
cells, including chicken embryonic cells, as mammalian cytokines are
much more readily available. In my own laboratory, we routinely use
mammalian cytokines for establishment and culture of avian cells.
Petitte Deel. ,r 10( e ). We also find persuasive the other statements of the Petitte
Declaration concerning the state and predictability of the art of the art at the time
of invention. Id. at ,r 1 O(a-d).
We are thus persuaded by Appellants' argument that the claims are enabled
by the Specification in view of the knowledge of a person of ordinary skill of the
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prior art. See Nat'! Recovery Techs., Inc. v. Magnetic Separation Sys., Inc., 166
F.3d 1190, 1196 (Fed. Cir. 1999) (The scope of enablement is that which is
disclosed in the specification plus the scope of what would be known to one of
ordinary skill in the art without undue experimentation). We consequently reverse
the Examiner's rejection of the claims upon this ground.
D.
Issue
Rejection of claims 13-19 and 28-34 under 35 U.S.C. § 102(b) as being
anticipated by Pain
Appellants argue the Examiner erred in concluding that Pain anticipates all
of the limitations of the claims. App. Br. 25.
Analysis
The Examiner finds that Pain discloses chicken ES cells obtained from a
blastodermal disk of a fertilized chicken egg that were cultured over a period of
time and permitted germline transmission upon transplantation into a recipient
chicken embryo. Final Act. 41. The Examiner finds that the ES cells of Pain are
inherently capable of proliferating in the absence of growth factors for at least 50
days as in claim 13 by withdrawal of a growth factor, cytokine, serum or feeder
cell. Id. Specifically, the Examiner finds that the description of adding cytokines
in the initial phase of culture described by applicants is taught by Pain. Id. at 42
( citing Pain 2339--40 ( culturing in DMEM, using feeder cells, fetal bovine serum,
bFGF, IGF-1, SCP, and LIP), 2340 (removing LIP), 2341 (effects ofLIF, IL-6,
CNTF, OSM, IL-11 on embryonic cells evaluated)). The Examiner notes that the
steps of removing at least one cytokine, at least one growth factor, and/or removal
of fetal calf serum described in the specification do not alter the structure or
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function of the claimed cells, thereby distinguishing the cells claimed from those of
Pain. Id.
Appellants argue that Pain does not disclose avian stem cells that are capable
of proliferating in a basal culture medium in the absence of trophic factors and
cytokines for at least 50 days. App. Br. 25. Furthermore, Appellants argue, Pain
does not teach a cell line obtained from cells isolated from embryos of fertilized
avian eggs by a process as recited in claim 13. Id. Specifically, Appellants
contend, Pain does not teach culturing cells in a basal medium, progressively
reducing amounts of growth factors as recited in step (3), and continuing culturing
said cells in a basal medium in the absence of growth factors as recited in step ( 4).
Id.
We are not persuaded by Appellants' arguments. Pain teaches that:
[W]e observed that the cultures regularly maintained in the presence
of LIP progressively selected a more homogeneous population of cells
harbouring the ECMA-7 and EMA-I epitopes (not shown). Growing
cultures containing ECMA-7-, SSEA-1- and EMA-I-positive cells
could be maintained for at least 35 passages, i.e. more than 160 days in
the presence of LIP. Therefore the mammalian LIP is required for the
long-term growth of avian embryonic cells and the expression of
antigens characteristic of ES cells.
Pain 2343. Pain thus teaches a cell lineage capable of exhibiting telomerase
activity and expressing SSEA-1 and EMA-I, as required by claim 14. Pain next
teaches that:
Murine ES cells can be induced to differentiate in vitro into
various lineages. One way is to remove LIP and to prevent the adhesion
of ES cells to the culture dish. This procedure leads to the formation of
embryonic bodies (EB) which can then be induced to attach again and
to differentiate into various cell types including muscle, hematopoietic
and nerve cells (Doetschman et al., 1985; Sanchez et al., 1991;
Rohwedel et al., 1994; Fraichard et al., 1995).
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To test whether CEC could differentiate into several lineages, we
adapted this procedure to develop embryoid bodies from cultures at
different passages (see Materials and Methods). When seeded in non-
tissue culture dishes without LIP, CEC developed floating organised
structures resembling embryoid bodies (Fig. 6). These EB-like
structures could be maintained in these conditions for more than 10
days. Spontaneous differentiation occurred in these floating masses ....
When transferred onto tissue-culture dishes, these EB-like structures
attached and within a few days generated various cell phenotypes that
were characterised with specific antibodies.
Id. at 2344. Pain thus teaches that these embryoid bodies are capable of
proliferation (i.e., giving rise to lineages) in the absence of cytokines (in this
instance LIP) and are capable of being maintained for at least 10 days.
The Examiner reasons that Pain discloses that these cells (the embryoid
bodies) are inherently capable of proliferating for at least 50 days, as asserted in
claim 13. We do not agree. Pain discloses only that these cells are capable of
being maintained for 18 days (see Pain Fig. 4A), whereas cells cultured in the
presence of cytokine are capable of living for at least 25 days. Id. Furthermore,
Pain expressly discloses that deprivation of the cytokine LIP from the culture
medium induces strong phenotypic effects, including ten to fifteen times fewer
cells expressing EMA-I and SSEA-1. We are not persuaded that these embryonic
bodies, as taught by Pain, are necessarily capable of retaining their proliferative
ability for 50 days, or of expressing the activity or epitopes required by dependent
claim 14. We therefore reverse the Examiner's rejection of the claims on this
ground.
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E. Priority
Issue
Appellants argue that the Examiner erred in concluding that the present
application represents a continuation-in-part of Appellants' Application Ser. No.
12/717096 (the '096 application"), and therefore cannot claim the priority benefit
of the '096 application' filing date of March 3, 2010.
Analysis
The Examiner finds, in relevant part, that an avian cell line characterized by
proliferation and non-differentiation in claim 1 as originally filed in the instant
application does not have support in the '096 application. The Examiner finds the
'096 application is limited to establishing adherent or non-adherent cell lines
capable of proliferating in basal medium in the absence of exogenous growth
factors, serum and/or inactivated feeder layer. Final Act. 3 (citing '096 application
10). The Examiner finds that '096 application discloses that the cell line can be
used to obtain differentiated cell lines. Id. The Examiner finds that the scope of
stem cells discussed in the '096 application varies, and is different than the scope
of non-differentiated as recited in Appellants' claims. Id. The Examiner finds that
the term "non-differentiated' can mean different things in different stem cells, [and
that Appellants have not addressed this phrase]". Id.
Appellants argue that the Examiner has asserted a lack of priority without
any basis in the law. App. Br. 27. Appellants contend that it is well established
that the claims that must be considered for a determination of priority are the
claims as they now pending, including all amendments, and not the originally filed
claims (including claims filed in a preliminary amendment). Id. (citing MPEP §
2163 II.A.3(a)ii)(b)).
34
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Application 13/206,056
We do not find Appellants' arguments persuasive. "A continuation-in-part
is entitled to the parent's filing date as to any subject matter in common, but only
to its own filing date as to the new matter." Santarus, Inc. v. Par Pharms., Inc.,
694 F.3d 1344, 1360 (Fed. Cir. 2012) (quoting H.F. Schwartz et al., PATENT LAW
& PRACTICE§ 2.III.D.7.c (6th ed. 2008). The Examiner has made a finding that
certain limitations of Appellants' present claims on appeal lack written descriptive
support in the Specification of the '096 application. Appellants have made no
argument, nor adduced any evidence, that rebut the Examiner's primafacie
findings and conclusion. We consequently affirm the Examiner's conclusion that
Appellants' instant application is a continuation-in-part of the '096 application and
cannot claim the priority benefit of the '096 application's filing date.
DECISION
The Examiner's rejection of claims 13-19 and 28-34 as unpatentable under
35 U.S.C. § 101 is affirmed.
The Examiner's rejection of claims 13-19 and 28-34 as unpatentable under
35 U.S.C. § 112, first paragraph, on grounds of both lack of written description
and enablement is reversed.
The Examiner's rejection of claims 13-19 and 28-34 as unpatentable under
35 U.S.C. § 102(b) is affirmed.
The claims on appeal cannot claim the priority benefit of the '096
application's filing date.
No time period for taking any subsequent action in connection with this
appeal may be extended under 37 C.F.R. § 1.136(a)(l)(iv).
AFFIRMED
35
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte BERTRAND PAIN and F ABIENNE GUEHENNEUX
Appeal2017-002728
Application 13/206,056
Technology Center 1600
Before FRANCISCO C. PRATS, ULRIKE W. JENKS, and JOHN G. NEW,
Administrative Patent Judges.
PRATS, Administrative Patent Judge, dissenting-in-part.
I concur with my colleagues' decision to reverse the Examiner's rejections
for lack of enablement, lack of written description, and anticipation. However, I
respectfully dissent from the decision to affirm the Examiner's rejection of claims
13-19 and 28-34 as being directed to patent ineligible subject matter. In my
opinion that rejection should also be reversed.
Claim 13, the sole independent claim on appeal, recites an avian cell line
obtained by a specific process. App. Br. 29. In the first step of the process, cells
are isolated from a blastodermal disk of a fertilized avian egg (i.e., undifferentiated
cells are isolated from an avian embryo). Id. The cells are then cultured in a basal
cell culture medium in the presence of a layer of feeder cells, fetal calf serum, and
at least one of several specific recited trophic factors and at least one of several
specific recited cytokines. Id.
Appeal2017-002728
Application 13/206,056
After at least 20 passages in culture, the culture medium is modified by
progressively withdrawing the trophic factors and cytokines, after which the
resulting cells are cultured in a basal culture medium in the absence of trophic
factors and cytokines. Id.
Claim 13 recites that, after performing the steps outlined above, the "cells of
said cell line are capable of proliferating in a basal culture medium in the absence
of trophic factors and cytokines for at least 50 days." Id.
The Examiner's rejection, essentially, is that claim 13 is directed to naturally
occurring subject matter because the cells in the cell line recited in claim 13 are no
different from naturally occurring cells. See Final Act. 9 ("Limiting claim 13 to
cells also having the ability to proliferate in basal medium in the absence of trophic
factors and cytokines for at least 50 days does not alter the structure of the cell
population in a meaningful way."); see also Ans. 28:
The functional limitation of "capable of proliferating in a basal culture
medium in the absence of trophic factors and cytokines for at least 50
days" in claim 13 does not distinguish the cells from a natural product
because the structure and essential functions of the [non-specific] cell
type are the same.
The Examiner, however, does not identify any specific evidence that
supports a finding that naturally occurring avian cells are capable of proliferating
in a basal culture medium in the absence of trophic factors and cytokines for at
least 50 days, as claim 13 requires. Absent some corroborating evidence, or
rational explanation in that regard, I am not persuaded that the Examiner's
unsupported conclusory assertion is sufficient to establish that naturally occurring
avian cells possess the proliferative property required by Appellants' claim 13. See
In reKotzab, 217 F.3d 1365, 1370 (Fed. Cir. 2000) ("Whether the Board relies on
an express or an implicit showing, it must provide particular findings related
2
Appeal2017-002728
Application 13/206,056
thereto. Broad conclusory statements standing alone are not 'evidence."' (citation
omitted)).
Although the above statements in Kotzab were made in the context of an
obviousness rejection, Kotz ab nonetheless underscores the necessity of providing
evidence to support findings made in relation to a prima facie case of
unpatentability. In the present case, because the Examiner provides no evidence to
support a finding that naturally occurring avian cells are capable of proliferating in
a basal culture medium in the absence of trophic factors and cytokines for at least
50 days, as claim 13 requires, I am not persuaded that the Examiner has provided a
sufficient evidentiary basis for concluding that claim 13 is directed to naturally
occurring cells. I would therefore reverse the Examiner's rejection of claim 13,
and its dependent claims, as being directed to patent ineligible subject matter.
In addition, as Appellants argue (see App. Br. 6-7; Reply Br. 2-3), and
contrary to the Examiner's assertion above, the actual evidence of record does not
support a finding that naturally occurring avian cells are capable of proliferating in
a basal culture medium in the absence of trophic factors and cytokines for at least
50 days, absent performing the process steps recited in Appellants' claim 13. To
the contrary, on the current record, if cells are merely isolated from an avian
blastodermal disk and then cultured without performing the steps recited in
Appellants' claim 13, the cells will not proliferate for extended periods in the
absence of added trophic factors and/or cytokines, as claim 13 requires. See Spec.
2 ("To maintain avian stem cells in vitro for long periods of time, it is necessary to
observe specific culture and maintenance conditions as described in Pain et al.,
1996; US 6,114,168 and EP 787 180."); see also Pain 2345, Col. 1, ,r 2 ("We show
here that mammalian LIP is required to maintain cells with ES [ embryonic stem
cell] features in CEC [chicken embryonic cell] cultures. The addition ofIL-11,
3
Appeal2017-002728
Application 13/206,056
another member of the LIP family of cytokines, also facilitates the maintenance of
ES-like properties of avian blastodermal cells."). 7
In sum, for the reasons discussed, I am not persuaded that the Examiner has
advanced a sufficient evidentiary basis for concluding that the cells recited in
Appellants' claims are the same as naturally occurring cells. Nor am I persuaded
that the evidence of record supports such a finding. I would therefore reverse the
Examiner's rejection of Appellants' claims as being directed to naturally occurring
patent ineligible subject matter.
7 B. Pain et al., Long-term In Vitro Culture and Characterisation of Avian
Embryonic Stem Cells with Multiple Morphogenetic Potentialities, 122
DEVELOPMENT 2339--48 (1996).
4