Ex Parte Eller et al

Patent Trial and Appeal Board

Nov 20, 2018

14044050 (P.T.A.B. Nov. 20, 2018)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE
14/044,050 10/02/2013
69821 7590 11/23/2018
MERIT MEDICAL SYSTEMS, INC.
C/0 STOEL RIVES, LLP
ONE UTAH CENTER
201 SOUTH MAIN STREET -- SUITE 1100
SALT LAKE CITY, UT 84111
FIRST NAMED INVENTOR
Zeke Eller
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.
37621/54208 8952
EXAMINER
DIOP, ROKHAYA
ART UNIT PAPER NUMBER
3774
NOTIFICATION DATE DELIVERY MODE
11/23/2018 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):
msbethards@STOEL. COM
patlaw@stoel.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte ZEKE ELLER, JOHN WILLIAM HALL,
ROBERTS. KELLAR, RACHELL YNN SIMMONS,
ROBERT J. RADFORD, and BART DOLMATCH
Appeal2017-010572 1
Application 14/044,050
Technology Center 3700
Before JEFFREY N. FREDMAN, DEBORAH KATZ, and JOHN G. NEW,
Administrative Patent Judges.
NEW, Administrative Patent Judge.
DECISION ON APPEAL
1 Appellants identify Merit Medical Systems, Inc. as the real party-in-
interest. App. Br. 3.
Appeal2017-010572
Application 14/044,050
SUMMARY
Appellants file this appeal under 35 U.S.C. § I34(a) from the
Examiner's Final Rejection of claims 1-10, 12-17, 19, 21, and 22.
Specifically claims 1-10, 13-17, 19, 21, and 22 stand rejected as
unpatentable under 35 U.S.C. § I03(a) (pre-AIA) as being obvious over
Anneaux et al. (US 2011/0030885 Al, February 10, 2011) ("Anneaux").
Claim 12 stands rejected as unpatentable under 35 U.S.C. § I03(a) as
being obvious over the combination of Anneaux and Lee et al. (US
2007/0276477 Al, November 29, 2007) ("Lee").
Claims 1-10, 13, 14, 17, 19, 21, and 22 stand rejected as unpatentable
under the nonstatutory doctrine of obviousness-type double patenting. 2
We have jurisdiction under 35 U.S.C. § 6(b ).
We AFFIRM.
NATURE OF THE CLAIMED INVENTION
Appellants' invention is directed to a prosthesis coated with layers of
electrospun polytetrafluoroethylene (PTFE), by which the electrospun PTFE
of certain porosities may permit endothelial cell growth within the
prosthesis. Abstr.
2 Appellants do not argue or otherwise mention the obviousness-type double
patenting rejections in their Appeal Brief. We consequently summarily
affirm the Examiner's rejections on this ground. See 37 C.F.R.
§ 4I.37(c)(iv) ("[A]ny arguments or authorities not included in the appeal
brief will be refused consideration by the Board for purposes of the present
appeal.").
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Application 14/044,050
REPRESENTATIVE CLAIM
Claim 1 is representative of the claims on appeal and recites:
1. A vascular prosthesis, comprising:
a tubular body comprising
a first layer of electrospun polytetrafluoroethylene
(PTFE);
an impermeable layer, configured to be
impermeable to tissue ingrowth through the impermeable
layer, the impermeable layer comprising a polymer
material and wherein a portion of the polymer material of
the impermeable layer is disposed between openings in
the first layer of electrospun PTFE; and
a second layer of electrospun PTFE,
wherein at least one of the first and second layers of
electro spun PTFE has an average pore size of between about 2
microns and about 8 microns.
App. Br. 17.
ISSUES AND ANALYSIS
We are persuaded by, and expressly adopt, the Examiner's findings,
reasoning, and conclusion that Appellants' claims are prima facie obvious
over the prior art. We address the arguments raised by Appellants below.
Issue 1
Appellants argue the Examiner erred because a person of ordinary
skill in the art would not have a reasonable expectation of success of the
proposed modification. App. Br. 9.
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Application 14/044,050
Analysis
Independent claims 1 and 1 7 require first and second layers of
electrospun PTFE and an impermeable layer having a portion
disposed between openings in the first layer.
The Examiner finds that, in one embodiment, Anneaux discloses a
vascular prosthesis comprising a tubular body, first and second outer layers
of expanded PTFE having a pore size between 0.05 microns and 50 microns,
and an inner impermeable layer of electrospun PTFE in direct contact with
the first and second outer layers. Final Act. 7-8 ( citing Anneaux ,r,r 14, 20,
25, 28, 32, Fig. 4).
The Examiner finds that Anneaux does not expressly teach an
embodiment with electrospun PTFE in the first and second outer layers.
Final Act. 8. The Examiner finds that Anneaux also does not expressly
teach that a portion of the impermeable layer is disposed between openings
in the first outer layer. Id.
The Examiner finds that Anneaux teaches, in a different embodiment,
using electrospun PTFE in an outer layer to improve tissue infiltration with
the advantage of replicating the structure of the extracellular matrix. Final
Act. 8 (citing Anneaux ,r,r 17, 61-64). The Examiner finds that Anneaux
teaches optimizing the porosity of different layers of the vascular device by
using electrospun PTFE. Id. (citing Anneaux ,r,r 14, 15, 25Fig. 4). The
Examiner also finds that Anneaux teaches bonding different layers by
pressing and heating. Id. (citing Anneaux ,r,r 26, 47-55).
The Examiner concludes that it would have been obvious to a person
of ordinary skill in the art to use electrospun PTFE in the first and second
outer layers of the prosthesis using the bonding technique, which would
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Application 14/044,050
result in a portion of the electrospun PTFE of the impermeable layer being
disposed between openings in the first layer of electrospun PTFE. Final Act.
9. The Examiner further concludes that a person of ordinary skill in the art
would have had a reasonable expectation of success using electrospun PTFE
in the innermost and outermost layers, because Anneaux teaches a number
of advantages of electrospun PTFE, including replicating the extracellular
matrix, providing greater control of cellular response, and improving tissue
infiltration. Id. at 8, 13.
Appellants argue the Examiner erred because a person of ordinary
skill in the art at the time of the invention would not have a reasonable
expectation of success of replacing expanded PTFE with electrospun PTFE.
App. Br. 9. Appellants argue that electrospun PTFE and expanded PTFE
have very different microstructures, preventing "one of skill in the art from
equating properties of electrospun PTFE with [ expanded PTFE] in any
attempt to substitute electro spun PTFE for [ expanded PTFE]." Id. at 11.
Appellants argue the different microstructures would have a direct impact on
biological response precluding a reasonable expectation of successfully
interchanging electrospun PTFE with expanded PTFE. Id. (citing
Declaration of Mr. John Hall ,r,r 11-12 ( the "Hall Declaration")). 3
The Examiner responds that Anneaux offers a number of advantages
of incorporating "an espin layer that closely mimics ... the extracellular
matrix affording greater control of cellular response." Ans. 7 ( citing
3 Mr. John Hall, one of the named inventors of the instant application,
received his BSME degree from the University of Utah and is presently
R&D Manager at Merit Medical Systems. We have reviewed Mr. Hall's
credentials and consider him qualified to render an expert opinion.
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Appeal2017-010572
Application 14/044,050
Anneaux ,r 17). The Examiner finds that: "[a] skilled artisan could have
substituted the [ expanded PTFE] layers of Anneaux with layers of
electrospun PTFE by known methods with no change in their respective
functions, and the modification would have predictably yielded a functional
vascular graft in view of the teachings in Anneaux." Ans. 8.
We are not persuaded by Appellants' arguments. "Obviousness does
not require absolute predictability of success .... For obviousness under
[section] 103, all that is required is a reasonable expectation of success." In
re O'Farrell, 853 F.2d 894, 903---04 (Fed. Cir. 1988). The Examiner's
proposed modifications to Anneaux (substituting expanded PTFE with
electrospun PTFE) do not appear to be uniquely challenging, and Appellants
have not presented persuasive evidence that a person of ordinary skill in the
art would not have had a reasonable expectation of success in making the
proposed modifications to Anneaux.
Anneaux acknowledges the different microstructures of electrospun
PTFE ("fibers in a random orientation") and expanded PTFE ("a
microstructure consisting of solid nodes interconnected by fine, highly
oriented fibrils") are "designed to enhance, inhibit or retard the migration of
endothelium during the early phase of healing." Anneaux ,r,r 16 and 32.
Anneaux further teaches the same functional layers as the claimed invention:
The espin material selection can be adjusted to improve bonding
properties between layers and the espin layer can be used to
inhibit cellular proliferation through the middle on the
construction. In this instance, it may be advantageous to allow
cells to migrate and proliferate from both sides (luminal and
abluminal in the case of a graft) but communication between the
two may not be desired. The middle espin layer can be designed
with a porosity that will inhibit this cellular communication.
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Application 14/044,050
Id. ,r 24. In addition to the three-layer structure with an electrospun
impermeable layer, Anneaux teaches a stent with an electrospun layer that
provides "a substantially different pore size and structure on the luminal or
abluminal surface depending on the application." Id. ,r,r 21, 61. Anneaux
provides a number of reasons to use electro spun PTFE in the inner and outer
layers including:
1) [T]he ability to incorporate layers with vastly different pore
structures and sizes, these different structural layers can be used
to manipulate mechanical properties, cellular proliferation,
cellular permeability, fluid permeability, adhesion to a structural
frame, and/or incorporation of an active therapeutic component;
2) the ability to make a composite construction with vastly
different components enabling a broader range of therapeutic
uses and structures; 3) improved bonding of PTFE layers to
structural frames and to other layers of the construct; 4) the
ability to incorporate an espin layer that closely mimics that of
the extracellular matrix affording greater control of cellular
response; and 5) enabling the coating of complex geometries that
otherwise could not be covered with expanded PTFE or other
materials alone.
Id. ,I 17.
As discussed above, Anneaux teaches that expanded PTFE and
electrospun PTFE are both suitable materials for stent layers. Anneaux also
teaches both reasons to modify the layers and the expected benefits of the
modification. Given these teachings, we agree with the Examiner that a
person of ordinary skill in the art would have had a reasonable expectation
of success in making a stent having inner and outer layers of electrospun
PTFE. It is within the general skill of a worker in the art to select a known
material based on its suitability for the intended use as a matter of obvious
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design choice. See In re Leshin, 277 F.2d 197, 199 (CCPA 1960) (Selection
of a known plastic to make a container of a type made of plastics was held to
be obvious.).
Issue 2
Appellants argue that the Examiner erred because the proposed
modification renders the prior art unsatisfactory for its intended purpose.
App. Br. 14.
Analysis
Appellants argue that the proposed modification would result in a
covering composed solely of electrospun PTFE that would be inoperable for
its intended purpose. App. Br. 14. Appellants assert that because
electrospun PTFE has much lower tensile strength and creep resistance as
compared to expanded PTFE, the proposed covering would lack sufficient
structural strength for implantation into a body lumen. Id. 15 ( citing Hall
Declaration ,r 10).
We do not find Appellants' arguments to be persuasive. The
Examiner asserts "the proposed modification yields a vascular graft made
from the same materials and having the same structure as Appellant[s']
device; therefore it would function in the same manner." Ans. 10. We agree
with the Examiner's broadest reasonable interpretation of Appellants'
claimed invention that encompasses a device composed solely of electrospun
PTFE. For example, claim 2, depending from claim 1, specifically recites a
device wherein all three layers comprise electrospun PTFE. The device of
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Application 14/044,050
claim 2 encompasses the same all electrospun PTFE device that Appellants
argue "lacks sufficient structural integrity." App. Br. 14; Reply Br. 5.
Moreover, Anneaux teaches manipulating the mechanical properties
of an electrospun PTFE device, including tensile strength and creep
resistance. Specifically, Anneaux teaches "different structural layers can be
used to manipulate mechanical properties" and "[t]he devices of the present
disclosure can be prepared with controlled fiber, node and fibril sizes and
manipulated mechanical values such as bond strength, elongation properties
and tensile strengths." Anneaux ,r 31 (emphasis added). As such, we are
not persuaded that an all electrospun PTFE device, with its mechanical
properties manipulated, as taught by Anneaux, would lack sufficient
structural integrity.
Issue 3
Appellants argue that unexpected results rebut any prima facie case of
obviousness. App. Br. 11.
Analysis
Appellants submit experimental data as evidence of an "unexpected
biologic response." App. Br. 11-12 (citing Hall Declaration ,r,r 13-24). In
particular, "the electrospun PTFE (MME 1) ... had a lower inflammatory
score when accounting for both the inside diameter ("ID") and outer
diameter ("OD"), than any of the commercially available ( expanded PTFE)
grafts." Id. at 12 (emphasis in original). Appellants argue that these results
are unexpected as expanded PTFE has "been the gold standard for biological
contact layers of vascular prosthesis, and that suitable substitutes are
generally unavailable." Id. at 13.
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Even if the experimental data indicates a lower inflammatory
response, we do not find Appellants' arguments persuasive.
As an initial matter, we are not persuaded that the commercially
available expanded PTFE grafts are the closest prior art to the Appellants'
claimed invention. The commercially available expanded PTFE grafts do
not include electrospun PTFE. Instead, the closest prior art is Anneaux,
which teaches a stent including at least one electrospun PTFE layer inner
and/or outer layer. At best, the experimental results indicate electrospun
PTFE, as taught in the prior art, would induce a lower inflammatory
response than expanded PTFE devices. "Mere recognition of latent
properties in the prior art does not render nonobvious an otherwise known
invention." In re Baxter Travenol Labs., 952 F.2d 388, 392 (Fed. Cir.
1991 ).
Furthermore, "evidence of unexpected results must establish that there
is a difference between the results obtained and those of the closest prior art,
and that the difference would not have been expected by one of ordinary
skill in the art at the time of the invention." Bristol-Myers Squibb Co. v.
Teva Pharm. USA, Inc., 752 F.3d 967, 977 (Fed. Cir. 2014). In addition,
"[ u ]nexpected results that are probative of nonobviousness are those that are
different in kind and not merely in degree from the results of the prior art."
Galderma Labs., L.P. v. Tolmar, Inc., 737 F.3d 731, 739 (Fed. Cir. 2013).
We address each of these principles in tum.
First, there is no indication that the superior properties of electrospun
PTFE used in an outer or inner layer are unexpected. "[I]n order to properly
evaluate whether a superior property was unexpected, the court should have
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considered what properties were expected." Pfizer, Inc. v. Apotex, Inc., 480
F.3d 1348, 1371 (Fed. Cir. 2007).
Appellants argue that "[ n Jot only would one of ordinary skill in the art
not expect electro spun PTFE to perform as well as [ expanded PTFE] ... but
it would have been even more unexpected for the electrospun PTFE
materials to outperform commercially optimized [ expanded PTFE]
prosthesis." App. Br. 13. Appellants explain what would not have been
expected, but do not explain what properties were expected.
Second, the experimental results show a decrease of average
inflammatory score in terms of percentages. "Results which differ by
percentages are differences in degree rather than kind, where the
modification of the percentage is within the capabilities of one skilled in the
art at the time." Galderma Labs. 737 F.3d at 739. Anneaux teaches that
incorporating an electrospun PTFE layer affords greater control of cellular
response. The evidence indicates that skilled artisans were capable of
adjusting the cellular response of the electro spun layer and the results
constitute a difference in degree, not kind. On balance then, we do not find
that Appellants' argument claiming unexpected results outweighs the other
evidence of record that the claims are prima facie obvious over the
combined cited prior art. See also Pfizer, 480 F.3d at 1372 (Unexpected
results are not sufficient to outweigh a stronger showing of obviousness.).
Appellants do not argue the dependent claims separately, relying on
their arguments for claims 1 and 1 7. We consequently affirm the
Examiner's rejection of claims 1-10, 12-17, 19, 21, and 22.
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DECISION
The Examiner's rejection of claims 1-10, 13-17, 19, 21, and 22 under
35 U.S.C. § 103(a) is affirmed.
The Examiner's rejection of claims 1-10, 13, 14, 17, 19, 21, and 22
under the nonstatutory doctrine of obviousness-type double patenting is
affirmed.
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
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