Ex Parte Burdick et al

Patent Trial and Appeal Board

Aug 3, 2018

13139537 (P.T.A.B. Aug. 3, 2018)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE
13/139,537 09/01/2011
23377 7590 08/07/2018
BAKER & HOSTETLER LLP
CIRA CENTRE 12TH FLOOR
2929 ARCH STREET
PHILADELPHIA, PA 19104-2891
UNITED ST A TES OF AMERICA
FIRST NAMED INVENTOR
Jason Alan Burdick
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.
103241.005580 I V4899 1635
EXAMINER
FALKOWITZ, ANNA R
ART UNIT PAPER NUMBER
1617
NOTIFICATION DATE DELIVERY MODE
08/07/2018 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):
eofficemonitor@bakerlaw.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
ExparteJASON ALAN BURDICK, SUJATA SAHOO, and
CINDY CHUNG
Appeal2017-005693
Application 13/139,537
Technology Center 1600
Before ULRIKE W. JENKS, JOHN E. SCHNEIDER, and RYAN H. FLAX,
Administrative Patent Judges.
JENKS, Administrative Patent Judge.
DECISION ON APPEAL
Pursuant to 35 U.S.C. § 134(a), Appellants 1 appeal from Examiner's
decision to reject claims as anticipated and obvious. We have jurisdiction
under 35 U.S.C. § 6(b ).
We AFFIRM.
1 Appellants identify the real party in interest as Trustees of the University of
Pennsylvania. Br. 1.
Appeal2017-005693
Application 13/139,537
STATEMENT OF THE CASE
Claims 11-15, 21, 23, 24, 27, 31, 33, 50, and 51 are on appeal, and
can be found in the Claims Appendix of the Appeal Brief. Independent
claims 11, 50, and 51 are representative of the claims on appeal, and read as
follows:
11. A composition, comprising:
a polymer comprising a plurality of repeat units,
at least one repeat unit comprising
a biocompatible backbone; and
a hydrolytically degradable linker disposed
between the biocompatible backbone and a
crosslinker group,
the crosslinker group covalently binding at
least one repeat unit to a second repeat unit.
50. A polymeric composition, comprising:
at least one repeat unit that comprises hyaluronic acid
and a methacrylate, at least one lactic acid being disposed
between the hyaluronic acid and the methacrylate.
51. A polymeric composition, comprising:
at least one repeat unit that comprises hyaluronic acid
and a methacrylate, at least one caprolactone being disposed
between the hyaluronic acid and the methacrylate.
Appellants request review of the following grounds of rejection:
I. Claims 11-13, 15, 21, and 31 stand rejected under 35 U.S.C.
§ 102(b) as anticipated by Hennink. 2
II. Claims 11-15, 21, 23, 24, and 31 stand rejected under
35 U.S.C. § I03(a) as unpatentable over the combination of
Hennink and Sawhney. 3
2 Hennink et al., US 2007/0185008 Al, publ. Aug. 9, 2007 ("Hennink").
3 Sawhney et al., US 7,220,270 B2, issued May 22, 2007 ("Sawheny").
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III. Claims 11-15, 21, 23, 24, and 31 stand rejected under
35 U.S.C. § I03(a) as unpatentable over the combination of
Hennink and Bellamkonda. 4
IV. Claims 11-13, 15, 21, 27, 31, 50, and 51 stand rejected under
35 U.S.C. § I03(a) as unpatentable over the combination of
Hennink and Gerecht-Nir. 5
I. Anticipation by H ennink
Does the preponderance of evidence of record support Examiner's
findings that Hennink anticipates the claims?
Findings of Fact
FF 1. Hennink teaches "three-dimensional polymeric networks in which
polymer chains are crosslinked with each other primarily by non-
covalent links." Hennink ,r 1. "In chemically crosslinked gels, the
polymers are connected primarily by covalent bonds." Id. ,r 2.
Hydrogels are described as "water-swollen, three-dimensional
polymeric networks in which polymer chains are physically or
chemically crosslinked." Id. ,r 20 ( emphasis added). "Stereocomplex
hydro gels are 'physical' hydro gels ... formed by structures such as
polymeric or oligomeric regions (such as grafts or blocks) of opposite
chirality." Id. ,r 21.
FF2. Hennink teaches that "the polymers preferably represent graft
polymers in which the hydrophilic region is the backbone and the
4 Bellamkonda et al., US 5,834,029, issued Nov. 10, 1998 ("Bellamkonda").
5 Gerecht-Nir et al., US 2007/0122392 Al, publ. May 31, 2007 ("Gerecht-
Nir").
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degradable regions are grafts, side chains of the polymers." Id. ,r 15.
"[T]the graft polymers participating in the three-dimensional hydrogel
network all have the same backbone composition, even if they differ
in their side chain chirality." Id. ,r 30. Preferred backbones include:
native and modified or derivatised polysaccharides such as dextran,
cellulose including water soluble cellulose ethers such as methyl
cellulose, among others. Id.
FF3. Hennink teaches that "the linking groups between the polymer
backbone and the grafts may contribute to the overall degradability of
the hydrogel." Id. ,r 7. The biodegradable regions "are hydrolysable
under physiological conditions. . . . [Having degradation times that
span] over several hours, days, weeks, months, or a few years, without
requiring enzymatic catalysis." Id. 1133. "[T]he enantiomerically
enriched degradable regions of the polymers are preferably based on
(L)- or (D)-lactate units ... derived from glycolic acid, caprolactone,
or propriolactone." Id. 1135; see id. ,r 43 ("Most often, linking groups
are ester, amide, or urethane groups .... [E]enantiomerically enriched
biodegradable side chains are grafted to hydrophilic backbones via
ester groups"). "[T]he linking group could also be applied to enhance
the biodegradability of the product." Id. ,r 44. "[F]or achieving
intermediate gel stabilities, it may be useful to incorporate linkers
with different degrees of stability." Id. ,r 45.
FF4. Hennink teaches that hydrogels are used to deliver pharmaceutically
active compounds. Id. ,r 59. The active compounds can be
incorporated into the hydrogel either when forming the hydrogel or
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they may be loaded into the hydrogel by soaking the gel in the
solution. Id. Active compounds include living cells. Id. ,r 62.
Principles of Law
"Anticipation requires that all of the claim elements and their
limitations are shown in a single prior art reference." In re Skvorecz, 580
F.3d 1262, 1266 (Fed. Cir. 2009). "The use of patents as references is not
limited to what the patentees describe as their own inventions or to the
problems with which they are concerned. They are part of the literature of
the art, relevant for all they contain." In re Heck, 699 F.2d 1331, 1332-33
(Fed. Cir. 1983) (quoting In reLemelson, 397 F.2d 1006, 1009 (CCPA
1968).
Analysis
Appellants contend that Hennink does not teach or suggest ( 1) "the
cross-linker group covalently binding at least one repeat unit to a second
repeat unit" (Br. 4); (2) the linkers are not positioned between the backbone
in the crosslinker group (id.); and (3) lacks crosslinker structures that are
covalently bonded to one another (id.).
We are not persuaded by Appellants' contention that the reference
does not teach covalent bonding between the polymers. Hennink explains
that hydrogels are water swollen three-dimensional polymeric networks
where the polymer chains are either physically or chemically crosslinked.
FF 1. Hennink also teaches that the polymer backbones include
polysaccharides, containing linkages between graft and polymer backbone,
and additionally contemplates carrying other active compounds in the
hydrogel. FF2-FF4. As explained by Examiner, Hennink discloses
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compositions that utilize both physical and chemical bonding. See Ans. 6
(citing Hennink ,r 21), FPL Hennink discloses that "[i]n addition to
stereocomplexes, other types of crosslinks may be present in a
stereocomplex hydrogel and contribute to its stability." Hennink ,r 21. The
other type crosslinks include chemical crosslinks. See FF 1. The evidence
supports Examiner's finding that Hennink discloses both physically and
covalently bonded hydrogels. Accordingly, we agree with Examiner's
finding that Hennink discloses the covalently linked structures as claimed.
We are also not persuaded by Appellants' contention that the linker
group is not located in a position between the backbone and the crosslinker
group. Here, Hennink teaches that the degradable regions are attached to the
hydrophilic region by linkers. See Hennink ,r 43; FF3. "Such linking
structure usually represent relatively small chemical groups, but also
[includes] larger entities such as oligomers." Hennink ,r 43. Examiner
explains "the linker and crosslinker group is for example (L)- or (D)-lactate
units with the linking groups of ester, amide or urethane groups is between
the two backbone polysaccharides." Ans. 5; see FF3. Because the linker
groups bind the lactate crosslinker unit to the polysaccharide polymer the
linker would necessarily be in between the backbone polymer and the
crosslinker. Accordingly, Appellants' argument is not persuasive.
We are also not persuaded by Appellants' contention that Hennink
does not exemplify covalently bonded crosslinker structures.
"[ A ]nticipation does not require actual performance of suggestions in a
disclosure. Rather, anticipation only requires that those suggestions be
enabled to one of skill in the art." Impax Labs., Inc. v. Aventis Pharms. Inc.,
468 F.3d 1366, 1382 (Fed. Cir. 2006)(citations omitted). Hennink might not
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exemplify a chemically crosslinked hydrogel, but that does not negate the
reference's disclosure of such structures. Examiner has identified (L )- or
(D)-lactate units as the crosslinkers. Ans. 5. Hennink further discloses that
the polymers can interact physically or chemically via crosslinking. FF 1.
One of ordinary skill in the art would understand that chemical crosslinks
are covalent bonds. See id. ("In chemically crosslinked gels, the polymers
are connected primarily by covalent bonds."). Accordingly, we are not
persuaded by Appellants' argument.
Thus, for the reasons above, we affirm the rejection of claim 11 as
anticipated by Hannink. Claims 12, 13, 15, 21, and 31 have not been argued
separately and therefore fall with claim 11. 37 C.F.R. § 4I.37(c)(l)(iv).
II. Obviousness over H ennink and Sawhney
Appellants contend that Sawnhey does not cure Hennink's
deficiencies relating to the claimed covalent crosslinking. Br. 6.
Sawhney teaches "[p ]hysical crosslinking may be intramolecular or
intermolecular or in some cases, both." Sawhney 5:11-12. Physical
gelation can be obtained using natural polymers as well. "[N]atural
polymers, such as glycosaminoglycans, e.g., hyaluronic acid, contain both
anionic and cationic functional groups along each polymeric chain. This
allows the formation of both intramolecular as well as intermolecular ionic
crosslinks, and is responsible for the thixotropic ( or shear thinning) nature of
hyaluronic acid." Id. at 6:24--29.
Having found no error with Examiner's position that Hennink
anticipated claim 11 and no deficiency in Hennink's disclosure regarding the
claimed covalent crosslinking (see above I.), we are not persuaded by
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Appellants' argument that Sawnhey fails to make up for such an alleged
deficiency in Hennink. As explained by Examiner, "Hennink specifically
discloses the presence of other types of crosslinks may be present to
contribute to the hydro gel's stability." Ans. 5---6 ( citing Hannink ,r 21 ); cf
FF2. Accordingly, we affirm this rejection for the reasons set out above and
those provided by Examiner in the Final Action and Answer.
III. Obviousness over Hennink and Bellamkonda
Appellants contend that Bellamkonda does not cure Hennink' s
deficiencies regarding the claimed covalent crosslinking. Br. 6-7.
Bellamkonda teaches bioartificail hydrogel matrices that can be used
to incorporate cells such as stem cells. Bellamkonda 6: 1-10.
Having found no error with Examiner's position that Hennink
anticipated claim 11 and no deficiency in Hennink's disclosure regarding the
claimed covalent crosslinking (see above I.), we are not persuaded by
Appellants' argument that Bellamkonda fails to make up for such an alleged
deficiency in Hennink. Similar to the teaching of Bellamkonda, Hannink
also teaches that hydrogels can be used to deliver pharmaceutically active
compounds that include living cells. FF4. Examiner reasons that
Final Act. 8.
it would have been prima facie obvious to include
the stem cell, which is a mammalian cell, into the
polymer composition, as instantly claimed, with a
reasonable expectation of success, at the time of
the instant invention because Bellamkonda et al.,
discloses that hydrogel matrices are useful as
extracellular matrix (ECM) and the components
may better mimic the in vivo environment as well
as facilitate tissue engineering and manipulation.
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We find no error with Examiner's rationale. Accordingly, we affirm
the rejections for the reasons discussed above and those provided by
Examiner in the Final Action and Answer.
IV. Obviousness over Hennink and Gerchet-Nir
Regarding this rejection, the issue is whether the preponderance of
evidence of record support Examiner's conclusion that it would have been
obvious to incorporate a hyaluronic acid backbone and a methacrylate
crosslinker into Hennink's composition.
Findings of Fact
FF5. Gerecht-Nir teaches a crosslinked hyaluronic acid containing
biocompatible matrix. Gerecht-Nir ,r 6. "[T]he hyaluronic acid may
be cross-linked through methacrylate moieties or through acrylate,
thiol, or amine groups, or through biotin-streptavidin interactions."
Id.
FF6. Gerecht-Nir also discloses incorporating embryonic stem cells (ESC)
in to the hydrogels. "[V]iable, proliferating ESCs can be maintained
in their undifferentiated state when cultured in HA hydrogels, and
released without the loss of cell viability." Id. ,r 36.
Analysis
Examiner acknowledges that Hennink does not teach the specific
methacryl-lactic acid-hyaluronic acid polymers, but finds that these are
taught by Gerecht-Nir. Final Act. 10. Examiner concludes that "[a] person
of [ordinary] skill in the art would be motivated to polymerize the
biodegradable lactic acid oligomer [ of Hennink] with the hyaluronic acid
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(polysaccharide backbone) [ of Gerecht-Nir] through methacrylate crosslinks
. . . [for] improving the use of these hydro gel polymers in tissue engineering
applications." Id.
Appellants contend that "[a]pplying any chemical crosslinking
allegedly taught in Gerecht-Nir to Hennink would violate the well-
established prohibition against modifying references so as to change the way
in which the references operate." Br. 7.
We are not persuaded. The law does not require that the teachings of
the reference be combined for the reason or advantage contemplated by the
inventor, as long as some suggestion to combine the elements is provided by
the prior art as a whole. In re Beattie, 974 F.2d 1309, 1312 (Fed. Cir. 1992);
In re Kronig, 539 F.2d 1300, 1304 (CCPA 1976). Here, Examiner identifies
that the motivation for the combination is for "improv[ing] the use these
hydrogel polymers in tissue engineering applications." (See Gerecht-Nir
,r 36). Hennink already contemplated incorporating cells into the matrix
(FF4) and Gerecht-Nir (FF5-FF6) similarly incorporates cells into the
polymer matrix. See Final Act. 10 (citing Gerecht-Nir ,r 36). Because both
references incorporate cells into the polymer matrix that allows for survival
of these cells within the matrix we find no error with Examiner's reliance on
incorporating the teaching of Gerecht-Nir' s use of hyaluronic acid polymer
matrix backbone with a methacrylate crosslinker in conjunction polymer
matrix of Hennink. Accordingly, we are not persuaded by Appellants
contention that the combination of references as proposed by Examiner
changes the principle of operation of Hennink.
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Accordingly, we affirm the rejection of claims 11-13, 15, 21, 27, 31,
50, and 51 as obvious over Hannink and Gerecht-Nir as set out by Examiner
in the Final Action and Answer.
SUMMARY
We affirm the rejection of claim 11 under 35 U.S.C. § 102(b) over
Hennink. Claims 12, 13, 15, 21, and 31 were not separately argued and fall
with claim 11.
We affirm the rejection of claims 11-15, 21, 23, 24, and 31 under
35 U.S.C. § 103(a) over Hennink and Sawhney.
We affirm the rejection of claims 11-15, 21, 23, 24, and 31 under
35 U.S.C. § 103(a) over Hennink and Bellamkonda.
We affirm the rejection of claims 11-13, 15, 21, 27, 31, 50, and 51
under 35 U.S.C. § 103(a) over Hennink and Gerecht-Nir.
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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