Xiamen Sinopeg Biotech, Ltd.

Patent Trials and Appeals Board

Apr 28, 2021

2020003036 (P.T.A.B. Apr. 28, 2021)

UNITED STATES PATENT AND TRADEMARK OFFICE
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
14/138,026 12/21/2013 WenGui WENG 1049/0111PUS1 9270
60601 7590 04/28/2021
Muncy, Geissler, Olds & Lowe, P.C.
4000 Legato Road
Suite 310
Fairfax, VA 22033
EXAMINER
REYNOLDS, FRED H
ART UNIT PAPER NUMBER
1658
NOTIFICATION DATE DELIVERY MODE
04/28/2021 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):
MAILROOM@MG-IP.COM
PTOL-90A (Rev. 04/07)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________

Ex parte WENGUI WENG, CHAO LIU,
JINCHENG LIAO, and JINCHUN YUAN
____________

Appeal 2020-003036
Application 14/138,026
Technology Center 1600
____________

BEFORE DONALD E. ADAMS, JOHN G. NEW, and
MICHAEL A. VALEK, Administrative Patent Judges.

ADAMS, Administrative Patent Judge.

DECISION ON APPEAL
Pursuant to 35 U.S.C. § 134(a), Appellant1 appeals from Examiner’s
decision to reject claims 1, 2, 6, 8, 9, 19–21, 23–27, 29–31, 33, 34, and 36–
41(Final Act.2 2).3 We have jurisdiction under 35 U.S.C. § 6(b).
We AFFIRM.

1 We use the word “Appellant” to refer to “applicant” as defined in
37 C.F.R. § 1.42. Appellant identifies the real party in interest as Xiamen
Sinopeg Biotech Co., Ltd.” (Appellant’s July 3, 2019, Appeal Brief (Appeal
Br.) 2).
2 Examiner’s January 15, 2020, Final Office Action.
3 Claims 6, 20, 21, 23, 29–31, 33, 37, and 40 stand withdrawn from
consideration (Final Act. 2).
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STATEMENT OF THE CASE
Appellant’s disclosure “relates to poly(ethylene glycol) derivatives.
In particular, the invention relates to a monofunctional branched
poly(ethylene glycol) (PEG) and a bio-related substance modified with the
monofunctional branched poly(ethylene glycol).” (Spec.4 ¶ 1). Appellant’s
claims 1 and 24 are reproduced below:
1. A monofunctional branched poly(ethylene glycol) (PEG)
represented by general formula (1):

wherein X1 and X2 are each independently a hydrocarbon
group having 1 to 20 carbon atoms, n1 and n2 are each
independently a value selected from 1 to 1000, n3 is a value
selected from 11 to 1000, L1 and L2 are each independently a
divalent hydrocarbon group having 1 to 20 carbon atoms, or a
divalent hydrocarbon group having 1 to 20 carbon atoms and
comprising at least one from the group consisting of an ether
bond, a thioether bond, a double bond, a triple bond, and an
amino group,
both L1s are the same, p is 0 or 1,
R1 is a hydrogen atom, a hydrocarbon group having 1 to
20 carbon atoms, or a hydrocarbon group having 1 to 20 carbon
atoms with a group stable under anionic polymerization
conditions,
R is a reactive group capable of forming a covalent bond;
and
wherein L1 and L2 are each independently a divalent
hydrocarbon group having 1 to 20 carbon atoms and containing

4 Appellant’s December 21, 2013, Specification.
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at least one of a group consisting of an ether bond, a thioether
bond, an amide bond, a double bond, a triple bond, and an
amino group, when p is 0.
(Appeal Br. 16–17.)5
24. The monofunctional branched PEG according to Claim 1,
wherein n3 is a value selected from 68 to 1000.
(Id. at 20.6)
Claims 1, 2, 8, 9, 19, 24–27, 34, 36, 38, 39, and 41 stand rejected
under 35 U.S.C. § 103(a) as unpatentable over the combination of Harris,7
Lee,8 and Nektar.9
ISSUE
Does the preponderance of evidence relied upon by Examiner support
a conclusion of obviousness?
FACTUAL FINDINGS (FF)
FF 1. Harris “relates to monofunctional derivatives of poly(ethylene
glycol) and related polymers and to methods for their synthesis and
activation for use in modifying the characteristics of surfaces and
molecules” (Harris 1:10–13; see Ans.10 4).

5 We limit the scope of our review to Appellant’s elected invention (see
Final Act. 2 (Examiner states Appellant “elected group I (compounds) and
the compound of example 1 in the reply filed 24 Nov, 2014”)). Ex parte
Ohsaka, 2 USPQ2d 1460, 1461 (BPAI 1987).
6 The page numbering of Appellant’s Brief stops at page 16. We, therefore,
refer to the remaining pages of Appellant’s Brief as if they were numbered
consecutively after page 16 of Appellant’s Brief.
7 Harris et al., US 5,932,462, issued Aug. 3, 1999.
8 Lee et al., Rapid Gel Formaiton and Adhesion in Photocurable and
Biodegradable Block Copolymers with High DOPA Content, 39
Macromolecules 1740–1748 (2006).
9 Nektar Advanced PEGylation Catalog 2005–2006.
10 Examiner’s January 15, 2020, Answer.
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FF 2. Harris discloses “a branched or ‘multi-armed’ amphiphilic polymer
derivative that is monofunctional, hydrolytically stable, can be prepared in a
simple, one-step reaction, and possesses no aromatic moieties in the linker
fragments forming the linkages with the polymer moieties” (Harris 7:33–37;
see generally Ans. 4).
FF 3. Harris’ polymers
can be represented structurally as polya––P––CR(––Q––polyb)–
–Z or:

Polya and polyb represent nonpeptidic and substantially
nonreactive water soluble polymeric arms that may be the same
or different. C represents carbon. P and Q represent linkage
fragments that may be the same or different and that join
polymer arms polya and polyb, respectively, to C by
hydrolytically stable linkages in the absence of aromatic rings
in the linkage fragments. R is a moiety selected from the group
consisting of H, substantially nonreactive, usually alkyl,
moieties, and linkage fragments attached by a hydrolytically
stable linkage in the absence of aromatic rings to a nonpeptidic
and substantially nonreactive water soluble polymeric arm. The
moiety ––Z comprises a moiety selected from the group
consisting of moieties having a single site reactive toward
nucleophilic moieties, sites that can be converted to sites
reactive toward nucleophilic moieties, and the reaction product
of a nucleophilic moiety and moieties having a single site
reactive toward nucleophilic moieties.
Typically, the moiety ––P––CR(––Q––)––Z is the
reaction product of a linker moiety and the reactive site of
monofunctional, nonpeptidic polymer derivatives, polya––W
and polyb––W, in which W is the reactive site. Polymer arms
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polya and polyb are nonpeptidic polymers and can be selected
from polymers that have a single reactive moiety that can be
activated for hydrolytically stable coupling to a suitable linker
moiety. . . .
For example, in one embodiment polya and polyb are
each monomethoxy-poly(ethylene glycol) (“mPEG”) of the
same or different molecular weight. The mPEG-disubstituted
derivative has the general structure mPEGa––P––CH(Q––
mPEGb)––Z. The moieties mPEGa–– and mPEGb–– have the
structure CH3––(CH2CH2O)nCH2CH2–– and n may be the same
or different for mPEGa and mPEGb. Molecules having values
of n of from 1 to about 1,150 are contemplated.
(Harris 7:65–8:58; see Ans. 4.)
FF 4. Harris discloses that “moiety ––Z can include a reactive moiety or
functional group, which normally is a carboxyl moiety, hydroxyl moiety, or
activated carboxyl or hydroxyl moiety” (Harris 24:59–61; see Ans. 4).
FF 5. Harris’
moiety ––Z may also include a linkage fragment, represented
as RZ in the moiety, which can be substituted or unsubstituted,
branched or linear, and joins the reactive moiety to the central
carbon. Where a reactive group of the ––Z moiety is carboxyl,
for activation after substitution with nonpeptidic polymers, then
the ––Z moiety has the structure ––RZ––COOH if the RZ
fragment is present. For hydroxyl, the structure is
––RZ––OH. . . . It should be understood that the carboxyl and
hydroxyl moieties normally will extend from the RZ terminus,
but need not necessarily do so.
RZ can also include the reaction product of one or more
reactive moieties including reactive amino, thiol, or other
moieties, and a suitably activated mPEG arm or related
nonpeptidic polymer arm. In the latter event, RZ can have the
structure (––L––polyc)––COOH or (––L––polyc)––OH in which
––L–– is the reaction product of a portion of the linker moiety
and a suitably activated nonpeptidic polymer, polyc––W, which
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is selected from the same group as polya––W and polyb––W but
can be the same or different from polya––W and polyb––W.
(Harris 25:4–25 (emphasis added); see Ans. 4.)
FF 6. Examiner finds that although Harris discloses that the central core of
its polymer “can be anything with multiple attachment points” and
exemplifies a central core that is “lysine” or “diamino alcohol,” Harris does
not disclose “a hydroxymethyl propanediol core molecule” (Ans. 5 (citing
Harris 19:8, 24: 6–17 and 24:20)).
FF 7. Examiner relies on Lee to establish “that hydroxymethyl propanediol
is known in the art as a branch point for synthesizing multichain PEG
molecules” (Ans. 5; see also id. at 4–5 (citing Lee, Abstract, 1741:Scheme 1,
and 1742:Scheme 2)).
FF 8. Examiner finds that Harris discloses that suitable “PEG compounds
are [commercially available] from Shearwater polymer” (Ans. 4 (citing
Harris 15:19–20)).
FF 9. Examiner relies on Nektar, formally known as Shearwater, “which
describes generic branched chain PEG compounds,” to establish that
“polymers, in the size used by Harris . . ., have a polydispersity of
approximately 1.01-1.02” (Ans. 4 (citing Nektar, unnumbered page before
table of contents and page 25).
ANALYSIS
Examiner reasons:
Harris . . . describe[s] a molecule with two mPEG molecules
(with between 1-1,150 repeat units, greatly overlapping with
the polymer lengths described by the instant claims) attached
via a handful of linkages, including ether, to a central core,
which is also attached to a reactive group (which can be
hydroxyl). This reactive group can be connected via a PEG
spacer, again with 1-1,150 repeat units. Lee . . . describes using
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hydroxymethyl propanediol for as very similar purpose, which
would lead to ether linkages, which Harris . . . describe (and
lists as stable). Thus, the combination of references meets the
limitations of [Appellant’s] claims [1 and 24].
(Ans. 5; see FF 1–9.) Therefore, based on the combination of Harris, Lee,
and Nektar, Examiner concludes that, at the time Appellant’s invention was
made, it would have been prima facie
obvious to use hydroxymethylpropanediol as the central
molecule for the multiarm PEG molecules of Harris . . ., as this
is a simple substitution of one known element (the core element
of Lee . . .) for another (the core element of Harris . . .) yielding
expected results (a mulitarm PEG compound). As Lee . . .
use[s] this molecule for essentially the same purpose as Harris .
. ., and that reference defines their invention in a way that
would include this molecule, an artisan in this field would make
this substitution with a reasonable expectation of success.
(Ans. 5.)

Claim 1:
Harris discloses a monofunctional branched poly(ethylene glycol)
(PEG) comprising a reactive ––Z moiety (see FF 1–4). Harris discloses a
––Z moiety that includes a linkage fragment, RZ, which joins the reactive
moiety, ––Z, to the central carbon (FF 5). Thus, when the ––Z moiety is
carboxyl, “then the ––Z moiety has the structure ––RZ––COOH” and when
the ––Z moiety is a hydroxyl, “the structure is ––RZ––OH,” wherein “the
carboxyl and hydroxyl moieties normally will extend from the RZ terminus”
(id.). Harris discloses that “RZ can have the structure (––L––polyc)––COOH
or (––L––polyc)––OH,” wherein “––L–– is the reaction product of a portion
of the linker moiety and a suitably activated nonpeptidic polymer, polyc––
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W, which is selected from the same group as polya––W and polyb––W” (FF
5).
Harris discloses that polya and polyb “are nonpeptidic polymers and
can be selected from polymers that have a single reactive moiety that can be
activated for hydrolytically stable coupling to a suitable linker moiety,” such
as (CH2CH2O)nCH2CH2, wherein n is from 1 to about 1,150 (FF 3).
Therefore, we are not persuaded by Appellant’s contention that
Examiner incorrectly interpreted the length of Harris’ ––Z moiety as an
mPEG having “between 1 and 1,150 repeat units,” which, according to
Appellant, corresponds to the polya and polyb moieties of Harris’ polymer,
rather than the ––Z moiety (see Appeal Br. 6–7; see also id. at 7 (“Harris
does not distinctly teach or disclose a long polymer spacer between the
single reactive site with the moiety ––Z and the carbon center”); cf. Ans. 7
(Harris “explicitly states that the polymer used to link the reactive moiety
[––Z] to the central carbon can be the same as used for polya and polyb”); FF
3–5). For the same reasons, we are not persuaded by Appellant’s contention
that “Harris does not teach or disclose that RZ can contain a hydrolytically
stable polymer linkage with at least 11 oxyethylene units” (Appeal Br. 9) or
asserted “representative structure . . ., wherein, polyc is the grafted polymer
chain, and COOH is the merely one remain[ing] reactive moiety of RZ”
(Appeal Br. 11).
For the foregoing reasons, we are not persuaded by Appellant’s
contentions that Harris’ “limits the linkage length to 10 carbons or
equivalents for antigenic purposes, namely, alkyl fragments” and is different
from Appellant’s polymer linkage (Appeal Br. 7–8 (citing Harris 26:11–19);
cf. Ans. 8 (citing Harris 25:16–24) (Examiner asserts that Harris “explicitly
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discusses the polymer as part of a linking moiety.”); FF 3–5). See In re
Lamberti, 545 F.2d 747, 750 (CCPA 1976) (“A reference disclosure is not
limited only to its preferred embodiments, but is available for all that it
discloses and suggests to one of ordinary skill in the art.”).
Examiner relies on Lee to disclose the use of hydroxymethyl
propanediol, which is known in the art as a branch point for synthesizing
multichain PEG molecules, as the core of Harris’ monofunctional
derivatives of poly(ethylene glycol) (FF 6–7). We find no error in
Examiner’s conclusion that it would have been prima facie obvious to
substitute hydroxymethyl propanediol for Harris’ central core, which “can
be anything with multiple attachment points” (see Ans. 5 (Examiner
concludes that it would have been prima facie “obvious to use
hydroxymethylpropanediol as the central molecule for the multiarm PEG
molecules of Harris . . ., as this is a simple substitution of one known
element (the core element of Lee . . .) for another (the core element of
Harris . . .) yielding expected results (a multiarm PEG compound)”); see
also FF 6–7). Therefore, we are not persuaded by Appellant’s contentions
regarding the particulars of Lee’s synthesis method (Appeal Br. 11–12;
Reply Br. 4).
We find no polydispersity index limitation in Appellant’s claim 1.
Therefore, we are not persuaded by Appellant’s contentions regarding the
“polydispersity for a multi-branched polymer” (Appeal Br. 12–13; Reply Br.
2–4).

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Claim 24:
The monofunctional branched PEG of Appellant’s claim 24,
reproduced above, depends from and further limits n3, of Appellant’s claim
1, to a value selected from 68 to 1000.
The combination of Harris, Lee, and Nektar makes obvious a
monofunctional branched PEG, wherein the PEG moieties have the structure
CH3––(CH2CH2O)nCH2CH2–– and n is from 1 to about 1,150 (FF 3). Thus,
the combination of Harris, Lee, and Nektar makes obvious a monofunctional
branched PEG that encompasses Appellant’s claim 24. See Iron Grip
Barbell Co. v. USA Sports, Inc., 392 F.3d 1317, 1322 (Fed. Cir. 2004)
(“[W]here there is a range disclosed in the prior art, and the claimed
invention falls within that range, there is a presumption of obviousness.”).
We find no polydispersity index limitation in Appellant’s claim 24.
Therefore, we are not persuaded by Appellant’s contentions regarding
polydispersity (Appeal Br. 13–14).
CONCLUSION
The preponderance of evidence relied upon by Examiner supports a
conclusion of obviousness. The rejection of claims 1 and 24 under
35 U.S.C. § 103(a) as unpatentable over the combination of Harris, Lee, and
Nektar is affirmed. Claims 2, 8, 9, 19, 25–27, 34, 36, 38, 39, and 41 are not
separately argued and fall with claim 1.

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DECISION SUMMARY
In summary:
Claim(s)
Rejected
35 U.S.C. § Reference(s)/Basis Affirmed Reversed
1, 2, 8, 9, 19,
24–27, 34, 36,
38, 39, 41
103 Harris, Lee, Nektar 1, 2, 8, 9,
19, 24–27,
34, 36, 38,
39, 41

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