Ex Parte Pacetti et al

Patent Trial and Appeal Board

Sep 12, 2013

11824011 (P.T.A.B. Sep. 12, 2013)

UNITED STATES PATENT AND TRADEMARK OFFICE
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BEFORE THE PATENT TRIAL AND APPEAL BOARD
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Ex parte STEPHEN D. PACETTI and MIKAEL TROLLSAS
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Appeal 2012-001376
Application 11/824,011
Technology Center 1600
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Before LORA M. GREEN, MELANIE L. McCOLLUM, and
ULRIKE W. JENKS, Administrative Patent Judges.

GREEN, Administrative Patent Judge.

DECISION ON APPEAL
This is a decision on appeal1 under 35 U.S.C. § 134 from the
Examiner’s rejection of claims 1-5, 7 and 9-39. We have jurisdiction under
35 U.S.C. § 6(b).
We affirm.

1 The Real Party in Interest is Abbott Cardiovascular Systems, Inc. (Appeal
Br. 2.)
Appeal 2012-001376
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STATEMENT OF THE CASE
The Specification discloses “biodegradable polymeric materials used
for implantable devices (e.g., stents)” (Spec. 2, ¶ 0007). The Specification
discloses that the “polymeric materials are configured to completely or
substantially completely erode after the devices accomplish their intended
functions (e.g., maintaining vascular patency and locally delivering drugs),
thereby avoiding adverse effects such as late stent thrombosis” (id.). The
Specification discloses, as one embodiment, “a composition comprising a
biodegradable triblock copolymer of the structure A-B-A’” (id. at 2, ¶ 0008).
Claim 1, the only independent claim, reads as follows:
1. A composition comprising a biodegradable triblock copolymer of
the structure A-B-A’, wherein:
the A and A’ blocks each independently are hard blocks having a Tg
or Tm above body temperature;
the B block is a soft block having a Tg less than the Tg or Tm of the A
and A’ blocks;
the A, B and A’ blocks each independently have a polymer number-
average molecular weight (Mn) from about 1 kDa to about 500 kDa; and
the A and A’ blocks may be the same or different.

Issue
The Examiner has rejected claims 1, 2, 4, 5, 7, 9, 12-18, 21-23, 25-27,
29, 31-34 and 36-392 under 35 U.S.C. § 103(a) as obvious in view of

2 The “Status of Claims” section of the Appeal Brief (page 2) includes claim
39 as one of the claims being appealed (App. Br. 2). The Examiner’s
rejections do not specifically refer to that claim. We conclude that omission
to be a typographical error on the part of the Examiner, as the Advisory
Action dated September 15, 2010, states that claim 39 is rejected.
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Pacetti ‘8883 and DesNoyer.4 As Appellants do not argue the claims
separately, we focus our analysis on claim 1, and claims 2, 4, 5, 7, 9, 12-18,
21-23, 25-27, 29, 31-34 and 36-39 stand or fall with that claim. 37 C.F.R.
§ 41.37(c)(1)(vii). The Examiner has also rejected claims 3, 10, 11, 19, 20,
24, 28, 30 and 35 under 35 U.S.C. § 103(a) in view of Pacetti ‘888 and
DesNoyer, and further in view of one of Hossainy ‘203,5 Hossainy ‘1026 or
Pacetti ‘454.7 We will consider these rejections together since Appellants
rely on the arguments made with respect to claim 1 as to claims 3, 10, 11,
19, 20, 24, 28, 30 and 35 (Appeal Br. 7-8).
The Examiner finds that Pacetti ‘888 discloses “a composition
comprising a biodegradable triblock copolymer of the structure A-B-A’ …
[such that] the A block contains monomers chosen from glycolide and D, L
Lactide, and specifically teaches poly(D, L, co-glycolide)” (Ans. 4).8 The
Examiner finds that Pacetti ‘888 discloses that the “B [b]lock is comprised
of biologically compatible polymers which include caprolactone and
glycolide” (id. at 4-5). The Examiner finds that Pacetti ‘888 discloses “a
triblock copolymer of the structure A-B-A which is then coupled to the X
moiety … [such that] the block copolymer exists in the form A-B-A prior to
coupling to the X moiety,” wherein “X” is a linking moiety (id. at 12, citing
Pacetti ‘888 at ¶ 0090). According to the Examiner, “[b]ecause the block

3 Pacetti et al. ‘888, U.S. 2006/0034888 A1, published Feb. 16, 2006.
4 DesNoyer et al., U.S. 2006/0089485 A1, published Apr. 27, 2006.
5 Hossainy et al., ‘203, U.S. 2004/0253203 A1, published Dec. 16, 2004.
6 Hossainy et al., ‘102, U.S. 2006/0041102 A1, published Feb. 23, 2006.
7 Pacetti ‘454, U.S. 7,563,454 B1, issued Jul. 21, 2009.
8 All references to the Examiner’s Answer refer to the Answer mailed on
August 2, 2011.
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copolymer exists in the form A-B-A prior to coupling to the X moiety, the
fact that the triblock copolymer may then be linked is irrelevant” (id.).
The Examiner relies on DesNoyer to supply dependent claim
limitations, i.e. the Examiner finds that Pacetti ‘888 “does not teach [that]
the B block includes the monomer trimethylene carbonate” (id. at 5).
Appellants contend that the cited references would not have made
obvious a composition comprising a polymer with the A-B-A’ structure
recited in claim 1 because the triblock A-B-A polymers of Pacetti ‘888 are
linked to other polymeric entities (Appeal Br. 5-6). The issue presented is:
Does the evidence of record support the Examiner’s conclusion that the cited
references would have made obvious the claim 1 composition comprising a
biodegradable triblock copolymer with the structure A-B-A’ and with the
recited properties for the A, B and A’ blocks?
Findings of Fact
FF1. The disclosure as filed teaches that A and A’ made of poly(L-lactide)
(PLLA), poly(D,L-lactide) or poly(glycolide) (PGA), among others, have a
Tg or Tm above body temperature (Spec. 51, claims 1 and 7).
FF2. Pacetti ‘888 discloses “coatings for drug delivery devices, such as
drug eluting vascular stents” (Pacetti 1, ¶ 0002).
FF3. Pacetti ‘888 discloses block-copolymers shown by Formula I,
reproduced below:

“wherein A are blocks of a poly(hydroxyacids) or a poly(hydroxy-
alkanoate), B are blocks of a polymeric biocompatible moiety, X is a linking
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moiety, and n is an integer having a value between about 1 and about 880”
(id. at 3, ¶¶ 0044-0045).
FF4. Pacetti ‘888 discloses that the “number average molecular weight of
a poly(hydroxyacid) or poly(hydroxy-alkanoate) A-blocks can be between
about 72 and about 100,000 Daltons” (id. at 3, ¶ 0046).
FF5. Pacetti ‘888 discloses that A blocks may be polylactides, among
other things (id. at 3, ¶ 0044).
FF6. Pacetti ‘888 discloses that “B-blocks are biologically compatible
polymers … [that] include … poly(alkylene glycols), for example, PEG” (id.
at 4, ¶¶ 0069-0070).
FF7. Pacetti ‘888 discloses that a “molecular weight of a suitable
biocompatible polymeric moiety can be … between about 100 and about
40,000 Daltons” (id. at 4, ¶¶ 0086).
FF8. DesNoyer discloses “an end-capped poly(ester amide) [(]PEA) …
polymer … [which] can form a coating on an implantable device”
(DesNoyer, abstract).
FF9. DesNoyer discloses that the end-capped PEA polymer can be used in
conjunction with a biobeneficial material and with one or more
biocompatible polymers (id. at 2, ¶ 0011).
FF10. DesNoyer discloses that “[g]enerally, the biobeneficial material has a
relatively low glass transition temperature (Tg), e.g., a Tg below … that of
the biocompatible polymer” (id. at 6, ¶ 0036).
FF11. DesNoyer discloses that “[r]epresentative biobeneficial materials
include, but are not limited to, polyethers such as poly(ethylene glycol)” (id.
at 6, ¶ 0038).
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Principles of Law
“In cases involving overlapping ranges … even a slight overlap in
range establishes a prima facie case of obviousness.” In re Peterson, 315
F.3d 1325, 1329 (Fed. Cir. 2003). In addition, as noted by Peterson, “[t]he
normal desire of scientists or artisans to improve upon what is already
generally known provides the motivation to determine where in a disclosed
set of percentage ranges is the optimum combination of percentages.” Id. at
1330.
Analysis
Claim 1 discloses a composition comprising a biodegradable triblock
copolymer of the structure A-B-A’, wherein the A and A’ blocks may be the
same or different and wherein the A, B, and A’ blocks each have a polymer
number-average molecular weight (Mn) from about 1 kDa to about 500 kDa.
Claim 1 also requires that the A and A’ blocks are hard blocks having a Tg
or Tm above body temperature. Claim 1 also requires that the B block is a
soft block having a Tg less than the Tg or Tm of the A and A’ blocks. Thus,
since the A and A’ blocks of claim 1 may be the same or different, claim 1 is
directed to a triblock copolymer having the structure A-B-A’ or A-B-A.
Pacetti ‘888 discloses block copolymers having the Formula I, which
is as follows: A-[-B-A-X-A-]n-B-A, wherein A blocks are
poly(hydroxyacids) or a poly(hydroxy-alkanoate) and B blocks are a
polymeric biocompatible moiety. Pacetti ‘888 discloses that, in Formula I,
X is a linking moiety and n is an integer having a value between 1 and 880.
Pacetti discloses that one way to synthesize the compound of Formula I is to
first form ABA blocks and then link them together with a linking component
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X. Thus, Pacetti ‘888 discloses the synthesis of the triblock-copolymer
poly(lactic acid) (PLA)-polyethylene glycol (PEG)-poly(lactic acid) (PLA),
i.e. PLA-PEG-PLA, and the subsequent linking together of the tri-block
polymers to form PLA-[PEG-PLA-X-PLA]n-PEG-PLA. Thus, as
recognized by the Examiner (Ans. 12), a composition comprising tri-block
polymers of the structure A-B-A would have been present prior to the
linking step. Pacetti ‘888 discloses that the average molecular weight of the
A-blocks and the B-blocks, is between about 72 and about 100,000 Daltons
and between about 100 and about 40,000 Daltons, respectively. Thus, the
instantly claimed size range for the A, A’, and B blocks of 1 kDa to about
500 kDa (i.e. 1000 Daltons to 500,000 Daltons) overlaps the size ranges
disclosed for the A and B blocks of Pacetti ‘888. In accord, with In re
Peterson a slight overlap in range establishes a prima facie case of
obviousness. Thus, Pacetti would have made obvious the A-B-A’ or A-B-A
triblock polymer composition as encompassed by claim 1.
Appellants argue that Pacetti ‘888 discloses “multi-block copolymers
wherein various blocks are joined … together by linking moieties designated
as ‘X’ in the structures. Thus, Pacetti [‘888] … does not render the general
triblock structure of the current invention obvious” (Appeal Br. 5-6).
Appellants argue that Pacetti’s only disclosure of “a separate and distinct
triblock copolymer is … [the disclosure of] PLA-PEG-PLA or PEG-PLA-
PEG … [with] PLA being poly(lactic acid) and PEG being polyethylene
glycol” (Reply Br. 3). Appellants argue that Pacetti’s “triblock copolymer is
then linked together with some other polymeric entity using an ‘X’” (id.).
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This argument is not persuasive. As recognized by Appellants, Pacetti
discloses a composition comprising a PLA-PEG-PLA triblock polymer. The
fact that Pacetti also discloses that the triblock polymer may then be used to
synthesize a different polymer by linking the triblock polymers does not
negate Pacetti’s disclosure of a composition comprising an ABA triblock
copolymer.
Appellants argue that Pacetti ‘888 does not discuss “the properties of
the individual block of the copolymer or the interrelation between the
properties of the end blocks and the center block as expressly required by
[instant] claim 1” (Reply Br. 3). That argument is not persuasive. We note,
however, that absent a showing of good cause, the Board is not required to
address arguments in the Reply Brief that could have been presented in the
principal Brief. See Ex parte Borden, 93 USPQ2d 1473, 1474 (BPAI 2010)
(“informative”).
Thus, we affirm the rejection of claim 1 as obvious in view of Pacetti
‘888 and DesNoyer. Claims 2, 4, 5, 7, 9, 12-18, 21-23, 25-27, 29, 31-34,
and 36-39 fall with that claim. We also affirm remaining obviousness
rejection as Appellants only repeat the arguments made with respect to
claim 1.
Conclusion of Law
The evidence of record supports the Examiner’s conclusions that the
cited references would have made obvious the claim 1 composition
comprising a biodegradable triblock copolymer with the structure A-B-A’
and with the recited properties for the A, B, and A’ blocks.
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SUMMARY
We affirm the rejection of claims 1-5, 7 and 9-39 under 35 U.S.C.
§ 103(a).
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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