Ex Parte Ng et al

Board of Patent Appeals and Interferences

Mar 24, 2005

09854435 (B.P.A.I. Mar. 24, 2005)

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The opinion in support of the decision being entered
today was not written for publication and is not binding
precedent of the Board.

UNITED STATES PATENT AND TRADEMARK OFFICE
_______________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
_______________

Ex parte STEVEN Y. NG
and JORGE HELLER
______________

Appeal No. 2005-0590
Application 09/854,435
_______________

ON BRIEF
_______________

Before KIMLIN, WARREN and KRATZ, Administrative Patent Judges.

WARREN, Administrative Patent Judge.
Decision on Appeal
This is an appeal under 35 U.S.C. § 134 from the decision of the examiner finally
rejecting claims 1 through 14 and 17 through 19. Claims 20 through 35 are also of record and
have been withdrawn from consideration by the examiner under 37 CFR § 1.142(b).
Claim 1 illustrates appellants’ invention of a polyorthoester, depicted by the structural
formula set forth in this claim, which polymers are disclosed to be bioerodible and thus useful in,
for example, orthopedic implants and vehicles for controlled release drug delivery (specification,
e.g., pages 5-6). A copy of appealed claim 1 taken from appellants’ brief is appended to this
decision.

The references relied on by the examiner are:
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Application 09/854,435
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Sparer et al. (Sparer) 4,549,010 Oct. 22, 1985
Heller et al. (Heller) 5,968,543 Oct. 19, 1999
The examiner has rejected appealed claims 1 through 14 and 17 through 19 under 35
U.S.C. § 103(a) as being unpatentable over Heller combined with Sparer (answer, page 3).1
Appellants state that they “will argue the patentability of appealed claims 1-14 and 17-19
together” (brief, page 3). Thus, we decide this appeal based on appealed claim 1. 37 CFR
§ 1.192(c)(7) (2003); see also 37 CFR § 41.37(c)(1)(vii) (effective September 13, 2004; 69 Fed.
Reg. 49960 (August 12, 2004); 1286 Off. Gaz. Pat. Office 21 (September 7, 2004)).
We affirm.
Rather than reiterate the respective positions advanced by the examiner and appellants,
we refer to the answer and to the brief for a complete exposition thereof.
Opinion
The review of the ground of rejection of claim 1 requires that we first interpret this claim
by giving the language thereof the broadest reasonable interpretation in light of the written
description in appellants’ specification as it would be interpreted by one of ordinary skill in this
art, without reading into the claim any limitation or particular embodiment disclosed in the
specification. See In re Morris, 127 F.3d 1048, 1054-55, 44 USPQ2d 1023, 1027 (Fed. Cir.
1997); In re Zletz, 893 F.2d 319, 321-22, 13 USPQ2d 1320, 1322 (Fed. Cir. 1989); In re Priest,
582 F.2d 33, 37, 199 USPQ 11, 15 (CCPA 1978). The structural formulae and accompanying
formula member and subscript definitions depict any polyorthoester falling within formula (I),
wherein formula member “A” must be “R1” and “R4” to the extent of “at least 0.1 mol% of
the A units,” with no further limitation on the number of units of each of the components “A is
R1, R1, R1, or R1” selected to constitute 100 mol% of the “A units,” and wherein subscript “n” is

1 The examiner states that the ground of rejection is set forth in the prior Office action mailed
February 26, 2003. At page 2 of this Office action, the examiner refers to the prior Office action
mailed September 27, 2002. While the examiner has not stated the ground of rejection in the
answer or incorporated the ground of rejection from a single prior Office action as permitted by
the practice in Manual of Patent Examining Procedure §§ 1208 (8th ed., Rev. 2, May 2004;
1200-17), we will not in this instance remand the application to the examiner for the purpose of
preparing a supplemental examiner’s answer to cure this deficiency because we find consistent
statements of the ground of rejection in the above two Office actions, and so have considered the
ground of rejection advanced on appeal.
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Application 09/854,435
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the range of “units” or “segments” in a polyorthoester chain of “at least 5” to no specified upper
limit. We note that there is no limitation on the manner in which the claimed polyorthoesters are
prepared, and thus the claimed polyorthoesters include block as well as random distribution of
the “units” or ‘segments” in the polymer chain. See generally, In re Thorpe, 777 F.2d 695, 697,
227 USPQ 964, 966 (Fed. Cir. 1985).2
We find that Sparer would have disclosed to one of ordinary skill in this art
polyorthoester polymers which are prepared by reacting a diketene acetal with certain diols,
wherein the diols are reacted either separately, to form a block copolymer, or in admixture, to
form a random polymer (e.g., col. 1, ll. 33-35, and col. 4, ll. 36-45). One of ordinary skill in this
art routinely following the teachings of Sparer would have arrived at polyorthoesters which
contain units that correspond to “A units” “R2,” “R3” and “R4” of structural formula (I) of
appealed claim 1, wherein the units are hard or rigid units, flexible or soft units, and hard or rigid
units, respectively, and unit “R4” is a hydrogen bonding unit containing at least one amide,
imide, urea and urethane group (e.g., col. 2, l. 42, to col. 3, l. 43, col. 3, l. 65, col. 4, ll. 13-19).
The amounts of and arrangement of the respective units in the polyorthoesters are disclosed to be
based on the properties desired for bioerodibility and in the fabrication of medical devices, such
as implants, and controlled release drug delivery forms, wherein the polymer can be cross-linked
(e.g., col. 1, ll. 7-22 and 34-68, col. 2, ll. 2-28, col. 4, ll. 16-45). Thus, because the hydrogen
bonding unit can be present at least in some amount, the polyorthoesters of Sparer differ from the
claimed polyorthoesters encompassed by claim 1 in the absence of unit(s) corresponding to “A
unit” “R1,” that is, wherein “A” is derived from an α-hydroxyacid containing diol to provide
units of the structure shown in the claim 1 (specification, e.g., page 5, ll. 19-21).

2 We note, in this respect, that appealed claim 17 is drawn to a method of preparing a claimed
polyorthoester wherein a diketene diacetal is reacted with at least two and optionally more diols
without specifying whether the diols are reacted with the diketene acetal separately, resulting in
a block polymer, or in mixtures, resulting in a random polymer. See also specification, e.g., page
13, l. 23, to page 14, l. 2, and page 16, l. 27, to page 17, l. 2. In contrast, appealed claims 18 and
19 are couched in product-by-process format wherein the claimed polyorthoester product is
characterized as being prepared by the reaction of a diketene diacetal and a polyol or mixture of
polyols even though diols are structurally depicted and specified in these claims. See Thorpe,
supra. We interpret claims 18 and 19 to encompass random or block polyorthoesters
encompassed by appealed claim 1.
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We further find that Heller would have disclosed polyorthoester polymers which are
prepared from a diketene acetal and a mixture of diols to form a random polymer (e.g., col. 2, ll.
11-22, col. 5, l. 18, to col. 7, l. 63, and col. 8, l. 52, to col. 9, l. 26). One of ordinary skill in this
art routinely following the teachings of Heller would have arrived at polyorthoesters which
contain units that correspond to “A units” “R1,” “R2” and “R3” to provide units of the structure
shown in of structural formula (I) of appealed claim 1, wherein the former unit is derived from
an α-hydroxyacid containing diol and the latter two units are hard or rigid units and flexible
or soft units, respectively, and (e.g., col. 5, l. 58, to col. 6, l. 32, col. 6, l. 33 and 45-65, and col.
4, ll. 1 and 11-27). The amounts of and arrangement of the respective units in the
polyorthoesters are disclosed to be based in the properties desired for bioerodibility and in the
fabrication of medical devices such as implants, and controlled release drug delivery forms,
wherein the polymer can be cross-linked (e.g., col. 1, ll. 16-22, col. 2, ll. 12-18, col. 5, ll. 31-32,
col. 7, ll. 55-67, and col. 10, ll. 15-54). Thus, because the units is derived from α-hydroxyacid
containing diols can be present at least in some amount, the polyorthoesters of Heller differ from
the claimed polyorthoesters encompassed by claim 1 in the absence of unit(s) corresponding to
“A unit” “R4,” that is, hydrogen bonding unit(s) containing at least one amide, imide, urea and
urethane group.
The examiner finds that, prima facie, one of ordinary skill in the art would have modified
the polyorthoester polymers of Heller by using the hydrogen bonding unit(s) containing at least
one amide, imide, urea and urethane group as taught by Sparer in the expectation of obtaining
bioerodible polyorthoester polymers, pointing out that the polyorthoesters of each reference are
prepared in the same manner from diketene acetals and diols (Office action, mailed September
27, 2002; pages 2-3; see also answer, pages 3-4).
We find in the combined teachings of Heller and Sparer substantial evidence supporting
the examiner’s position with respect to appealed claim 1 as we have interpreted this claim above.
We determine that in view of the common polyorthoester chemical structure, the common
bioerodible-based utility, the common method of preparation as random polymers, and the
common direction in these references to use the same type of groups that provide bioerodibility
to the polyorthoesters for purposes of the common utility, there is in the combined teachings of
Heller and Sparer ample direction to one of ordinary skill in this art to use the hydrogen bonding
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Application 09/854,435
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units of Sparer in the polyorthoesters of Heller in the reasonable expectation of obtaining
bioerodible polyorthoester polymers having the same or similar properties, as submitted by the
examiner. Indeed, we find that these same facts provide substantial support for the position that,
prima facie, one of ordinary skill in this art would have modified the polyorthoesters of Sparer
by using the α-hydroxyacid containing unit(s) taught by Sparer in the reasonable expectation of
obtaining bioerodible polyorthoester polymers having the same or similar properties.
Accordingly, we are convinced that, prima facie, one of ordinary skill in this art routinely
following the combined teaching of Heller and Sparer would have reasonably arrived at the
claimed polyorthoester polymers encompassed by claim 1, without resort to the written
description in appellants’ specification. See In re Payne, 606 F.2d 303, 315, 203 USPQ 245,
254-55 (CCPA 1979) (“An obviousness rejection based on similarity in chemical structure and
function entails the motivation of one skilled in the art to make a claimed compound, in the
expectation that compounds similar in structure will have similar properties.”); see also In re
Dillon, 919 F.2d 688, 692-93, 16 USPQ2d 1897, 1901 (Fed. Cir. 1990)(in banc) (“This court . . .
reaffirms that structural similarity between claimed and prior art subject matter, proved by
combining references or otherwise, where the prior art gives reason or motivation to make the
claimed compositions, creates a prima facie case of obviousness, and that the burden (and
opportunity) then falls on an applicant to rebut that prima facie case.”); In re Grabiak, 769 F.2d
729, 731-32, 226 USPQ 870, 872 (Fed. Cir. 1985) (“[W]e have concluded that generalizations
should be avoided insofar as specific chemical structures are alleged to be prima facie obvious
one from the other. . . . [I]n the case before us there must be adequate support in the prior art for
the ester/thioester change in structure, in order to complete the PTO’s prima facie case and shift
the burden of going forward to the applicant.”).
We have determined that the examiner has advanced a prima facie case of obviousness
and thus, we again evaluated all of the evidence of obviousness and nonobviousness based on the
record as a whole in light of appellants’ rebuttal arguments in the brief. See generally, In re
Oetiker, 977 F.2d 1443, 1445, 24 USPQ2d 1443, 1444 (Fed. Cir. 1992); In re Piasecki, 745 F.2d
1468, 1472, 223 USPQ 785, 788 (Fed. Cir. 1984).
Appellants submit that the examiner has not established a prima facie case of
obviousness because one of ordinary skill in the art would not look to Sparer to modify Heller,
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Application 09/854,435
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contending that this person would have understood that Heller is “directed to a random
copolymer,” and while Sparer “does permit random copolymerization,” that for Sparer to
“achieve the stated goal of providing a thermoplastic elastomer, the poly(ortho ester) can not be
a random copolymer but must be a block copolymer” (brief, page 5). Thus, appellants argue that
no reason has been advanced for making the proposed modification.
In order to render the claimed polyorthoesters obvious within the meaning of § 103(a),
the combined teachings of Heller and Sparer must provide an enabling disclosure that places the
claimed polyorthoesters in the possession of the public. Payne, 606 F.2d at 314, 203 USPQ at
255. Here, as we found above, Sparer discloses the preparation of random polyorthoester
polymers as does Heller. Appellants’ contrary allegations that one of ordinary skill in this art
would necessarily have to form a block copolymer to obtain the thermoplastic elastomeric
polyorthoesters of Sparer are unsupported and thus, are entitled to little, if any, weight,
particularly since appellants’ position, in this respect, encompasses the allegation that Sparer
does not operably enable the random polyorthoester polymers encompassed by, e.g., Sparer
patent claim 1. See Payne, 606 F.2d at 315, 203 USPQ at 256; In re Lamberti, 545 F.2d 747,
751, 751 n.2, 192 USPQ 278, 281, 281 n.2 (CCPA 1976); In re Weber, 405 F.2d 1403, 1406-07,
160 USPQ 549, 552-53 (CCPA 1969).
We find that appellants have failed to carry the burden of establishing the patentability of
the claimed polyorthoester polymers encompassed by appealed claim 1 over the combined
teachings of Heller and Sparer by presenting effective argument or objective evidence
establishing that the claimed polyorthoester polymers possess unexpectedly advantageous or
superior properties. See Payne, 606 F.2d at 315, 203 USPQ at 256.
Accordingly, based on our consideration of the totality of the record before us, we have
weighed the evidence of obviousness found in the combined teachings of Heller and Sparer with
appellants’ countervailing evidence of and argument for nonobviousness and conclude that the
claimed invention encompassed by appealed claims 1 through 14 and 17 through 19 would have
been obvious as a matter of law under 35 U.S.C. § 103(a).
The examiner’s decision is affirmed.

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Application 09/854,435
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No time period for taking any subsequent action in connection with this appeal may be
extended under 37 CFR § 1.136(a)(1)(iv) (effective September 13, 2004; 69 Fed. Reg. 49960
(August 12, 2004); 1286 Off. Gaz. Pat. Office 21 (September 7, 2004)).
AFFIRMED

Appeal No. 2005-0590
Application 09/854,435
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EDWARD C. KIMLIN )
Administrative Patent Judge )
)
)
)
CHARLES F. WARREN ) BOARD OF PATENT
Administrative Patent Judge ) APPEALS AND
) INTERFERENCES
)
)
PETER F. KRATZ )
Administrative Patent Judge )

Appendix

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Application 09/854,435
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Appeal No. 2005-0590
Application 09/854,435
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Heller Ehrman White & Mcauliffe LLP
275 Middlefield Road
Menlo Park, CA 94025-3506