Ex Parte Chang et al

Patent Trial and Appeal Board

Sep 15, 2017

12545812 (P.T.A.B. Sep. 15, 2017)

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.
12/545,812 08/22/2009 Han-Ting Chang RLY 07071.301 2182
79158 7590 09/19/2017
Senniger Powers LLP (RLY)
100 NORTH BROADWAY
17TH FLOOR
ST. LOUIS, MO 63102
EXAMINER
GULLEDGE, BRIAN M
ART UNIT PAPER NUMBER
1612
NOTIFICATION DATE DELIVERY MODE
09/19/2017 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):
uspatents @ senniger.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte HAN-TING CHANG, DOMINIQUE CHARMOT, MINGJUN
LIU, and WENER STRUVER
Appeal 2015-0064391
Application 12/545,812
Technology Center 1600
Before RICHARD M. LEBOVITZ, TAWEN CHANG, and
RYAN H. FLAX, Administrative Patent Judges.
LEBOVITZ, Administrative Patent Judge.
DECISION ON APPEAL
This appeal involves claims directed to a crosslinked cation exchange
polymer. The Examiner rejected the claims under 35 U.S.C. § 103 as
obvious and under 35 U.S.C. § 112 as lacking a written description. We
have jurisdiction under 35 U.S.C. § 6(b). The rejections are affirmed.
1 The Appeal Brief (“Appeal Br.”) 2 identifies Relypsa, Inc., as the real-
party-in-interest.
Appeal 2015-006439
Application 12/545,812
STATEMENT OF THE CASE
The claimed crosslinked cation exchange polymer is described in the
Specification as useful to bind excess potassium cations in the
gastrointestinal tract when administered to a patient having a potassium
excess. Spec. Tflf 2-4. The condition of excess potassium in a patient is also
known as “hyperkalemia.” Id.
Claims 1, 4, 6—9, 13, 16, 17, 22, 25, 28, and 30 are pending and stand
rejected by the Examiner as follows:
1. Claims 1, 4, 6—9, 13, 16, 17, 22, 25, 28, and 30 under pre-AIA 35
U.S.C. § 103(a) as obvious in view of PCT Patent Application Publication
WO 2007/041569 Al, publ. Apr. 12, 2007 (“Cope”) and U.S. Patent
Application Publication 2005/0220751 Al, publ. Oct. 6, 2005 (“Charmot”).
Examiner’s Answer, Apr. 17, 2015 (“Ans.”) 3; and
2. Claims 1, 4, 6, 7, 13, 16, 17, 22, 25, and 30 under pre-AIA 35
U.S.C. § 112 (pre-AIA), first paragraph, as failing to comply with the
written description requirement. Ans. 2.
Claims 1 and 8 are the only independent claims on appeal. Claim 1 is
representative and reads as follows:
1. A crosslinked cation exchange polymer in acid or salt
form comprising a reaction product of a hydrolysis agent and a
crosslinked cation exchange polymer, the crosslinked cation
exchange polymer being a reaction product of a polymerization
mixture comprising three or more monomers, the monomers
corresponding to Formula 11, Formula 22, and Formula 33;
wherein
(i) the monomers corresponding to Formula 11 constitute
at least about 85 wt.% based on the total weight of monomers
of Formulae 11, 22, and 33 in the polymerization mixture, and
the weight ratio of the monomer corresponding to Formula 22
to the monomer corresponding to Formula 33 is from about 4:1
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Application 12/545,812
to about 1:4, or
(ii) the mole fraction of the monomer of Formula 11 in
the polymerization mixture is at least about 0.87 based on the
total number of moles of the monomers of Formulae 11, 22, and
33, and the mole ratio of the monomer of Formula 22 to the
monomer of Formula 33 in the polymerization mixture is from
about 0.2:1 to about 7:1, and
Formula 11, Formula 22, and Formula 33 correspond to
the following structures:
Fosnnuk 22 Formula 33
wherein
Ri and R2 are each independently hydrogen, alkyl,
cycloalkyl, or aryl;
Ai 1 is an optionally protected carboxylic, phosphonic, or
phosphoric;
Xi is arylene; and
X2 is alkylene, an ether moiety or an amide moiety, and
wherein the overall yield of the crosslinked cation
exchange polymer in acid or salt form is at least 90%.
OBVIOUSNESS REJECTION
The claims are drawn to a crosslinked cation exchange polymer which
is a reaction product of a hydrolysis agent and a crosslinked cation exchange
polymer.
The crosslinked cation exchange polymer is further claimed as a
reaction product of a polymerization mixture of monomers corresponding to
1) Formula 11; 2) Formula 22, and 3) Formula 33. Each claimed formula
represents a genus of structures. In dependent claim 2, species of the genus
are claimed: Formula 11 is a protected fluoroacrylate; Formula 22 is
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Application 12/545,812
divinylbenzene (also referred to as “DVB”); and Formula 33 is 1,7-
octodiene (also referred to as “ODE”).
The claim requires each of the monomers to be present in specific
weights, weight ratios, and mole fractions. See claim limitations (i) and (ii).
The claim is a product-by-process claim, i.e., the product is claimed as
a reaction product of hydrolysis and polymerization of three specific
monomers. A product-by-process limitation defines a product in terms of
how it is made. SmithKline Beecham Corp. v. Apotex Corp., 439 F.3d 1312,
1315 (Fed. Cir. 2006). “[E]ven though product-by-process claims are
limited by and defined by the process, determination of patentability is based
on the product itself.” In re Thorpe, 111 F.2d 695, 697 (Fed. Cir. 1985).
The claim recites that “the overall yield of the crosslinked cation
exchange polymer in acid or salt form is at least 90%.” Thus, the hydrolysis
and polymerization processes used to produce the polymer result in a yield
of 90% of the claimed polymer. However, only the polymer in pure form is
claimed.
Rejection
The Examiner found that Cope discloses “polymerized 2-fluoroacrylic
acid and the crosslinking agent is selected from a group consisting of
divinylbenzene, 1,7-octadiene, and combinations thereof,” which correspond
to Formula 11, Formula 22, and Formula 33, respectively, of claim 1. Ans.
3. The Examiner found that Cope does not describe the amounts and ratios
recited in claim limitations (i) and (ii). However, the Examiner found that
Charmot discloses polymers for the same purpose of Cope, namely, binding
potassium cations and treating hyperkalemia. Id. Example 5 of Charmot, as
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acknowledged by Appellants, further teaches hydrolysis of the polymerized
2-fluoroacrylic acid and cross-linker (divinylbenzene) (the claim is directed
to a crosslinked cation exchange polymer, which is a reaction product of a
hydrolysis agent and a crosslinked cation exchange polymer, and thus
includes hydrolysis). Charmot para. 151; Appeal Br. 7. The Examiner also
found that Charmot’s polymer comprises fluoroacrylic acid and
divinylbenzene as a cross-linker in amounts and proportions that overlap
with the claims. Ans. 3^4. Based on this overlap, the Examiner found the
claim limitations obvious. Id. at 4.
Lead compound
Applicants contend that Cope does not suggest to one of skill in the
art that one would have selected alpha-fluoroacrylic acid crosslinked with at
least two crosslinking agents as the lead compound. Appeal Br. 12.
Appellants contend that “the only in vitro data disclosed by the Cope
reference might not have suggested starting with an alpha-fluoroacrylate
polymer as the most promising compound for further development” because
it was used with “vinyl-benzyl-polyethyleneimine” and not with DVB or
ODE as disclosed in Cope and claimed. Id. at 12—13.
This argument is not persuasive. Paragraph 105 of Cope expressly
states that in “some preferred embodiments the core-component polymer
comprises 2-fluoroacrylic acid [claimed formula 11 compound] crosslinked
with a crosslinking agent.” The same paragraph states that in “some
preferred embodiments, the crosslinking agents are selected from
divinylbenzene [DVB], 1,7-octadiene [ODE], 1,4-divinyloxybutane, and
combinations thereof.” The latter two monomers fall within the scope of the
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claimed Formula 22 and Formula 33 compounds. The fact that a different
cross-linking agent was used in Example 21 does not negate the other
disclosure in Cope characterizing DVB and ODE as preferred. Appellants
also have not addressed Charmot which also teaches using fluoroacrylic acid
and divinylbenzene as a cross-linker (see above).
Appellants argue that the skilled worker would have selected
KAYAXELATE®, the “only commercially available polymer product for
removing potassium from the gastrointestinal tract to treat hyperkalemia . . .
as the most promising compound for further development.” Appeal Br. 13.
According to Appellants, “KAYEXALATE® comprises a polystyrene
sulfonate monomer crosslinked with a divinylbenzene crosslinking
monomer.” Id.
We are not persuaded by the Appellants’ arguments that the Examiner
erred in rejecting the claims as obvious.
In Otsuka Pharmaceuticals v. Sandoz, 678 F.3d. 1280, 1284 (Fed. Cir.
2012), the claimed compounds possessed antipsychotic activity. The court
rejected the choice of several of the compounds disclosed in the prior art as
“lead compounds” for further modification because there was data that such
compounds were either inferior in activity or lacked evidence of
antipsychotic activity. Otsuka at 1296. Here, there is no evidence that the
polymers in Cope relied upon by the Examiner lacked potassium binding
activity.
Furthermore, Cope identifies a deficiency with Kayexalate®, namely,
it is “not suitable for outpatient or chronic treatment, due to the large doses
necessary that leads to very low patient compliance, severe GI side effects
and significant introduction of sodium (potentially causing hyponatremia
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and related fluid retention and hypertension”, and states there “remains a
need for improved compositions for binding inorganic monovalent cations
such as potassium ion and sodium ion.” Cope H 4, 7. Thus, Cope provides
an express reason for following its guidance and making a polymer within
the scope of claim 1.
In addition to this, Otsuka involved the issue of the structural
obviousness of the claimed compound based on the prior art. As stated in
the Manual of Patent Examination and Procedure (“MPEP”), “[i]n the
chemical arts, the cases involving so-called ‘lead compounds’ form an
important subgroup of the obviousness cases that are based on substitution.”
MPEP § 2143. In these cases, a lead compound is identified and a reason is
provided to modify it to have arrived at the claimed compound. Id.
However, here, the issue is not structural obviousness because Cope teaches
making a polymer utilizing the same monomers recited in the claim. Cope
1105.
Unexpected results
Appellants contend that “[njeither the Cope nor Charmot references
disclose the problem solved by the current application, specifically, that a
reduction in yield upon hydrolysis is caused by a difference in reactivity of
the monomer of Formula 11 and the cross linker of Formula 22.” Appeal
Br. 7. Appellants further argue:
The Charmot reference suggests that the hydrolysis step in
Example 5 is straightforward, without mentioning the yield
before or after the polymerization step in the example nor in
other portions of the specification. The Cope reference in fact
does not exemplify or disclose the hydrolysis step for the core
potassium binding polymer at all. As discovered in this
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application, the hydrolysis was not straightforward, and the
claimed yield was not disclosed nor recognized by the
references.
Id.
Appellants contend that “the yield results disclosed in Table 1 [of the
Specification] are unexpected since this selection of the ratio of the
crosslinking monomers would not have been expected to provide the
increase in overall yield that was observed.” Id. at 8. Based on the data in
Table 1, Appellants state “the overall yield was increased from 77% to 93%
or 95% from comparative example 2 (90% MeFA [methyl fluoro-acrylic
acid], 10% DVB [divinylbenzene]) to examples 789, 794 and 801 (90%
MeFA and 8%/2%, 5%/5% or 2%/8% DVB/ODE [1,7-octadiene]).” Id.
The examples cited by Appellants were conducted without buffer, at 3.75%
salt, and with 90% MeFA. Table 1 also shows that, under the same
conditions, MeFA and ODE had a yield of 85% which is less than 90%.
MeFA, DVB, and ODE are species of claimed Formulae 11, 22, and 33,
respectively. In other words, the comparative examples utilize one cross-
linker with MeFA (formula 11 compound) (DVB or ODE) whereas the
examples within the scope of the invention use two cross-linkers (DVB and
ODE) and show higher yields.
The Examiner did not consider the results sufficient because the
results related to the process of producing the claimed crosslinked cation
exchange polymer, and not to the polymer, itself. Ans. 7. Appellants
respond that the “unexpected effect of an increased yield based on the . . .
overall reaction (including the hydrolysis reaction) is a result of the
difference in the polymer structure, including the additional crosslinking
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Application 12/545,812
from the combination of the divinylbenzene (DVB) and octadiene (ODE) in
the claimed ratios, which determines the overall yield.” Appeal Br. 9.
Appellants’ argument does not persuade us that the Examiner erred.
When the three monomers (MeFA and the cross-linking agents DVD
and ODE) are reacted together under the salt conditions and amounts
disclosed in Table 1, a yield of more than 90% of the cross-linked polymer is
reported to have been obtained. Such yield is not obtained when only two
monomers are reacted together, i.e., MeFA and DVB or MeFA and ODE. It
is true that the chemical structure of the polymer formed from three
monomers is different than the chemical structure of the polymer formed
from two monomers. However, the yield is determined by the chemical
reaction of the two or three monomers under the specific salt conditions and
amounts described in Table 1. Appellants have not explained how the
structure of the final and claimed crosslinked cation exchange polymer
affects the yields reported in Table 1. Moreover, as mentioned, only the
polymer is claimed and not the presence of the other products of the
hydrolysis and polymerization reactions used to make it. Thus, we agree
with the Examiner that the results do not establish the non-obviousness of
the polymer claimed.
Nevertheless, even if the yields of the claimed polymer could be
considered a basis for non-obviousness, the data is insufficient.
A showing of “unexpected results” can be used to demonstrate the
non-obviousness of a claimed invention. In re Soni, 54 F.3d 746, 750 (Fed.
Cir. 1995) (“One way for a patent applicant to rebut a prima facie case of
obviousness is to make a showing of ‘unexpected results,’ i.e., to show that
the claimed invention exhibits some superior property or advantage that a
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person of ordinary skill in the relevant art would have found surprising or
unexpected.”). Those results must be “surprising or unexpected” to one of
ordinary skill in the art when considered in the context of the closest prior
art. Soni, 54 F.3d at 750. Evidence of secondary considerations does not
always overcome a strong showing of obviousness. See e.g., Leapfrog
Enters. Inc. v. Fisher-Price, Inc., 485 F.3d 1157, 1162 (Fed. Cir. 2007);
Richardson-Vicks Inc. v. Upjohn Co., 122 F.3d 1476, 14831484 (Fed. Cir.
1997); Asyst Techs., Inc. v. Emtrak, Inc., 544 F.3d 1310, 1316 (Fed. Cir.
2008).
In this case, we have not been directed to evidence that the results in
Table 1 would have been surprising or unexpected to one of ordinary skill in
the art. The Specification states that the yields are “improved.” Spec. 197.
However, a demonstration of mere improvement, without a showing that the
improvement is significant or unexpected to the ordinary skilled worker in
view of the closest prior art, is insufficient evidence of unexpected results.
See Soni, 54 F.3d at 751 (“Mere improvement in properties does not always
suffice to show unexpected results. . . . [W]hen an applicant demonstrates
substantially improved results. . . and states that the results were unexpected,
this should suffice to establish unexpected results in the absence of evidence
to the contrary.”).
In addition, we note that the experiments summarized in Table 1 used
only one species each of Formulae 11, 22, and 33, while the claimed
formulae are directed to a genus of compounds. Unexpected results must be
“commensurate in scope with the degree of protection sought by the claimed
subject matter.” In re Harris, 409 F.3d 1339, 1344 (Fed. Cir. 2005).
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When unexpected results are proffered by Appellants to rebut a prima
facie case of obviousness, Appellants must “provide[] an adequate basis to
support the conclusion that other embodiments falling within the claim will
behave in the same manner” in order to “establish that the evidence is
commensurate with [the] scope of the claims.” In re Kao, 639 F.3d 1057,
1068 (Fed. Cir. 2011). One data point is insufficient to “to ascertain a trend
in the exemplified data which would allow [one having ordinary skill in the
art] to reasonably extend the probative value thereof.” In re Kollman, 595
F.2d 48, 56 (Fed. Cir. 1979). Appellants must therefore demonstrate or
explain why the result of the single, tested species would establish
unexpected results for the genus of compounds which were not tested.
Appellants have not done so.
Summary
For the foregoing reasons, we affirm the rejection of claim 1. Claim 8
has similar limitations and falls with claim 1 for the same reasons.
Dependent claims 4, 6, 7, 9, 13, 16, 17, 22, 25, 28, and 30 were not argued
separately, and therefore fall with claims 1 and 8. 37 C.F.R. § 41.37(c)(iv).
WRITTEN DESCRIPTION REJECTION
The Examiner rejected the claims under 35U.S.C. § 112 as lacking a
written description. The Examiner found that the claims contains subject
matter that was not described in the specification in such a way as to
reasonably convey to one skilled in the relevant art that the at the time the
application was filed, had possession of the claimed invention. Ans. 2. The
Examiner stated:
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Instant claim 1 recites that the overall yield of the
polymer “is at least 90%.” There does not appear to be
sufficient support for this limitation in the originally filed
disclosure. The specification discusses the yield when making
a particular species of polymer that was prepared by a particular
process (“[u]sing this suspension polymerization process”;
paragraph [48]). However, the claims are broader in scope as
the yield is not limited to preparing that specific polymer by a
suspension polymerization process, which is what is disclosed
by the originally filed disclosure.
Ans. 2—3.
Appellants contend that the Examiner erred. Appellants state:
First, a skilled person would have understood that when
contemplating paragraphs [0046] to [0048] of the specification
that the protected acid groups of the crosslinked polymer
defined by claim 1 could be hydrolyzed and that a polymer
having ester groups or more specifically polymethyl fluoro-
acrylic acid (polyMeFA) were specific examples of the broader
teaching. The difference in scope of claim 1 and claim 2 is not
so great that a person of ordinary skill in the art would have
concluded that the invention described by claim 1 was not
possessed by applicants. The description provides “enough
detail to allow a person of ordinary skill in the art to understand
what is claimed and to recognize that the inventor invented
what is claimed.” [University of Rochester v. G.D. Searle &
Co., Inc., 358 F.3d 916, 928 (Fed. Cir. 2004).]
Appeal Br. 5.
The examiner has the initial burden of presenting evidence or reasons
why a person skilled in the art would not recognize that the written
description of the invention provides support for the claims. Hyatt v.
Dudas, 492 F.3d 1365, 1371 (Fed. Cir. 2007). “[A]n examiner can make out
a prima facie case of lack of adequate written description, thus shifting the
burden of production to the applicant, simply by identifying specific claim
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limitations and stating that despite reviewing the specification, he could not
find support for those limitations.” Hyatt v. Doll, 576 F.3d 1246, 1274 (Fed.
Cir. 2009). The Examiner satisfied this burden here by identifying the lack
of support for the 90% limitation for the full scope of the claims.
Appellants did not provide adequate evidence or reasoning to rebut
the rejection. As stated by the Examiner, the rejection is not based on the
lack of a hydrolyzing step, but instead the rejection is based on the statement
in paragraph 48 of the Specification that the 90% yield was obtained
“[ujsing this suspension polymerization process.” The claims, however, are
not limited to a suspension polymerization process. Appellants merely
asserted the one of ordinary skill in the art would have recognized that the
inventor invented what is claimed, but did not explain why the skilled
worker would have understood that the 90% yield was applicable to other
polymerization processes. Consequently, we affirm the Examiner’s
rejection of the claims as failing to comply with the written description
requirement.
TIME PERIOD
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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