Ex Parte Riggs-Sauthier et al

Patent Trial and Appeal Board

Jun 28, 2018

12682778 (P.T.A.B. Jun. 28, 2018)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE
12/682,778 06/18/2010
21968 7590 06/28/2018
NEKT AR THERAPEUTICS
455 Mission Bay Blvd., South, Suite 100
San Francisco, CA 94158
FIRST NAMED INVENTOR
Jennifer Riggs-Sauthier
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.
SHE0180.00 5628
EXAMINER
WESTERBERG, NISSA M
ART UNIT PAPER NUMBER
1618
MAIL DATE DELIVERY MODE
06/28/2018 PAPER
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.
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte JENNIFER RIGGS-SAUTHIER and BO-LIANG DENG 1
Appeal2017-008061
Application 12/682,778
Technology Center 1600
Before ERIC B. GRIMES, JEFFREY N. FRED MAN, and
JOHN E. SCHNEIDER, Administrative Patent Judges.
SCHNEIDER, Administrative Patent Judge.
DECISION ON APPEAL
This is an appeal under 35 U.S.C. § 134(a) involving claims to
antiarrhythmic drug which have been rejected as obvious. We have
jurisdiction under 35 U.S.C. § 6(b ).
We AFFIRM.
STATEMENT OF THE CASE
"Lidocaine and its derivatives ( e.g., tocainide, mexiletine) are
typically classified as Class IB antiarrhythmic drugs." Spec. ,r 3. Among
the side effects associated with these drugs are "paresthesias, tremor, blurred
vision, lethargy, light-headedness, hearing disturbances, slurred speech and
convulsions." Spec. ,r 4. The Specification describes a compound
1 Appellants identify the Real Party in Interest as Nektar Therapeutics. Br.
3.
Appeal2017-008061
Application 12/682,778
comprising a lidocaine residue which overcomes the disadvantages of the
prior art. Spec. ,r,r 7-8.
Claims 33-372 are on appeal. Claim 33 is the sole independent claim
and reads as follows:
33. A compound of formula:
wherein n is 4 or 5.
The claims have been rejected under 35 U.S.C. § I03(a) as
unpatentable over Marquess3 in view ofNewman. 4
DISCUSSION
Issue
The issue with respect to this rejection is whether a preponderance of
the evidence supports the Examiner's conclusion that claims 33-37 would
have been obvious over Marquess combined with Newman.
The Examiner finds that Marquess discloses dimeric compounds of
the formula
2 Claims 38 and 39 are pending in the application but have been withdrawn
from consideration. Final Act. 1.
3 Marquess et al., US 6,420,354 Bl, issued July 16, 2002 ("Marquess").
4 Newman et al., US 2005/0187147 Al, published Aug. 25, 2005
("Newman").
2
Appeal2017-008061
Application 12/682,778
where X2 is a linker such as polyethylene oxide. Final Act. 4. The
Examiner also finds that Marquess teaches the introduction of one or more
polyethylene glycol ("PEG") groups into the linker to "enhance[] the
hydrophilicity and water solubility of the multibinding compound, increase[]
both the molecular weight and the PEG may decrease antigenicity and
potentially enhances the overall rigidity of the linker." Id.
The Examiner finds that Newman teaches the use of linkers
containing a PEG chain having up to 50 carbon atoms. Id. The Examiner
concludes:
It would have been obvious to the person of ordinary
skill in the art at the time the invention was made to vary the
number of ethylene oxide ( ethylene glycol) units in the dimeric
mexiletine compounds disclosed by Marquess. The claimed
compounds vary from those explicitly disclosed in the prior art
by the number of ethylene oxide repeating units and are
therefore homologous compounds. One of ordinary skill in the
art would optimize linker length to optimize the hydrophilicity,
water solubility, antigenicity and/or overall rigidity of the
linker, depending on the type of formulation desired for
administration that may contain water ( e.g., suspension) or not
(e.g., tablet). Newman et al. explicitly discloses that linkers
containing at least 9 ethylene oxide units are known in the art as
suitable for use as a linker.
Id. at 5.
3
Appeal2017-008061
Application 12/682,778
Appellants contend that the Examiner has improperly applied a lead
compound analysis. Br. 5. Appellants argue that the Examiner has not
shown why one skilled in the art would select the specific compound cited
by the Examiner from the multitude of compounds cited in Marquess. Br. 6.
Appellants also argue that the Examiner has not stated a reason why one
skilled in the art would modify the selected compound to increase the
number of PEG units in the linker. Br. 6-7. Appellants also contend that
the results of such a modification would have been unpredictable. In support
of this last argument, Appellants rely on the Declaration of Dr. Gursahani 5
which states that the use of 4 or 5 PEG repeating units produced unexpected
results.
Principles of Law
[T]he examiner bears the initial burden, on review of the
prior art or on any other ground, of presenting a prima facie
case ofunpatentability. If that burden is met, the burden of
coming forward with evidence or argument shifts to the
applicant.
After evidence or argument is submitted by the applicant
in response, patentability is determined on the totality of the
record, by a preponderance of evidence with due consideration
to persuasiveness of argument.
In re Oetiker, 977 F.2d 1443, 1445 (Fed. Cir. 1992).
5 Declaration Under 37 C.F.R. § 1.132, filed May 22, 2013 ("Gursahani
Deel.").
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Application 12/682,778
Analysis
We adopt the Examiner's findings of fact, reasoning on scope and
content of the prior art, and conclusions set out in the Final Action and
Answer regarding this rejection. We find the Examiner has established that
the subject matter of the claims would have been obvious to one of ordinary
skill in the art at the time the invention was made in view of Marquess
combined with Newman. Appellants have not produced evidence showing,
or persuasively argued, that the Examiner's determinations on obviousness
are incorrect. Only those arguments made by Appellants in the Brief have
been considered in this Decision. Arguments not presented in the Brief are
waived. See 37 C.F.R. § 4I.37(c)(l)(iv) (2015). We have identified claim
33 as representative; therefore, all claims fall with claim 33. We address
Appellants' arguments below.
Appellants argue that the Examiner has not stated a reason why one
skilled in the art would select the compound modified by the Examiner as
the lead compound. Br. 6. Appellants contend that Marquess does not
provide any guidance which would lead to selection of the compound used
by the Examiner. We are not persuaded.
The basic structure relied on by the Examiner was specifically listed
Marquess as a dimer structure that can be used in the practice of the
invention. Marquess col. 109, 11. 48-60. In addition, the dimer structure
was specifically claimed in Marquess. Marquess, col. 185, claim 9.
As to the selection of a PEG containing linker, Marquess teaches that
the introduction of one or more poly( ethylene glycol) (PEG)
groups onto the linker enhances the hydrophilicity and water
solubility of the multibinding compound, increases both
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Appeal2017-008061
Application 12/682,778
molecular weight and molecular size and, depending on the
nature of the unPEGylated linker, may increase the in vivo
retention time. Further, PEG may decrease antigenicity and
potentially enhances the overall rigidity of the linker.
Marquess col. 91, 11. 3-10. We agree with the Examiner that the teachings
of Marquess would lead one skilled in the art to select the dimer cited by the
Examiner and to use a PEG containing moiety as the linking element. Ans.
5.
Appellants argue that the Examiner has not shown why one skilled in
the art would modify the dimer of Marquess to increase the number of PEG
units in the linker. Br. 6-7. Appellants argue that the teachings of Marquess
with respect to PEG in the linker are limited to the advantage of using PEG
as opposed to other linker compounds. Id. Appellants contend that this
would not lead one skilled in the art to increase the number of PEG units in
the linker. Id.
We have considered Appellants' argument and find it unpersuasive.
While we agree with Appellants that the cited teaching of Marquess
discusses the improved effects of a PEG linker versus one without PEG, the
Examiner does not rely on Marquess to teach increasing the number of PEG
units. As the Examiner points out, increasing the number of PEG units in
the linker is suggested by Newman. Newman ,r 135, Ans. 4. Thus, it is the
combined teachings of the references which renders the claims obvious.
Attack on the teachings of Marquess alone does not rebut the Examiner's
finding of obviousness. In re Merck & Co., 800 F.2d 1091, 1097 (Fed. Cir.
1986).
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Application 12/682,778
Appellants conclude their argument by contending that the results of
the proposed modification of the dimer cited by the Examiner would have
been unpredictable. Br. 7. In support of this contention, Appellants offer
the Declaration of Dr. Gursahani who conducted a series of experiments to
study the potency of a series of compounds to block Na+ channels.
Gursahani Deel. ,r 7. Dr. Gursahani compared the Na+ blocking potency of a
lidocaine derivative, mexiletine, against the potency of two mexiletine
moieties joined by linkers corresponding ton= 1-5 in the claimed
compound. Id. Dr. Gursahani observed that the "compounds where n = 4
and 5" exhibited an unexpectedly greater frequency-dependent block than
the other compounds. Gursahani Deel. ,r 8.
We have considered Appellants' argument and Dr. Gursahani' s
Declaration and find them unpersuasive. Appellants base their argument on
the proposition that the increased blocking capability of the dimers with the
linkers containing n = 4 or 5 ethylene oxide moieties was unexpected.
However, "to be particularly probative, evidence of unexpected results must
establish that there is a difference between the results obtained and those of
the closest prior art, and that the difference would not have been expected by
one of ordinary skill in the art at the time of the invention." Bristol-Myers
Squibb Co. v. Teva Pharms. USA, Inc., 752 F.3d 967, 977 (Fed. Cir. 2014).
Dr. Gursahani did not report any data relating to the blocking ability of the
dimer disclosed in Marquess (n = 0). See Gursahani Deel. f 7. Thus, there
is no comparison with the closest prior art and the Declaration is not
probative to the issue of unexpected results.
Conclusion
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Application 12/682,778
We conclude that a preponderance of the evidence supports the
Examiner's conclusion that the subject matter of the claims would have been
obvious in view of Marquess combined with Newman.
SUMMARY
We affirm the rejection under 35 U.S.C. § I03(a).
TIME PERIOD FOR RESPONSE
No time period for taking any subsequent action in connection with
this appeal may be extended under 3 7 C.F .R. § 1.13 6( a )(1 )(iv).
AFFIRMED
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