Ex Parte Klunk et al

Board of Patent Appeals and Interferences

Apr 27, 2010

10645847 (B.P.A.I. Apr. 27, 2010)

UNITED STATES PATENT AND TRADEMARK OFFICE
__________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
__________

Ex parte WILLIAM E. KLUNK, CHESTER A. MATHIS, JR.,
and YANMING WANG
__________

Appeal1 2009-007431
Application 10/645,847
Technology Center 1600
__________

Decided: April 27, 2010
__________

Before ERIC GRIMES, JEFFREY N. FREDMAN, and
STEPHEN WALSH, Administrative Patent Judges.

FREDMAN, Administrative Patent Judge.

DECISION ON APPEAL

1 Oral hearing held April 22, 2010.

Appeal 2008-6320
Application 09/945,225

This is an appeal under 35 U.S.C. § 134 involving claims to
benzothiazole derivative compounds. We have jurisdiction under 35 U.S.C.
§ 6(b). We affirm.

Statement of the Case
Background
“Studies suggest that amyloid deposition in the brain is an early,
causative event in the pathogenesis of Alzheimer's disease (AD)” (Spec. 1,
ll. 2-3). The Specification teaches that “[s]ince the initial deposition of
amyloid may occur long before clinical symptoms of AD are noticeable, the
detection and quantitation of amyloid deposits could facilitate the diagnosis
of AD in its early, pre-symptomatic stages” (Spec. 1, ll. 8-10).
“The inventive compound may be used to determine the presence,
location and/or amount of one or more amyloid deposit(s) in an organ or
body area, including the brain, of an animal.” (Spec. 7, ll. 12-14.)
The Claims
Claim 1 is on appeal. Claim 1 reads as follows:
1. A compound of formula I

or a pharmaceutically acceptable salt, hydrate, solvate
or prodrug of the compound, wherein:
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R1 is hydrogen, -OH, -NO2, -CN, -COOR, -OCH2OR,
C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C1-C6 alkoxy or
halo;
R is C1-C6 alkyl;
R2 is a non-radioactive halo or a radioactive halo;
R3 is hydrogen, C1-C6 alkyl, C2-C6 alkenyl or C2-C6
alkynyl; and
R4 is C1-C6 alkyl, C2-C6 alkenyl or C2-C6 alkynyl,
wherein the alkyl, alkenyl or alkynyl comprises a radioactive
carbon or is substituted with a radioactive halo when R2 is a
non-radioactive halo.

The prior art
The Examiner relies on the following prior art reference to show
unpatentability:
Klunk et al. US 7,270,800 B2 Sep. 18, 2007

The issue
The Examiner rejected Claim 1 on the ground of nonstatutory
obviousness-type double patenting over Claim 4 of U.S. Patent 7,270,800
(Ans. 4-6).
The Examiner finds that “both sets of claims are directed to products
having a radiolabeled halogen. The claims differ in that those of the patented
invention do not limit the location of the radiolabeled halogen” (Ans. 4).
The Examiner finds that
a skilled artisan would recognize that since both sets of
claims require a radioisotope (i.e., radiohalogen) and the
radioisotopes of the patented invention are not limited to any
particular location, the skilled artisan would recognize that it
is within the skill of an ordinary practitioner in the art to
have a radioactive halogen at position R2 because
Compounds 4, 8, 12, 16, 20, and 39 of the patented
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invention all contain a halogen in the R2 position and fulfill
the requirements of the other variables (R1, R3, and R4) of
the instant invention.

(Id.)
Appellants argue that “the choices of (1) a specific halogen isotope
and (2) the position on a benzothiazole where that isotope is to reside give
rise to myriad possible combinations of (1) and (2)” (App. Br. 10).
Appellants argue that “[t]he PTO’s analysis fails to account for a much
larger group of compounds that fall outside the scope of rejected claim 1 by
virtue of radiohalogen substitution occurring at positions other than present
R2” (id.). Appellants argue that “the PTO’s analysis fails to specify why the
skilled artisan would first select a benzothiazole in claim 4 of the '800 patent
bearing a non-radioactive halogen substituent at the 2- position,
corresponding to present R2” (id. at 12). Appellants argue that “[a]s far as
Appellants are aware, there is no rule of patent law holding that atom
isotopes are prima facie obvious variants of each other” (id.).
In view of these conflicting positions, we frame the nonstatutory
obviousness-type double patenting issue before us as follows:
Does the evidence of record support the Examiner’s conclusion that
Claim 1 is not patentably distinct from Claim 4 of U.S. Patent 7,270,800?

Findings of Fact (FF)
1. The Klunk et al patent, U.S. Patent 7,270,800, was filed on
March 14, 2003 as U.S. application 10/388,173 and issued on September 18,
2007.
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2. The instant application, U.S. application 10/645,847, was filed
on August 22, 2003.
3. Claim 4 of U.S. Patent 7,270,800 is partially reproduced below,
with the chemical structures identified as relevant by the Examiner included:
4. A method of synthesizing a compound selected
from the group consisting of:

wherein at least one of the atoms in each of the formulae 1-34, 36, and
38-45 is replaced by a member selected from the group consisting of 131I,
125I, 123I, 76Br, 75Br, 18F, and 19F, the method comprising reacting a tri-alkyl
tin derivative of a compound according to one of formulae 1-34, 36, and 38-
45 with a halogenating agent containing 131I, 125I, 123I, 76Br, 75Br, 18F, or 19F.

Principles of Law
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“Obviousness-type double patenting … requires rejection of an
application claim when the claimed subject matter is not patentably distinct
from the subject matter claimed in a commonly owned patent. Its purpose is
to prevent an unjustified extension of the term of the right to exclude granted
by a patent by allowing a second patent claiming an obvious variant of the
same invention to issue to the same owner later.” In re Berg, 140 F.3d 1428,
1431 (Fed. Cir. 1998).
The question of obviousness is resolved on the basis of underlying
factual determinations including: (1) the scope and content of the prior art;
(2) the level of ordinary skill in the art; (3) the differences between the
claimed invention and the prior art; and (4) secondary considerations of
nonobviousness, if any. Graham v. John Deere Co., 383 U.S. 1, 17 (1966).
The Supreme Court has emphasized that “the [obviousness] analysis
need not seek out precise teachings directed to the specific subject matter of
the challenged claim, for a court can take account of the inferences and
creative steps that a person of ordinary skill in the art would employ.” KSR
Int'l Co. v. Teleflex Inc., 550 U.S. 398, 418 (2007).

Analysis
The dispute centers on whether it would have been obvious, over
Claim 4 of U.S. Patent 7,270,800, to place a radioactive halogen in the
position which corresponds to R2 of the compound of formula I in instant
Claim 1. That is, is Claim 1 patentably distinct from Claim 4 of U.S. Patent
7,270,800?
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Three separate lines of reasoning support the obviousness position of
the Examiner.
First, the ordinary artisan is taught by Claim 4 of U.S. Patent
7,270,800 that “at least one of the atoms in each of the formulae 1-34, 36,
and 38-45 is replaced by a member selected from the group consisting of
131I, 125I, 123I, 76Br, 75Br, 18F, and 19F.” The ordinary artisan of ordinary
creativity would reasonably have selected to replace the nonradioactive
iodine at the R2 position in compound 4 of Claim 4 of U.S. Patent 7,270,800
with the radioactive iodine, since this replacement would least affect the
chemical properties of the resulting molecule. That is, the ordinary artisan
would reasonably infer, for example, that the modification of compound 4 of
Claim 4 of U.S. Patent 7,270,800 that minimally would affect the use of that
compound would be replacement of the nonradioactive iodine with 131I, 125I,
or 123I, a modification expressly suggested by Claim 4 of U.S. Patent
7,270,800.
Second, “[s]tructural relationships often provide the requisite
motivation to modify known compounds to obtain new compounds.” In re
Mayne, 104 F.3d 1339, 1343 (Fed. Cir. 1997). The chemical compounds of
Claim 4 of U.S. Patent 7,270,800 are extremely similar to those of the
instant Claim 1, differing only in that each of the compounds of Claim 4 of
U.S. Patent 7,270,800 permits the radioactive halogen to be located at
positions other than R2, as well as the R2 position. However, “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
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obviousness.” In re Dillon, 919 F.2d 688, 692 (Fed. Cir. 1990) (en banc).
Here, there is both significant structural similarity between the claimed and
prior art subject matter, and the prior art of Claim 4 of U.S. Patent 7,270,800
specifically suggests that “at least one of the atoms in each of the formulae
1-34, 36, and 38-45 is replaced by a member selected from the group
consisting of 131I, 125I, 123I, 76Br, 75Br, 18F, and 19F.”
Third, the relationship of Claim 4 of U.S. Patent 7,270,800 relative to
Appellants’ Claim 1 is substantially analogous to the situation the Court of
Customs and Patent Appeals addressed in In re Petering, 301 F.2d 676
(CCPA 1962). In Petering, the Court contrasted the effect of the disclosure
of a broad generic class of compounds with the disclosure of a limited class
of compounds (limited genus). Id. at 681. Specifically, the Court held that
the disclosure of a broad class of compounds without more is not
anticipatory; however, the Court held that the disclosure of a limited class of
compounds anticipates all species within that limited genus when a person of
ordinary skill in the art would “at once envisage each member” of the
limited class. Id.
Here, while the instant rejection is based on obviousness and not
anticipation, we find it reasonable that one skilled in the art would at once
envisage that each of the compounds of Claim 4 of U.S. Patent 7,270,800
has only about 9 possible positions on which the halogens can be substituted
(see App. Br. 10; “[C]ited compound 2 features at least (9) positions
including R2 where an existing atom can be replaced by one of the halogen
isotopes recited by claim 4 of the ‘800 patent”). Substitution at one of those
9 positions, the R2 position, would anticipate, and therefore render obvious,
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the compound of Claim 1. Further, substitution at that position with any of
the radioactive halogens suggested by Claim 4 of U.S. Patent 7,270,800
would satisfy the requirement of instant Claim 1 that the R2 position
comprise a radioactive halo and anticipate. Accordingly, Claim 4 of U.S.
Patent 7,270,800 reasonably renders the instant Claim 1 obvious.
Appellants argue that “the choices of (1) a specific halogen isotope
and (2) the position on a benzothiazole where that isotope is to reside give
rise to myriad possible combinations of (1) and (2)” (App. Br. 10).
Appellants argue that “[t]he PTO’s analysis fails to account for a much
larger group of compounds that fall outside the scope of rejected claim 1 by
virtue of radiohalogen substitution occurring at positions other than present
R2” (id.).
We are not persuaded. Simply because some of the compounds
rendered obvious by Claim 4 of U.S. Patent 7,270,800 fall outside the scope
of the instant Claim 1 does not mean that the claimed subject matter is
“patentably distinct from the subject matter claimed in a commonly owned
patent.” Berg, 140 F.3d at 1431. The question is whether Claim 1 is
patentably distinct from Claim 4 of U.S. Patent 7,270,800. For the three
reasons given above, we conclude that Claim 1 is not patentably distinct
from Claim 4 of U.S. Patent 7,270,800.
Appellants argue that “the PTO’s analysis fails to specify why the
skilled artisan would first select a benzothiazole in claim 4 of the '800 patent
bearing a non-radioactive halogen substituent at the 2- position,
corresponding to present R2” (App. Br. 12).
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We are not persuaded. The Examiner reasonably concludes that the
“obviousness of having a radiolabeled halogen in that position stems from
the fact that the patented claim (see claim 4) discloses that at least one atom
in the formula is replaced with a radiolabeled halogen such as 131I, 125I, or
123 halogen, for example” (Ans. 8). This obviousness argument is
consistent with the first reason identified above, that the ordinary artisan of
ordinary creativity would reasonably have selected to replace the
nonradioactive iodine at the R2 position in compound 4 of Claim 4 of U.S.
Patent 7,270,800 with the radioactive iodine, since this replacement would
minimally affect the chemical properties of the resulting molecule. Further,
the structural similarity reasoning of Dillon also supports obviousness. See
In re Dillon, 919 F.2d at 692.
Appellants argue that “[a]s far as Appellants are aware, there is no
rule of patent law holding that atom isotopes are prima facie obvious
variants of each other” (App. Br. 12).
We agree that there is no per se rule of obviousness for isotopes.
However, the facts of the instant case provide more suggestion, since Claim
4 of U.S. Patent 7,270,800 expressly teaches that “at least one of the atoms
in each of the formulae 1-34, 36, and 38-45 is replaced by a member
selected from the group consisting of 131I, 125I, 123I, 76Br, 75Br, 18F, and 19F.”
It is this express teaching to substitute a radioactive isotope for a different
atom on the compounds which renders the claim obvious for the three
reasons given above, not due to a per se rule.

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Conclusion of Law
The evidence of record supports the Examiner’s conclusion that Claim
1 is not patentably distinct from Claim 4 of U.S. Patent 7,270,800.

SUMMARY
In summary, we affirm the rejection of Claim 1 on the ground of
nonstatutory obviousness-type double patenting over Claim 4 of U.S. Patent
7,270,800.
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a)(1)(iv)(2006).
AFFIRMED

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