Coalition for Affordable Drugs VI LLCv.Celgene Corporation

Patent Trial and Appeal Board

Nov 16, 2015

08690258 (P.T.A.B. Nov. 16, 2015)

Trials@uspto.gov Paper 22
Tel: 571-272-7822 Entered: November 16, 2015

UNITED STATES PATENT AND TRADEMARK OFFICE
_______________
BEFORE THE PATENT TRIAL AND APPEAL BOARD
_______________
COALITION FOR AFFORDABLE DRUGS VI LLC,
Petitioner,
v.
CELGENE CORPORATION,
Patent Owner.
_____________

Case IPR2015-01169
Patent 5,635,517
______________

Before TONI R. SCHEINER, JACQUELINE WRIGHT BONILLA, and
TINA E. HULSE, Administrative Patent Judges.

BONILLA, Administrative Patent Judge.

DECISION
Denying Institution of Inter Partes Review
37 C.F.R. § 42.108

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I. INTRODUCTION
Coalition For Affordable Drugs VI LLC (“Petitioner” or “CFAD”)
filed a Petition requesting inter partes review of claims 1–10 of U.S. Patent
No. 5,635,517 (Ex. 1001, “the ’517 Patent”). Paper 1 (“Pet.”). Celgene
Corporation (“Patent Owner”) filed a Preliminary Response. Paper 16
(“Prelim. Resp.”). We have jurisdiction under 35 U.S.C. § 314(a), which
provides that an inter partes review may not be instituted “unless . . . there is
a reasonable likelihood that the petitioner would prevail with respect to at
least 1 of the claims challenged in the petition.”
Upon consideration of the Petition and the Preliminary Response, and
for the reasons explained below, we determine that Petitioner has not
established a reasonable likelihood that it would prevail in showing the
unpatentability of any claim challenged in the Petition. Accordingly, we
decline to institute an inter partes review.
A. Related Proceedings
The parties indicate that the ’517 patent is the subject of a district
court proceeding, Celgene Corporation v. Natco Pharma Ltd., C.A. No.
2:10-cv-5197 (D.N.J.) (including consolidated related C.A. No. 2:12-cv-
4571 (D.N.J.)). Pet. 8; Paper 7. On October 27, 2015, the Board instituted
inter partes reviews of challenged claims in two unrelated patents owned by
Patent Owner, challenged by Petitioner, in Case Nos. IPR2015-01092 (Paper
20), IPR2015-01096 (Paper 21), IPR2015-01102 (Paper 21), and IPR2015-
01103 (Paper 22).
B. The ’517 Patent
The ’517 patent is directed to methods of reducing levels of tumor
necrosis factor α (“TNFα”) in a mammal by administering “amino
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substituted 2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolines and 1,3-
dioxoisoindolines,” i.e., certain thalidomide analogs with an added amino
group (-NH2) in a benzene ring of the chemical structure. Ex. 1001, 1:6–11;
see also Pet. 1, 15–16 (showing chemical structures of thalidomide and
compounds recited in claims 3–10).
The ’517 patent discloses that TNFα is a cytokine released by
mononuclear phagocytes in response to immunostimulators. Ex. 1001,
1:14–16. Excessive or unregulated TNFα production has been implicated in
a number of diseases. Id. at 1:21–3:18. “Decreasing TNFα levels and/or
increasing cAMP levels” may help treat “many inflammatory, infectious,
immunological or malignant diseases.” Id. at 3:59–4:6.
The ’517 patent describes the discovery that certain compounds
“decrease the levels of TNFα and elevate the levels of adenosine 3’,5’-cyclic
monophosphate” (“cAMP”), and that such compounds have the formula:

Id. at 4:20–33. Thus, the disclosed compounds have an amino group (-NH2)
group attached to a carbon in the left 6-carbon benzene ring portion and, in
some compounds, X is a C=O and Y is a CH2 in the 5-carbon ring portion.
C. Illustrative Claims
The ’517 patent contains ten claims. Independent claims 1 and 10 and
dependent claims 2 and 7 are representative, and are reproduced below.
1. The method of reducing undesirable levels of TNFα in a
mammal which comprises administering thereto an effective
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amount of a compound of the formula:

in which in said compound one of X and Y is C=O and the
other of X and Y is C=O or CH2.
2. The method according to claim 1 in which X is C=O and Y
is CH2.
7. The method according to claim 1 in which each of X and Y
is C=O.
10. A compound selected from the group consisting of
1-oxo-2-(2,6-dioxopiperidin-3-yl)-5-aminoisoindoline,
1-oxo-2-(2,6-dioxopiperidin-3-yl)-4-aminoisoindoline,
1-oxo-2-(2,6-dioxopiperidin-3-yl)-6-aminoisoindoline, and
1-oxo-2-(2,6-dioxopiperidin-3-yl)-7-aminoisoindoline.
Dependent claims 3–6 depend from claim 2, and claims 8 and 9 depend from
claim 7.
D. Proposed Grounds of Unpatentability
Petitioner advances three grounds of unpatentability under 35 U.S.C.
§ 103 in relation to the challenged claims in the ’517 patent (Pet. 11):
References Statutory
Basis
Challenged
Claims
Piper (Ex. 1002)
1
in view of Kaplan (Ex. 1003)
2
§ 103 1, 7–9

1
Piper et al., Anti-inflammatory immunosuppressive thalidomide analogs,
49(4) INT’L J. OF LEPROSY 511–512 (1981) (“Piper”) (Ex. 1002)
2
Kaplan et al., U.S. Patent No. 5,385,901, filed Oct. 2, 1992, issued Jan. 31,
1995 (“Kaplan”) (Ex. 1003).
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References Statutory
Basis
Challenged
Claims
Piper in view of Kaplan, Agrawal (Ex. 1004),
3

and WO ’085 (Ex. 1005)
4

§ 103 2–6, 10
Piper in view of Kaplan, Agrawal, and Keith
(Ex. 1006)
5

§ 103 2–6, 10

In addition, Petitioner supports its challenges in the Petition with the
Declaration of Clayton H. Heathcock, Ph.D. (Ex. 1007). Pet. 11.
II. ANALYSIS
A. Claim construction
For inter partes review, claim terms in an unexpired patent are given
their broadest reasonable interpretation in light of the patent specification.
37 C.F.R. § 42.100(b); In re Cuozzo Speed Techs., LLC, 793 F.3d 1268,
1278–79 (Fed. Cir. 2015). Claim terms are given their ordinary and
customary meaning, as would be understood by one of ordinary skill in the
art in the context of the entire disclosure. In re Translogic Tech., Inc.,
504 F.3d 1249, 1257 (Fed. Cir. 2007). Any special definition for a claim
term must be set forth in the specification with reasonable clarity,
deliberateness, and precision. In re Paulsen, 30 F.3d 1475, 1480 (Fed. Cir.
1994).

3
Agrawal et al., Structure activity relationship studies of thalidomide
analogs as anti-inflammatory and immunosuppressive agents, 49(4) INT’L J.
OF LEPROSY 512 (1981) (“Agrawal”) (Ex. 1004).
4
D’Amato et al., WO 94/20085, published Sept. 15, 1994 (“WO ‘085”)
(Ex. 1005).
5
Keith & Walters, NATIONAL TOXICOLOGY PROGRAM’S CHEMICAL
SOLUBILITY COMPENDIUM (Lewis Publishers, Inc. 1992) (“Keith”) (Ex.
1006).
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Petitioner presents chemical names and structures for the different
compounds recited in claims 3–6 and 8–10 of the ’517 patent. Pet. 13–16.
Patent Owner does not dispute those names and structures. Prelim. Resp. 4–
5. We are persuaded that the chemical names and structures provided in the
Petition (Pet. 15–16) in relation to those compounds correspond to the
ordinary and customary meaning of the recited terms as understood by one
of ordinary skill in the art, consistent with disclosures in the specification.
Notably, all compounds recited in the challenged claims contain an
amino group (-NH2) on the benzene ring of the compound. Id.; Ex. 1001,
claims 1–10. We determine that other claim terms need not be construed
explicitly for purposes of this Decision.
B. Asserted ground of obviousness of claims 1 and 7–9 over Piper
(Ex. 1002) and Kaplan (Ex. 1003)
Petitioner contends that claims 1 and 7–9 of the ’517 patent would
have been obvious over Piper and Kaplan. Pet. 24–36. Petitioner contends
that “one of ordinary skill in the art would have readily combined the
teachings of Piper and Kaplan to develop thalidomide analogs having one or
both of [anti-inflammatory and immunosuppressive] functional activities for
use in effectively treating at least [erythema nodosum leprosum] by reducing
TNFα.” Pet. 32–33 (citing Ex. 1007 ¶¶ 112–115). Petitioner also contends
that one would have reasonably expected “Piper’s amino-thalidomide
analogs AH 14 and AH 13 to successfully exhibit the same activity as their
common parent compound (thalidomide) because AH 14 and AH 13 have
high structural similarity to the parent and also exhibit at least one key
activity of the parent (i.e., anti-inflammation or immunosuppression).” Pet.
33–35 (citing Ex. 1007 ¶¶ 116–128).
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1. Piper (Ex. 1002)
Piper discloses that thalidomide is effective in controlling erythema
nodosum leprosum (“ENL”) reactions in lepromatous leprosy. Ex. 1002,
511, 1st col. Piper states that ENL has two clinically relevant cites of action:
(1) an anti-inflammatory cite of action, detectable in a “carrageenan” assay
in rats, and (2) an immunosuppressive site of action, detectable in a plaque
forming cells (“PFC”) assay in mice. Using those two assays, Piper
screened “[a]pproximately 50 thalidomide analogs.” Id. at 511, 2nd col.
Discussing over 40 different analogs in particular, Piper states that it
screened “[t]hirteen α-substituted glutarimides with changes in the 6
membered phthalimide moiety.” Id. In this context, in addition to other
compounds, Piper discusses “[f]our compounds involv[ing] electron
donating substitutions (amino- or hydroxyl-) on the 6 membered phthalimide
system.” Id. Regarding those four compounds, Piper states that “three are
active in carrageenan (4-hydroxythalidomide or AH 20, 3-
hydroxythalidomide or AH 22, and 4-aminothalidomide or AH 13),” and
“[o]ne, AH 20, is active in PFC and one, 3-aminothalidomide or AH 14,
enhances PFC.” Id. Thus, according to Piper, AH 22 (3-hydroxy) and AH
13 (4-amino) are “active” in the carrageenan assay, i.e., exhibit anti-
inflammatory activity, AH 20 (4-hydroxy) is “active” in both assays, and
AH 14 (3-amino) “enhances PFC.” Id.
Piper also discusses “[t]wo compounds represent[ing] changes in the 5
membered ring system of the phthalimide moiety and two involv[ing] major
alterations of the phthalimide system.” Id. Two out of those four
compounds, “EM 12 and glutethimide, are active in carrageenan.” Id.
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Although a number of disclosed compounds are active in only one or
neither assay, Piper states, in addition to AH 20, that a “pyridine N-oxide-
substituted phthalimide, AH 3, has activity in both systems.” Id. Piper also
teaches that D,L-thalidomide and D-thalidomide are active in both assays,
although L-thalidomide is only active in the PFC assay. Id. at 512, 1st col.;
see also Prelim. Resp. 23 (contending that D-thalidomide, AH 3, and AH 20
were active in both assays, but “[f]or the remaining compounds, some were
active in one but not both assays, while some were inactive in both.”). Piper
does not mention TNFα. Ex. 1002, 511–12.
2. Kaplan (Ex. 1003)
Kaplan discloses methods for treating toxic concentrations of TNFα
using thalidomide and certain analogs of thalidomide, such as “preferred
compounds” encompassed by formula II:

Ex. 1003, 4: 4–26. Kaplan teaches that “[e]specially preferred compounds”
are compounds A–H, which include compounds C, D, G, and H depicted
below.
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Id. at 4:26–5:39. The parties do not dispute that compound H corresponds to
EM 12 in Piper. Pet. 30; Prelim. Resp. 30.
Figures 1–4 in Kaplan show results of assays testing the effect of
thalidomide and/or a TNFα inhibitor pentoxyfylline (“PTN”) on induced
TNFα production, protein synthesis by human peripheral blood monocytes,
levels of different cytokines, and inhibition of reverse transcriptase
production. Ex. 1003, 8:29–10:48. Figures 5–7 show results in assays
measuring the inhibition of reverse transcriptase (“RT”) production, for
example in cells stimulated with TNFα, comparing the effect of thalidomide
and PTN with compounds C, D, G, and H. Id. at 10:49–60.
Figure 5 indicates that compound G presents the highest percent of
RT inhibition, and compound D presents the second highest. Id. at Fig. 5.
Figures 6 and 7 present more variable results in relation to compounds C, D,
G, and H, as compared to thalidomide, but in all three figures, compound G
presents the highest percentage inhibition activity. Id. at Figs. 5–7.
In its background section, Kaplan teaches that “thalidomide has long
been employed for the treatment of erythema nodosum leprosum (ENL),”
among other diseases. Id. at 2:42–55. Additionally, Kaplan discloses that
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TNFα is “one of several cytokines released mainly by mononuclear
phagocytes together with several other cytokines in response to stimuli to the
immune system.” Id. at 2:56–59; see also id. at 3:41–49 (stating that TNFα,
IL-1, IL-6, IL-8, GM-CSF “are necessary for a proper immune response”
and “produced by mononuclear phagocytes,” and “[s]till other cytokines are
produced by the T-cells”). In addition to being associated with the
destruction of tumor cells, and present “in response to immunostimulators
such as bacterial and viral infections,” TNFα “is markedly elevated in ENL.”
Id. at 2:60–3:2.
Kaplan teaches that toxicity associated with TNFα is observed in
conditions such as cachexia, septic shock, and infections with retroviruses
(e.g., HIV). Id. at 3:3–40. Kaplan further discloses that “antiinflammatory
and immunosuppressive steroids such as prednisolone and dexamethasone
have been employed to treat the debilitating effects of TNFα,” but those
“agents also block the production of other cytokines so that the patients
become susceptible to life threatening infections.” Id. at 3:50–55.
3. Analysis
We agree with Petitioner that Piper discloses, among other
thalidomide analogs, the three compounds known as 3-aminothalidomide
(AH 14), 4-aminothalidomide (AH 13), and EM-12, which have the
following chemical structures.

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Pet. 3, 27–28. Petitioner persuades us that the composition recited in claim
8 corresponds to AH 14, and, therefore, compositions recited in method
claims 1, 7, and 8 encompass AH 14. Pet. 29. Petitioner also persuades us
that the composition recited in claim 9 corresponds to AH 13, and, therefore,
compositions recited in method claims 1, 7, and 9 encompass AH 14. Id.
As noted above, both Piper and Kaplan teach that thalidomide is
effective to treat ENL reactions in leprosy. Piper teaches that ENL involves
two cites of action, i.e., anti-inflammatory activity (measured by the
carrageenan assay) and immunosuppressive activity (measured by the PFC
assay). Piper teaches that most of the 50 screened analogs are active in only
one or neither assay. Piper teaches that thalidomide itself, as well as two
analogs, AH 3 and AH 20, are active in both assays. None of those three
compounds contains an amino group on the benzene ring, as required by
each of the challenged claims. See Prelim. Resp. 23 (presenting chemical
structures).
Petitioner refers us to two compounds in Piper (of the 50 screened) as
analogs having an amino group on the benzene ring, AH 13 and AH 14. Pet.
26–28. Petitioner and Patent Owner agree that AH 13 is active in only one
assay, the carrageenan (anti-inflammatory) assay. Pet. 26; Prelim. Resp. 29.
Petitioner asserts that AH 14 is only active in the other assay, the PFC
(immunosuppressive) assay, but Patent Owner contends that AH 14 actually
is active in neither assay. Pet. 26; Prelim. Resp. 13, 28–29. Evidence cited
by Patent Owner persuades us that AH 14 is inactive in both assays—that
the statement in Piper that AH 14 “enhances PFC” means that AH 14 is
immunostimulatory, not immunosuppressive. Id. at 28–29 (citing Ex. 1002,
511; Ex. 2029, 69–70).
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Petitioner agrees that Kaplan does not disclose thalidomide analogs
having an amino group on the benzene ring, but points to EM 12, also
disclosed in Piper, called compound H in Kaplan. Pet. 30; Ex. 1002, 511,
2nd col.; Ex. 1003, 5:30–39. EM 12 contains no amino group on the
benzene ring, but contains one C=O on the 5-carbon ring. Pet. 28, 30–31.
Petitioner contends that Kaplan teaches a method of inhibiting TNFα
production by administering EM 12, citing claim 1 in Kaplan (Ex. 1003),
which recites a compound encompassing EM 12. Pet. 30. Petitioner also
contends that Kaplan indicates that EM 12 is one of eight “[e]specially
preferred” analogs disclosed in the reference. Id. at 31; Ex. 1003, 4:27–5:39.
Independent claim 1 and dependent claims 7–9 of the ’517 patent
recite methods of reducing TNFα levels in a mammal by administering
certain thalidomide analogs having an amino group on the benzene ring. As
Patent Owner points out, Piper does not mention TNFα. Prelim. Resp. 19;
Ex. 1002, 511–12. Consequently, Petitioner necessarily combines certain
teachings in Piper (disclosing AH 13 and AH 14, each having an amino
group on the benzene ring) with those in Kaplan (disclosing methods of
inhibiting TNFα using different thalidomide analogs). As such, Petitioner’s
contentions regarding reasons to combine relevant teachings from the two
references, as well as assertions regarding a reasonable expectation of
success in performing recited methods, are critical to our analysis. Pet. 32–
35.
a) Alleged Reasons to Combine Piper and Kaplan
Petitioner contends that disclosures in Piper and Kaplan “would have
been easily combined by one of ordinary skill” because “each one teaches
the same parent compound (thalidomide) and various analogs thereof in
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relation to treating the same condition (ENL).” Pet. 32–33 (citing Ex. 1007,
¶¶ 112–115). We are not persuaded, however, that Piper sufficiently teaches
or suggests that AH 13, AH 14, or EM 12 would be useful to treat ENL.
Piper discloses that ENL involves two mechanisms of action, and, therefore,
suggests that compounds exhibiting both activities (as measured in the two
assays) might be useful to treat ENL. Such compounds include D, L- and D-
thalidomide (expressly disclosed in Piper as useful to treat ENL), AH 3, and
AH 20. We are not persuaded that Piper teaches or suggests sufficiently that
any other disclosed compounds active in only one or neither assay, such as
AH 13, AH 14, or EM 12, would have been effective in treating ENL.
In addition, Patent Owner persuades us that Kaplan does not teach
treating ENL with any compound other than thalidomide itself. Prelim.
Resp. 16–17. Kaplan does not describe using any of the disclosed analogs,
e.g., any of compounds A–H, such as EM 12, to treat ENL. Rather, at most,
in its background section, Kaplan states that “thalidomide has long been
employed for the treatment” of ENL, as well as other diseases, and that
TNFα “is markedly elevated in ENL.” Ex. 1003, 2:42–55, 3:1–2.
Petitioner contends that Kaplan teaches using EM 12 to reduce TNFα
levels, and both Piper and Kaplan “teach the well-known analog EM 12, and
that anti-inflammatory and immunosuppressive properties are important to
the efficacy and activity of thalidomide and its analogs.” Pet. 30–33 (citing
Ex. 1007 ¶¶ 90–120). Thus, according to Petitioner, “one of ordinary skill in
the art would have readily combined the teachings of Piper and Kaplan to
develop thalidomide analogs having one or both of these important
functional activities for use in effectively treating at least ENL by reducing
TNFα.” Id.
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We agree with Petitioner that both Piper and Kaplan disclose EM 12
and at least Piper suggests that both “anti-inflammatory and immuno-
suppressive properties are important to the efficacy and activity of
thalidomide and its analogs.” Id. As discussed above, however, we are not
persuaded that Piper discloses sufficiently that EM 12, which exhibits only
anti-inflammatory activity in Piper, would have been useful to treat ENL.
Moreover, while Kaplan suggests that EM 12 may be useful to reduce TNFα
levels, Kaplan, alone or in combination with Piper, does not suggest
sufficiently that a thalidomide analog containing an amino group on the
benzene ring (in contrast to compounds, including EM 12, disclosed in
Kaplan) would be useful to reduce TNFα levels.
Piper, which discusses ENL, does not mention TNFα, nor does it
establish a relationship between results from the two assays regarding ENL’s
two sites of action (carrageenan and/or PFC) and TNFα levels. Prelim.
Resp. 19–20. Kaplan, at most, states that thalidomide is useful to treat ENL
and reduce TNFα levels, and that TNFα levels are “markedly elevated in
ENL.” Ex. 1003, 2:42–45, 3:1–2. Nonetheless, and even if Kaplan also
suggests that EM 12 may reduce TNFα levels, the reference does not suggest
sufficiently that by doing so, EM 12 would be useful to treat ENL. In
addition, while Piper discloses EM 12 (among many analogs), and may
indicate that this analog is active in the carrageenan assay (i.e., has at least
some anti-inflammatory activity), we agree with Patent Owner that neither
Piper nor Kaplan (which is silent on the two Piper assays) establishes
sufficiently that anti-inflammatory activity alone by any analog (such as AH
13) necessarily corresponds to an ability to reduce TNFα levels.
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Additional information cited by Patent Owner further persuades us
that Petitioner does not establish sufficiently that a link exists between
treating ENL and reducing TNFα levels. For example, Patent Owner
provides information indicating that EM 12, which Kaplan suggests may
reduce TNFα, only “has marginal activity in the carrageenan assay with
activity at the highest dose tested but no activity in lower doses, and it lacks
activity in the PFC assay.” Prelim. Resp. 43–44 (citing Ex. 2028, 673, 1st
col.; Ex. 2029, 70). Such evidence runs counter to the notion that an
ordinary artisan would have understood that one could treat ENL by using
any thalidomide analog (such as EM 12) that reduces TNFα, as Petitioner
suggests. Pet. 33.
Furthermore, as noted by Patent Owner and stated in Kaplan, immune
responses involve a number of different biological molecules, including
cytokines such as IL-1, IL-6, IL-8, GM-CSF, as well as other cytokines
produced by T-cells, in addition to TNFα. As Patent Owner notes, “some
anti-inflammatory agents, such as nonsteroidal anti-inflammatory drugs
(NSAIDs), actually increase TNFα production in rheumatoid synovia and
whole blood.” Prelim. Resp. 22 (citing Ex. 2020, Abstract). Information
before us, therefore, fails to establish sufficiently a correlation between anti-
inflammatory activity (as measured in the carrageenan assay in Piper) with a
reduction in TNFα levels in particular, even assuming the references indicate
that EM 12 does both things.
Lastly, as noted by Patent Owner, data in Kaplan suggests that
compound G works better than EM 12 to inhibit TNFα, indicating that
Kaplan does not favor using EM 12 in particular. Ex. 1003, Figures 5–7;
Prelim. Resp. 33–34.
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Thus, at most, Piper and Kaplan together indicate that thalidomide is
useful to both treat ENL and reduce TNFα levels, and EM 12 (and other
analogs lacking the amino group on the benzene ring) may reduce TNFα,
even if EM 12 exhibits activity in only one out of two relevant sites of action
for ENL. Petitioner does not establish sufficiently that an ordinary artisan
reading those two references would have had reason to pick AH 13 or AH
14 (out of over 40 analogs discussed in Piper) in particular for use in a
method to reduce TNFα levels (disclosed in Kaplan in relation to different
analogs).
b) Alleged Reasonable Expectation of Success
Petitioner also contends that an ordinary artisan would have
reasonably expected Piper’s AH 14 and AH 13 to exhibit the same activity
as thalidomide because AH 14 and AH 13 have high structural similarity to
that parent compound and exhibit “at least one key activity of the parent
(i.e., anti-inflammation or immunosuppression).” Pet. 33. In support,
Petitioner refers to EM 12 and its activities (as shown in Piper and Kaplan),
and cites Dr. Heathcock’s Declaration for the proposition that “those of
ordinary skill may expect compounds of high structural similarity that have
an important functional activity in common to have other activities in
common as well.” Pet. 34 (citing Ex. 1007, ¶¶ 118, 119). We note that
other than referring to Piper and Kaplan generally, the cited paragraphs in
Dr. Heathcock’s Declaration cite no evidence in support of that proposition.
Ex. 1007, ¶¶ 118, 119.
Other information of record before us, by contrast, indicates that even
the smallest of chemical differences in thalidomide analogs impacts
biological activity. Teachings in Piper alone indicate that different analogs,
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even those differing only by the addition and/or location of a single
“electron donating” group on the benzene ring, exhibit different activities.
Piper discusses “[t]hirteen α-substituted glutarimides with changes in the 6
membered phthalimide moiety.” Ex. 1002, 511, 2nd col. Of those, many
are active in one or the other assay (carrageenan or PFC) or neither assay.
Among those thirteen, Piper also discusses “[f]our compounds involv[ing]
electron donating substitutions (amino- or hydroxyl-) on the 6 membered
phthalimide system.” Id. Among those four compounds, and even among
the two compounds containing an amino group on the 6-carbon benzene ring
(AH 13 and AH 14), Piper found differing results in the two assays. For
example, Piper states that AH 13 is active in the carrageenan assay but not
the PFC assay, while AH 14 “enhances PFC” and is inactive in the
carrageenan assay. Id.; see also Prelim. Resp. 29 (noting differing assay
results for thalidomide and different analogs, including those with a
hydroxyl group on the benzene ring, AH 22 and AH 20).
Thus, Patent Owner persuades us, consistent with binding case law,
that “even minor structural modifications to a chemical compound can have
significant and highly unpredictable effects on functionality,” as evidenced
by Piper and other references of record here. Prelim. Resp. 26–27 (citing
relevant Federal Circuit and other case law) (citations omitted). We are not
persuaded by Petitioner’s contention that “those of ordinary skill may expect
compounds of high structural similarity that have an important functional
activity in common to have other activities in common as well.” Pet. 34.
When arguing a reasonable expectation of success, Petitioner also
contends that “by disclosing steroids [prednisolone and dexamethasone] that
exhibit anti-inflammation, immunosuppression, and TNFα inhibition,
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Kaplan identifies another direct relationship—i.e., between compounds that
are anti-inflammatory or immunosuppressive and compounds that block
TNFα.” Pet. 34–35 (citing Ex. 1007 ¶ 120 (citing Ex. 1003, 3:50–55)).
Petitioner does not contend, however, that either steroid is a thalidomide
analog. In addition, Kaplan teaches that those steroids exhibit both anti-
inflammatory and immunosuppressive activities, similarly to thalidomide,
but unlike EM 12 (as disclosed in Piper). In any event, Kaplan’s discussion
about steroids unrelated in structure does not indicate sufficiently that one
would have expected entirely different compounds (e.g., AH 13 or AH 14)
to reduce TNFα levels.
4. Conclusion
For the reasons discussed above, Petitioner has not established a
reasonable likelihood of prevailing on the ground that claims 1 and 7–9 of
the ’517 patent would have been obvious over Piper in view of Kaplan.
C. Asserted ground of obviousness of claims 2–6 and 10 over Piper,
Kaplan, Agrawal (Ex. 1004), and WO ’085 (Ex.1005)
Petitioner contends that claims 2–6 and 10 of the ’517 patent would
have been obvious over Piper, Kaplan, Agrawal, and WO ’085. Pet. 37–52.
In relation to Piper and Kaplan, Petitioner raises similar contentions to those
discussed above. Id. at 39–40. Petitioner additionally relies on Agrawal
(published alongside Piper), which discusses carrageenan and PFC assay
results using thalidomide analogs, and WO ’085, which discloses methods of
inhibiting angiogenesis using thalidomide and thalidomide analogs. Id. at
40–42. Petitioner again contends that an ordinary artisan would have had
reason to combine teachings in those references to reach the recited methods
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and compounds, and one would have had a reasonable expectation of
success in doing so. Id. at 43–49.
1. Agrawal (Ex. 1004)
Like Piper, Agrawal describes a study in an effort to develop
thalidomide analogs that are effective in controlling ENL—again using the
carrageenan (anti-inflammatory) and PFC (immunosuppressive) assays.
Agrawal discusses many different analogs, including “analogs containing
NO2, COOH, NH2, or OH groups.” Ex. 1004, 512, 2nd col. In this context,
Agrawal states that “agents containing the electron donating groups such as
3 or 4-hydroxy and 4-aminothalidomide retained the anticarrageenan
activity, whereas the analogs with electron withdrawing groups such as 4-
nitro or 4-carboxy were not active in this assay.” Id. Agrawal goes on to
state, however, that “the biological activity in the PFC assay did not
correlate with electronic properties since not only the 4-nitro and 4-carboxy
analogs but also the 4-hydroxythalidomide was active in this system.” Id.
Thus, consistent with teachings in Piper, Agrawal indicates that 4-
hydroxythalidomide (AH 20) is active in both assays, and 3-hydroxy-
thalidomide (AH 22) and 4-aminothalidomide (AH 13) are active only in the
carrageenan assay. While it does not discuss 3-aminothalidomide (AH 14)
per se, teachings in Agrawal also are consistent with the fact that AH 14 is
inactive in both assays, as indicated in Piper.
Agrawal also states that study results “suggest that modifications in
the parent thalidomide molecule can be made which retain the anti-
inflammatory and immunosuppressive activity, but yet may be expected to
alter the neurotoxic and teratogenic properties.” Id. (emphasis added). Like
Piper, therefore, Agrawal suggests that thalidomide analogs that exhibit both
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anti-inflammatory and immunosuppressive activities (i.e., active in both
assays) would be useful to treat EML.
2. WO ’085 (Ex. 1005)
WO ’085 discloses methods for preventing unwanted angiogenesis by
administering thalidomide and “related compounds.” Ex. 1005, 1:20–25.
6

As noted in WO ’085, angiogenesis is the generation of new blood vessels
into a tissue or organ. Id. at 1:28–29.
WO ’085 discloses that “[s]pecific preferred compounds . . . of the
present invention include thalidomide, its precursors, metabolites and
analogs,” and that “[p]articular analogs include EM-12, N-phthaloyl-DL-
glutamic acid (PGA) or N-phthaloyl-DL-glutamine anhydride.” Id. at 14:8–
12. WO ’085 discloses using “epoxides of thalidomide, EM-12 and EM-
138” (id. at 16:1–15) and that the epoxides can be hydrolyzed to form six
compounds, including the two compounds reproduced below.

Id. at 16:20–17:9. WO ’085 further teaches that “the hydroxyl group can be
on carbons 1, 2, 3, 4, 5 and 6 of the benzene ring.” Id. at 17:10–11.
3. Analysis—Claims 2–6
Claims 2–6 of the ’517 patent depend from claim 1, and recite
methods of reducing TNFα in a mammal by administering compositions

6
Page citations in relation to Ex. 1005 refer to pages numbers in the
original document, located at the top of the reference.
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corresponding to thalidomide analogs having an amino group on the benzene
ring, and a single C=O in the 5-carbon ring.
In relation to those claims, Petitioner contends that Agrawal teaches a
preference for amino-substituted analogs, as well as “a preference for
analogs with an amino- or hydroxyl substituted benzo ring.” Pet. 40–41
(citing Ex. 1004, 512, Ex. 1007 ¶¶ 87–89, 139 (similarly discussing and
citing Agrawal)). We are not persuaded.
As discussed above, Agrawal, like Piper, discloses the testing of many
thalidomide analogs and suggests that analogs exhibiting both anti-
inflammatory and immunosuppressive activities (i.e., active in both the
carrageenan and PFC assays) would be useful to treat ENL. Ex. 1004, 512;
see also Pet. 41–42 (referring to that teaching in Agrawal). Both Piper and
Agrawal indicate that 4-hydroxythalidomide (AH 20) is active in both
assays, 3-hydroxy-thalidomide (AH 22) and 4-amino-thalidomide (AH 13)
are active only in the carrageenan assay (not the PFC assay), and 3-amino-
thalidomide (AH 14) is inactive in both assays. Thus, at most, both
references suggest a preference, in the context of treating ENL, for an analog
with a hydroxyl group at a specific location in the benzene ring (4-hydroxy,
not 3-hydroxy), and no particular preference for analogs with an amino
group on the benzene ring.
Petitioner contends that WO ’085 “teaches that each of thalidomide,
EM 12, and 3-, 4-, 5-, and 6-hydroxyl-substituted EM 12 inhibit
angiogenesis,” and that “EM 12 is a more potent inhibitor of angiogenesis
than thalidomide.” Pet. 42. Petitioner then contends that an ordinary artisan
“would have readily combined the teachings” of the four cited references “to
develop thalidomide analogs having an amino or hydroxyl-substituted benzo
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ring, and at least one important functional activity of thalidomide (i.e., anti-
inflammation or immunosuppression) for use in effectively treating at least
ENL by reducing TNFα.” Id. at 43–44 (citing Ex. 1007 ¶¶ 145–153).
Petitioner does not point us to anything in Agrawal or WO ’085 that
overcomes the deficiencies mentioned above in relation to Petitioner’s
assertion that an ordinary artisan would have combined the teachings of
Piper and Kaplan to develop thalidomide analogs having an amino group on
the benzene ring for use in reducing TNFα levels.
As discussed above, teachings in Agrawal and Piper are very similar
and, at best, suggest a preference for an analog with a hydroxyl group at a
specific location in the benzene ring (4-hydroxy, not 3-hydroxy), without
sufficiently indicating a preference for analogs with an amino group on the
benzene ring. In addition, Kaplan, the only cited reference to discuss
methods of reducing TNFα, does not discuss, much less indicate a
preference for, thalidomide analogs with an amino group on the benzene
ring.
In relation to WO ’085, Petitioner does not explain or reasonably
support that inhibiting angiogenesis correlates to reducing TNFα. Even
assuming Petitioner had established such a correlation, however, all four
references in combination potentially would have suggested a preference for
EM 12 or EM 12 containing a 4-hydroxyl group in the benzene ring. For the
reasons discussed above, however, we are not persuaded that any of the four
references, either alone or in combination, sufficiently suggests using a
thalidomide analog containing an amino group on the benzene ring, whether
to treat ENL, reduce TNFα, or inhibit angiogenesis.
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Petitioner’s discussion of WO ’085 does not persuade us “that
structural similarity is reasonably predictive of functional similarity.” Pet.
42 (citing Ex. 1007 ¶¶ 94–96, 140–141). We likewise are not persuaded by
Petitioner’s assertions regarding a reasonable expectation of success, which
again rely on contentions that an ordinary artisan “would have reasonably
expected other structurally similar analogs of thalidomide and EM 12 to
behave like their parent compounds.” Id. at 44–45 (citing Ex. 1007 ¶¶ 155–
165). As discussed above, information of record, such as Piper and
Agrawal, indicates that one of ordinary skill would have known that even
small chemical differences in thalidomide analogs impacted biological
activity. For example, Piper and Agrawal indicate that the absence or
presence, as well as the specific location, of a hydroxyl or amino group on
the benzene ring impacts whether that analog exhibits anti-inflammatory
and/or immunosuppressive activity (as tested in carrageenan and PFC
assays).
In addition, as Petitioner concedes, neither Kaplan (the only reference
discussing TNFα) nor WO ’085 discloses the use of a thalidomide analog
containing an amino group on the benzene ring. Pet. 47. As Petitioner also
recognizes, no cited reference discloses the use of an EM 12 analog
containing an amino group on the benzene ring. Id. For the reasons
discussed above, we are not persuaded that any cited reference, either alone
or in combination, reasonably suggests substituting a hydroxyl group with
an amino group on the benzene ring to produce a thalidomide analog useful
in reducing TNFα levels.
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4. Analysis—Claim 10
We likewise are not persuaded that an ordinary artisan would have
had sufficient reason to prepare any of the four compounds recited in claim
10. All four compounds in claim 10 comprise an amino group on the
benzene ring (like AH 13 and AH 14) and a single C=O in the 5-carbon ring
(like EM 12). Petitioner has not established sufficiently, with reasonable
underpinnings, why one would have produced such compounds for any
reason, for example to produce analogs that inhibit angiogenesis (discussed
in WO ’085). As Petitioner notes, none of the cited references disclose EM
12 (or other analog having a single C=O in the 5-carbon ring) modified to
have an amino group on the benzene ring. Pet. 47. While WO ’085 teaches
a compound having a hydroxyl group on the benzene ring (like AH 20) and
a single C=O on the 5-carbon ring (like EM 12), Petitioner does not explain
sufficiently why one would substitute the hydroxyl group in that analog with
an amino group.
For example, we are not persuaded that Petitioner contends or
reasonably establishes a link between inhibiting angiogenesis (disclosed in
WO ’085), treating ENL (or anti-inflammatory and/or immuno-suppressive
activities) (disclosed in Piper and Agrawal), and/or reducing TNFα
(disclosed in Kaplan). Petitioner’s general arguments regarding the “known
activities and structures of thalidomide, EM 12, and structurally similar
amino- and hydroxyl-substituted analogs thereof” do not establish that link,
nor reasonably provide a reason to make the specific hydroxyl to amino
substitution needed here.
Piper and Agrawal disclose that AH 20 (4-hydroxythalidomide), but
not AH 22 (3-hydroxylthalidomide), exhibits both anti-inflammatory and
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immunosuppressive activities (both sites of action for ENL). Ex. 1002, 511,
2nd col. Kaplan discloses EM 12 (Ex. 1003, 5:30–39), and WO ’085
discloses EM 12 with a hydroxyl group on any of carbons 1, 2, 3, 4, 5 and 6
of the benzene ring (Ex. 1005, 17). Thus, at most, even if we assume a link
exists between treating ENL, reducing TNFα, and/or inhibiting
angiogenesis, the four references would have led an ordinary artisan to make
a specific version from a genus disclosed in WO ’085, i.e., a species of EM
20 modified to include a hydroxyl group at the same location in the benzene
ring as AH 20. For the same reasons discussed above, Petitioner’s assertion
that “known activities and structures of thalidomide, EM 12, and structurally
similar amino- and hydroxyl-substituted analogs” would have provided a
reason to prepare a thalidomide analog having an amino group on the
benzene ring is not supported reasonably by information before us. Pet. 43.
Furthermore, we are not persuaded that the compounds of claim 10
correspond to only a “few known options” of possible relevant thalidomide
analogs, as Petitioner contends. Pet. 48. As noted by Patent Owner, the
cited references disclose a large number of possible thalidomide analogs.
See Prelim. Resp. 42 n.15 (“WO ’085 alone discloses billions of thalidomide
analogs,” “Kaplan discloses over one hundred,” “Piper discloses
‘approximately 50 thalidomide analogs,’” and “Agrawal discloses various
modifications suggesting hundreds of additional analogs”) (citations
omitted). Of those many possible thalidomide analogs, the cited references
suggest that a subset of analogs—analogs lacking an amino group on the
benzene ring—may be useful to treat ENL, reduce TNFα, or inhibit
angiogenesis. Information before us does not establish adequately that one
of ordinary skill in the art would have had reason to modify one specific
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analog disclosed in WO ’085 (out of many) to prepare the specific “four
amino-substituted EM 12 analogs” recited in claim 10. Pet. 48.
5. Conclusion
For the reasons discussed above, Petitioner has not established a
reasonable likelihood of prevailing on the ground that claims 2–6 and 10 of
the ’517 patent would have been obvious over Piper in view of Kaplan,
Agrawal, and WO ’085.
D. Asserted ground of obviousness of claims 2–6 and 10 over Piper,
Kaplan, Agrawal, and Keith (Ex.1006)
Petitioner contends that claims 2–6 and 10 of the ’517 patent would
have been obvious over Piper, Kaplan, Agrawal, and Keith. Pet. 52–59. In
relation to Piper, Kaplan, and Agrawal, Petitioner asserts similar contentions
to those discussed above. Id. at 52–55. In this ground, Petitioner
additionally relies on Keith, which, as Petitioner notes, discloses “solubility
information for a variety of chemical compounds, including thalidomide and
EM 12.” Pet. 55 (citing Ex. 1006 at 190, 397).
Petitioner does not explain adequately how Keith overcomes the
deficiencies mentioned above in relation to Petitioner’s assertion that an
ordinary artisan would have combined the teachings of Piper, Kaplan, and
Agrawal—deficiencies equally applicable to the assertion in this ground—to
practice the methods of claims 2–6, or prepare the specific compounds
recited in claim 10.
At most, Petitioner argues, based on Keith, that an ordinary artisan
would have known that thalidomide and EM 12 “are practically insoluble in
water.” Pet. 55 (citing Ex. 1007 ¶ 178). Petitioner also contends, citing
conclusory statements by Dr. Heathcock in support, that “increasing the
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solubility of a drug can significantly enhance its bioavailability,” and that an
ordinary artisan “would have generally known that the addition of an
electron donating substituent (e.g., an amino or hydroxyl group) to the benzo
ring of EM 12 would likely increase its solubility.” Id. (citing Ex. 1007
¶¶ 178, 187). Thus, according to Petitioner, “one would have been driven to
aminate EM 12 in order to improve its poor solubility.” Id. at 55–56 (citing
Ex. 1007 ¶¶ 178, 187–188).
For all the reasons discussed above, information before us does not
suggest or point adequately to modifying EM 12 or another relevant
compound to contain an amino group on the benzene ring. Keith does not
overcome that deficiency by merely disclosing the solubility of EM 12 and
thalidomide. Even assuming one would have had reason to prepare a more
soluble thalidomide analog, Patent Owner persuades us that an ordinary
artisan would have faced “a potentially limitless list of modifications,”
without sufficient guidance pointing to the addition of an amino group on
the benzene ring in particular. Prelim. Resp. 54–55.
For the reasons discussed above, Petitioner has not established a
reasonable likelihood of prevailing on the ground that claims 2–6 and 10 of
the ’517 patent would have been obvious over Piper in view of Kaplan,
Agrawal, and Keith.
III. CONCLUSION
For the foregoing reasons, the information presented in the Petition
and accompanying evidence does not establish a reasonable likelihood that
Petitioner would prevail in showing the unpatentability of claims 1–10 of the
’517 patent.
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IV. ORDER
It is
ORDERED that the Petition is denied and no trial is instituted.

For PETITIONER:

Jeffrey Blake
jblake@merchantgould.com

Dianna El Hioum
delhioum@merchantgould.com

For PATENT OWNER:

Francis Cerrito
nickcerrito@quinnemanuel.com

Anthony Insogna
aminsogna@jonesday.com