Identification of NVP-BKM120 as a potent, selective, orally bioavailable class i PI3 kinase inhibitor for treating cancer

Article abstract of DOI:10.1021/ml200156t

Phosphoinositide-3-kinases (PI3Ks) are important oncology targets due to the deregulation of this signaling pathway in a wide variety of human cancers. Herein we describe the structure guided optimization of a series of 2-morpholino, 4-substituted, 6-heterocyclic pyrimidines where the pharmacokinetic properties were improved by modulating the electronics of the 6-position heterocycle, and the overall druglike properties were fine-tuned further by modification of the 4-position substituent. The resulting 2,4-bismorpholino 6-heterocyclic pyrimidines are potent class I PI3K inhibitors showing mechanism modulation in PI3K dependent cell lines and in vivo efficacy in tumor xenograft models with PI3K pathway deregulation (A2780 ovarian and U87MG glioma). These efforts culminated in the discovery of 15 (NVP-BKM120), currently in Phase II clinical trials for the treatment of cancer.

Full text of DOI:10.1021/ml200156t

LETTER
pubs.acs.org/acsmedchemlett
Identification of NVP-BKM120 as a Potent, Selective, Orally
Bioavailable Class I PI3 Kinase Inhibitor for Treating Cancer
Matthew T. Burger,* Sabina Pecchi,* Allan Wagman, Zhi-Jie Ni, Mark Knapp, Thomas Hendrickson,
Gordana Atallah, Keith Pfister, Yanchen Zhang, Sarah Bartulis, Kelly Frazier, Simon Ng, Aaron Smith,
Joelle Verhagen, Joshua Haznedar, Kay Huh, Ed Iwanowicz, Xiaohua Xin, Daniel Menezes, Hanne Merritt,
Isabelle Lee, Marion Wiesmann, Susan Kaufman, Kenneth Crawford, Michael Chin, Dirksen Bussiere,
Kevin Shoemaker, Isabel Zaror, Sauveur-Michel Maira, and Charles F. Voliva
Global Discovery Chemistry/Oncology & Exploratory Chemistry, Novartis Institutes for Biomedical Research, 4560 Horton Street,
Emeryville, California 94608, United States
S Supporting Information
b
ABSTRACT: Phosphoinositide-3-kinases (PI3Ks) are important oncology targets due to
the deregulation of this signaling pathway in a wide variety of human cancers. Herein we
describe the structure guided optimization of a series of 2-morpholino, 4-substituted, 6-hetero-
cyclic pyrimidines where the pharmacokinetic properties were improved by modulating the
electronics of the 6-position heterocycle, and the overall druglike properties were fine-tuned
further by modification of the 4-position substituent. The resulting 2,4-bismorpholino
6-heterocyclic pyrimidines are potent class I PI3K inhibitors showing mechanism modula-
tion in PI3K dependent cell lines and in vivo efficacy in tumor xenograft models with PI3K
pathway deregulation (A2780 ovarian and U87MG glioma). These efforts culminated in the
discovery of 15 (NVP-BKM120), currently in Phase II clinical trials for the treatment of
cancer.
KEYWORDS: NVP-BKM120, phosphoinositide-3-kinase, PI3K/AKT3 pathway
he phosphoinositide-3-kinase (PI3K) family of lipid kinases
is involved in a diverse set of cellular functions, including cell
and tyrosine kinases). We have further reported on non-phenol
containing heterocyclic, morpholino pyrimidines12 such as com-
pound 1 which demonstrate in vivo PI3K pathway modulation
and modest tumor growth inhibition. Described herein are our
efforts to identify potent morpholino pyrimidinyl inhibitors of
class I PI3Ks that exhibit potency and pharmacokinetic proper-
ties which allow for maximal pathway modulation in vivo and
have druglike properties suitable for clinical development. These
efforts culminated in the identification of 15, NVP-BKM120.
Aminopyrimidine 1 and analogues such as 3 (Figure 1) exhibit
low or sub-nanomolar biochemical potency and sub-micromolar
cellular potency against PI3KR. Even with high rodent CL values,
such analogues can demonstrate PI3K pathway modulation in
mouse xenograft models.12 During our exploration of the C6 position,
it was noted that C6 aminopyridine analogue 4, while being less
potent than 3 against PI3KR (>10ꢁ potency loss), exhibited a
markedly reduced (>9ꢁ) rat CL value, increased %F, and increased
oral AUC. Thus, superior pharmacokinetic properties were achiev-
able within this scaffold and the challenge remaining was to retain
this kind of pharmacokinetic profile while optimizing all the
other attributes (potency, solubility, permeability, safety) neces-
sary for advancement. To address this challenge, the approach
taken focused on modifying the electronic properties of the C6
T
growth, proliferation, motility, differentiation, glucose transport,
survival, intracellular trafficking, and membrane ruffling.1 PI3K’s
can be categorized into class I, II, or III, depending on their
subunit structure, regulation, and substrate selectivity.2 Class IA
PI3K’s are activated by receptor tyrosine kinases and consist of a
regulatory subunit (p85) and a catalytic subunit (p110). There
are three catalytic isoforms: p110R, β, and δ. A single class IB
PI3K, activated by GPCRs, consists of only one member: a p110γ
catalytic subunit and a p101 regulatory subunit. The primary
in vivo substrate of the class I PI3K’s is phosphatidylinositol (4,5)
diphosphate (PtdIns(4,5)P2), which upon phosphorylation at
the 3-position of the inositol ring to form phosphatidylinositol
triphosphate (3,4,5)P3 (PIP3) serves as a second messenger by
activating a series of downstream effectors that mediate the cellular
functions mentioned above. The PI3K isoforms have different
distributions and share similar cellular functions, which are context
dependent. In particular, p110R pathway deregulation has been
demonstrated in ovarian, breast, colon, and brain cancers.3,4
Inhibitors of PI3KR represent an intriguing therapeutic modality
for these indications, and as such, there is much interest in
generating suitable molecules to test this hypothesis in the
clinic.5ꢀ10
We have previously reported on a series of 6-hydroxyphenyl-2-
morpholino pyrimidines,11 as potent pan class I PI3K inhibitors that
exhibit high selectivity toward protein kinases (serine/threonine
Received: June 27, 2011
Accepted: August 16, 2011
Published: August 26, 2011
r
2011 American Chemical Society
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ACS Medicinal Chemistry Letters
LETTER
intermolecular crystal packing and improve aqueous solubility.
Finally, upon identification of preferred C6 aminoheterocycles,
further optimization at the central pyrimidine C4 position to
modulate druglike properties and maintain potency was antici-
pated, since the cocrystal structure indicated this position was
partially solvent exposed and would tolerate a range of substituents.
0
C4 modified, C6 pyridyl or pyrimidyl substituted 2-morpho-
lino 4-aminoquinolyl pyrimidines, synthesized as previously
described,12 were initially screened in biochemical PI3K assays,
and compounds with PI3KR IC50 values < 100 nM were tested in
the A2780 ovarian carcinoma cell line (where the PI3K pathway
is deregulated due to PTEN deletion) for inhibition of cell
proliferation and phosphorylation of AKTSer473 as target mod-
ulation readout.
Figure 1. PI3KR enzymatic potency and rat PK properties of 6-sub-
stituted, 4-(aminopyrid-3-yl), 2-morpholino pyrimidines.
0
The results of the C4 modified, C6 substituent survey (Table 1)
indicate that the biochemical potency of the C6 aminopyridine
can be improved by introduction of an electron withdrawing
0
group at the C4 position, as is evident in the 3ꢁ, 12ꢁ, and 20ꢁ
biochemical potency improvement in CF3, CN, and Cl re-
0
placement of H. Additionally, substitution at the C4 position
of the aminopyridine does not compromise the rat PK properties,
as the CL and AUC are minimally impacted with the CF3 sub-
stitution, 7 vs 4. In contrast to the trends in C6 aminopyridines,
0
substitution at the C4 position of the C6 aminopyrimidine does
not markedly increase the 0enzymatic or cellular potency. How-
ever, substitution at the C4 position of the C6 aminopyrimidine
can improve the PK properties, as is evident in 10, where the rat
CL is reduced 3-fold and oral AUC increased 3-fold relative to 3.
While the biochemical and PK parameters can be improved
0
with C4 substitution on the C6 aminoheterocycle, all com-
Figure 2. Structure of 2 in PI3Kγ.
pounds with the C4 aminoquinoline exhibit low aqueous solubi-
lity, as well as low Caco-2 permeability.18 The low solubility and
permeability potentially could play a role in the lack of correla-
tion between the biochemical potency and cellular activity.
Additionally, this solubility range would not be sufficient for
further development if concentrations in excess of the cell activity
(0.1ꢀ1 μM) would need to be achieved in vivo for efficacy, as well
as not sufficient to assess the safety profile of the compound.
With these considerations in mind, we further explored C4
aminopyridine and C6 aminopyrimidine moieties. It was
hypothesized that electron withdrawing substituents would im-
prove potency in the aminopyridines.13 In parallel, a series of
substituted pyrimidines was surveyed, assessing the impact of
substitution on PK.
To guide the C6 aminoheterocycle modifications, we looked
to the cocrystal structure of aminopyrimidine 2 (X = CH, R =
OCH3) in PI3Kγ to gain an understanding of the aminopyr-
imidine binding interactions.14 Given the high homology be-
tween the R and γ isoforms and the nanomolar potency of 2
against the two isoforms,15 p110γ was used as a surrogate for
p110R. The cocrystal structure of 2 in the ATP binding site of
PI3Kγ (Figure 2) indicates the key binding contacts being made
by the aminopyrimidine as well as the morpholine group. The
aminopyrimidine interacts via hydrogen bond interactions with
0
position SAR with the preferred C4 substituted C6 aminohetero-
cycles, to arrive at potent PI3K inhibitors with improved solubility.
From earlier work12 it was known that the C4 position could
tolerate a wide range of moieties. Additionally, it was known that
a morpholine group at the C4 position maintained reasonable
potency while improving solubility relative to the aminoquinoline
(compound 12, Table 2). As such, compounds which contained the
C4 morpholine and the C4 substituted C6 aminopyridines or
aminopyrimidines were prepared. The properties of these analo-
gues are shown in Table 2.
All bis morpholino compounds demonstrate biochemical
activity against PI3K in the nanomolar range, mechanism mod-
ulation <300 nM, and inhibition of cell proliferation approxi-
mately between 0.5 and 1.5 μM. Additionally, the solubility at
pH 7 was markedly improved for all bis morpholino compounds
(at least 10ꢀ1000ꢁ) relative to the C4 aminoquinoline analo-
gues. This increased solubility, along with the high permeability,
vide infra, may account for the comparable cellular potency of the
bismorpholino compounds in Table 2 relative to the more bio-
chemically potent but less soluble aminoquinoline compounds in
Table 1. The additional morpholine at the C4 position did not
compromise the rat PK parameters,19 as, for both C6 substituted
aminopyridines as well as C6 substituted aminopyrimidines in
0
0
Asp836, Asp841, and Tyr867. The C4 position of the aminopyr-
imidine appears to provide a vector to a region of the active site
where small groups would be tolerated. The morpholine oxygen
forms a known hydrogen bond to the hinge Val882 NH.16,17 The
central pyrimidine C4 substituent extends out toward solvent and
does not appear to make any specific hydrogen bonds. These latter
two features are consistent with earlier structures of morpholino
pyrimidines.11,12
With this structural insight, our strategy0to find optimal C6
aminoheterocycles was to substitute the C4 position of the C6
0
aminopyrimidine or the C4 position of the C6 aminopyridine
with small groups that could modulate the electronic properties
of the heterocycle. Additionally, it was envisioned that the C4
substitution would enforce the nonplanar conformation between
the central pyrimidine and the C6 heterocycle, which could disrupt
0
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ACS Medicinal Chemistry Letters
LETTER
Table 1. Selected C6 Aminopyridyl/Pyrimidyl Analogue SAR
pAKTSer473 EC50b (μM)
CLc
AUCd
Vss
e
entry
X
R
PI3KR IC50a (μM)
prolif EC50b (μM)
3
N
H
<0.002 ( 0.004 (15)
0.11 ( 0.15 (16)
0.146 ( 0.10 (6)
0.54 ( 0.19 (10)
0.28 ( 0.14 (4)
0.19 ( 0.05 (4)
0.083 ( 0.24 (17)
0.17
0.042 ( 0.01 (4)
0.31 ( 0.09 (3)
0.29
37 ( 5.7
5 ( 0.8
7 ( 2.6
92 ( 22
1.9 ( 0.2
0.8 ( 0.1
4
CH
CH
CH
CH
N
H
5
Cl
0.0024 ( 0.0004 (2)
0.0041 ( 0.0001 (2)
0.021 ( 0.010 (9)
0.0026 ( 0.0001 (2)
0.0074 ( 0.0008 (2)
0.0022 ( 0.002 (8)
0.008 ( 0.009 (8)
6
CN
CF3
NH2
O
1.3 ( 0.78 (2)
0.45 ( 0.22 (7)
0.18
7
8 ( 0.3
114 ( 19
26 ( 3.4
2.6 ( 0.4
2.8 ( 0.8
8
9
NH
N
3.2 ( 1.2 (4)
10
11
CF3
CH3
0.58 ( 0.49 (12)
0.19 ( 0.11 (8)
0.43 ( 0.11 (4)
11. ( 3 2
N
0.09
a ATP depletion assay; the value in parentheses is the number of replicates. b A2780 cell line. c Rat, IV, 5 mg/kg dose, mL/(min kg). d Rat, oral, 20 mg/kg
3
dose, μM h. e Rat, IV, 5 mg/kg dose, L/kg.
3
Table 2. Selected 2,4-Bismorpholino Pyrimidyl Analogue SAR
pAKTSer473 EC50b (μM)
prolif EC50b (μM)
CLc
AUCd
Vss
%F
solf
e
entry
X
R
PI3KR IC50a (μM)
12
13
14
15
16
17
18
N
H
0.0184 ( 0.001 (2)
0.034 ( 0.006 (6)
0.068 ( 0.014 (5)
0.030 ( 0.017 (24)
0.023 ( 0.011 (10)
0.015 ( 0.008 (8)
0.014 ( 0.006 (14)
0.10
0.93 ( 0.11 (2)
1.77 ( 0.68 (4)
0.51 ( 0.48 (3)
0.52 ( 0.50 (30)
1.46 ( 2.0 (33)
0.68 ( 0.22 (4)
0.45 ( 0.10 (3)
25
45
11
132
8
CH
CH
CH
N
Cl
0.11
22 ( 5
11 ( 2
3 ( 0.4
9 ( 0.1
24 ( 4
11 ( 2
29 ( 6
86 ( 5
178 ( 3
64 ( 7
24 ( 3
62 ( 5
1.11 ( 0.7
1.6 ( 0.1
3.1 ( 0.4
4.5 ( 0.9
2.8 ( 1.2
2.1 ( 0.2
69 ( 14
98 ( 6
50 ( 7
68 ( 14
56 ( 15
83 ( 3
CN
CF3
NH2
O
0.10 ( 0.10 (3)
0.055 ( 0.02 (11)
0.079 ( 0.03 (11)
0.073 ( 0.01 (2)
0.070 ( 0.03 (3)
NH
22
61
N
CF3
a ATP depletion assay; the value in parentheses is the number of replicates. b A2780 cell line. c Rat, IV,19 mL/(min kg). d Rat, oral,19 μM h. e Rat, IV,19
3
3
L/kg. f Solubility at pH 7, μM
Table 2, low to moderate CL and moderate to high %F were
observed. All bismorpholino compounds in Table 2 exhibit high
most common p110R mutants. Additionally, 15 exhibited lower
potency against class III and class IV PI3K's, where 2, 5, >5, and
>25 μM biochemical activity was observed for inhibition of
VPS34, mTOR, DNAPK, and PI4K, respectively. No significant
activity was observed against the protein kinases tested.
In vitro evaluation of 15 across a range of PI3K deregulated cell
lines from a variety of tumor types, including ovarian, glioblas-
toma, breast, and prostate, was conducted (Table 4). Across all
cell lines, pathway modulation and antiproliferative activity was
consistent with cellular PI3K inhibition.
The behavior consistent with selective in vitro inhibition of
class I PI3K’s translated to in vivo settings in two models of PI3K-
AKT pathway driven cancers: the A2780 ovarian carcinoma and
the U87MG glioma model, which carry a PTEN deletion. In
A2780 xenograft tumors (Figure 4), oral dosing of 15 at 3, 10, 30,
60, and 100 mg/kg resulted in a dose dependent modulation of
stability in both rat and human liver microsomes, with Clint
e
9 μL/min/mg in both species.
Compound 15 was of particular interest, as the solubility was
the highest (170 μM on crystalline material) and it was among
the most potent bismorpholine compounds in cell based assays
(50 nM target modulation; 500 nM cell proliferation). Figure 3
shows the cocrystal structure of 15 in PI3Kγ.20 The binding
mode was as expected with one of the morpholines binding to the
hinge at Val882 and the aminopyridine group interacting via
hydrogen bonds to Asp836, Asp841, and Tyr867.
The biochemical activity of 15 was assessed across class I
PI3K’s, related lipid kinases, and against more than 200 protein
kinases. Some of the data are shown in Table 3. Compound 15
exhibited 50ꢀ300 nM activity for class I PI3K’s, including the
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Figure 5. Efficacy of compound 15, NVP-BKM120, in an A2780
xenograft model.
Figure 3. Structure of 15, NVP-BKM120, in PI3Kγ.
Table 3. Biochemical Activity of 15, NVP-BKM120, against
Class I, III, IV, PI3, and Related Kinases
class
enzyme
IC50 (μM)
enzyme
IC50 (μM)
Class I PI3K'sa p110R
0.052 ( 0.037 p110β
0.166 ( 0.029
0.116
p110RꢀH1047R 0.058 ( 0.002 p110δ
p110RꢀE545K 0.099 ( 0.006 p110γ
0.262 ( 0.094
Class III PI3K'sb VPS34
Class IV PI3K's mTORc
PI4Kb
PI4Kβ
2.4 ( 1.5
4.6 ( 1.9
>25
DNAPKd >5
a Filter binding assay. b ATP depletion assay. TR-FRET assay. d Pro-
c
mega SignaTECT.
Figure 6. Antitumor activity of 15, NVP-BKM120, against the sub-
cutaneous U87MG glioma tumor model.
Table 4. Cellular Activity of 15 across Multiple Cell Lines
with PI3K Pathway Deregulation
doses of 30, 60, or 100 mg/kg, respectively. Inhibition of pAKT
(normalized to total AKT) tracked well with both plasma and
tumor drug exposure. pAKT modulation was also time depen-
dent, with >90% target modulation achieved with the 60 and
100 mg/kg dose at the 10 h time point when the plasma and
tumor exposure was ca. 2 μM.21
Consistent with the mechanism modulation observed, signifi-
cant tumor growth inhibition was obtained in the A2780 tumor
model at 60 mg/kg upon multiple dosing (Figure 5). Efficacy was
associated with significant inhibition of the PI3K pathway, as
assessed by reduction in pAktSer473, for up to 16 h.
cell line
genotype
pAKTSer473 EC50 (μM)
GI50 (nM)
A2780
PTEN del
0.074
0.13
0.635
0.698
0.158
0.435
U87MG
MCF7
DU145
PTEN del
E545KꢀPIK3CA
LKB1 mutant
<0.100
0.073
As was the case in vitro, 15 displays in vivo activity across a
range of PI3K pathway deregulated tumor xenograft models.22 In
the established U87MG glioma model, significant single agent
activity was obtained with 15 at daily oral doses of 30 and 60 mg/kg
(Figure 6) in a well tolerated manner.23 This activity in the
U87MG model, coupled with the high permeability and lack of
efflux exhibited by 15,24 suggests that 15 may have utility in
PI3K-driven gliomas.
With these encouraging rodent pharmacology activities, com-
pound 15 was studied further. Profiling indicated that 15 exhibited
no reversible or time dependent CYP450 (3A4, 2C9, 2D6)
inhibition up to 50 μM or CYP3A4 induction up to 25 μM,
exhibited high permeability with no propensity for efflux,23
demonstrated no cardiotoxicity potential,25 and showed a clean
profile (>10 μM) against enzymes, receptors, and transporters
included in internal safety and the external MDS Pharma Services
panels. The melting point of 15 is 153 °C, its log D (pH 7.4) is
2.9, and its pKa is 5.1. The synthesis of 15 is straightforward,
proceeding in four steps for the research route (Scheme 1).
Figure 4. pAKTser473 inhibition and plasma exposure of 15, NVP-
BKM120, in an A2780 xenograft model.
pAKTSer473. Partial inhibition of pAKTser473 was observed at 3
and 10 mg/kg, and near complete inhibition was observed at
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LETTER
Scheme 1. Synthesis of 15
and pharmacology model procedures. This material is available
free of charge via the Internet at http://pubs.acs.org.
’ AUTHOR INFORMATION
Corresponding Author
*Joint authorship. E-mail: matthew.burger@novartis.com.
’ ACKNOWLEDGMENT
The authors thank Dr. Frederic Stauffer for his help in
completing the in vitro selectivity and safety profiling of NVP-
BKM120, Dr. Giorgio Caravatti for his support and coordination
of the predevelopment activities, and Weiping Jia and Dr. Gavin
Dollinger for analytical chemistry support.
Table 5. PK Properties of 15 across Species26
’ ABBREVIATIONS
PI3K, phosphoinositide-3-kinase; DNAPK, DNA dependent
protein kinase; PI4K, 1-phosphatidylinositol-4-kinase; mTOR,
mammalian target of rapamycin; PTEN, phosphatase and tensin
homologue; NBS, N-bromosuccinimide; DIEA, diisopropylethy-
lamine; Pd(dppf)Cl2-DCM, dichloro[1,10-bis(diphenylphosphino)-
ferrocene] palladium(II) dichloromethane adduct; DIEA,
diisopropylethylamine; DME, dimethoxyethane; CYP, cyto-
chrome P450; CL, clearance; PK, pharmacokinetics
IV
PO
%F
a
c
species
t1/2
CLb
Vss
1.4
mouse
rat
1.6
11
11
71ꢀ89
50
3 ( 0.4
7.3 ( 1.5
13
3.1 ( 0.4
3.1 ( 0.4
3.1
dog
6.6 ( 0.8
>100
44
monkey
3.6
a Units of hour. b Units of mL/(min kg). c Units of L/kg.
’ REFERENCES
The pharmacokinetic properties of 15 were evaluated across
multiple species (Table 5). Low to moderate CL was observed
for 15 across species, as CL values of 11, 3, 13, and 7 mL/(min
kg) were observed in mouse, rat, dog, and monkey, respectively.
Additionally, 15 exhibited medium to high oral bioavailability
across species as 80%, 50%, 44%, and 100% was observed in
mouse, rat, dog, and monkey, respectively.
With the favorable cellular potency, kinase selectivity, pre-
clinical pharmacology, rodent, dog, and monkey pharmacoki-
netics, physical properties, and preclinical safety profile, 15 was
advanced into clinical trials in 2008 and has since shown clinical
activity in patients with cancer.27 Specifically promising activity
has been observed in those patients with an activated PI3K
pathway.28
In summary, we have described the structure guided optimization
of a series of 6-aminoheterocyclic, 4-substituted, 2-morpholino
pyrimidines which exhibited high CL and low aqueous solubility
into a compound suitable for clinical development. Modification
of the aminoheterocycle with small groups that modulated the
ring electronics either improved potency or reduced the in vivo
CL values. Incorporation of a morpholine group at the C4 central
pyrimidine position increased the aqueous solubility while retaining
sufficient potency, selectivity, and favorable in vivo properties.
The combination of these modifications led to the discovery of a
series of substituted 6-aminoheterocyclic, 2,4-bismorpholino pyr-
imidines. From this series, compound 15 (NVP-BKM120) has
advanced into humans and is currently being assessed in phase II
trials.29
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’ ASSOCIATED CONTENT
S
Supporting Information. Experimental details for the
b
synthesis and characterization of all compounds, biological assay,
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a Potent, Selective, Orally Bioavailable Inhibitor of Class I PI3 Kinase for
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female beagles, 1 mg/kg IV, 2 mg/kg PO), monkey PK (male cyno-
molgus monkeys, 1 mg/kg IV, 2 mg/kg PO).
(27) ”Oral Pan-Class I PI3K Inhibitor BKM120 Monotherapy in
Patients with Advanced Solid Tumors: an Update on Safety and
Efficacy”. Gra~na-Suꢀarez, B.; Burris, H. A.; Anhert, J. R.; Abdul Razak,
A. R.; De Jonge, M. J.; Eskens, F.; Siu, L. L.; Ru, Q. C.; Homji, N. F.;
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(28) Novartis internal data.
(29) www.clinicaltrials.gov and NVP-BKM120.
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(13) By mimicking the electronics and H bond donating capabilities
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Biological Hydrogen Donors. J. Am. Chem. Soc. 1988, 110, 3071–3075.
(14) Structure of 2 in PI3Kγ submitted under PDB accession code
3JTP.
(15) For 2, PI3KR and γ IC50 values = 0.003 and 0.142 μM.
(16) Walker, E. H.; Pacold, M. E.; Perisic, O.; Stephens, L.; Hawkins,
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(18) Compound 7 has a solubility of 0.3 μg/mL, while its perme-
ability in the Caco-2 assay is PappA-B (cm/s ꢁ10ꢀ6) = 1.56 and PappA-B
(cm/s ꢁ10ꢀ6) = 2.15.
(19) 5 mg/kg IV dose and 20 mg/kg oral dose for all compounds
except 16, which was dosed 5 mg/kg IV and 10 mg/kg orally.
(20) Structure of 15 in PI3Kγ submitted under PDB accession code
3SD5.
(21) With >95% mouse plasma protein binding, the free plasma
concentrations required for in vivo target modulation correlated with the
cellular activity.
(22) “NVP-BKM120, a novel inhibitor of phosphoinositide 3-kinase
in Phase I/II clinical trials, shows significant antitumor activity in
xenograft models”. Maira, M.; Menezes, D.; Pecchi, S.; Shoemaker, K.;
Burger, M.; Schnell, C.; Fritsch, C.; Brachmann, S.; Nagel, T.; Sellers,
W. R.; Garcia-Echeverria, C.; Wiesmann, M.; Voliva, C. F. 2010 AACR
annual meeting, Washington, D.C., Abstract 4497.
(23) Female nude mice (6ꢀ8 weeks of age from Charles River)
were implanted with 5 ꢁ 106 U87MG cells (in 0.2 mL 50% matrigel)
s.c. into the right flank. Mice were randomized when tumors reached
a mean size of 350 mm3 (n = 12/group) and were treated with either
vehicle or BKM120 at 30 or 60 mg/kg, q.d. Body weights are included
in the Supporting Information for both A2780 and U87MG efficacy
studies.
(24) PappA-B (cm/s ꢁ10ꢀ6) = 42, PappB-A (cm/s ꢁ10ꢀ6) = 21.
(25) Dofetilide binding IC50 > 30 μM; no significant findings in
isolated rabbit heart model and dog telemetry.
(26) Mouse PK (female CD1 mice, 5 mg/kg IV, 10 mg/kg PO), rat
PK (female CD rats, 5 mg/kg IV, 20 mg/kg PO), dog PK (male and
779
dx.doi.org/10.1021/ml200156t |ACS Med. Chem. Lett. 2011, 2, 774–779