Discovery of a Series of 3-Cinnoline Carboxamides as Orally Bioavailable, Highly Potent, and Selective ATM Inhibitors

Article abstract of DOI:10.1021/acsmedchemlett.8b00200

We report the discovery of a novel series of 3-cinnoline carboxamides as highly potent and selective ataxia telangiectasia mutated (ATM) kinase inhibitors. Optimization of this series focusing on potency and physicochemical properties (especially permeability) led to the identification of compound 21, a highly potent ATM inhibitor (ATM cell IC₅₀ 0.0028 μM) with excellent kinase selectivity and favorable physicochemical and pharmacokinetics properties. In vivo, 21 in combination with irinotecan showed tumor regression in the SW620 colorectal tumor xenograft model, superior inhibition to irinotecan alone. Compound 21 was selected for preclinical evaluation alongside AZD0156.

Full text of DOI:10.1021/acsmedchemlett.8b00200

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Letter
Discovery of a Series of 3-Cinnoline Carboxamides as Orally
Bioavailable, Highly Potent and Selective ATM Inhibitors
Bernard Barlaam, Elaine Cadogan, Andrew Campbell, Nicola Colclough, Allan Dishington,
Stephen T. Durant, Kristin Goldberg, Lorraine A. Hassall, Gareth D. Hughes, Philip A.
MacFaul, Thomas M. McGuire, Martin Pass, Anil Patel, Stuart Pearson, Jens Petersen,
Kurt G. Pike, Graeme R. Robb, Natalie Stratton, Guohong Xin, and Baochang Zhai
ACS Med. Chem. Lett., Just Accepted Manuscript • DOI: 10.1021/acsmedchemlett.8b00200 • Publication Date (Web): 13 Jul 2018
Downloaded from http://pubs.acs.org on July 14, 2018
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ACS Medicinal Chemistry Letters
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Discovery of a Series of 3-Cinnoline Carboxamides as Orally Bioa-
vailable, Highly Potent and Selective ATM Inhibitors
Bernard Barlaam,*,1 Elaine Cadogan,1 Andrew Campbell,2 Nicola Colclough,1 Allan Dishington,2 Steꢀ
phen Durant,1 Kristin Goldberg,1 Lorraine A. Hassall,2 Gareth D. Hughes,1 Philip A. MacFaul,2 Thomas
M. McGuire,1 Martin Pass,1 Anil Patel,2 Stuart Pearson,1 Jens Petersen,3 Kurt G. Pike,1 Graeme Robb,1
Natalie Stratton,4 Guohong Xin,5 Baochang Zhai5
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1 Oncology, IMED Biotech Unit, AstraZeneca, Cambridge, UK.
2 Oncology, IMED Biotech Unit, AstraZeneca, Macclesfield, UK.
3 Discovery Sciences, IMED Biotech Unit, AstraZeneca, Gothenburg, Sweden.
4 Discovery Sciences, IMED Biotech Unit, AstraZeneca, Cambridge, UK.
5 Pharmaron Beijing Co., Ltd., 6 Taihe Road BDA, Beijing, P.R. China.
KEYWORDS: ATM, Ataxia Telangiectasia Mutated Kinase, PIKK, DDR
ABSTRACT: We report the discovery of a novel series of 3ꢀcinnoline carboxamides as highly potent and selective ATM inhibiꢀ
tors. Optimisation of this series focusing on potency and physicochemical properties (especially permeability) led to the identificaꢀ
tion of compound 21, a highly potent ATM inhibitor (ATM cell IC50 0.0028 ꢀM) with excellent kinase selectivity and favourable
physicochemical and pharmacokinetics properties. In vivo, 21 in combination with irinotecan showed tumour regression in the
SW620 colorectal tumour xenograft model, superior inhibition to irinotecan alone. Compound 21 was selected for preclinical evalꢀ
uation alongside AZD0156.
The Ataxia Telangiectasia Mutated (ATM) kinase1 is involved
in the DNA damage responses (DDR),2 specifically in the
repair of DNA double strand breaks (DSB). Upon recruitment
to sites with DNA DSB, which is mediated by the MRN
(MRE11ꢀRAD50ꢀNBS1) complex, ATM is autophosphoryꢀ
lated on Ser1981 and signals activation of downstream DNA
repair and cell cycle checkpoint.3 As DSBs can result from
ionizing radiation (IR) or chemically induced DNA damage
(e.g. DNA topoisomerase I inhibitors such as irinotecan4), the
combination of ATM inhibition with clinically induced DNA
damage in tumour cells could bring important benefits to canꢀ
cer patients.5, 6 In addition to its DNA damage signalling funcꢀ
tion, ATM has an additional role in signalling and protecting
against Reactive Oxygen Species (ROS). ATM has been reꢀ
ported as a redox sensor becoming directly activated by oxidaꢀ
boxamides led to compounds 1-3 as highly selective and orally
active ATM inhibitors (Figure 1).12 We subsequently disclosed
the optimisation of a series of imidazo[5,4ꢀc]quinolinꢀ2ꢀones
leading to 4, a highly potent and selective ATM inhibitor with
acceptable permeability and good bioavailability in multiple
preclinical species. 4 (also known as AZD0156), is currently
being evaluated in Phase I clinical trials.13 We also reported
the identification of another series based on an imidazopyraꢀ
zine scaffold showing evidence of brain penetration.14
During the optimisation of the quinoline carboxamide series,
we noted that introduction of a basic side chain at Cꢀ6 at a
suitable distance dramatically improved potency (e.g. comꢀ
pound 5, see Figure 2), but led to reduced permeability, preꢀ
cluding good oral bioavailability.13 This observation was subꢀ
sequently integrated in the optimisation of the imidazo[5,4ꢀ
c]quinolinꢀ2ꢀone series. Starting from 7, which has much
higher permeability than its equivalent quinoline carboxamide,
exploration of various basic side chains at Cꢀ6 led to the idenꢀ
tification of 4. As part of the modifications of the quinoline
hinge binder, we identified that cinnoline carboxamides may
be a suitable replacement for quinoline carboxamides. In this
Letter, we report the optimisation of this novel series as selecꢀ
tive and orally active ATM inhibitors.
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tion.7, This ROSꢀprotecting function may be important for
promoting neovascularisation of tumours.9
ATM is a serine/threonine protein kinase belonging to the
PIKK (PhosphatidylInositol 3’ꢀKinase [PI3K]ꢀrelated kinase)
family together with DNAꢀdependent Protein Kinase
(DNAPK), Ataxia Telangiectasia mutated and RAD3ꢀrelated
(ATR) kinase and mammalian Target Of Rapamycin (mTOR).
One of the first selective ATM inhibitor reported was Kuꢀ
55933.10 Although it was shown to be an ATM inhibitor with
suitable PIKK selectivity, its poor physicochemical properties
have precluded its use as an in vivo probe. Subsequent optimiꢀ
sation led to the identification of Kuꢀ60019, a more potent and
selective ATM inhibitor.11 However, its physicochemical
properties again still limit its use in vivo, especially for oral
administration. We recently reported significant advances in
the development of potent and selective ATM inhibitors with
suitable physicochemical and pharmacokinetic properties for
oral administration. Optimisation of a series of quinoline carꢀ
Although there is no reported crystal structure of ATM to aid
design of inhibitors, the similarity of the binding mode of
quinoline carboxamides (e.g. 6) and imidazo[5,4ꢀc]quinolinꢀ2ꢀ
ones (e.g. 7) in PI3Kγ supports the parallel SAR observed at
Cꢀ6 against ATM between the two series (see Figure 3). Both
compounds exhibit key hydrogenꢀbonding interactions to
Val882 and Asp964 and form a πꢀinteraction with Tyr867.
Although no crystal structure of cinnoline carboxamides
bound to PI3Kγ was available, we hypothesized that they
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ACS Medicinal Chemistry Letters
would have a similar binding mode as quinoline carboxꢀ
Page 2 of 7
model, the dimethylamino group sits in a highly polar subꢀ
pocket beyond the back pocket, surrounded by acidic residues
Asp2725, Asp2720 and Asp2889.13 Indeed, introduction of
this same chain again dramatically increased potency (ATM
cellular potency 0.9 nM to 3.9 nM for compounds 12-14). Yet
those compounds maintained acceptable permeability and
limited efflux (measured in MDCK and/or Cacoꢀ2), high metꢀ
abolic stability and good solubility. Further modifications of
the basic side chain were tolerated (e.g. pyrrolidines 15ꢀ17).
As previously seen in the imidazo[5,4ꢀc]quinolinꢀ2ꢀone series,
the length of the linker was critical for maintaining the nM to
subꢀnM potency, the dimethylaminopropoxy side chain being
significantly more active than the dimethylaminoethoxy side
chain (e.g. 18 vs. 13; 21 vs. 19). It is worth noting that an amiꢀ
no link (e.g. 20) is also tolerated as well as an ether link. Finalꢀ
ly with the observation that methylation of carboxamide at Cꢀ3
was tolerated (compound 11), we combined the methylcarboxꢀ
amide at Cꢀ3 with the dimethylaminopropyloxy side chain at
Cꢀ6 (compounds 21 and 22) with the expectation that permeaꢀ
bility would be increased vs. the carboxamide (compounds 12
and 14), because of a lower number of Hꢀbond donors. Altꢀ
hough no significant improvement was seen, compounds 21
and 22 maintained a similar degree of moderate to high perꢀ
meability / low to moderate efflux.
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4
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6
7
8
amides.
Figure 3. Overlay of crystal structures of compounds 6 (blue)
and 7 (purple) in PI3Kγ, PDB codes 5G55 and 6GQ7, respecꢀ
tively. Hydrogenꢀbonds are indicated in green and πꢀ
interactions indicated in grey.
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Compounds 8-22 were made from a common intermediate
(see synthetic section and details procedures in Supporting
Information). The first cinnoline carboxamides 8, 9 and 10,
having the same side chains at Cꢀ6 and Cꢀ4 as their quinoline
carboxamide counterparts 1, 2 and 3 respectively, maintained
a good level of ATM cellular potency, just slightly reduced
compared to the corresponding quinoline carboxamides. Howꢀ
ever, 8 and 10 showed significantly higher permeability and
lower efflux ratio in both Cacoꢀ2 and MDCK cell lines than
their quinoline carboxamide counterparts 1 and 3. The reasons
for this increased permeability / lower efflux may be a combiꢀ
nation of lower basicity for cinnoline carboxamides vs. quinoꢀ
line carboxamides (measured pKa 5.3 vs. 7.6 for the cinnoline
group in 12 vs. the quinoline group in 1) and a reduced numꢀ
ber of effective Hꢀbond donors (due to the potential intramoꢀ
lecular Hꢀbond between amidic NꢀH and N2 of the cinnoline).
The other physical and pharmacokinetic properties of 8-10
were considered as suitable for further optimisation: moderate
in vitro metabolic stability in rat hepatocytes and HLM for 8-
10, low clearance in vivo and moderate to good bioavailability
for 8 (pharmacokinetic parameters in rats for 8 after iv and
oral administration of 0.5 mg/kg and 1 mg/kg respectively: CL
21 mL/min/kg; Vdss 0.7 L/kg; F 56%), although solubility was
to be monitored (Table 1). Methylation of the carboxamide
maintained similar potency (see compound 11 vs. 8). This
observation is not in line with what was observed in the quinoꢀ
line carboxamide series, where loss of potency was observed
based on one pair of compounds.12 The exact reason for this
difference in SAR between the two series is not understood, as
our initial assumption was that the SAR would be fully transꢀ
ferable from the quinoline carboxamide series to the cinnoline
carboxamide series.
Table 2. Biological profile of compounds 12 and 21.
Cpd 12
IC50 (ꢀM)a
Cpd 21
IC50 (ꢀM)a
Assay
details
Enzyme
ATM
0.00029
5.3
0.0007
21
inhibition mTOR
DNAPK
PI3Kα
1.8
2.8
2.2
3.8
8.1
10.3
3.0
PI3Kβ
2.9
PI3Kγ
0.80
0.0019
>30
>30
>15
0.73
0.0028
>30
>30
>19
PI3Kδ
Cellular
inhibition ATR
PI3Kα
PI3Kβ / mTOR
ATM
a Geometric means of multiple IC50 determinations.
Compounds 12 and 21 as representative compounds of this
series were further evaluated in vitro and in vivo. The kinase
selectivity of compounds 12 and 21 was assessed further. 12
and 21 did not show appreciable activity against other kinases
of the PI3K or PIKK families (see Table 2: PI3Kα−δ, mTOR
and DNAPK enzyme assays; PI3Kα and PI3Kβ, ATR and
mTOR cellular assays). The excellent kinase selectivity was
further confirmed in several kinase panels. Compound 12 did
not show significant inhibition at 1 ꢀM in a panel of 125 kiꢀ
nases (‘Millipore panel’): no kinase with >70% inhibition, 1
kinase between 50ꢀ70% inhibition: CSF1R (56%). Compound
21 did not show significant inhibition at 1 ꢀM in a panel of
272 kinases (‘extended Millipore panel’): no kinase with
>70% inhibition, 3 kinases between 50ꢀ70% inhibition: Fltꢀ4
(63%), RET (59%) and NTRK2 (51%). The kinase selectivity
of 21 was confirmed in the Ambit panel (KINOMEscan)
against a panel of 392 kinases at 1 ꢀM, with PI4KB being the
We then explored the Cꢀ6 side chain. During optimisation of
the imidazo[5,4ꢀc]quinolinꢀ2ꢀone series, introduction of a diꢀ
methylaminopropyloxy side chain dramatically increased poꢀ
tency against ATM, leading to the identification of 4. This
observation was rationalised from a homology model of ATM
based on the structure of the related protein mTOR. In this
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ACS Medicinal Chemistry Letters
only kinase showing less than 50% of control (PI4KB 17% of
schedule: (irinotecan: 50 mg/kg, i.p. once weekly; then 21: 50
mg/kg p.o. once daily for 3 days every week starting 24 hours
post irinotecan dosing). The combination was well tolerated
and resulted in excellent growth inhibition of the tumour
(106%), whilst irinotecan alone resulted in only 74% tumour
growth inhibition (see Figure 5). No single arm with 21 as
monotherapy was present in the experiment as a control, based
on our previous experience with other ATM selective inhibiꢀ
tors.
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control).
Table 3. Physicochemical, pharmacokinetic and other properꢀ
ties of compounds 12 and 21.
Properties
Hu / rat / dog / mo ppb; fu (%)a
Cpd 12
Cpd 21
13; 6; 44; 46
4; 2; 30; 21
5.7; 8.8; 4.1
Rat / dog / hu hepatocyte Clint 3.4; 5.1; 2.8
(ꢀL/min/106 cell)b
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Rat / dog pharmacokinetic paꢀ
rameters
Clearance: Cl (mL/min/kg)c
Vd (L/kg)c
Bioavailability: F (%)c
Terminal halfꢀlife (h)
Aqueous solubility (ꢀM)d
Intrinsic permeability
(10ꢀ6 cm.sꢀ1)e
Figure 4. Mouse free plasma exposure of compound 21 after
oral administration (10 mg/kg)
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870
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880
2.8
2.0
CYP inhibition IC50 (ꢀM)f
>30 (all)
24
>30 (all)
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hERG IC50 (ꢀM)g
a
Plasma protein binding (ppb) in human, rat, dog and mouse plasma,
fraction unbound fu; determined from DMSO stock solution by equilibriꢀ
um dialysis in 10% plasma.
b
Intrinsic clearance measured from fresh rat/dog hepatocytes and cryoꢀ
preserved human hepatocytes, Clint.
c
From plasma concentrations in male Han Wistar rats and male Beagle
dogs (at least n=2), compound administered at 1 mg/kg i.v. and 2 mg/kg
p.o. as a formulation in 0.5% (w/v) HPMC, 0.1% (w/v) Tween 80 in water
for the oral arm and as a solution formulation in 5% DMSO, 95% SBEꢀβꢀ
cyclodextrin (30% w/v in water) for the iv arm. Intravenous parameters
(including halfꢀlife) calculated from an intravenous bolus; bioavailability,
from oral and i.v. AUC.
Figure 5. Tumour growth inhibition in the SW620 xenograft
model of 21 in combination with irinotecan vs. irinotecan
alone.
d Solubility in aqueous phosphate buffer, pH 7.4 after 24 h at 25 °C.
e Intrinsic permeability measured in Cacoꢀ2 cell line, A pH 6.5, B pH 7.4.,
measured in the apical to basolateral (A to B) direction in the presence of
an efflux inhibitor.
f Inhibition of cytochrome P450, IC50 (1A2, 2C9, 2C19, 2D6, 3A4)
g
Inhibition of the hERG tail current was measured using a plateꢀbased
planar patch clamp system (IonWorks).
On the basis of their high ATM potency, their excellent kinase
selectivity and their overall suitable physicochemical and in
vitro metabolic properties, in vivo pharmacokinetics of 12 and
21 were evaluated in rat and dogs (Table 3). Both compounds
showed long half lives in both rat and dogs, consistent with a
high volume of distribution (as a consequence of the strong
basicity of the dimethylaminopropoxy side chain), and acꢀ
ceptable oral bioavailability. Physical properties and safety
properties of 12 and 21 were further investigated (see Table
3). Both 12 and 21 had excellent aqueous solubility: 870 and
880 ꢁM in aqueous phosphate buffer (pH 7.4) from crystalline
material. Mouse oral exposure was assessed for 21. At 10
mg/kg, compound 21 displayed free plasma exposure above
the in vitro cellular ATM assay for at least 12 hours (see Figꢀ
ure 4). Previous studies conducted in our laboratories had
shown that monotherapy treatment with a selective ATM inꢀ
hibitor did not result in significant efficacy in the SW620
model, but combination with topoisomerase I inhibitor iriꢀ
notecan (acting as a DNA damaging agent, generating DSBs)
resulted in significantly greater tumour growth inhibition
compared to irinotecan alone. Indeed, in this same model, 21
was dosed in combination with irinotecan using the following
In conclusion, we have discovered a series of cinnoline carꢀ
boxamides as highly potent and selective ATM inhibitors.
Optimisation of this series focusing on potency and physical
properties (especially permeability) led to the identification of
compound 21, a highly potent ATM inhibitor (ATM cell IC50
0.0028 ꢀM) with excellent kinase selectivity and favourable
physicochemical and pharmacokinetic properties. In vivo, 21
in combination with irinotecan showed tumour regression in
the SW620 colorectal tumour xenograft model, superior effiꢀ
cacy to irinotecan alone. Compound 21 was selected for preꢀ
clinical evaluation alongside AZD0156.
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repair protein complexes by DNA topoisomerase I drug 7ꢀethylꢀ10ꢀ
ASSOCIATED CONTENT
Supporting Information
hydroxyꢀcamptothecin. Mol. Pharmacol. 2002, 61, 742ꢀ748.
(5) Weber, A. M.; Ryan, A. J. ATM and ATR as therapeutic targets
in cancer. Pharmacol. Ther. 2015, 149, 124ꢀ138.
(6) Teng, P.; Bateman, N. W.; Darcy, K. M.; Hamilton, C. A.;
Maxwell, G. L.; Bakkenist, C. J.; Conrads, T. P. Pharmacologic inhiꢀ
bition of ATR and ATM offers clinically important distinctions to
enhancing platinum or radiation response in ovarian, endometrial, and
cervical cancer cells. Gynecol. Oncol. 2015, 136, 554ꢀ561.
(7) Guo, Z.; Kozlov, S.; Lavin, M. F.; Person, M. D.; Paull, T. T.
ATM activation by oxidative stress. Science 2010, 330, 517ꢀ521.
(8) Alexander, A.; Cai, S. L.; Kim, J.; Nanez, A.; Sahin, M.; Mac
Lean K. H.; Inoki, K.; Guan, K. L.; Shen, J.; Person, M. D.;
Kusewitt, D.; Mills, G. B.; Kastan, M. B.; Walker, C. L. ATM signals
to TSC2 in the cytoplasm to regulate mTORC1 in response to ROS.
Proc. Natl. Acad. Sci. USA 2010, 107, 4153ꢀ4158.
1
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Details of the full synthesis and spectroscopic characterisation of
all compounds and intermediates can be found in the Supporting
Information, together with crystallographic information and all
protocols for in vitro and in vivo experiments, kinase selectivity.
This material is available free of charge via the Internet at
http://pubs.acs.org.
AUTHOR INFORMATION
Corresponding Author
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* To whom correspondence should be addressed: eꢀmail: berꢀ
nard.barlaam2@astrazeneca.com; telephone: +44(0)1625237335
(9) Okuno, Y.; NakamuraꢀIshizu, A.; Otsu, K.; Suda, T.; Kubota,
Y. Pathological neoangiogenesis depends on oxidative stress regulaꢀ
tion by ATM. Nature Medicine 2012, 18, 1208ꢀ1216.
(10) Hickson, I.; Zhao, Y.; Richardson, C. J.; Green, S. J.; Martin,
N. M. B.; Orr, A. I.; Reaper, P. M.; Jackson, S. P.; Curtin, N. J.;
Smith, G. C. M. Identification and Characterization of a Novel and
Specific Inhibitor of the AtaxiaꢀTelangiectasia Mutated Kinase ATM.
Cancer Res. 2004, 64, 9152ꢀ9159.
(11) Golding, S. E.; Rosenberg, E.; Valerie, N.; Hussaini, I.; Frigꢀ
erio, M.; Cockcroft, X. F.; Chong, W. Y.; Hummersone, M.;
Rigoreau, L.; Menear, K. A.; O'Connor, M. J.; Povirk, L. F.; van
Meter, T.; Valerie, K. Improved ATM kinase inhibitor KUꢀ60019
radiosensitizes glioma cells, compromises insulin, AKT and ERK
prosurvival signaling, and inhibits migration and invasion. Mol. Can-
cer Ther. 2009, 8, 2894ꢀ2902.
(12) Degorce, S. L.; Barlaam, B.; Cadogan, E.; Dishington, A.;
Ducray, R.; Glossop, S. C.; Hassall, L. A.; Lach, F.; Lau, A.;
McGuire, T. M.; Nowak, T.; Ouvry, G.; Pike, K. G.; Thomason, A. G.
Discovery of Novel 3ꢀQuinoline Carboxamides as Potent, Selective
and Orally Bioavailable Inhibitors of Ataxia Telangiectasia Mutated
(ATM) Kinase J. Med. Chem. 2016, 56, 6281ꢀ6292.
(13) Pike, K. G.; Barlaam, B.; Cadogan, E.; Campbell, A.; Chen,
Y.; Colclough, N.; Davies, N. L.; deꢀAlmeida, C.; Degorce, S. L.;
Didelot, M.; Dishington, A.; Ducray, R.; Durant, S. T.; Hassall, L. A.;
Holmes, J.; Hughes, G. D.; MacFaul, P. A; Mulholland, K. R.;
McGuire, T. M.; Ouvry, G.; Pass, M.; Robb, G.; Stratton, N.; Wang,
Z.; Wilson, J.; Zhai, B.; Zhao, K.; AlꢀHuniti, N. The Identification of
Potent, Selective, and Orally Available Inhibitors of Ataxia Telangiꢀ
ectasia Mutated (ATM) Kinase: The Discovery of AZD0156 (8ꢀ{6ꢀ[3ꢀ
(Dimethylamino)propoxy]pyridinꢀ3ꢀyl}ꢀ3ꢀmethylꢀ1ꢀ(tetrahydroꢀ2Hꢀ
pyranꢀ4ꢀyl)ꢀ1,3ꢀdihydroꢀ2Hꢀimidazo[4,5ꢀc]quinolinꢀ2ꢀone) J. Med.
Chem. 2018, 61, 3823ꢀ3841.
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Ducray, R.; Ouvry, G.; Degorce, S.; Wilson, J.; Smith, A.; Patel, B.;
Thomason, A.; Vincent, J.; Colclough, N.; Ahmad, S. F.; Beckta, J.
M.; Tokarz, M.; Mukhopadhyay, N. D.; Barlaam, B.; Pike, K. G.;
Cadogan, E.; Pass, M.; Valerie, K.; Durant, S., Bloodꢀbrain barrier
penetrating ATM inhibitor radioꢀsensitizes intracranial gliomas in
mice, AACR 2016 (abstract #3041).
Author Contributions
The manuscript was written through contributions of all authors.
All authors have given approval to the final version of the manuꢀ
script.
ACKNOWLEDGMENT
We acknowledge chemists at Pharmaron, Beijing for the synthesis
of some compounds; Paul Davey, Eva Lenz for the assistance
with characterization of compounds; Rebecca Morris for mouse
pharmacokinetic data; Ian Barrett and Caroline Truman for their
input into assay design and data generation; Andrew Thomason
for leading the in vitro biological evaluation of ATM inhibitors
and to Philip Jewsbury for helpful discussions regarding the manꢀ
uscript.
ABBREVIATIONS
2nd
Generation
XꢀPhos
precatalyst,
chloro(2ꢀ
dicyclohexylphosphinoꢀ2′,4′,6′ꢀtriisopropylꢀ1,1′ꢀbiphenyl)[2ꢀ(2′ꢀ
aminoꢀ1,1′ꢀbiphenyl)]palladium(II); ATM, Ataxia telangiectasia
mutated; ATR, Ataxia Telangiectasia Rad3ꢀrelated; BPin, pinacoꢀ
latoboryl; Clint, intrinsic clearance; DIPEA, NꢀethylꢀNꢀ
isopropylpropanꢀ2ꢀamine; CSF1R, colony stimulating factor 1
receptor kinase; DDR, DNA damage repair; DNAPK, DNAꢀ
dependent protein kinase; DSB, double strand break; Fltꢀ4, Fmsꢀ
related tyrosine kinase 4; HLM, human liver microsome; MDCK,
MadinꢀDarby Canine Kidney epithelial cell line; mTOR, mammaꢀ
lian target of rapamycin; NTRK2, Neurotrophic Tyrosine Recepꢀ
tor Kinase Type 2; Papp, apparent permeability; PI4K, phosphatiꢀ
dylinositol 4ꢀkinase; PIKK, PI3Kꢀrelated kinase; PTEN, phosphaꢀ
tase and tensin homolog; RET, "rearranged during transfection"
kinase; SAR structureꢀactivity relationship.
REFERENCES
(1) Savitsky, K.; BarꢀShira, A.; Gilad, S.; Rotman, G.; Ziv, Y.;
Vanagaite, L.; Tagle, D. A.; Smith, S.; Uziel, T.; Sfez, S.; Ashkenazi,
M.; Pecker, I.; Frydman, M.; Harnik, R.; Patanjali, S. R.; Simmons,
A.; Clines, G. A.; Sartiel, A.; Gatti, R. A.; Chessa, L.; Sanal, O.;
Lavin, M. F.; Jaspers, N. G.; Taylor, A. M.; Arlett, C. F.; Miki, T.;
Weissman, S. M.; Lovett, M.; Collins, F. S.; Shiloh, Y. A single ataxꢀ
ia telangiectasia gene with a product similar to PIꢀ3 kinase. Science
1995, 268, 1749ꢀ53.
(2) Kurz, E. U.; LeesꢀMiller, S. DNA damageꢀinduced activation of
ATM and ATMꢀdependent signaling pathways. DNA Repair 2004, 3,
889ꢀ900.
(3) Abraham, R. T. Cell cycle checkpoint signaling through the
ATM and ATR kinases. Genes Dev. 2001, 15, 2177ꢀ2196.
(4) Wu, J.; Yin, M.; Hapke, G.; Toth, K.; Rustum, Y. M. Induction
of biphasic DNA double strand breaks and activation of multiple
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Figure 1. Structure of selected ATM inhibitors (compounds 1-4) previously reported.
1
2
3
O
N
N
R
O
O
N
4
5
6
7
8
9
N
O
O
NH
N
O
O
O
NH
N
N
N
N
NH2
NH2
F
N
N
1
4 (AZD0156)
2 (R= H)
3 (R= Me)
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Figure 2. Structure of compounds 5-7.
7
6
5
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Table 1: Biological, physicochemical and metabolic data of compounds 8-22 vs. previously reported compounds 1-3.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
A
B
C
ATM
cell
IC50
0.046
0.033
0.010
0.14
0.26
0.044
0.33
0.0019
0.0039
0.0009
ATR
cell
IC50
Cacoꢀ2
Papp, AꢀB
(ER)d
8.5 (3.2)
11 (3.1)
12 (1.2)
27 (0.7)
NA
18 (0.9)
25 (0.5)
7.5 (2.5)
NA
MDCK
Papp, AꢀB
(ER)d
4.8 (7.3)
15 (2.4)
13 (2.7)
19 (1.3)
NA
27 (0.7)
20 (0.6)
3.5 (9.0)
2.9 (12)
2.1 (16)
Log
D7.4
HLM
Clint
Rat hep.
Clint
Cpd Core
R3
R6
Sol.c
b
e
f
a
a
>30
>19
>30
>30
>30
>30
>30
>30
>30
>30
2.5
2.7
3.0
2.7
3.0
2.8
3.0
1.9
1.7
2.1
590
69
42
>1000
76
8
34
870
65
26
15
39
33
14
31
42
28
10
27
<5.3
5.3
6.9
5.6
4.9
18
5.8
3.4
7.0
12
1
2
3
A
B
C
A
A
B
C
H
H
H
Me
H
H
CH2OMe
CH2OMe
CH2OMe
8
9
10
11
12
13
14
CH2OMe
OCH2CH2CH2NMe2
OCH2CH2CH2NMe2
OCH2CH2CH2NMe2
OCH2CH2CH2ꢀ
pyrrolidine
OCH2CH2CH2ꢀ
pyrrolidine
OCH2CH2CH2ꢀ
pyrrolidine
OCH2CH2NMe2
OCH2CH2NMe2
NHCH2CH2NMe2
OCH2CH2CH2NMe2
OCH2CH2CH2NMe2
H
290
NA
A
B
C
H
H
H
0.0018
0.0011
0.0005
>30
>30
>30
1.9
1.8
2.1
620
490
510
NA
NA
NA
1.4 (24)
1.5 (23)
1.5 (20)
23
10
40
1.9
4.6
8.1
15
16
17
B
A
A
A
C
H
Me
H
Me
Me
0.035
0.049
0.061
0.0028
0.0039
>30
>30
>30
>30
>30
1.9
2.5
2.0
2.3
2.3
910
990
>1000
880
NA
NA
NA
5.0 (2.6)
4.0 (1.6)
NA
NA
NA
2.5 (6.6)
3.7 (3.2)
25
26
18
22
33
13
4.8
4.2
5.7
6.7
18
19
20
21
22
620
a ꢀM; unless stated otherwise, geometric means of at least two IC50 determinations per compound.
b Measured using shakeꢀflask methodology with a buffer:octanol volume ratio of 100:1.
c Solubility in aqueous phosphate buffer, pH 7.4 after 24 h at 25 °C; ꢀM.
d Apparent permeability (Papp, AꢀB) in Cacoꢀ2 or MDCKꢀMDR1 cell line, A pH 7.4, B pH 7.4; 10ꢀ6 cm.sꢀ1. Permeability was measured in both the apical to
basolateral (A to B) and basolateral to apical (B to A) direction. Efflux ratio (ER) determined as the ratio of both permeabilities (B to A permeability divided
by A to B permeability)
e human liver microsome intrinsic clearance (HLM Clint); ꢀL.minꢀ1.mgꢀ1.
f Intrinsic clearance measured from fresh rat hepatocytes, Clint; ꢀL/min/106 cell
NA for not assessed
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Table of Contents
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
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31
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35
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51
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53
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60
ATM cell IC 0.046
M
1
ꢀ
50
21
ATM cell IC50 0.0028
M
ꢀ
Excellent kinase selectivity
Acceptable permeability
Good bioavailibility in preclinical species
ATM cell IC 0.0086
M
ꢀ
5
50
low permeability
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