Discovery & Optimisation of Novel Agonists of GPR119Discovery & Optimisation of Novel Agonists of...
Transcript of Discovery & Optimisation of Novel Agonists of GPR119Discovery & Optimisation of Novel Agonists of...
Discovery & Optimisation of
Novel Agonists of GPR119:
James S. Scott
AstraZeneca
Alderley Park, UK
17th RSC/SCI Medicinal Chemistry
Symposium
R&D | CVGI | AP Jamie Scott| 04 2012
Outline of talk
• Introduction to target and start point
• Cyanopyridyl as a replacement for sulphone
• Improving solubility
• Seizure assay and a return to the sulphone…..
• A hERG beating methylene
• Summary and learning
R&D | CVGI | AP Jamie Scott| 04 2012
• Enhanced incretin (GLP-1) secretion and direct effect on pancreas
• ‘Oral GLP-1’ concept – combination opportunity with DPPIV inhibitors
GPR119 as a target for diabetes
• Class A GPCR (deorphanised)
• Expression reported in pancreas, gut, (brain)
• Targeting an Agonist
[Shah, U. RSC Drug Discovery
Series, 2012, Chapter 7]
R&D | CVGI | AP Jamie Scott| 04 2012
When something is too good to be true....
N
N
O
F3C
S
O O
N
N
OS
O O
F
S
N
Stop Series
hGPR119 pEC50 6.3 (42%)* hGPR119 pEC50 7.6 (44%)
hERG IC50 2.5 mM hERG IC50 16 mM
logD 2.9 logD 2.1
• Robust Glucose lowering
• But also in GPR119 knock-out mice.....
• Off target activity
*cAMP potency EC50 with intrinsic activity (% effect) relative to 50 mM oleoylethanol amide (OEA; endogenous ligand)
[Bioorg. Med. Chem. Lett. 2011, 21, 7310.]
R&D | CVGI | AP Jamie Scott| 04 2012
ON
N
NN
O
O S
OO
pEC50 7.2 (83%)*
Sol 0.03 mM [c]
logD 3.2
hERG >33 mM
Potency in mouse similar
pEC50 7.3 (99%)
No hERG and on target efficacy
3x
1000x
A) Sulphone
increase
needed
Plan B - A second series.....
*cAMP potency EC50 with intrinsic activity (% effect) relative to 50 mM oleoylethanol amide (OEA; endogenous ligand)
R&D | CVGI | AP Jamie Scott| 04 2012
ON
N
N
N
NO
O
ON
N
NN
O
O S
OO
pEC50 7.2 (83%)
Sol 0.03 mM [c]
logD 3.2
hERG >33 mM
Potency in mouse similar
pEC50 7.3 (99%)
Key issues to address: Solubility / Potency / logD / Boc group
No hERG and on target efficacy
pEC50 6.2 (71%)
Sol 23 mM [c]
logD 3.4
hERG >33 mM
3x
1000x
Pyridyl N acting as acceptor
(but less optimal than SO2Me)
A) Sulphone B) Pyridine
• Pharmacophoric elements are lipophile (often carbamate) and acceptor
• Struggled to move from neutrals and retain potency
increase
needed 30x
3x
increase
needed
Plan B - A second series.....
R&D | CVGI | AP Jamie Scott| 04 2012
ON
N
NN
O
O S
OO
Sol 0.03 mM [c]
logD 3.2
• Molecules pack – end to end via
sulphone – sulphone interactions
And in ladder interactions
• Seen in 1/4 of sulphones in CSD
A) Understanding the insolubility of the sulphone
End-End 18%
Ladder 18%
Both 23%
None 41%
R&D | CVGI | AP Jamie Scott| 04 2012
Acceptor SAR – around pyridyl
O
ON ON
N
N
N
R
• Summary of pyridine SAR with lines of
constant pEC50-logD
Ligand Lipophilic Efficiency (LLE)
Sized by intrinsic activity (10-155%)
• CN represents a breakthrough!
pEC50 6.2 (71%)
Sol 23 [c]
logD 3.4
LLE 2.8
N
pEC50 <5.7
Sol 66 [c]
logD 3.7
N
pEC50 7.1(101%)
Sol 4 [c]
logD 3.8
LLE 3.3
N • 2-substitution potency
• 3-substitution potency
B) Optimisation of pyridine
GP
R11
9 p
EC
50
logD
ON
N
N
N
NO
O
LLE=2
LLE=3
LLE=4 LLE=5
R&D | CVGI | AP Jamie Scott| 04 2012
ON
N
N
N
NO
O
pEC50 6.2 (71%)
Sol 23 mM
logD 3.4
LLE 2.8
ON
N
N
N
NO
O
N
pEC50 7.7 (155%)
Sol 32 mM
logD 2.8
LLE 4.9
ON
N
N
N
NO
O
pEC50 6.7 (68%)
Sol 45 mM
logD 3.8
LLE 2.9
Me adds potency (& logD)
CN adds potency (& lowers logD)
Bringing it all together
R&D | CVGI | AP Jamie Scott| 04 2012
ON
N
N
N
NO
O
pEC50 6.2 (71%)
Sol 23 mM
logD 3.4
LLE 2.8
ON
N
N
N
NO
O
N
ON
N
N
N
NO
O
N
pEC50 7.7 (155%)
Sol 32 mM
logD 2.8
LLE 4.9
ON
N
N
N
NO
O
pEC50 6.7 (68%)
Sol 45 mM
logD 3.8
LLE 2.9
pEC50 8.2 (171%)
Sol 21 mM
logD 3.3
LLE 4.9
Me adds potency (& logD)
CN adds potency (& lowers logD)
100x potency improvement
LogD neutral
Solubility maintained
Key issues to address: Solubility / Potency / logD / Boc group
Bringing it all together
R&D | CVGI | AP Jamie Scott| 04 2012
ON
N
N
N
NO
O
N
Key issues to address: Solubility / Potency / logD / Boc group
NO
NON
N
N
N
N
N
F3C
pEC50 8.2 (171%)
Sol 21 mM
logD 3.3
LLE 4.9
pEC50 8.7 (243%)
Sol 3 mM
logD 4.0
LLE 4.7
Oxadiazole as an isostere for Boc
• Compound is active in vivo
in wild-type BUT NOT knock-out mouse
• Glucose & GLP-1 endpoints
On target efficacy
NO
NON
N
N
N
N
N
pEC50 8.1 (199%)
Sol 7uM
logD 3.3
LLE 4.8
R&D | CVGI | AP Jamie Scott| 04 2012
Improving Solubility #1 - An alternative to Boc.
Key issues to address: Solubility / Potency / logD / Boc group
ON
N
N
N
NO
O
N
pEC50 8.2 (171%)
Sol 21 mM
logD 3.3
LLE 4.9
pEC50 7.7 (171%)
Sol 110uM
logD 2.5
LLE 5.2
ON
N
N
N
NO
O
N
O
CF3ON
N
N
N
NO
O
N
O
pEC50 5.9 (95%)
Sol 690uM [c]
logD 1.9
LLE 4.0
Strong ether acceptor not
satisfied by any H-bond donors
R&D | CVGI | AP Jamie Scott| 04 2012
Improving Solubility #2 - Not all oxadiazoles are equal...
Acceptor scales - logKb
[Abraham et al. J. Chem. Soc., Perkin Trans. 2, 1989, 1355.]
Subsequently shown to correlate with electrostatic potential by
[Kenny, P.; J. Chem. Soc., Perkin Trans. 2, 1994, 199.]
NO
OPh
2.1
NO
NN
F3C
0.4
-0.8
ON
NN
F3C
0.2
0.4
NN
ON
F3C
1.4 1.0
Key issues to address: Solubility / Potency / logD / Boc group
NO
NON
N
N
N
N
N
F3C
pEC50 8.7 (243%)
Sol 3 mM
logD 4.0
LLE 4.7
NN
OON
N
N
N
N
N
F3C
pEC50 7.6 (220%)
Sol 120 mM
logD 2.7
LLE 4.9
[Boström, J et al J. Med. Chem., 2011, 1817]
pEC50 8.3 (236%)
Sol 5uM
logD 3.1
LLE 5.2
ON
NON
N
N
N
N
N
F3C
R&D | CVGI | AP Jamie Scott| 04 2012 14
Riding the line of LLE down to improve properties
ON
N
N
N
N
N
F3C
Hu
EC50
(uM) LogD
LLE
pEC50
-logD
Mouse
PPB
(%)
hERG
IC50
(uM)
Sol
(uM)
0.002 4.0 4.7 1.2 7 3.1 [c]
0.005 3.1 5.2 3.8 6 4.8 [c]
0.026 2.7 4.9 11 18 120 [c]
N
NO
NF
3C
N
ON
NF
3C
N
NN
OF
3C
1
2
3
GP
R11
9 p
EC
50
logD
LLE=5
• Control of lipophilicity by oxadiazole isomer
• Big impact in terms of solubility
• Benefits in terms of hERG
• Loss in potency offset by increased free levels
Potency vs logD
[MedChemCommun., 2013, 4, 95]
R&D | CVGI | AP Jamie Scott| 04 2012
Problems seen in mouse toxicity studies
Clonic convulsions in 2 mice (day 10 @ 300mpk) whilst undergoing an IRWIN assessment
NO
NON
N
N
N
N
N
• Seizure: synchronized abnormal neuronal activity that may result in a number of behavioral
symptoms including tonic-clonic convulsion
• Convulsion: the behavioral consequence of a seizure – typically muscle rigidity followed by rhythmic
jerking movements
• Convulsion ≠ seizure
• Abnormal motor events, syncopal events, etc. may be incorrectly mistaken for convulsions
How can we find a back-up compound?
R&D | CVGI | AP Jamie Scott| 04 2012
• Evoked population spike: Summated firing of CA1
pyramidal neurones (measure of cell excitability and
underlying synaptic activity)
• Potentially seizurogenic compounds can induce
excitatory effect by variety of potential mechanisms
In vitro Brain Slice
[Easter A. et al., J Pharmacol Toxicol Methods. 2007, 56, 223]
R&D | CVGI | AP Jamie Scott| 04 2012
• Evoked population spike: Summated firing of CA1
pyramidal neurones (measure of cell excitability and
underlying synaptic activity)
• Potentially seizurogenic compounds can induce
excitatory effect by variety of potential mechanisms
In vitro Brain Slice
[Easter A. et al., J Pharmacol Toxicol Methods. 2007, 56, 223]
Compound caused a
concentration-dependent
increase in excitability,
consistent with a
convulsant compound
R&D | CVGI | AP Jamie Scott| 04 2012
Results from Brain Slice Assay
NO
NON
N
N
N
N
N
NN
OON
N
N
N
N
N
F3C
+ve Brain slice
logD 3.3
+ve Brain slice
logD 2.7
NO
NON
N
N
N
N
N
F3C
+ve Brain slice
logD 4.0
Matched Pair
S
OO
NN
OON
N
NN
F3C
F
-ve Brain slice
logD 3.0
• Future compounds should not contain a CN pyridyl to avoid this issue
• Impact is that achieving high solubility will be challenging.....
• & compounds may have a hERG issue.....
pEC50 7.6 (220%)
logD 2.7
Sol 140uM
hERG 18uM
pEC50 7.6 (121%)
logD 3.0
Sol 1uM
hERG 7uM
R&D | CVGI | AP Jamie Scott| 04 2012
hERG can be circumvented – the CH2SO2Me!
pEC50 7.6 (121%)
logD 3.0
hERG 7uM
NN
OF3C
ON
N
NN
S
OO
F
‘Unlucky’ here – can we fix it?
hERG can be difficult to predict
- Structure driven rather than logD
- Small changes can have a big effect
Circumventing hERG GPR119 hERG
R&D | CVGI | AP Jamie Scott| 04 2012
hERG can be circumvented – the CH2SO2Me!
pEC50 7.6 (121%)
logD 3.0
hERG 7uM
NN
OF3C
ON
N
NN
S
OO
F
pEC50 7.6 (100%)
logD 2.9
hERG >33uM
SO O
NN
OF3C
ON
N
NN
F
pEC50 8.4 (89%)
logD 3.6
hERG 4uM
ON
NF3C
ON
N
NN
S
OO
F
CH2 spacer to polar sulphone
removes hERG liability
(potency and logD neutral)
Oxadiazole isomer
raises logD (increases
potency & hERG)
‘Unlucky’ here – can we fix it?
hERG can be difficult to predict
- Structure driven rather than logD
- Small changes can have a big effect
Circumventing hERG GPR119 hERG
R&D | CVGI | AP Jamie Scott| 04 2012
SO O
ON
NF3C
ON
N
NN
F
hERG can be circumvented – the CH2SO2Me!
pEC50 7.6 (121%)
logD 3.0
hERG 7uM
NN
OF3C
ON
N
NN
S
OO
F
pEC50 8.1 (84%)
logD 3.4
hERG >33uM
pEC50 7.6 (100%)
logD 2.9
hERG >33uM
SO O
NN
OF3C
ON
N
NN
F
pEC50 8.4 (89%)
logD 3.6
hERG 4uM
ON
NF3C
ON
N
NN
S
OO
F
CH2 spacer to polar sulphone
removes hERG liability
(potency and logD neutral)
Oxadiazole isomer
raises logD (increases
potency & hERG)
Combination gives
good potency & hERG
‘Unlucky’ here – can we fix it?
hERG can be difficult to predict
- Structure driven rather than logD
- Small changes can have a big effect
Circumventing hERG GPR119 hERG
R&D | CVGI | AP Jamie Scott| 04 2012
Further results from Brain Slice Assay
NO
NON
N
N
N
N
N
NN
OON
N
N
N
N
N
F3C
+ve Brain slice
logD 3.3
+ve Brain slice
logD 2.7
NO
NON
N
N
N
N
N
F3C
+ve Brain slice
logD 4.0
Matched Pairs
S
OO
NN
OON
N
NN
F3C
F
-ve Brain slice
logD 3.0
• CH2sulphone also clean in brain slice assay
O
OON
N
NN
SO O
F
O
CF3
-ve Brain slice
logD 2.9
NN
OON
N
NN
F3C
SO O
F
-ve Brain slice
logD 2.9
SO O
ON
NF3C
ON
N
NN
F
-ve Brain slice
logD 3.4
Sol 1.8 uM
R&D | CVGI | AP Jamie Scott| 04 2012
Sol 1.8 mM [c]
logD 3.4
• End to end interaction is absent
• Ladder interactions observed
(Both a-CH interacting with O)
Understanding the solubility of the CH2 sulphone
SO O
ON
NF3C
ON
N
NN
F
SO O
O
F
ON
NF3C
N
N
NN H
H
SO O
O
F
ON
NF3C
N
N
NN H
H
R&D | CVGI | AP Jamie Scott| 04 2012
Overall Profile looks good
SO O
ON
NF3C
ON
N
NN
F
Good Suspension PK (m,r,d) with dose linearity On-target, glucose lowering & GLP-1 release
Hu pEC50 8.1 (84%)
Mu pEC50 7.2 (71%)
logD 3.4
LLE 4.7
Clean in Brain Slice assay
-8
-6
-4
-2
0
2
0 10 20 30 40 50
vo
lta
ge
(m
V)
time (ms)
0.1% DMSO
1 µM AZ13457680
3 µM AZ13457680
10 µM AZ13457680
30 µM AZ13457680
100 µM 4-AP80
90
100
110
120
130
140
0.1 1 10 100
PS
l are
a (
% v
eh
icle
)
[AZ13457680] μM
hERG >33uM
Sol 1.8 uM
R&D | CVGI | AP Jamie Scott| 04 2012 25
Synthesis – Oxadiazole isomers from N-CN
N N
N
N
ORNO
NX
N N
N
N
ORN
NH N
N
N
OR
N N
N
N
ORON
NX
N N
N
N
ORNN
OX
i) NaN3, Et3N.HCl, toluene, D;
ii) (iPr)2NEt, (XCO)2O,
Chlorobenzene, D
CNBr, NaHCO3,
CH2Cl2/H2O, 59%
i) NH2OH.HCl, Na2CO3, DMF;
ii) (XCO)2O, pyridine, toluene, D
i) XC(=NOH)NH2, ZnCl2,
THF/EtOAc;
ii) HCl, EtOH, D
• All 3 isomers available from common building block
• Chemistry works on phenol (R=H) or with protection (R=Bn)
R&D | CVGI | AP Jamie Scott| 04 2012 26
Synthesis II
ON
N
CF3
CF3
N
ON
NN N
N
N
BrCF
3
OH
F
SO
O
O
O
ON
NN N
CF3
O
O
NH NO
O
N NN
N
N
BrCl
ON
NN N
N
N
OCF
3
SO O
F
ON
NN NH
CF3
ON
NN N
N
N
OHCF
3
F
SO
O
O
MeOF
BrO
MeO
F
O
MeO
F
O
OH
• CH2SO2Me building block introduced as last step
• NaSO2Me displacement of bromo avoids need for S-oxidation
• Pd catalysed Br to OH conversion works in presence of heterocycle
Convergent synthesis of 10 steps.
Longest linear sequence 6 steps
Run on >100g scale
R&D | CVGI | AP Jamie Scott| 04 2012
Summary ON
N
NN
O
O S
OO
pEC50 7.2 (83%)
Sol 0.03 mM [c]
logD 3.2
hERG >33 mM
NO
NON
N
N
N
N
N
pEC50 8.1 (199%)
Sol 7uM
logD 3.3
LLE 4.8
NN
OON
N
N
N
N
N
F3C
pEC50 7.6 (220%)
Sol 120 mM
logD 2.7
LLE 4.9
pEC50 7.6 (121%)
Sol 1uM
logD 3.0
hERG 7uM
NN
OF3C
ON
N
NN
S
OO
F
SO O
ON
NF3C
ON
N
NN
F
pEC50 8.1 (84%)
Sol 1.8uM
logD 3.4
hERG >33 mM
R&D | CVGI | AP Jamie Scott| 04 2012
Conclusions & Learning
Oxadiazoles - Not all bio-isosteres are equal!
- Subtle changes have big impact
Startpoint - Biggest difference to where you end up!
- Potency lead
- Solubility lead
confidence that contradiction
could be resolved
LLE - pEC50-logD
- good guide to progress (cpd quality)
- keeps phys props at the forefront
- Use with caution (agonists)
‘CH2’ - a small group makes a big difference
- solved hERG
X-ray structures - Can really assist design teams
- “Beauty is truth, truth beauty”
R&D | CVGI | AP Jamie Scott| 04 2012
Acknowledgements Lead Generation (Mö)
Anders Broo
Öjvind Davidsson
Udo Bauer
Linda Sundström
Birgitta Svalstedt Karlsson
Walter Lindberg
Ann-Charlotte Egnell
Chemistry
Roger Butlin
Jamie Scott
Paul Schofield
David Clarke
Jules Hudson
Sam Groombridge
Kristen Goldberg
Alan Birch
Ruth Poultney
Sue Bowker
Phys / Comp Chem
Andrew Leach
Matt Wood
Phil MacFaul
DMPK
Charles O’Donnell
Hayley Brown
Pablo Morentin Gutierrez
Teresa Collins
Pharmaceutical Development
Claire Patterson
Project Leader
Darren McKerrecher
Legal
Tom Miller
Large Scale Chemistry
Neil Hawkins
David Rudge
Pete McLachlan
Informatics
Jasen Chooramun
Statistics
Liz Mills
Bioscience
Katy Brocklehurst
Carina Ämmälä
Joanne Teague
David Laber
David Baker
Rob Garcia
Simon Poucher
Steve Bloor
Animal Science & Welfare
Bill Brown
Neil Reavey
Diane Tibbs
Ruth Storer
Adrienne Sanders
Paul Sheridan
Lisa Shawcross
John Burton
Gary Slade
Laura Hayward
X-Ray
Per Svensson
Anne Ertan