loui madakamutil, ph.d 0 discovery of a small molecule inhibitor of burton’s tyrosine kinase (btk)...
TRANSCRIPT
1
Loui Madakamutil, Ph.D
Discovery of a small molecule inhibitor of Burton’s Tyrosine Kinase (BTK) for autoimmune diseases
3rd International Conference and Exhibition on Clinical & Cellular Immunology (Immunology Summit-2014) Sept 29-Oct 1 2014Baltimore, USA
2
Bruton’s Tyrosine Kinase - Btk
• Tec family kinase required for B-cell receptor signaling in B cells and FCg receptor signaling in myeloid cells
• Btk is not expressed in T cells• Aberrant signaling through Btk implicated in
the pathogenesis of diffuse large B-cell lymphoma, mantle cell lymphoma and chronic B-cell leukemia
• Ibrutinib (PCI32765) recently approved for the treatment of mantle cell lymphoma
Hendrix, Nat Chem Biol. 2011Kuppers, Nature Rev. Cancer, 2005, 5, 251-62
Efficacy and Commercial Opportunity
BTKi in SLEpathology
Efficacy: BTKi >> Belimumab and other single axis biologics.
• BTKi has multiple nodes of intervention in SLE pathology
– Immune-modulation– Prevent tissue damage– DMARD – Faster onset due to activity on multiple nodes
• Small molecules compartmentalize to organs unlike biologics
• Preclinical validation of BTKi for SLE published* – PCI32765
Commercial Opportunity: • Once daily pill >> biologic
nature reviews rheumatology, volume 6, 2010 pg547
4
Published Lead Series
• Published Btk inhibitor series were either covalent or high molecular weight >500 Da and ligand efficiency ≤ 0.3
• Our question: Could a fragment based lead generation approach successfully deliver a reversible BTK inhibitor lead
N
N NN
NH2
N
OPh
O
N
HN
NH
N
N
OH
O
N
N
OHN
NH
O
S
N
N
O
O
NF
IbrutinibPharmacyclicsIrreversible
RN486 RocheMwt 592 DaBtk Kd 0.3 nMLE 0.30
GDC0834 GileadMwt 596 DaBtk IC50 6 nMLE 0.27
5
Fragment and Crystal structure based discovery of BTK inhibitor
P-Loop
Floor pocket
Hinge
NN
NH2
NH2
OFragment Hit
Btk IC50 3.5 mMLE 0.53
X-ray Co-crystal Structure – Btk kinase domain
NN
NH2
NH2
O
NNH
Mwt 318 DaLogD 1.8
tPSA 123 ÅpBtk EC50 28 nM
Compound 9
BTK inhibitor: Pharmacology in vitro
Compound pBTKRat WBB cells
FceRMast cells
BAFFB cells
FcgRMacrophages
Compound 9 42 157 320 733 80
PCI-32765Ibrutinib
3.1 30 380 300 10
Slide 6
Activity in several pathology nodes
• BCR signaling
• FceR signaling
• BAFF signaling
• FcgR signaling
Demonstrates selective activity to B cell and spares T cells
7
Pla
sma
IL-2
(p
g/m
l)
IgG
Veh
icle 1 3 10
0
500
1000
1500
2000U
nt.
Veh
icle 1 3 10
0
10
20
30
40
50
mg/kg
% C
D86
+ B
Cel
ls
Slide 8
Efficacy in CIA models
D22D0 D7 D11 D12
Immun. Group Treatment
D21D19D16
Norm. Veh. 0.1 0.3 1 3 10 30-0.2
0.0
0.2
0.4
0.6
mg/kg
% Inhibition
10% 29% 43% 66% 94% 140%
P
aw v
olu
me
(mL
, D2
2-D
11
)
D0 D21 D21-24 D24
Immun. Group Treatment
D34
0 5 100
2
4
6
8NormalVehicle3 mg/Kg10 mg/Kg 30 mg/Kg
Study Day
To
tal A
rth
riti
s S
core
Rat CIA Mouse CIA
Slide 9
Efficacy in anti-GBM nephritis model
Day 1 B35: 30 mg/rat i.v.
B.W. , plasma and urine sampling @ Day 0,4, 6, 9, 12
Day 4Dosing start
0 5 10 150
50
100
150
200NormalVehicleDex 0.1mg/kg
Cpd 9, 10 mg/Kg
Days
To
tal p
rote
in in
Uri
ne
(mg
)
Cpd 9, 30 mg/Kg
Cpd 9, 3 mg/Kg
Increased prominence of membrane cells (loss of Bowman's space)
Infiltration of inflammatory cells
10
Summary and Conclusions
• Compound 9 was identified as a potent and selective inhibitor of BTK
• Compound 9 prevented downstream events mediated by BCR and FcR in vitro. Further it also demonstrates the ability to block BAFF mediated B cell survival
• Compound 9 shows no appreciable activity in T cell inhibitory activity
• Compound 9 shows potent and dose dependent inhibition of clinical arthritis in CIA models
• Compound 9 shows unique activity in the IC mediated kidney damage model
• BTK inhibitors are promising approach to treat diseases like RA and nephritis mediated by IC
11
Acknowledgements
Enzyme PharmacologyChed GrimshawPetro Halkowycz
Structural BiologyDoug DouganBiChing SangMichael Klein
Computational SciencesDave Lawson
Experimental TherapeuticsLoui MadakamutilJonathan ZalevskyKeiko IshigamiAshleigh KellerYoshiki NakamuraMyra NgCorey Wyrick
Cell PharmacologyEwan TaylorKim PeacockJoe RussoPamela FarrellDeepika Balakrishna
DMPKRon XuRon ChenHeather GarciaMelinda ManuelLisa RahbaekJana Yu
Analytical ChemistryCatherine PhamHaihong WuLu Zeng
CMCChunrong MaDavid Provencal
Medicinal ChemistryChristopher SmithMark SabatPhong VuNick ScorahHaixia Wang
Takeda California, San Diego Shonan Research Center, YokohamaShonan Research Center, Japan
Tokyo
Shonan