kinase inhibitors in rheumatoid arthritis: jak/ stat...

Kinase inhibitors in rheumatoid arthritis: JAK/STAT signaling pathway

Professor Peter C. Taylor MA, PhD, FRCP

Tyrosine Kinase Inhibitors in Health and Rheumatic Diseases Ankara, Turkey. 12 March 2011

Cytokines Regulate Many Biological Processes

2

SCF, IL-3, TPO, EPO, GM-CSF, G-CSF, M-CSF

Hematopoietic

PDGF, EGF, FGF, IGF, TGFβ, VEGF

Growth/Differentiation

TGFβ, IFNγ, IL-2, IL-4, IL-5, IL-7, IL-9, IL-10, IL-11, IL-12, IL-13, IL-15, IL-16,

IL-17, IL-18, IL-232

Immunoregulatory

IL-1α, IL-1β, TNFα, LT, IL-6, LIF, IL-17, IL-182,

IL-333

Pro-inflammatory

IL-1RA, IL-4, IL-10, IL-13

Anti-inflammatory†

IL-8, MIP-1α, MIP-1β, MCP-1, RANTES

Chemotactic

*The definition of cytokine function is ever-changing, with many cytokines playing multiple roles. †Some cytokines, such as IL-4 and IL-13, can be either pro -or anti-inflammatory, depending on the environment and circumstances. 1. Arend WP. Arthritis Rheum. 2001;45:101-106; 2. Murphy K, et al. Janeway’s Immunobiology. 7th ed. NY: Garland; 2008; 3. Hsu C-L, et al. PLOS One. 2010;5:E1944.

Cytokines Are Implicated in Each Phase of RA Pathogenesis

3

Cellular recruitment1

Immunologic activation and organization1

Cellular retention and

survival1

Tissue Response1,2

BMPs=bone morphogenetic proteins, RANKL=receptor activator of nuclear factor Kappa B ligand. 1. McInnes IB, Liew FY. Nat Clin Pract Rheumatol. Nov 2005;1:31-39. 2. Schett G, et al. Arthritis Rheum. 2008;58:2936-2948. Figure adapted from McInnes IB, Liew FY. Nat Clin Pract Rheumatol. Nov 2005;1:31-39.

Cytokines and Intracellular Signaling Pathways in RA

Cytokine Receptor Superfamilies

Chemokine Toll/IL-1 TGFβ TNF Type I/II Cytokine

Receptor tyrosine kinase

Trimeric proteins usually associated with

cell surface

Receptor serine/

threonine kinase

G-protein-coupled

receptor family

Enzyme-linked receptors

specific for tyrosine residues

Heterodimeric or homodimeric

receptors

Single-pass membrane

receptors with Toll-IL-1 receptor domains

5

Adapted from Baker SJ, et al. Oncogene. 2007;26:6724-6737 and Murphy K, et al. Janeway’s Immunobiology. 7th ed. NY: Garland ; 2008.

Type I/II Cytokine Receptor Families

IL-2, IL-4 IL-7, IL-9 IL-15, IL-211

Growth hormone, erythropoietin,

prolactin, thrombopoietin

IL-3, IL-5 GM-CSF

IL-6 IL-11, IL-312,

(IL-12,23,27,35)3 OSM,CNTF,CT-1

IFN α/β IFN γ

IL-19,20,22,�� 25,28,29

α β γc

α

βc

α gp130

α β

CNTF=ciliary neurotrophic factor, OSM=oncostatin M. 1. Leonard WJ. Nat Rev Immunol. 2001;1:200-208; 2. Zhang Q, et al. Cytokine Growth Factor Rev. 2008;19(5-6):347–356.3; 3. Collison LW, et al. Immunol Rev. 2008;226:248–262. Figure adapted from Baker SJ, et al. Oncogene. 2007;26:6724-6737.

6

JAK Pathways

7

Cytokine binding to its cell surface receptor leads to receptor polymerization and autophosphorylation of associated JAKs

1

Activated JAKs phosphorylate the receptors that dock STATs

2

Activated JAKs phosphorylate STATs, which dimerize and move to the nucleus to activate new gene transcription

3

JAK JAK

STAT

P STAT

P STAT

P STAT

P STAT

Gene transcription

7

Figure adapted from Shuai K, et al. Nat Rev Immunol. 2003;3:900-911.

Cytokines Signal Through Different JAK Combinations

GH=growth hormone. 1. Murray P. J Immunol. 2007;178:2623-2629; 2. Ghoreschi K, et al. Immunol Rev. 2009;228:273-287.

TYK 2

IL-10 IL-6 IL-11 OSM LIF CTNF IL-22

JAK 1

TYK 2

JAK 1

JAK 1

JAK 1

JAK 2

JAK 2

JAK 2

JAK 2

IFN-αβ IL-2 IL-4 IL-7 IL-9 IL-15 IL-21

JAK 1

JAK 3

EPO TPO IL-3 IL-5 Leptin GM-CSF Prolactin GH

IL-12 IL-23

IFN-γ G-CSF

8

  JAKs work in pairs of 2 different JAKs or pairs of identical JAKs1,2

  JAK1 and JAK3 are required for γ-chain cytokine receptor signaling1,2

Signaling Through JAK Pathways Is Critical for Immune Cells

9

Perinatal lethality1,2

JAK1

Pathogen hypersensitivity1

TYK2

Embryonic lethality1,2

JAK2

SCID1

JAK3

Lethal

Viable

SCID: Severe Combined Immunodeficiency Disease. 1.  Shuai K, Liu B. Nat Rev Immunol. 2003;3:900-911; 2. Leonard WJ. Nat Rev Immunol. 2001;1:200-208.

JAK Pathway Signaling Is Important for Immune Cell Development, Survival, Proliferation, and Differentiation

10

IL-21 IL-15

IL-15Rα

IL-2

IL-2Rα

IL-4 IL-7 IL-9

γc γc γc γc γc γc IL-4R IL-2Rβ IL-7R IL-9R IL-2Rβ

•  T-cell proliferation

•  Cell death

•  B-cell proliferation

•  Th2 cell development

•  T-cell and B-cell development

•  Actions on T cells, NK cells, and B cells

•  Mucus production

•  Mast-cell proliferation

•  NK-cell development

•  T-cell homeostasis

Figure adapted from Leonard WJ. Nat Rev Immunol. 2001;1:200-208.

IL-21R

An Important Subset of Pro-inflammatory Cytokines Utilize JAK Pathways

IFNα and IFNβ IL-6 IL-7

IL-10 IL-12 IL-15 IL-23 IL-1

IL-17 IL-18 TGF-β TNF

IFNα and IFNβ IL-6 IL-7

IL-10 IL-12 IL-15 IL-23

Key cytokines in the pathogenesis of RA1 Key cytokines in RA

that utilize JAK2,3

11

1. McInnes IB, et al. Nat Rev Immunol. 2007;7:429-442; 2. Leonard WJ. Nat Rev Immunol. 2001;1:200-208. 3. Riese RJ, et al. Best Pract Clin Res Rheumatol. 2010;24:513-526.

Cytokine Expression and JAK3-specific Localization Indicate JAK Expression In the Synovium

Normal synovium

RA synovium

Walker JG, et al. Ann Rheum Dis. 2006;65:149-156.

STAT1 STAT6 STAT4 JAK3

12

Signaling Pathways in the Cycle of Chronic Inflammation

Cytokines activate cells through several signaling pathways

2

Signaling induces production of further pro-inflammatory signals

3

Further recruitment and activation of cells and effector function occurs

4

Pro-inflammatory cytokines recruit cells

1 Cytokines

Activated immune cells

McInnes IB, Liew FY. Nat Clin Pract Rheumatol. 2005;1(1):31-39.

13

Opar A. Nat Rev Drug Discov 2010;9:257-8

Compound (developer) Target(s) Selected indications (Phase)

INCB28050 (Eli Lilly, Incyte) JAK1/2 Rheumatoid arthritis (Phase II)

Tofacitinib (CP-690,550) (Pfizer)

JAK1/3 Rheumatoid arthritis (Phase III), psoriasis (Phase II), inflammatory bowel disease (Phase II)

VX-509 (Vertex) JAK3 Rheumatoid arthritis (Phase II)

VX-702 (Vertex) p38 MAPK Rheumatoid arthritis (Phase II)

BMS-582949 (Bristol-Myers Squibb)

p38 MAPK Rheumatoid arthritis, atherosclerosis (Phase II), psoriasis (Phase I-II)

Fostamatinib/R-788 (AstraZeneca, Rigel Pharmaceuticals)

SYK Rheumatoid arthritis, B-cell lymphoma, immune thrombocytopaenic purpura, peripheral T-cell lymphoma, solid tumours (Phase II)

JAK = janus kinase; p38 MAPK = mitogen-activated protein kinase; SYK = spleen tyrosine kinase

Selected protein kinase inhibitors in clinical development

  Orally available, small molecule, highly selective inhibitor of the JAK family of kinases

  Displays nanomolar potency against JAK3; exhibits functional selectivity for JAK1 and JAK 3 over JAK2

  Inhibits gamma cytokine signalling

  Some attenuation of signalling through additional cytokines, such as IFN-γ and IL-6

  Demonstrated efficacy in patients with rheumatoid arthritis (RA),1,2 psoriasis,3 and the prevention of acute renal allograph rejection4

  Also in Phase I/II trials in patients with ulcerative colitis, Crohn’s disease, and dry eye5

1Kremer et al. Arthritis and Rheumatism 2009; 60 (7): 1895-1905; 2Kremer et al. Arthritis and Rheumatism 2008; 58 (12): 4030-4031 3Boy et al. J Invest Dermatol 2009; 129: 2299-2302; 4Busque et al. Am J Transplant 2009; 9: 1936-1945 5West. Curr Opin Investig Drugs 2009; 10(5): 491-504 JAK, Janus kinase; IFN, interferon; IL, interleukin

Tofacitinib inhibits the JAK/Signal Transducer of Activated Transcription (STAT) Pathway

Tofacitinib

Selectivity of Tofacitinib for the JAK Family of Kinases

  Small-molecule kinase interaction map depicts selectivity for the JAK family of kinases1

  Displays ~1000-fold selectivity over 82 other kinases tested in a selectivity panel compared with the potency against JAK3 (1 nM)2

Jak3 (2.2nM)

Jak2 (5nM) Tyk2 (620nM)

1.  Karaman MW, et al. Nature Biotech. 2008;26(1):127-132; 2. Investigator’s brochure, June 2009. 2.  Investigator’s brochure and data on file.

JAK inhibition in vitro (Human blood) FACS analysis of Phospho-STAT

-25

0

25

50

75

100

125

1 100 10000

[CP-690,550] (nM)

% C

ontr

ol

IL-15 CD8 T cells IL-6 Monocytes IL-6 CD8 T cells GM-CSF Monocytes

JAK Enzyme JAK 1 JAK 2 JAK 3

IC50 nM (SEM) (Ki)

3.2 (1.4)

(0.7) 4.1 (0.4)

(1.0) 1.6 ( 0.2)

0. 2

Cell IC50 (nM) (JAK1/2)

HU. WB (SEM) 287 (83) 1377 (185) 56 (6)

Mouse WB (SEM) 186 (73) 4379 (655) 42 (12)

(JAK 2) (JAK 1/3)

JAK inhibition in vitro (Mouse blood) FACS analysis of Phospho-STAT

-25 0

25 50 75

100 125

1 100 10000 [CP-690,550] (nM)

% o

f Con

trol

IL15 (JAk1/3)

IL6 (JAk1/2))

GMCSF (JAk 2)

TYK2

34 ( 6)

(4)

(TYK2/JAk2

300

ND

CP-690,550 Inhibits JAK1 & JAK 3 with Functional Selectivity Over JAK2

CP-690550 Shows a Prolonged PD Effect

  Efficacy achieved in mouse CIA model at exposures that only inhibit JAK 1/3 & 1/2 signaling for 4-6 hrs per 12 hr dosing interval; little to no inhibition at minimum plasma concentrations

  Comparable efficacy is achieved in rat AIA model with BID, QD, and every-other-day dosing

Ghosh, Lee, Jesson, Warner, Funckes-Shippy

Mouse CIA JAK mediated STAT

phosphorylation assay 50 mg/kg dose

50 mg/kg

5 mg/kg

vehicle 0.5 mg/kg

CP-690,550 Normalizes Plasma Cytokines and Chemokines in the CIA Model

SAA (CRP) 0

200

400

600

800

gm

/mL

pla

sma

p = 0.008

G-CSF 0

200

400

600

800

pg

/mL

pla

sma

p = 0.010

MCP-1/CCL2 0

15

30

45

60

pg

/mL

pla

sma

p = 0.016

IL-6 0

10

20

30

40

pg

/mL

pla

sma

p = 0.005

IP-10/CXCL10 0

60

120

180

240

pg

/mL

pla

sma

p = 0.0001

Normal Vehicle CP-690,550

MIP-1α /CCL3 0

60

120

180

240

pg

/mL

pla

sma

p = 0.044

0 100 200 300 400 500 600

CXCL9/MIG

pg/m

l

p=0.050

KC/CXCL1 0

30

60

90

120

pg

/mL

pla

sma

p = 0.025

(IL8)

2.0

2.5

3.0

3.5

4.0

4.5

5.0

4 h 4 days

Paw

vol

ume

(ml)

vehicle

tasocitinib normal

Time after onset of therapy 7 days

* * * p=0.002

Assess for arthritis

Immunize M Butyricum in Squalene

Day 0 16 23 ’4hr

QD dosing, ED80 @ 6.2 mg/kg

Therapeutic dosing design

20

Sort into matched groups by edema

Rat Adjuvant-Induced Arthritis (AIA)- Model for Robust Bone Absorption

Rat AIA model  T-cell mediated

 Primary arthritic lesion is synovitis, followed by pannus formation, lymphocyte infiltration, & robust bone destruction

 Increased level of inflammatory cytokines and acute phase proteins

 Monitor effects of Tasocitinib therapeutic dosing at 4h, 4 days and 7 days

Inflammation and Osteoclast Mediated Bone Resorption is Reversed by Tofacitinib

tasocitinib 7 days vehicle 7 days

tasocitinib 7 days

F D E

0

1

2

3

4

5 vehicle tasocitinib normal

Infla

mm

. Sev

erity

sco

re

4 h 4 d 7 d

0

1

2

3

4

5

Bon

e Se

verit

y s

core

vehicle tasocitinib normal

4 h 4 d 7 d

Time after onset of therapy

Time after onset of therapy

vehicle 7 days

*

*

#

*

*

*

Osteoclast Osteoblast LaBranche, Shevlin

Tofacitinib Development Plan in RA

POC

2007 2006 2008 2009 2010 2011 2012 2013

+ MTX 1025

MTX IR Japan

Open Label Extension Studies

Follow-up Study

Mono 1019

Mono 1035

MTX IR

DMARD naïve Monotherapy Structure

Mono

DMARD IR

Vs. TNFi (+ MTX)

TNFi IR (+ MTX)

Mono Japan

Clinical Responses; tofacitinib studies

1019 1025 1035 1039 1024 1045

% Response

5mg 15mg 5mg 10mg 5mg 10mg 5mg 10mg 5/10 5mg 10mg

ACR20 70 81 61 60 59 71 96 81 ≈ 80 60 66

ACR50 33 54 37 31 37 44 82 58 ≈ 60 31 37

ACR70 13 22 18 13 12 25 33 35 ≈ 40 15 20

HAQ ↓ 57% 71% -0.49 -0.39 -0.48 -0.64 NR NR -.70 -0.5 -0.57

Δ DAS28 -2.0 -2.3 NR NR -2.1 -2.5 -2.8 -3.0 -2.86 -2.04 -2.26

DAS28<2.6 ≈ 15 ≈ 35 18 29.6 10.8 16.1 35 45 NR 6 9.6

Phase II studies LTE Phase III

6 wk MTX IR 12 wk MTX IR 12 wk MTX IR 12 wk mono 2 yr 12 wk mono

Safety; tofacitinib studies

% 1019 1025 1035 1039 1024 1045

Dose 5mg 15mg 5mg 10mg 5mg 10mg 5mg 10mg 5/10 5mg 10mg

AE 59 75.4 66.2 67.6 55.1 59 70.4 76.9 86.8 51 56.7

SAE 0 1.4 5.6 9.5 0 1.6 3.7 7.7 17.5 <1 2.0

SIE 0 1.4 1.4 1.4 0 0 NR NR 3.2 0 <1

OI 0 0 0 0 0 0 0 0 NR- 0 0

Deaths 0 0 0 0 0 0 0 0 NR 0 0

D/Cs 2° AE 1.6 8.6 4.2 6.8 2 1.6 14.8 15.4 6.5 <1 2.4

AST (% pts ↑) NR NR 22 21 15 16 14.8 3.8 0.3 9.5 11.8

AL T (% pts ↑) NR NR 24 27 11 11 22.2 7.7 0.8 9.5 11.4

ANC (↓) 940 1620 ≈500 ≈500 850 1550 1300 1640 ? 830 1350

LDL (% pts ↑) 16.4 28.4 ≈17 ≈20 18 26 3.7 3.8 NR 13.6 19.1

6 wk MTX IR 12 wk MTX IR 12 wk mono 12 wk mono 12 wk MTX IR 2 yr

Phase II studies LTE Phase III

Tofaocitinib vs PBO in DMARD-IR First Phase 3 Trial Report

Day 1 Randomization

Month 3 Primary Endpoint

Month 6 Study End

5 mg BID (n=243)

Placebo (n=61)

Placebo (n=61) 10 mg BID (n=61)

5 mg BID (n=61)

10 mg BID (n=245)

5 mg BID (n=243)

10 mg BID (n=245)

Fleischmann, et al. ACR 2010, Atlanta, #L8

26

Tofacitinib vs PBO in DMARD-IR

Baseline characteristics PBO n=122

Tofa 5 mg BID n=243

Tofa 10 mg BID n=245

TJC, mean 28.9 29 29.1 SJC, mean 17.3 16.3 17.0 HAQ-DI, mean 1.53 1.53 1.50

DAS28(ESR), mean 6.63 6.71 6.67 ESR, mm/h 50.9 53.1 52.1 CRP, mg/L 17.8 22.9 19.1

RF and/or anti-CCP + (%) 72.9 83.1 80.4

Prior TNF inhibitor, % 19.7 14.0 16.7 Prior MTX (%) 83.6 86.0 84.5

 Primary end-point at Month 3:   ACR20, HAQ-DI improvement, % DAS28 remission


* p<0.05

** p<0.001

*** p<0.0001 vs PBO

PBO Tofa 5 mg BID Tofa 10 mg BID PBO 5 mg BID

PBO 10 mg BID

Tasocitinib vs Placebo in DMARD IR: Efficacy

ACR20

ACR70

ACR50

Pat

ien

ts (

%)

***

*** ***

***

***

*** ***

***

3 0 1 2 4 5 6 0

20

60

100

***

** **

***

Pat

ien

ts (

%)

* *

3 0 1 2 4 5 6 0

10

20

30

40

Month

*

Pat

ien

ts (

%)

* ***

***

***

***

***

***

3 0 1 2 4 5 6 0

20

40

60


Tofacitinib vs PBO in DMARD-IR: Efficacy

DAS28 <2.6

HAQ-DI

* p<0.05

** p<0.001

*** p<0.0001 vs PBO

DAS28(ESR) Improvement

***

*** ***

*** ***

***

*

**

3 4 5 6 0 1 2

-0.9

-0.6

-0.3

0

Pat

ient

s (%

)

3 4 5 6 0 1 2 0

10

20

30

LS m

ean

chan

ge fr

om B

L

***

***

3 0 1 2 4 5 6

-3

-2

-1

0

LS m

ean

chan

ge fr

om B

L

Red dotted line indicates MCID HAQ (-0.22)

PBO Tofa 5 mg BID Tofa 10 mg BID PBO 5 mg BID

PBO 10 mg BID

Month


Months 0–3 Months 3–6

PBO n=122

Tofa 5 n=243

Tofa 10 n=245

PBO Tofa 5 n=61

Tofa 5 n=243

PBO Tofa 10

n=61 Tofa 10 n=245

AE 127 279 295 40 170 54 207

Pts with AE (%) 54.9 51.0 56.7 36.1 39.9 39.3 41.2

SAE (%) 4.9 <1.0 2.0 1.6 2.1 0 2.9 SIE (%) 0 0 <1.0 1.6 <1.0 0 1.2

Confirmed Op Inf 0 0 0 0 0 0 0

Deaths (%) 0 0 0 0 0 0 <1.0

D/Cs 2° AE (%) 4.1 <1.0 2.4 0 <1.0 0 2.0

Tofacitinib vs PBO in DMARD-IR: Safety


Tofacitinib vs PBO in DMARD-IR: Toxicity

No significant differences between groups in AST/ALT 1–3x ULN; *P<0.001;**P<0.0001 vs PBO

Tofacitinib monotherapy efficacy and safety similar to Phase II

Month 3 Month 6

PBO n=122

Tofa 5 n=243

Tofa 10 n=245

PBO Tofa n=61

Tofa 5 n=243

PBO Tofa 10 n=61

Tofa 10 n=245

LS mean change from BL

ANC, 103/mm3 -0.06 -0.83* -1.35** -0.90 -0.78 -1.18 -1.15

Hgb, g/dL -0.12 0.28 0.03 0.21 0.25 -0.22 0.15 % LDL change 3.5 13.6* 19.1** 16.9 12.8 16.8 19.1 Serum creatinine

0 0.04 0.05 0.06 0.06 0.08 0.08

Patients (%) n=122 n=243 n=245 n=57 n=239 n=52 n=232 ALT >3x ULN <1.0 <1.0 0 1.75 <1.0 0 <1.0 AST >3x ULN <1.0 1.7 0 1.8 <1.0 0 0


Tofacitinib : Long-term extension study

1 1,5

0,2

1,7

2,8

4,2

0,9

2,3

0

1

2

3

4

5

Anemia AST/ALT Cytopenia SIE

Incidence (%) per 100 pt-yrs

Tofa Tofa + MTX   SAE2: 66 Tofa vs 57 Tofa + MTX   18.4% infections   32 SIE (2.62/100 pt-yrs)   70 discontinued due to AEs   All with SIE discontinued   Clinical responses maintained in LTE

  1,070 pts from double-blind studies of Tofacitinib 5 mg or 10 mg BID1

  Allowed rescue drugs, background therapy, adjustments in dosages

  Efficacy maintained over 24 months

1.  Connell, et al. ACR 2010, Atlanta, #1129; 2.  Connell, et al. Ibid, Atlanta, #2171

JAK 1/2 Inhibitor from Incyte / Lilly

  Phase II in 127 DMARD-IR pts

  4, 7 or 10 mg QD vs PBO

  1° EP at 12 weeks

  Disease duration: 7–9 yrs; BL DAS scores 6.1–6.3

  Failed biologics: 13, 38, 6 vs 20% PBO

  Frequent TEAEs: HA, URI, diarrhoea

  H. zoster: 2.1% active vs 0 PBO

  HDL, LDL, and HDL:LDL ratios 10.6% vs 0 PBO

Positive proof of concept at Week 12

Greenwald, et al. ACR 2010, Atlanta, #2172

Responders (%) 1° EP: Week 12 ACR and LDAS

* * *

*P<0.05 (one sided)

*TEAE: Treatment emergent adverse emergent

Conclusions

  JAK pathways operate as one of several hubs in the inflammatory cytokine network.

  JAK pathways modulate the incoming signal of an important subset of pro-inflammatory cytokines.

  Tofacitinib is an orally available, small molecule, highly selective inhibitor of the JAK family of kinases with nanomolar potency against JAK3; exhibits functional selectivity for JAK1 and JAK 3 over JAK2

  Phase 2 trials demonstrate impressive efficacy in patients with an incomplete response to MTX in combination with MTX and as monotherapy in DMARD failures

  Stable safety profile:   Decreased neutrophils (not associated with infection)

  Elevation of lipids

  Elevation of transaminases (especially in combination with MTX)

kinase inhibitors in rheumatoid arthritis: jak/ stat...

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