Do the benefits of complement blockade extend to all patients with PNH clone?

YESAntonio M. Risitano, M.D., Ph.D.

HematologyDepartment of Biochemistry and

Medical BiotechnologiesFederico II University of Naples

The 1st World Congress on Controversies in Hematolo gy

Rome, September 4th

Without the complement inhibitorsCD55 and CD59 PNH RBC are susceptible to complement attack

PNH

Hemolysis of PNH RBC

Complementactivation

CLINICAL CONSEQUENCES OF HEMOLYSIS IN PNH

Renal Failure

Pulmonary Hypertension

Anemia ThrombosisHemoglobinuria

Smooth Muscle Dystonias including

Dysphagia, Abdominal Pain, and Male Erectile

Dysfunction

Fatigue

Eculizumab (h5G1.1mAb)Anti-C5 Humanized mAb

hinge

Variable heavychain

Variablelight chain

Human constantlight chain Ck

Human constantheavy chainIgG4 CH2 and CH3

Human constantheavy chainIgG2 CH1 and hinge

Human framework regions

Murinecomplementarity

determining regions

CH1

Ck

CH

2C

H3

Lectin PathwayActivation (MBL)

Targeting Complement Inhibitors

C5 C5b-9C5b

C6 C7 C8 C9

Classical Pathway ActivationAntibody/Antigen Complexes

Alternative Pathway ActivationMicrobiological membranes

Bacterial LPSImmune Complexes

Mammalian Cell Membranes

C3bC3

C1q Activated C1

C4+C2 C4b2a C4b2a3bC3 Convertase C5 Convertase

C5a

C3 Convertase C5 ConvertaseC3bBb3bC3bBb

C3a

C3b

Factor B+D

C3, C3H2O

WeakAnaphylatoxin

Immune Complexesand MicrobialOpsonization

Cell ActivationLysis

Potent AnaphylatoxinChemotaxis Cell

Activation

X

Eculizumab

EFFECT OF ECULIZUMAB ON HEMOLYSISLactate dehydrogenase (LDH)

Time, Weeks

Lact

ate

Deh

ydro

gena

se (

U/L

)

0

500

1000

1500

2000

2500

3000

0 10 20 30 40 50

TRIUMPH – Placebo/extensionTRIUMPH – SOLIRIS/extensionSHEPHERD – SOLIRIS

Study Week

0 2 4 6 8 10 12 14 16 18 20 22 24 26

Pat

ient

s A

void

ing

Tra

nsfu

sion

(%

)

0

10

20

30

40

50

60

70

80

90

100

P < 0.000001

Eculizumab

Placebo

51%

0%

44% reduction in PRBC units

transfused

EFFECT OF ECULIZUMAB ON TRANSFUSIONSTime to first transfusion

�SHEPHERD study : a non randomized trial for broader PNH population– patients with thrombocytopenia and minimal transfusion al need

Transfusion Requirements (12 Months Prior to Treatm ent)

51% of patients treated with eculizumabwere transfusion independent (12 m)

Efficacy demonstrated in all patient cohort

(n = 97) (n = 21) (n = 47) (n = 15) (n = 14)

8

2

8

17

33,5

0 0 0

4

7,5

0

5

10

15

20

25

30

35

40

Overall < 4 Units 4 - 14 Units 15 - 25 Units > 25 Units

Med

ian

Uni

tsP

acke

dR

BC

s

1 Year Pre-Treatment

1 Year Post-Treatment

Patient Age

Years from

diagnosis

Treatment duration (months)

LDH before

Ecu

LDH during

Ecu

Hbbefore

Ecu

Hbduring

EcuHb

gain

PNH RBC before

Ecu (%)

PNH RBC during

Ecu (%)

1 41 15 17 680 225 10 12,8 +2,8 n.a. 48

2 25 2 18 1216 356 7,5 10 +2,5 23 60

3 51 10 16 727 250 9,3 10,5 +1,2 40 89

4 16 1 1 1425 342 7,3 9 +1,7 10 24

5 50 7 39 3968 860 8 10 +2 19 89

6 59 17 4 3100 290 7 11,6 +4,6 50 n.a.

7 39 10 5 2190 250 10,7 11,5 +0,8 46 48

8 38 3 18 1500 360 9 10,7 +1,7 12 45

9 16 1 9 2100 250 9 11,7 +2,7 13 52

Mean 37 6,1 14,1 1878 353 8 10 +2,2 26,6 58,1

Median 39 5 16 1500 290 9 10,7 +2 21 52

ECULIZUMAB IN NON TRANSFUSED PATIENTSAn Italian pilot experience (Risitano et al, EHA 2009)

� Terminal complement inhibition by eculizumab in non t ransfused PNH patients leads to improvement of most clinical m anifestations, including symptoms of intravascular hemolysis and ane mia

0

2

4

6

8

10

12

14

16

Pre-Eculizumab Treatment Eculizumab Treatment

Thr

ombo

sis

Eve

nt R

ate

(TE

per

100

pt-y

ears

)

� 92% reduction in event rate with eculizumab

(n=195) (n=195)

39 events 3 events

P = 0.0001

Hillmen et al., Blood 2007

Normalized by time of observation (pre and post)

Hill et al., ASH 2009

Blocking C5 Activity Lead to An Increase in Platele t Counts in Thrombocytopenic Patients

30

40

50

60

70

80

90

100

0 26 52Eculizumab Treatment (Weeks)

Mea

n P

late

let C

ount

s (x

109 /L

)

-20

-15

-10

-5

0

5

10

15

20

25

26 52

Eculizumab Treatment (Weeks)M

ean

Cha

nge

in P

late

lets

(x1

09 /L

)

<100,000>100,000

� Complement-mediated platelet consumption?

� Possible relation with thrombophilia?

Platelet count in thrombocytopenic patients

Platelet count change in thrombocytopenic vs non-thrombocytopenic patients

�Markers of thrombin generation and fibrinolisis decrease during eculizumab treatment

�Markers of endothelial activation decrease during eculizumab treatment

Haematologica. 2010 Apr;95(4):574-81. Epub 2010 Jan 15.

Evaluation of hemostasis and endothelial function in pa tients withparoxysmal nocturnal hemoglobinuria receiving eculizumab.

Helley D, de Latour RP, Porcher R, Rodrigues CA, Galy-Fauroux I, MatheronJ, Duval A, Schved JF, Fischer AM, Socié G; French Society of Hematology.

NATURAL HISTORY OF PNH

De Latour et al, Blood 2008

Increased mortality due to:– Thromboembolism– Severe marrow failure– (Clonal evolution to

MDS/leukemia?)

Overall survival by subcategory

NATURAL HISTORY OF PNHCumulative incidence of complications

De Latour et al, Blood 2008

CytopeniaThrombosis

MDS/AML

Am J Hematol. 2010 Aug;85(8):553-9.

Long-term effect of the complement inhibitor eculizumab o n kidney function in patients with paroxysmal nocturnal

hemoglobinuria.

Hillmen P, Elebute M, Kelly R, Urbano-Ispizua A, Hill A, RotherRP, Khursigara G, Fu CL, Omine M, Browne P, Rosse W.

Br J Haematol. 2010 May;149(3):414-25. Epub 2010 Mar 8.

Effect of eculizumab on haemolysis-associated nitric oxi dedepletion, dyspnoea, and measures of pulmonary

hypertension in patients with paroxysmal nocturnalhaemoglobinuria.

Hill A, Rother RP, Wang X, Morris SM Jr, Quinn-Senger K, Kelly R, Richards SJ, Bessler M, Bell L, Hillmen P, Gladwin MT.

� Soliris TM is the first and only approved therapy for the treatment of hemolysis of transfusion-dependent PNH (USA March 2007, Europe June 2007)

� In Italy, extended access program ( law #648) for all PNH patients (even not transfusion dependent) with either:

� Severe symptomatic intravascular hemolysis (frequent paroxisms, invalidating symptoms)

� Overt life-threatening thromboembolism

ECULIZUMAB AND PNHIndication to the treatment

Caveat:Caveat:

� Patients with concomitant aplastic anemia are very unlikely to respond

CLINICAL OVERLAP BETWEEN PNH AND BMF

AA

Florid PNH

AA/PNH

HypoplasticPNH Subclinical

PNH

MDS? IMF?

PNH in the context of other hematological

disorders

� In almost all patients, optimal control of intravascu lar hemolysis, with:� Reduced transfusion requirement, improvement of ane mia

� Improved hemolysis-related symptoms and QoL

� Marked reduction in thromboembolic risk

� Improvement of markers of pulmonary hypertension and chronic kidney failure (clinically relevant?)

� Possible effect on survival

� No major safety concerns

ANTI-COMPLEMENT THERAPY AND PNHReasons to treat all PNH patients (but not patients with PNH clone)

However:However:

1. Elevated cost

2. Life-long supportive treatment, without expected cure

3. No effect on underlying bone marrow failure

4. Minor hematological benefit (as Hb level) in many pati ents

� Proven reasons and possible solutions

Hematological response

Hgb ≥≥≥≥1136.6%

8 ≤≤≤≤ Hgb < 1143.9%

≤≤≤≤50%12.2%

>50%7.3%

THE CLINICAL RESPONSE TO ECULIZUMABThe Italian experience

• Normal or almost-normal LDH level in all patients• Persistent reticulocytosis in almost all patients

n= 41

Risitano et al, Blood 2009

Untreated PNH

Anti C3d FITC

An

ti C

D59

PE

C3 coating on RBCs from PNH patients on eculizumabDouble color flow cytometry

PNH on eculizumab

Risitano et al, Blood 2009

THE COMPLEMENT CASCADE REGULATION IN PNH

C3b

C3

+ C5b

C5

C3b

C5 convertase

PNH RBCs

Classicalpathway

Lectinpathway

Alternativepathway

C6 MAC

PhysiologicalC3 tick-over

C7 C8 C9

CD55 CD55 CD59

Amplification loop

C3b

MAC-mediated intravascular hemolysis

THE COMPLEMENT CASCADE REGULATION IN PNH

C3b

C3

+

C5

C3b

C5 convertase

PNH RBCs

Classicalpathway

Lectinpathway

Alternativepathway

PhysiologicalC3 tick-over

CD55 CD55

Amplification loop

Eculizumab

C3b,iC3b,C3d

C3-mediated extravascular hemolysis

Risitano et al, Blood 2009

C3

RES macrophages

Liver Spleen

C3C3

In vivo RBC survival51Cr hepato-splenic uptake after RBC labeling

Risitano et al, Blood 2009

3000

2000

1000

0

-5000 96 192 288 384 480

Spleen

Liver

Exc

ess

coun

t

Hours

PNH #2

PNH #3

control

Hemolyticanemia

SPLENECTOMY: THE PROOF OF PRINCIPLEOvercoming extravascolar hemolysis in PNH on eculizumab

LDH

IU/L

0,0

2,0

4,0

6,0

8,0

10,0

12,0

-100 -12 -1 1 3 5 7 9 13

Weeks from splenectomy

0

500

1000

1500

2000

2500

3000

3500

4000H

bg/

dLTransfusions

Splenectomy

% P

NH

RB

C

Eculizumab

Placebo

100

80

60

40

20

0

Risitano et al, Blood 2008

Lectin PathwayActivation (MBL)

Targeted Complement Inhibitors

C5 C5b-9C5b

C6 C7 C8 C9

Classical Pathway ActivationAntibody/Antigen Complexes

Alternative Pathway ActivationMicrobiological membranes

Bacterial LPSImmune Complexes

Mammalian Cell Membranes

C3bC3

C1q Activated C1

C4+C2 C4b2a C4b2a3bC3 Convertase C5 Convertase

C5a

C3 Convertase C5 ConvertaseC3bBb3bC3bBb

C3a

C3b

Factor B+D

C3, C3H2O

WeakAnaphylatoxin

Immune Complexesand MicrobialOpsonization

Cell ActivationLysis

Potent AnaphylatoxinChemotaxis Cell

Activation

C3 inhibitors?

Anti-C3 mAb as candidate agents for PNHPreclinical data (Lindorfer et al, Blood 2010)

3E7 and its chimeric deimmunized derivative H17 are anti-C3 mAb which inhibit the C3 convertase

� Inhibit hemolysis of PNH RBCs in vitro

� Prevent C3 accumulation on surviving PNH RBCs in vitro

� Specific for CAP C3 convertase (CCP is preserved)

THE COMPLEMENT CASCADE REGULATION IN PNH

C3b

C3

+

C5

C3b

C5 convertase

Classicalpathway

Lectinpathway

Alternativepathway

PhysiologicalC3 tick-over

C5bC6 MACC7 C8 C9

CD55 CD55

Amplification loop

Factor H

CD59

TARGETING THE COMPLEMENT INHIBITIONCombining a targeting protein (CR2) with a complement regulator (fH)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

CR2

Factor H (fH)

1 2 3 4 5

1 2 3 4

1 2 3 4 51 2 3 4

SCR 1-4 of CR2 (targeting module) fused toSCR 1-5 of fH (complement inhibitor module)

TT30fH

CR

2

ECULIZUMAB FOR THE TREATMENT OF PNH PATIENTSAn evidence-based medicine assessment

Classical PNH•Massive hemolysis•No SAA

AA/PNH•IAAAS criteria•PNH clone (>1%)

Clinically relevant hemolysis•Transfusion dependency•Severe anemia•Hemolysis-related symptoms

Life-threatening thrombosis•Budd-Chiari, and other splancnic veins•CNS

RecommendationClinical featuresDiagnosis

Elevated thrombotic risk•Previous TE events•PNH clone size (>50%)•Additional genetic risk factors

Standard thrombotic risk•PNH clone size (<50%)•No additional genetic risk factors

Not clinically relevant PNH• Minor PNH clone•No signs or symptoms of hemolysis

A I

A II

B II

C III

E III

Clinically relevant PNH•PNH clone size (>10%)•Signs or symptoms of hemolysis

C III