PowerPoint Presentation · 2016-05-03 · 3/22/2016 1 Paroxysmal Nocturnal Hemoglobinuria (PNH): Current Thinking on the Disease Rodrigo T. Calado, MD/PhD Ribeirão Preto School of
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3/22/2016
1
Paroxysmal Nocturnal Hemoglobinuria (PNH):
Current Thinking on the Disease
Rodrigo T. Calado, MD/PhDRibeirão Preto School of Medicine
University of São Paulo
Bone Marrow Failure Disease Scientific SymposiumRockville, March 17-18, 2016
Extracellular
space
Cytoplasm
Transmembrane
COOH
GPI-
Anchored
NH2
COOH
1189 1452982849716
63 52 4
1
PIG-A gene
GPI-anchored protein
glycosylphosphoinositol
(GPI) anchor
C OC OO
CH CH2
O POO
O
O
CH2
INOS
GLU
MAN
O
O
O
(a 1-2)
(a 1-6)
C O
N
CH2
CH2
NH
O P O
O
O
MANO
PHOSPHATIDYL
-INOSITOL
GLYCAN COREPHOSPO-
ETHANOLAMINE
PROTEIN
MAN
PATHOGENESIS OF PNH
C3
PNH
CD59C3
conv CD55
PIG-A mutation: Absent GPI (anchor)Absent CD55 - higher C3 convertase
C3
b
Adapted from Abbas AK et al. Cellular and Molecular Immunology, 3rd ed.WB Saunders: Philadelphia, 1991
Adapted from Abbas AK et al. Cellular and Molecular Immunology, 3rd ed.WB Saunders: Philadelphia, 1991
C5b,6,7 C5b-8
C5b-9
C5b
C5 C5a C7C8
C5b
C7
C6
C7
C6
C5bC6
x 12–15
C5
con
vert
ase
C5
con
vert
ase
C8
CD59
C9
X
PNH
PIG-A mutation: Absent GPI (anchor)Absent CD55 - higher C3 convertaseAbsent CD59 – MAC formation
Adapted from Abbas AK et al. Cellular and Molecular Immunology, 3rd ed.WB Saunders: Philadelphia, 1991
C5b,6,7 C5b-8
C5b-9
PNH, paroxysmal nocturnal haemoglobinuria
C5b
C5 C5a C7C8
C5b
C7
C6
C7
C6
C5bC6
C9
C7
C5bC6
C7
C8
C5bC6
x 12–15
C5
con
vert
ase
C5
con
vert
ase
C8 C8C9
PNH
PIG-A mutation: Absent GPI (anchor)Absent CD55 - higher C3 convertaseAbsent CD59 – MAC formation
Anemia
Reduction in circulating
RBC mass
Free hemoglobin
Normal red blood cells are
protected from complement
CD55- and CD59-negative
RBCs are destroyed
Intact Red
Blood Cell
Complement
Activation
PNH
1. International PNH Interest Group. Blood. 2005;106:3699-3709. 2. Brodsky R Paroxysmal Nocturnal Hemoglobinuria. In: Hematology - Basic Principles
and Practices. 4th ed. R Hoffman; EJ Benz; S Shattil et al, eds. Philadelphia, PA: Elsevier Churchill Livingstone; 2005; 419-427. 3. Rother RP et al. JAMA.
2005;293:1653-1662. 4. Socie G et al. Lancet. 1996;348:573-577. 5. Hill A et al. Br J Haematol. 2007;137:181-192.
3/22/2016
2
Normal red blood cells are protected from complement attack by a shield of terminal complement inhibitors
Without this protective complement inhibitor shield, PNH red blood cells are destroyed
Intact RBCHemoglobin released from destroyed PNH
RBCs
ComplementActivation
Anaemia and release of free Hb Haemoglobinuria
Thrombosis
Fatigue
Renal Failure
Significant Impact on Morbidity
Significant Impact on Survival
Pulmonary Hypertension
Erectile Dysfunction
Dyspnoea
Dysphagia
Abdominal Pain
PNH is a Progressive Disease of Unregulated Complement Activity
NO↓A Hill, Leeds8
PNH clone expansion
9
PNH clone expansion
Cytopenia
Low level of Hemolysis
Cytopenia Hemolysis
Thrombosis
Aplastic anemia > AA PNH syndrome > Hemolytic PNH
Cytopenia
Defining “Patients with PNH”• Classical haemolytic PNH patients
• PNH associated with AA or MDS also with• Haemolysis• Organ impairment due to haemolysis• Thrombosis
PAROXYSMAL NOCTURNAL HEMOGLOBINURIA (PNH)
TRIAD OF CLINICAL FEATURES
Hemoglobinuria
Intravascular Haemolysis
• Disabling Symptoms
- Abdominal pain
- Dysphagia
- Erectile failure
- Severe lethargy
Budd-Chiari
Syndrome
Thrombosis
• Liver, cerebral
• 50% of patients;
fatal in 33%
Aplastic Anemia
Bone Marrow Failure
• Often precedes PNH
• Selects for PNH clone
1. somatic mutation of PIG-A in an hematopoietic stem cell
2. aborted GPI anchor synthesis
3. absent cell surface GPI-anchored proteins
4. clonal expansion of GP-AP deficient cells = PNH
hemolysis (CD59-) BM failure (?) thrombosis (?)
3/22/2016
3
complementarity determining regions
(murine origin)
CH
3C
H2
Hinge
human IgG4 heavy chain
constant regions 2 and 3
human framework regions
human IgG2 heavy chain
constant region 1 and hinge
ECULIZUMAB (ANTI-C5
ANTIBODY)TRIUMPH
Transfusion Reduction Efficacy and Safety Clinical Investigation, Randomized, Multicenter, Double-Blind, Placebo-Controlled, Using Eculizumab in
Paroxysmal Nocturnal Hemoglobinuria
Hemolytic
transfusion
dependent
PNH patient
Observation–
qualifying
transfusion
Up to 3 months
Eculizumab
Placebo
R
6 months
Extension
Study
24+ months
TRIUMPH ENTRY CRITERIA
• Inclusion criteria:
– 18 years-of-age
– 4 episodes of transfusions in the previous 12 mos
– PNH type III erythrocyte population 10%
– Platelets 100,000/mm3
– LDH 1.5 times ULN
• Exclusion criteria:
– Transfused with Hb >10.5 g/dL in prior year
– Complement deficiency
– Active bacterial infection
– Prior meningococcal disease
– Pregnancy
TRIUMPH STUDY DESIGN
• Dosing schedule: iv infusion of eculizumab over 30 min
– Induction period
• 600 mg every 7±2 days for 4 doses
– Maintenance period
• 900 mg 1 week later, followed by…
• 900 mg every 14±2 days for a total of 26 weeks
• Concomitant medications:
– No change in immunosuppressant drugs, steroids, anti-clotting agents or hematinics
– Patients were vaccinated against Neisseria meningitidis
TRIUMPH ENDPOINTS
• Co-primary endpoints:– Stabilization of Hb levels: Hb value above the Hb set
point without transfusions for entire trial period– Units of PRBCs transfused
• Secondary endpoints:– Hemolysis: lactate dehydrogenase (LDH) AUC– Fatigue assessed via the FACIT-Fatigue instrument
• Exploratory endpoints:– QoL measures including fatigue (EORTC QLQ-C30)– Thrombosis
• Safety reporting
*Value at which each patient received a qualifying transfusion
TRIUMPH PATIENT RECRUITMENT
115 Assessed for eligibility
Allocation
Follow-up
Analysis
Excluded (28 patients)
• 6 Failed inclusion criteria
• 21 Failed observation period
• 1 Randomization error87 Randomized and
received treatment
Enrollment
43 Received eculizumab
2 Discontinued treatment
• 1 inconvenience of travel
• 1 pregnant
43 Analyzed
44 Received placebo
10 Discontinued treatment
• Lack of efficacy but
monitored for duration
of study
44 Analyzed
3/22/2016
4
EFFECT OF ECULIZUMAB ON HEMOLYSIS – LDH
0
500
1000
1500
2000
2500
3000
-4 -2 0 2 4 6 8 10 12 14 16 18 20 22 24 26
Study Week
Placebo
Eculizumab
LD
H (
IU/L
)
P<0.001
Normal
Screening
EFFECT OF ECULIZUMAB ON TRANSFUSIONS
0
2
4
6
8
10
12
0
2
4
6
8
10
12
Placebo Eculizumab
Pre- Trial Pre- Trial Pre- Trial Pre- Trial
Placebo Eculizumab
Median Transfusions Mean Transfusions
Co-Primary Endpoint (1)
P<0.001
EFFECT OF ECULIZUMAB ON STABILIZATION OF HEMOGLOBIN
LEVELSCo-Primary Endpoint (2)
0
10
20
30
40
50
60
Sta
bil
iza
tio
n o
f H
b,
% p
ati
en
ts
Placebo Eculizumab
P<0.001
EFFECT OF ECULIZUMAB ON TIME TO FIRST TRANSFUSION
P<0.001
Eculizumab
Placebo
Study Week
0 2 4 6 8 10 12 14 16 18 20 22 24 26
Pa
tie
nts
Avo
idin
g T
ran
sfu
sio
n,
%
0
10
20
30
40
50
60
70
80
90
100
44% Reduction
in PRBC Units
Transfused
51%
0%
EFFECT OF ECULIZUMAB ON QOL
*Mixed model analysis†5-10 point change is considered clinically meaningful
Osoba D et al. J Clin Oncol. 1998;16:139,
Brodsky RA et al, Blood 2008; 111:1840
Diarrhoea
Nausea/Vomiting
Constipation
Financial Difficulties
Insomnia
Appetite Loss
Dyspnoea
Pain
Fatigue
Emotional
Physical
Cognitive
Social
Role
Global Health Status
Fu
nc
tio
na
lS
ym
pto
ms
/Ite
ms
Eculizumab Placebo Difference†
-0.9
-3.2
-6.3
-10.3
-12.8
-13.6
-16.9
-17.6
-27.0
11.2
13.0
14.0
14.6
24.8
19.4
P Value*
Favors Eculizumab Favors Placebo
-40 -30 -20 -10 0 10 20 30 40
=0.008
<0.001
=0.002
=0.003
<0.001
<0.001
=0.147
=0.056
=0.199
=0.186
=0.014
<0.001
<0.001
=0.002
<0.001
5.74.8
2.8-0.4
0.0-6.3
0.0-10.3
4.9-7.9
3.3-10.3
8.9-7.9
5.3-12.3
10.0-16.9
-3.77.5
-3.59.4
-6.17.9
2.016.7
-6.917.9
-8.510.9
ECULIZUMAB: IMMUNOGENICITY:HAHA (HUMAN ANTI-HUMAN
ANTIBODIES)Timing Eculizumab Placebo
IgG First dose 0/42 (0%) 0/44 (0%)
Week 12 0/41 (0%) 0/44 (0%)
Week 26 1/39 (2.5%) 1/43 (2.3%)
IgM First dose 0/42 (0%) 0/44 (0%)
Week 12 0/41 (0%) 0/44 (0%)
Week 26 0/40 (0%) 0/44 (0%)
3/22/2016
5
EFFECT OF ECULIZUMAB ON
HEMOLYSIS – LDH
0
500
1000
1500
2000
2500
3000
-4 -2 0 2 4 6 8 10 12 14 16 18 20 22 24 26
Study Week
Placebo
Eculizumab
LD
H (
IU/L
)
P<0.001
Normal
Screening
EXTRAVASCULAR HEMOLYSIS IN PNH UNCOVERED BY
ECULIZUMAB TREATMENT
16
2003
LDH
14
12
10
8
6
4
450
300
200
150
100
0
400
K/u
L
50
250
350
g/d
L
2500
1500
1000
500
0
U/L
2000
Corticosteroids
50 20 mg Pregnancy
2u prbc
4u prbc
Eculizumab
2004 2005 20072006
Reticulocytes
Hemoglobin
ECULIZUMAB REDUCES
THROMBOSES IN PNH• Combined data from TRIUMPH, SHEPHERD, UK cohort, and
phase III extension study compared to pre-treatment events
• Pre-rx: 126 thrombotic events in 195 patients (103 on anticoagulation)
• TE events:
pre-rx = 7.5 vs post-rx = 1.22/100 patient years
(84% reduction)
Hillmen P et al, Blood, 2007
ECULIZUMAB (SOLIRIS) IN
PRACTICEAdvantages
Dramatically reduces intravascular hemolysis and related symptoms
(anemia and NO-induced)
May be effective in preventing thrombosis without bleeding risk
Well tolerated
Disadvantages
Expensive (!)
Risk of specific infections with Gram- cocci
Life-long infusions
Unmasked extravascular hemolysis in some cases
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