Anticorpi monoclonali anti CD20 nella
terapia delle malattie ematologiche ed
autoimmuni:attualità e prospettive
Alessio P. Perrotti
Ematologia S.Eugenio
17 Giugno 2004
EHRLICH:1904
“… magic bullets “
• Kohler G, Milstein C:
“Continuous cultures fused
cells secreting antibody of
predefined specificity.”
Nature 1975; 256:495
Hybridoma Technology
B-cell:
Immunisation or
Infection
Myeloma cell:
Produces antibodies
cannot be cultured
in vitro for a long time
Humanisation
of antibody
No antibody
production.
Can be
cultured
indefinitely
Hybridoma cell:
Produces monoclonal antibodies
Can be cultured indefinitely
Monoclonal antibodies
human 1994–1999
…mumab
murine 1975
…momab
chimeric 1984
…ximab
Immunogenic
humanised 19881991
…zumab
Humanisation
Less immunogenic
Limiti degli anticorpi
monoclonali murini
• Immunogenicità
• Imperfetta attivazione dei
meccanismi della risposta immune
• Farmacocinetica non ottimale
Monoclonal antibodies
human 1994–1999
…mumab
murine 1975
…momab
chimeric 1984
…ximab
Immunogenic
humanised 19881991
…zumab
Humanisation
Less immunogenic
Major monoclonal antibodies used
in the treatment of lymphoma
Antibody
Antigen
Conjugate
Proven efficacy
Major references
Rituximab (MabThera,
Rituxan)
CD20
None
Follicular lymphoma
in relapse, DLCL in
combination with
chemotherapy
Maloney, Coiffier
Alemtuzumab (Campath)
CD52
None
Chronic lymphocytic
leukaemia
Keating, Lundin
Epratuzumab (Lymphocide)
CD22
None
In testing
Leonard
HLA-DR
None
In testing
Leonard
Ibritumomab tiuxetan
(Zevalin)
CD20
Y-90
Progression after
rituximab
Gordon, Witzig
Tositumomab (Bexxar)
CD20
I-131
Progression after
rituximab
Kaminski, Vose
Denileukin diftitox (Ontak)
IL-2R
Diphtheria
toxin
Mycosis fungoides
in relapse
Olsen
Hu1D10
RITUXIMAB
• Approvato
dalla FDA nel 1997 per il
trattamento dei linfomi a basso grado o
follicolari, recidivati o refrattari
• 300.000 pazienti trattati nel mondo
• All’Aprile 2003 approvato da 78 paesi
MabThera: structure
Chimeric anti-human CD20 monoclonal antibody
VH
C1
VL
C
Murine variable regions
Human constant  region
Human constant Fc region
Variable region: murine IgG1 kappa anti-CD20
Constant region: human IgG1 heavy chain and kappa light chain
L’antigene CD20: un bersaglio ideale
Antigene CD20
• >95% delle cellule dei linfomi B, ma
non delle cellule staminali
• Espressione stabile, no
modulazione o internalizzazione
Meccanismo di azione
• Citotossicità cellulo-mediata
anticorpo dipendente (ADCC )
• Citotossicità complemento
dipendente (CDC )
• Inibizione della crescita cellulare
• Induzione della apoptosi
• Sinergia con la chemioterapia
ADCC
NK,Mo,PMN
CR3
Sinergia
FcgR
Blocco della
Proliferazione
IL-10
iC3b
CDC
C1q
STAT3
Bcl-2
CD55
CD59
Apoptosi
Via
classica
INDICAZIONI EUROPEE PER
RITUXIMAB
• Linfoma Follicolare III-IV stadio
chemioresistente o in recidiva dopo
chemioterapia
• Linfoma non Hodgkin CD20+ diffuso a
grandi cellule B in associazione a
chemioterapia
The pivotal study
• 166 patients with relapsed or
refractory low-grade or follicular
lymphoma (FL)
• MabThera monotherapy (375 mg/m2,
once-weekly for 4 weeks)
• Non-bulky disease (<10 cm)
• At least 1 prior chemotherapy
McLaughlin P, J Clin Oncol 1998
Summary of results
ORR (%) CR (%)
Intent-totreat
n=161
Evaluable
n=151
PR (%)
48
6
42
50
6
44
 Median duration of response: 11.8 months
McLaughlin P, J Clin Oncol 1998
Grade 3-4 toxicities
Grade 3-4 toxicities are rare with
MabThera monotherapy
• Infusion-related reactions
• Cytopenia (1 or more lineages)
• Cardiac events
• Pulmonary events (BOOP)
• Infections
• Stevens-Johnson syndrome
• Abdominal pain
INDICAZIONI EUROPEE AL
RITUXIMAB
• Linfoma Follicolare III-IV stadio
chemioresistente o in recidiva dopo
chemioterapia
• Linfoma non Hodgkin CD20+ diffuso a
grandi cellule B in associazione a
chemioterapia
Rationale per associare
Rituximab e chemioterapia
• Efficacia dei singoli agenti
• Meccanismo d‘azione non-cross
resistente
• Tossicità non sovrapponibile
• Attività sinergica in vitro
• Sensibilizzazione del Rituximab ai
citotossici in vitro
GELA 98.5 trial:
response rates at end of treatment
Response rate (%)
80
CR + CRu = 76%
CR + CRu = 63%
CR
CRu
60
PR
40
SD
PD
20
0
p=0.005
Death
NE
R-CHOP
(n=202)
CHOP
(n=197)
Coiffier B et al. N Engl J Med 2002;346:235–42
LNH-98.5: median follow-up of 3 years
1.0
Event-free survival
Survival
1.0
0.8
0.8
0.6
R-CHOP
0.6
R-CHOP
0.4
0.4
CHOP
CHOP
0.2
0.2
0.0
0
0.0
0
1.0
2.0 3.0
Years
4.0
5.0
1.0
2.0 3.0
Years
4.0
5.0
Coiffier B et al. EHA 2003 (Abstract 356)
GELA 98.5 trial:
Events after 3-year median follow-up
70
Patients (%)
60
50
R-CHOP
CHOP
40
30
20
10
0
p=0.002
Coiffier B et al. EHA 2003 (Abstract 356)
Patologie autoimmuni: rationale per il
trattamento con Rituximab
La deplezione di linfociti B:
• riduce la produzione de novo di
anticorpi
• riduce il numero di cellule B
presentanti
l’antigene
e
la
conseguente attivazione di cellule T
coinvolte nei meccanismi autoimmuni
Disordini autoimmuni:trattamento
tradizionale
•
•
•
•
•
•
•
•
Corticosteroidi
Immunosoppressori
Chemioterapia
Splenectomia
…….ma
efficacia limitata
frequenti recidive
necessaria terapia di mantenimento
tossicità non trascurabile
Rituximab in non malignant disease:
22 investigator-sponsored trials (phase I/II
pilots)
Category
Diseases
N. of Trials
Autoimmune/
hematologic
ITP
AIHA
3
2
Rheumatologic
RA
SLE
2
3
Autoimmune/
neurologic
MG, MS
Polyneuropathy
MGUS neuropathy
GVHD
Dermatomyositis
Wagener’s, Antifactor VIII
2
1
2
2
1
2
Organ transplant rejection
solid tumor (with IL-2)
1
1
Autoimmune/
other
Other
Major monoclonal antibodies used
in the treatment of lymphoma
Antibody
Antigen
Conjugate
Proven efficacy
Major references
Rituximab (MabThera,
Rituxan)
CD20
None
Follicular lymphoma
in relapse, DLCL in
combination with
chemotherapy
Maloney, Coiffier
Alemtuzumab (Campath)
CD52
None
Chronic lymphocytic
leukaemia
Keating, Lundin
Epratuzumab (Lymphocide)
CD22
None
In testing
Leonard
HLA-DR
None
In testing
Leonard
Ibritumomab tiuxetan
(Zevalin)
CD20
Y-90
Progression after
rituximab
Gordon, Witzig
Tositumomab (Bexxar)
CD20
I-131
Progression after
rituximab
Kaminski, Vose
Denileukin diftitox (Ontak)
IL-2R
Diphtheria
toxin
Mycosis fungoides
in relapse
Olsen
Hu1D10
Radioimmunotherapy of NHL
•
Advantages of radiolabeled
antibodies in treating NHL:
– Lymphoma cells are
inherently sensitive to
radiotherapy
– Tumor cells distant from
the bound antibody can
be killed by ionizing
radiation from betaemitting isotopes,
important in bulky or
poorly vascularized
tumors
Choice of Isotope
• The higher beta energy and longer path length of yttrium-90
(90Y) make it a superior isotope for radioimmunotherapy
(RIT)
Property
131I
90
Y
131
I
Half-life
64 hours
192 hours
Energy emitter
Beta
(2.3 MeV)
Gamma (0.36 MeV)
Beta (0.6 MeV)
Path length
90 5.3 mm
90 0.8 mm
Urinary
excretion
Minimal
612% in 7
days
Extensive/variable
48–90% in 2 days
Based on
weight and
platelet count
Clearance-based
dosing using whole
body dosimetry
Outpatient
Inpatient or
restrictions to
protect
family/public
Dosing
Administration
RIT Produces a Crossfire Effect
Naked
antibody
Illidge et al. Br J Haematol 2000;108:679688
Radiolabelled
antibody
Zevalin® (90Y-Ibritumomab Tiuxetan) RIT

Monoclonal
antibody
Ibritumomab
– Murine monoclonal
antibody parent of
rituximab

Tiuxetan (MX-DTPA)
– Conjugated to
antibody, forming
strong urea-type bond
– Stable retention of
90Y
Chelator
90Y
radionuclide
Beta
radiation
Zevalin®: Indicazioni in USA
• Zevalin® è indicato per il
trattamento di pazienti adulti
affetti da Linfoma non Hodgkin
follicolare a cellule B CD20+
recidivato dopo Rituximab o
refrattario
The European Zevalin®
Treatment Regimen
Rituximab 250 mg/m2
Followed by Zevalin®
15 or 11 MBq
(0.4 or 0.3 mCi)/kg BW*;
max. dose 1200 MBq (32 mCi)
Rituximab 250 mg/m2
Day
1
2
3
4
5
6
7
8
*15
9
MBq (0.4 mCi)/kg body weight (BW) in patients with a platelet count  150,000/µl or
11 MBq (0.3 mCi)/kg BW in patients with a platelet count of 100,000 – < 150,000/µl.
The maximum dose is 1200 MBq (32 mCi). All MBq values are rounded up.
Response Rates in Zevalin® Trials
100
OR
CR
80
Response
rate
(%)
60
40
20
0
Phase III
Phase II
Rituximabrefractory
Witzig et al. Proc Am Soc Clin Oncol 2003;22:597, abstract 2400
Phase I/II
Follicular