Monoclonal antibodies in oncology: the limits of success Clara Natoli, M.D. Università G. d’Annunzio Chieti - Pescara Chieti - Pescara Monoclonal antibodies

Monoclonal antibodies in oncology:

the limits of success

Clara Natoli, M.D.Clara Natoli, M.D.Università G. d’AnnunzioUniversità G. d’Annunzio

Chieti - PescaraChieti - Pescara

History of monoclonal antibodies

1975 Kohler and Milstein develop the hybridoma method of murine antibody production

1984 Chimeric antibodies are first reported

1986 The first mAb reaches the market, Orthoclone OKT3

1986 Humanized antibodies are first reported

1997 1997 Rituximab is approved for non-Hodgkin Rituximab is approved for non-Hodgkin lymphoma lymphoma

2002 Tiuxetan, tiuxetan, the first radionuclide conjugated mAb is launched for non-Hodgkin lymphoma non-Hodgkin lymphoma

Recombinant production of human mAbs

Transgenic MouseTransgenic MouseTransgenic MouseTransgenic Mouse

Wayne A Marasco & Jianhua Sui Nature Biotechnology 25, 1421 - 1434 (2007)

Adalimumabα-TNF

Phage display Phage display strategies strategies

PanitumumaPanitumumabbOfatumumabOfatumumabα-DC20DC20

Creation of Fully Human mAbs From Transgenic Mouse - Xenomouse

Weiner LM. J Immunother. 2006;29:1-9. Yang X-D, et al. Crit Rev Oncol Hematol. 2001;38:17-23.

Mouse strain incapable ofproducing mouse antibodies

Breeding

BreedingMouse embryonic stem cells containing human antibody genes

Mouse strain producinghuman and mouse antibodies

Mouse embryonic stem cells with inactivated mouse heavy and light chain loci

Mouse strain producingonly human antibodies

Mouse embryonic stem cells

FDA/EMEA approved mAbs as cancer therapeuticsFDA/EMEA approved mAbs as cancer therapeutics

Mab nameMab name Cancer Approved in Cancer Approved in

1. Rituximab1. Rituximab non-Hodgkin lymphoma non-Hodgkin lymphoma 199719972. 2. TrastuzumabTrastuzumab breast cancer breast cancer 199819983. Gemtuzumab/ 3. Gemtuzumab/ ozogamicin ozogamicin acute myelogenous leukemia acute myelogenous leukemia 200020004. Alemtuzumab 4. Alemtuzumab chronic lymphocytic leukemia chronic lymphocytic leukemia 200120015. Ibritumomab/5. Ibritumomab/ tiuxetan tiuxetan non-Hodgkin lymphoma non-Hodgkin lymphoma 200220026. Tositumomab6. Tositumomab non-Hodgkin lymphoma non-Hodgkin lymphoma 200320037. 7. Cetuximab Cetuximab colorectal cancer colorectal cancer 2004 2004

head & neck cancers head & neck cancers 200620068. 8. Bevacizumab Bevacizumab colorectal cancercolorectal cancer 20042004

non-small cell lung cancernon-small cell lung cancer 20062006breast cancerbreast cancer 20082008glioblastomaglioblastoma 20092009kidney cancer kidney cancer 20092009

9. 9. Panitumumab Panitumumab colorectal cancer colorectal cancer 20062006

10. Ofatumumab 10. Ofatumumab chronic lymphocytic leukemiachronic lymphocytic leukemia 20092009

2010: Denosumab and Ipilimumab waiting FDA Review & Approval

… why so few mAbs are available for cancer therapy?

Source: Tufts Center for the Study of Drug Development

Phase III trial failures are becoming more frequent. The average R&D time from

discovery to marketing is ~ 8 years for mAbs.

Zalutumumab (α-EGFR) in a randomized Phase III trials in 286 refractory Head and Neck cancer patients with best supportive care failed to show improved median survival, the primary end point.

In early 2010, it has been announced the failure of Avastin to show efficacy in Phase III trials in prostate and gastric cancer.

Figitumumab (α-IGFR1) failed to show clear efficacy in Phase III trials in non small cell lung cancer.

In late 2009 it has been terminated the Phase III trials of Lumiliximab (α-CD23, primatized mAbs) in chronic lymphocytic leukemia CLL patients due to lack of efficacy.

Mapatumumab mimics the action of TRAIL by binding to the TRAIL receptor and induces cell death. Phase II trials with mapatumumab in NSCLC in combination with paclitaxel and carboplatin failed to show any additional benefit in response rate or progression free survival from the control group.

... strategies to improve efficacy of mAbs

Patient Selection

Biomarker(s) forthe intended mAb

Responders

Non Responders

Biochemical Mechanisms of Biochemical Mechanisms of Resistance! Resistance!

… technical barriers that have slowed their development …

mAbs: technical barriers

immunogenicity inability to deliver mAbs to the tumour production



Unwanted Immunogenicity of the mAbs

Human abs anti-mAbs

induce induce adverseadverseeffectseffects-anaphylactic

reactions/delayed hypersensitivity-

alteralterpharmaco-pharmaco-kinetics and kinetics and bioavailabilitbioavailabilit

yy

neutralize neutralize biologicalbiological

effects and effects and compromisecompromisefurther mAb-further mAb-

therapytherapy

no effect

are xenoproteins

Unwanted Immunogenicity of the mAbs

EMEA“GUIDELINE ON DEVELOPMENT, PRODUCTION, CHARACTERISATION

ANDSPECIFICATIONS FOR MONOCLONAL ANTIBODIES AND RELATED

PRODUCTS”

… the risk of inducing antibody responses in patients should be carefully considered … when potentially immunogenic epitopes are identified in the structure, as it may result in clinical adverse reactions and/or modify the therapeutic potential …

FDA

… the screening assays for monitoring the development of HAHA responses should be sensitive enough to detect low titre antibodies as well as Abs to conformational and linear epitopes…

2009



mAbs: poor tissue penetration

Supply Flux Consumption

Mw

Extracellular matrix components

Interstitialpressure

Binding affinityAntigen levels and

distribution

Sequestration

Tumor bloodflow



Pharmaceutical antibodies

Development and registration (D&R) of new drugs takes many years and huge investments

Pharmaceutical antibodies are produced in high tech facilities under strict “Good Manufacturing Practices”

Fully human antibodies

PRO:- easier penetration of tissues, particularly of solid tumors- better clearance- easier to produce, less costly- flexibility in structureCONS:- faster degradation, less stable- shorter circulating half-lives- lack of effector functions

Trends in Therapeutic mAbs Development

recombinant recombinant antibody fragmentsantibody fragments

Recombinant antibody fragments

Fab

IgG

Fv

Fc

Hinge region

CH2

CH3

150 KDa

CH1 CL

VH

VL

IgG CH2


scFv-Fc

Fab

IgG

Fv

Fc

Hinge region

CH2

CH3

150 KDa

CH1 CL

VH

VL

Fab

IgG

Fv

Fc

Hinge region

CH2

CH3

150 KDa

CH1 CL

VH

VL


Minibody 100 KDa


Fab

IgG

Fv

Fc

IgG

Anti-XYAnti-XX

Fc

Bispecific Trifunctional mAb

“An antibody which behaves like a man with a wife and a mistress”

Rev. Med. Virol. 2009; 19: 181–183

Ep-CamEp-Cam

Tumor cellsTumor cells

T cellsT cells

CD3CD3

Accessory Accessory cellcell(macrophage, dendritic (macrophage, dendritic

cell, NK cell…)cell, NK cell…)

FcFcγγ receptor receptor I/IIII/III

Cytokine activation andcoreceptor activationPhagocytosis and

antibody dependentcellular citotoxicity

Porin mediated lysis

Catumaxomab (Removab®)

EMEA market approval for the intraperitoneal treatment of malignant ascites in patients with EpCAM-positive carcinomas in

2009

rat/mouse hybrid molecule !

Fab 55 KDa


Fv

Fc

VH

IgG 150 KDa

Fab

50 KDaRanibizumab(Lucentis©)

Certolizumab pegol(α-TNF, Cimzia©)


Fv

Fc

VH

IgG 150 KDa

Fab

50 KDa

VH

F(ab’)2 110 KDa F(ab’)3 165 KDa

Bispecific trivalentF(ab’)3

Pretargeted radioimmunotherapy (PT-RAIT)tested in nude mice with Ramos B-cell lymphomas

Tumor targeting

Urinaryexcretion

Rapid tumor

targeting

90Y-DOTA-HSG Tumor

two Fabs αCD20 and one Fab α-histamine -succinyl-glycine (HSG)

Clear naturally from bloodαCD20αCD20

αHSG

CD20

SHARKEY R. M. et al, 2008

24h 24h laterlater

Domain VH – 15 KDa

Domain VL - 15 KDa

IgG

FvFab

Fc


VH scFv 28 KDa

CytosolCytosol

NucleusNucleus

IntrabodyIntracellulIntracellul

ararLocalizatiLocalizati

ononDomainDomain

Fvs

Fv

Fc

VH

IgG

Fab


Flexibody

Tandem antibody“TandAb”

Triabody 75 KDa Tetrabody 100 KDa

Diabody 55 KDa

Monospecific


Bispecific

Diabody

Fv

Fc

VH

IgG 150 KDa

Fab

50 KDa

Cancer Research 69, 4941, June 15, 2009

Bite® - Bi-specific T-cell Engagers

Target

cell

T cell

Cytotoxic granules

CD3

CEA

Tumor cell lysis

anti-CD3

anti- CEA

BiTE®bispecificdiabody

Fv

Fv

T cell

Bite® - Blinatumomab –

Anti - CD19expressed on malignant and normal B cells

Anti - CD3

Phase I study in NHL patients Phase II study in ALL patients with residual tumor cells in bone marrow Short serum half life and so continuous intravenous infusion by portable mini-pumps is required

CONCLUSIONS

Recombinant antibody fragments:

are small molecules have the potential for extended therapeutic benefits have simple, high yielding production processes lower manufacturing costs

Polyclonal Antibodies

Murine monoclonal antibodies

Chimeric antibodies

Humanized antibodies

Fully human antibodies

Fully human polyclonal antibodies!


Documents

Monoclonal antibodies in oncology: the limits of success Clara Natoli, M.D. Università G. d’Annunzio Chieti - Pescara Chieti - Pescara Monoclonal antibodies