Transcript TGN 1412 - Moodle Lille 2

February, the 16th 2007
A Clinical Trial
Disaster in UK
Laura BATIQUE,
Kelly BROWN,
Céline DELPLACE,
Bénédicte PALADINI,
& Pauline SALADIN
Introduction
The « TeGenero matter » in few words
Description


Clinical trial : phase 1
TGN 1412 : CD28 superagonist monoclonal
antibody
Role
Name
Location
Sponsor
TeGenero
Germany
Manufacturer
Boehringer
Ingelheim
Germany
Contract
Research
Organisation
Parexel
Northwick Park
Hospital, UK
What's happened ?
13th March 2006
Six healthy volunteers received TGN 1412 at Northwick Park Hospital
Phase 1 : Cytokine storm, lymphopenia, monocytopenia
Phase 2 : Reactive phase, multiorgan failure
Phase 3 : Recovery phase
Phase 4 : Steady state
PLAN







Part I : Media’s reaction
Part II : Scientific context & mechanism of action
Part III : Preclinical studies
Part IV : Transition to clinical development
Part V : Clinical trial
Part VI : Protagonist reaction
Part VII : Discussion
Part I : Media’s Reaction
MEDIA
Telegraph.co.uk
Media’s reaction
Some days after the trial


Violent Reaction to monoclonal antibody therapy
remains a Mystery (Science 15/03/06)
Tragic drug trial spotlights potent molecule (Nature 13/03/06 )

« There are a number questions that need answering […] what
happened […] monkeys were an appropriate animal
model to test […] TeGenero had tested the antibody on
human blood […] why Parexel did not leave a longer gap
between doses » (Pharmatimes 26/05/06)

British trial disaster casts doubts on testing guidelines
(Nature 01/04/06 )
What caused this event ?

Errors in manufacture, formulation or
administration?

Contamination with endotoxin, pyrogen,
microbiologic or other agents?

Mechanism of action?
Part II : Scientific context
& mechanism of action
Costimulation
of Lymphocyte T
The costimulation
T-Cell Costimulation — Biology, Therapeutic Potential, and Challenges Arlene H. Sharpe, M.D., Ph.D., and Abul K. Abbas, M.D.
Interaction with costimulary signals
booste immune response
induce tolerance
to enhance antimicrobial
response and antitumoral
response
to treat auto-immune
diseases and prevent graft
rejection
Improve the action of CD28
Inhibit the action of CD28
Inhibit the action of CTLA4
Improve the action of CTLA4
The first target:
CTLA4
Abatacept Orencia®
Ipilimumab and ticilimumab
In this context of « sucessful » development of drugs
targeting costimulary molecules, a new mecanism has
been found.
The second target:
CD28
What is a superagonist antibody?
 The first indication: leukemia
 The second indication: autoimmune diseases
 Risks of TGN1412

TGN 1412
CD 28 superagonist antibody
Humanized
 Ig G 4
 Superagonist : no costimulation

TCR
CD28
T cell
The first indication:
chronic lymphocytic
leukemia
What is chronic lymphocytic
leukemia?

Accumulation of
leukemic B cells

T cell abnormalities
Increase the risk of
infection
Tolerance versus leukemic
B cells: hamper the
recognition and elimination
of leukemic B cells
How does TGN1412 work?
T-cell
Activation of T cells
stoppes the
tolerance to the
leukemic B cells
CD3
TCR
CD4/CD8
CD28
CD28
Superagonist
T-cell
Signals
Costimulatory
Signals
Elimination of leukemic B cells
The second indication:
autoimmune diseases
Auto-immune diseases
Generation of self-reactive T cells
Regulatory T cells are not efficients
How does a CD28
superagonist work?
What are regulatory T cells?
Theoric effect of TGN1412 on the Treg
Production of regulatory T cells (Treg)
In the Thymus
T-cell
Thymic cell
Immunologic Synapse
Self antigen
CD3
MHC
TCR
T-cell
Signals
CD4/CD8
Costimulatory
Molecules
LFA-3
CD40
B7
CD2
CD40L
CD28
Costimulatory
Signals
Regulatory T cells are autoreactives
Regulatory T cells are autoreactives
Autoimmune process
Lesion of tissue
Self-antigen are released
APCs collect the self-antigen
presentation of the self-antigen to the Treg
Activation of Treg
Suppressive activity on the others T cells
Functional capacities of Tregs:
a suppression mediated by cell-to-cell contact
Autoimmunity: Basic Mechanisms and Implications in Endocrine Diseases Part II S. Ballotti F. Chiarelli M. de
Martino Department of Paediatrics, Anna Meyer Children’s Hospital, University of Florence, Florence , and
Department of Paediatrics, University of Chieti, Chieti , Italy
Effect of TGN1412
Activation of regulatory
T cells (Treg)
T-cell
CD3
TCR
T-cell
Signals
CD4
CD25
Costimulatory
Signals
CD28
CD28
Superagonist
activation of Treg
Risks of a CD28
superagonist
Presence of CD28 molecules

CD 28 is present at surface of CD4+ T
cells: Treg and others lymphocytes T4

CD28 is present on the half of
lymphocytes CD8+ and granulocytes
Selectivity of TGN 1412 ????????
Controlled activation of the cells
Establishing risk of human experimentation with drugs: lessons from TGN 1412; M J H Kenter, A F Cohen; the lancet; october 2006
Superagonist
Antibodies ?
 C’’D loop
 X-ray cristallographic analyses
 Agonistic anti-CD28 monoclonal abs:
 bind exclusively to a specific part of the CD 28
molecule: the laterally exposed C’’D loop of the Iglike extracellular domain of CD 28
Specificity closely correlated
with the superagonistic activity
of anti-CD28 antibodies
CD 28 with 5.11A1
 X ray cristallographic structure
(3D model: extracellular part of human CD28)
MYPPPY motif (aa 99- 104) for B7 binding (natural ligand)
Adjacent aa 98 residue for binding of conventional CD28-specific mAb
C’’D loop (aa 60-65) for the binding of superagonistic CD28-specific mAb
Topological Requirements and Signaling Properties of T Cell–activating, Anti-CD28 Antibody Superagonists
Fred Lühder,Yun Huang,Kevin M
Part III :
Preclinical Studies
(Toxicology)
 1.Rodent: rat
 2.Non human primate: monkey
1.Toxicology
On Rats
Preclinical On Rats

Presentation of molecules

Trials on healthy rats in vivo

Trials on unwell rats in vivo
Presentation of molecules
←
Monoclonal antibody
anti-humanCD28
←
Domaine
antiCD28
humain obtenu
à partir du rat
Domaine
constante
humain
CD28 rat defers by 68% with CD28 human :
Need of a Ab anti-CD28
specific for the rat : JJ316
Trials on healthy rats

The 2 phenotypes of CD4+Tcells

Identification of regulatory Tcells (Treg)

JJ316’s action on CD4+Tcells
 The phenotypes
2 phenotypes are possible for CD4+Tcells :
CD25+ ou CD25-
Experiment :
- isolation of Tcells lymph nodes from Lewis
rats
- marking : CD4+ with CFSE
CD25+ with anti-CD25 mAb
Observation : flow cytometric
CD4
CD25
 Identification of Treg
Experiment :
- Western Blot and flow cytometric
- detection of FOXP3 on the Treg
Observation : FOXP3 is only expressed on
CD25+
Conclusion : Treg’s phenotype is : CD4+CD25+
CD25+
CD25-
FoxP3 is an intracells marker,
specific of Tregcells
BUT, we need an extracells
marker to appreciate the rate of
cells !
→ CD25+
Pb : CD25+ not specific of Treg
↑ of Treg, but maybe other cells
 Ab’s action
Aim : to quantify the JJ316’s action
Experiment :
- injections of several JJ316 or MOPC-31C
dosages to Lewis rats (0.1 à 1mg/kg)
- isolation of lymph node and spleen
- flow cytometric
JJ316 ↑ both cells
Conclusion :
- 0.1 mg : significant ↑ of Treg
- 1 mg
: significant ↑ of Treg and Tconv
a low-dose of the JJ316 is
sufficient for increasing Treg
without increasing Tconv
 Abstract
 Identification of different CD4+ Tcells
(due to their phenotype) : Treg and Tconv
 To show clearly the selective ↑ of Treg
with dosage ≤ 0.3 mg/kg of JJ316
So don’t make mistakes in doses !
Trials on unwell rats
Experiment : determination of the DME
- treatment of rats with different doses :
0.03 / 0.1 / 0.3 mg/kg of JJ316
- evaluation of clinical symptoms
The weakest
clinical
symptoms is
obtained with
0.3 mg/kg
 Abstract
 Preferential ↑ of Treg at low-dose (0.1-0.3)
 Moreover : Treg ↑ IL10
Teff ↓ IL2 and IL4
No Problem concerning the rats
2.Toxicology On
Monkeys and Limits
 In vitro & Failure in Investigator’s brochure
 In vivo
 Pharmacokinetics & Toxicokinetics
In vitro: animal and human cells
 Total Peripheral Blood Mononuclear Cells (PBMC)
 Anti-human CD28 agonistics:
- 5.11A1 = parental antibody (TGN 1412: humanised
version of the mouse antibody 5.11A1)
- TGN 1112 (IgG1 variant)
- TGN 1412 ( IgG4)
Share specificity-function relations: C’’D loop
Non-Human primates:
Rhesus monkey
Cynomolgus monkey
Marmoset monkey
Selection of appropriate species
 Safety and toxicology studies
TGN 1412 reactive with human,
cynomolgus, rhesus T cells
 Failure in Investigator’s brochure
 No comparison result: activation of human/monkey PBMC
However, stimulation of Cynomolgus macaques and human PBMC
with TGN 1412:
Dose of TGN 1412 given to volunteers = close to
the maximum immunostimulatory dose
 Investigator: 100% identity between human and monkey
CD28 sequences
But no sequence comparison !
In fact some differences:
Comparison of the human and rhesus monkey CD 28 aminoacid sequences:
*
Establishing risk of human experimentation with drugs: lessons from TGN 1412; M J H Kenter, A F Cohen; the lancet; october 2006
C’’D loop:
Non conservative variation at position 65 in rhesus monkey
TGN 1412  different bindings
 different T cells activation
Amino acid
sequences homology
(C’’D loop)
Human
Cynomolgus
identical
Rhesus
Differs in 1 aa
Marmoset
30%
 Failure in Investigator’s brochure
 No test done to demonstrate identity CD28
sequences between cynomolgus monkeys and
humans
 No comparison between rhesus, cynomolgus
monkeys and human CD28 sequences
 No comparison: affinity of TGN 1412 on human and
monkey CD28
In vivo: animal models
 Rhesus monkey:
- TGN 1112  Activation and expansion of Tcells
- TGN 1412  significantly weaker pharmaceutical activity
 Cynomolgus monkey:
- TGN 1412  Activation and expansion of T cells
- Studies conducted in this monkey!
No comparison result between the
action of TGN 1412/TGN 1112 !!
Pharmacokinetics and Toxicokinetics
 Cynomolgus monkey: the most predictive
 Repeat-dose toxicity study:
- IV
- 5 up to 50mg/kg
 TGN 1412 : well tolerated up to 50mg/kg/week
 50mg/kg = NOAEL (No-Observed-Adverse-Effect Level)
 Half life = 8 days
 Full removal = 1 month
Part IV : Transition to Clinical
Development of TGN 1412
 Differences between mouse/rat models & humans
 Affinity differences between antibodies
 Use of healthy volunteers
 Dose calculation
Differences between
mouse/rat models and humans
Preclinical studies (mice) :
Work in pathogen-free conditions
 majority of naive T cells
Humans :
Microbe-rich natural habitat
 majority of memory T cells
 Activation of memory easier than naive T cells
 TGN 1412 : In humans, widespread immune activation not in mice
Affinity Differences between
Antibodies
 Differents Abs: JJ 316 # TGN 1112 # TGN 1412 # 5.11A1
 Pharmacological activity in rhesus monkey:
TGN 1412 << TGN 1112
 Anti-Human-CD28 Ab:
- weak agonist in monkeys
- Strong agonist in humans
 Stimulation of T cells: in humans >> in primates
 Target: (sub)epitopes probably present only in humans
Why did the compagny choose
healthy volunteers?
 No adverse effects in healthy animals
 No pre-activation or dysfunction of T cells
 No pre-existing imbalance: Tconv/Treg cells
 Homogenous population:
 No impact of pre/co-medication and/or disease activity
No interference with interpretation of
TGN 1412 safety and pharmacology
Choice of patients would be better!
 Case by case
 Pharmacokinetic (mAb):
 TGN 1412: Highly specific
 antigen dose
 pathological state
Target epitopes
Mechanism of action
 Responses of immune system: healthy volunteers # patients
A lack of information!!
Treatment targets immune system
How was the starting dose
calculated?
NOAEL 3,1
=
50mg/kg
HED =
16mg/kg
Human Equivalent Dose
10 (safety)
MSRD =
1,6mg/kg
+ Safety margin
Starting
dose =
0,1mg/kg
Maximum
Recommended
Starting Dose
 Normally ensure maximum patient safety
What precautions should have
been done ?
« MABEL » Minimal Anticipated Biological Effect Level
2,5
Cynomolgus
Rhesus
monkeys
pharmacological
activity
0,3
healthy &
arthritic
rats
25
MABEL
NOEL
If MABEL = 0,5mg/kg
1
5
50
?
mg/kg
NOAEL
mg/kg
optimal pharmacological
responses
+Safety criteria
(CPMP)
Safe starting dose
= 0,005mg/kg!!
Calculated receptor occupancy
with TGN 1412
 Example of receptor occupancy versus local concentration:
Dose
(mg/kg)
Receptor
occupancy
(%)
0,0001
0,6
0,001
5,9
0,01
38,4
0,1
86,2
1
98,4
10
99,8
Initial dose:
very high occupancy of CD28 receptors
likely to achieve maximum pharmacological effect
Part V : Clinical
Development
Trial protocol
 Adverse effects observed
 Consequences
 Failure in the protocol

Trial Protocol
Design of trial









Single-centre
Double-blind
Randomized
Placebo-controlled
4 groups of 8 healthy young male volunteers planned
Administration : single doses intravenously
Dosing range : 0.1, 0.5, 2.0 and 5.0 mg/kg BW
Dosing time : 8 to 10 a.m
First day : 13th March 2006
Volunteers



No notable medical history
Informed consent
£2000 fees + £30 per visit
First group of eight volunteers :
 19 – 34 years old
 Six received active agent
 Two received placebo
Objectives of trial
Primary :
 Assessment of the safety & tolerability
 Determination of the pharmacokinetics
Secondary :
 Determination of the effect on lymphocyte
subsets
 Assessment of the cytokine profile
 Assessment of anti-TGN1412 antibodies
Approval
 27th January 2006 : Authorization by the
Medicines and Healthcare products Regulatory
Agency (MHRA)
 14th February 2006 : Favourable opinion by the
Brent Medical Ethics Committee
Adverse Events
observed
Main adverse events
13th March 2006
8 to 9 a.m
TGN infusion
0.1 mg/kg
Desquamation, peripheral ischemia
Multiorgan failure
1h
1h30
12 to 16h
Severe headache
24h
2 days
Several months after the
event : inability to
Lymphopenia
Pulmonary infiltrates
Renal failure
Disseminated intravascular
coagulation
30 days
Admittance to
the intensive
care unit
Cytokine release syndrome
Respiratory distress
10 days
Monocytopenia
concentrate, headaches, loss
of fingers & toes.
Cytokine release syndrome
TNF α
IFN γ
IL-2
Source: EXPERT SCIENTIFIC GROUP ON PHASE ONE CLINICAL TRIALS
(20th July 2006)
Common
features
Striking phenomenon
=
Stereotypical response
• in all six patients
• in all organ systems affected
Source : www.nejm.org (September 7,2006)
Lymphopenia & monocytopenia
Blood level evolution of monocytes & lymphocytes
2
Blood level mean (x10 9/L)
1,8
1,86
1,6
1,4
1,2
M onocytes
Lymphocytes
1
0,8
0,6
0,4
0,26
0,06
0,2
0,03
0,04
0,03
0
Before infusion
8 hours after infusion
Tim e
16 hours after infusion
Consequences
Treatment

Initial : vasoconstrictor, analgesics, hydrocortisone

In Critical Care :







Ventilation
Hemodiafiltration
Hydrocortisone followed by methylprednisolone IV
Daclizumab
Treatments for infections/viral reactivation
Freshfrozen plasma & cryoprecipitate
Irradiated red cells & platelets
Measures taken by MHRA
Incidents reported to the MHRA on the afternoon of 14th March
The MHRA :




Immediately suspended the authorization
Confirmed that the drug was not in use in any other trial
Alerted international drug regulatory authorities
Sent a team of inspectors to the unit in Northwick Park
MHRA = The Medicines and Healthcare products Regulatory Agency
Failure in the
Protocol
Doses administered and timing
Subjects
1
2
3
4
5
6
Body weight (kg)
84.3
68.9
88.5
82.4
72.1
81.8
Dosing TGN 1412 8.4mg 6.8mg 8.8mg 8.2mg 7.2mg 8.2mg
Dosing time
08:00
08:20 08:30 08:40 08:50 09:00
Source: EXPERT SCIENTIFIC GROUP ON PHASE ONE CLINICAL TRIALS (20th July 2006)
Comments




Authorization by MHRA
All subjects are dosed at the same session
 Staff insufficient
Two placebo
 Two sessions ?
Subjects were dosed at ~ 10 minute intervals
 ↑ intervals ?
BUT longer therefore more expensive ?
Part VI : Protagonist
Reaction
Boehringer Ingelheim
 Parexel
 TeGenero

Boehringer Ingelheim

Sorry for the patients of trial

Contract manufacturer, the material for
investigational use only
Conformed to GMP
No contamination


Parexel

Sorry for the patients of clinical trial


To assist the pharmaceutical, biotech, and medical
device industries
Investigator
No deficiency during inspection by MHRA
Good practices and policies and procedures

MHRA confirmed the approved protocole

Te Genero’s Team





Sorry for trial patients, their family
« Develop innovative treatment to help millions
of people »
« Side effects could have been caused by one of
our products »
MHRA agreement for protocole used
« No sign of risk from preclinical test »
The victims

Tom Edward: lucky escape from trial
Myfanwy
Marshall’s boyfriend
Ryan Flanagan: 21, a student from Highbury
Ryan Wilson: 20, the most seriously ill
The consequences
 Ryan Wilson: 20, the most seriously ill
• Heads and bodies swelled up
• He was suffering from heart, liver and kidney
failure, pneumonia and septicaemia.
• Development gangrene
on his fingers
• Risk infections and cancer
Amputation parts
Indemnities
Phase I
Accident
13 March
April 2006
2007
2 900€
7 500€
15 000€
Before
safety
trial
Each of the
victims
(Tegenero)
No
condition
For accepting a no
fault agreement
Rejected by
victim’s lawyers
Process indemnity in
progress
Part VII : Discussion
Solutions to find
ESG’S Objectives (20/12/06)
To put in position new
recommendations to OPTIMISE
the SECURITY of Clinical Trials’Phase I
Recommendations

Characterisation of new agents’risks and
Harmonisation between all authorities

Choice of preclinical and clinical models

Doses’schema
 Wider approach for doses : the MABEL
 Staff & Environment
 Better communication for intra and intertests

Creation of the EAG

Time-Scale

Creation of Specialised Centres

Creation of Specialist Centres
Conclusion
TeGenero’s bankcruptcy
Catastrophic
safety trial
March
2006
13 March
Tegenero
Need result
Obtain
money by
Investors
To file for
Involvency
April
2006
Victim’s
indemnisation
3 000 000€
Insurance
4 July
2006
Need to attract the
investment
Impossible
Negative
attention
Bankcruptcy
December
2006
Anonymous
investor wants to
buy TeGenero
CONCLUSION

Could this disaster have been avoided?
Yes

The culpables & sanctions
In process

The lessons to remember:
Need changing and
Hardening of the system
More controls
Merci de votre
attention
Powerpoint bonus
abatacept Orencia®
soluble fraction of CTLA4 + Ig G Fc region
Fixation on B7 on peripheral
antigen-presenting cells
HLA
TCR
CD28 can’t interact with
B7 anymore
B7
abatacept CD28
Peripheral antigenpresenting cell
T cell
inhibition of the
activation of the T cells
Approved in 2005 for the treatment of rheumatoid arthritis and
in development for other indications
Adverse events:



Phase 4 trial:
One year, randomized, multicenter, double-blind, placebo-controlled
trial
Serious infections were more frequent in the abatacept group than in
the placebo group (2.9% versus 1.9%).
Safety of the selective costimulation modulator abatacept in rheumatoid arthritis patients receiving
background biologic and nonbiologic disease-modifying antirheumatic drugs: A one-year randomized,
placebo-controlled studyM. Weinblatt 1 *, B. Combe 2, A. Covucci 3, R. Aranda 3, J. C. Becker 3, E. Keystone 4
Antibody anti-CTLA4:
ipilimumab, ticilimumab
Blocking antibody anti-CTLA4:
No interaction between B7CTLA4
HLA
TCR
Promotes interaction
between B7-CD28 (and
HLA-TCR)
CTLA4
B7
CD28
antigen-presenting cell APC
T cell
Lenghtens the T cells
activation
Currently in development for the treatment of tumoral
disease
Efficacy of a human anti-CTLA4
antibody + IL2: a phase 1/2 study
Patients: metastatic melanoma
Treatments:
36 patients received injection of
ipilumimab at differents doses every 3
weeks
All patients received IL2 therapy
Efficacy:
8 patients (22%) experiences positive
response
6 of the 8 have ongoing the response at 11
to 19 months
Tumor regression and autoimmunity in patients treated with cytotoxic T lymphocyte-associated antigen
4 blockade and interleukin 2: a phase I/II study.
Ann Surg Oncol. 2005 Dec;12(12):1005-16. Epub 2005 Oct 21
Adverse effects
5 patients (14%) developed
autoimmune toxicities secondary to
anti-CTLA4 administration:
- 4 with enterocolitis
- 1 with arthritis and uveitis
Edema and ulcerations in the
descending colon of a patient
Tumor regression and autoimmunity in patients treated with cytotoxic T lymphocyte-associated antigen 4 blockade
and interleukin 2: a phase I/II study.
Ann Surg Oncol. 2005 Dec;12(12):1005-16. Epub 2005 Oct 21