Current dementia research: a local perspective
Clive HolmesUniversity of Southampton
The amyloid cascade hypothesis
Amyloid plaques/ dimers
Tangles
Microglia
Environment and
Genetic variation
Neuronal cell lossNeurotransmitter
changesClive Holmes - BGS Spring 2009
Plaque preventionAnti-aggregants
Metallopeptidases
Vaccination
Secretase inhibition/ promotion
Clive Holmes - BGS Spring 2009
Immunization with amyloid-β attenuates Alzheimer-disease-like pathology in the PDAPP mouse SCHENK et al. Nature, 1999
control Aβ42
immunized at 6 weeks
Aged 13 months
immunized at 11 months
Aged 18 months
control Aβ42
Clive Holmes - BGS Spring 2009
Phase I Human trials• First study entrant April 2000 and last entrant Aug 2000
• Undertaken to test the safety, tolerability andimmunogenicity of aggregated human Aβ42 (AN-1792) plus QS-21
• Four study sites in UK (including Southampton) recruited 80 subjects
– Randomisation 4:1 active : placebo
• Neuropsychological testing– ADAS-cog, MMSE, ADCS-CGIC, DAD– Screening (-3 weeks), 32; 64; 84 weeks
Clive Holmes - BGS Spring 2009
Phase II study
• Larger European study (n= 372) – started Sept 2001 (before end of phase I)– 225μg AN1792 + 50 μg QS-21 + 0. 4%
polysorbate
• Study halted Jan 2002– 6% meningoencephalitis
Orgogozo et al 2003 Clive Holmes - BGS Spring 2009
Neuropathology of human Alzheimer’s disease following immunization with amyloid β-peptide : phase I study
Nicoll et al Nature Medicine 2003Clive Holmes - BGS Spring 2009
Aβ immunotherapy approaches
AN 1792
Conjugate
HumanmAb
1
2
3
Aβ42
Aβ fragmentsActive
immunization
Passive immunization
Clive Holmes - BGS Spring 2009
Immunisation approaches
Aβ1-40Aβ1-40PfizerAnti-Aβ aa 33-40PF04360365
Elan Anti-Aβ aa 1-5Bapineuzumab
LillyAnti-Aβ aa 13-28LY2062430
Novartis Anti-Aβ aa 1-6 CAD106 9 (Active)
Intravenous immunoglobulin (IVIg) Clive Holmes - BGS Spring 2009
Immunisation Clinical outcomes
Efficacy
Clive Holmes - BGS Spring 2009
ADAS cog change by amyloid dose
-21
-18
-15
-12
-9
-6
-3
0
3
Baseline Week 32 Week 64/5 Week 84 Final visit
Mea
n ch
ange
in A
DA
S co
g fr
om b
asel
ine
QS-21 AN 1792 (+QS-21)
Bayer et al Neurology 2005
Phase I AN1792 study
Clive Holmes - BGS Spring 2009
Timeline and patient disposition of the long term clinical and post mortem follow up of patients entering the AN1792 phase I study.
80 subjects enrolledinto phase 1 study
Phase 1 study completed
24 patients and/or carers refused
consent for clinical follow up.
20 patients dead at baseline
(2 post mortems)
36 patients and/or carers agree to
clinical follow up and /or pm
12 patients dead 12 patients alive 10 patients dead (7 post mortems) 26 patients alive
September 2000Treatment study
commenced
June 2002Treatment study
completed
June 2003Follow up study
commenced
September 2006Follow up study
completed
Holmes et al Lancet 2008
Clive Holmes - BGS Spring 2009
Kaplan-Meier estimates of survival time to
severe dementia by treatment group.
806040200
Months
1.0
0.8
0.6
0.4
0.2Prob
abili
ty o
f non
pro
gres
sion
to s
ever
e de
men
tia Placebo group
AN1792 treatment group
Log rank p = 0.73
Holmes et al Lancet 2008
Clive Holmes - BGS Spring 2009
Histological patterns of Aβ in the temporal lobe
neocortex after immunization with AN1792.
Holmes et al Lancet 2008
Clive Holmes - BGS Spring 2009
Immunisation approaches
Aβ1-40Aβ1-40PfizerAnti-Aβ aa 33-40PF04360365
Elan Anti-Aβ aa 1-5Bapineuzumab
LillyAnti-Aβ aa 13-28LY2062430
Novartis Anti-Aβ aa1-6 CAD106 9 (Active)
Intravenous immunoglobulin (IVIg) Clive Holmes - BGS Spring 2009
Bapineuzumab• Passive immunisation study (N= 234)
– 18 month study
• Double-blind, placebo-controlled multiple ascending dose trial in mild-to-moderate Alzheimer’s disease
• In the total study population, statistical significance was not obtained on the pre-specified efficacy endpoints of ADAS-cog and DAD but – post-hoc efficacy analyses in ApoE4 Non-Carrier Population
· ADAS-cog treatment difference of 5.0; p=0.026· NTB treatment difference of 0.35; p=0.006· CDR-SB treatment difference of 1.5; p=0.040
– Phase III study (n ~ 4,100)
ICAD Unpublished data 2008
Clive Holmes - BGS Spring 2009
Elan share prices
2008Clive Holmes - BGS Spring 2009
Immunisation Clinical outcomes
Side effect profile
Clive Holmes - BGS Spring 2009
Neuropathology of human Alzheimer’s disease following immunization with amyloid β-peptide : phase I study
Nicoll et al Nature Medicine 2003Clive Holmes - BGS Spring 2009
Histological patterns of Aβ in the temporal lobe
neocortex after immunization with AN1792.
Holmes et al Lancet 2008
Clive Holmes - BGS Spring 2009
CasescAD iAD
CasescAD iAD
0
2
4
6
Aβ 4
2
cAD
immunised AD
Parenchymal Aβ42
Vascular Aβ42
Parenchymal Aβ42
Vascular Aβ42
Parenchymal Aβ42
Vascular Aβ42
Control AD
Distribution of Aβ42 in parenchyma vs vasculature
Boche et al Brain 2008
Clive Holmes - BGS Spring 2009
LiverKidney
BBBBlood Brain
Mechanism of Action
Clive Holmes - BGS Spring 2009
LiverKidney
BBBBlood Brain
Mechanism of Action
Clive Holmes - BGS Spring 2009
MSI
/ 5
0 fi
elds
*
0
2
4
6
AD iAD PSP 2 1 3 4 6 7 9 8
Mic
rova
scul
arle
sion
s /
50 f
ield
s
Cases
0.0
0.2
0.4
0.6
AD iAD PSP 2 1 3 4 6 7 9 8
*
Microvascular lesions
Quantification of microhaemorrhages /microvascular lesions
Haemorrhage severity(Perls staining)
11.24 clusters per 50 fields in the severe CAA case represent 0.35% of the parenchyma.
H&E GFAP CD68
P = 0.021
P = 0.033
Boche et al Brain 2008
Clive Holmes - BGS Spring 2009
Immunisation approaches
Aβ1-40Aβ1-40PfizerAnti-Aβ aa 33-40PF04360365
Elan Anti-Aβ aa 1-5Bapineuzumab
LillyAnti-Aβ aa 13-28LY2062430
Novartis
Anti-Aβ aa 1-6
CAD 106
Intravenous immunoglobulin (IVIg) Clive Holmes - BGS Spring 2009
Immunisation approaches
Aβ1-40Aβ1-40Elan Anti-Aβ aa 1-5Bapineuzumab Vasogenic oedema in ~10% of ApoE e4
carriers
Clive Holmes - BGS Spring 2009
Will anti-amyloid therapies work?
• Prevention v.s. treatment?• What Aβ species is being targeted?• Is early onset AD different to late
onset AD?• Better understanding of the
molecular biology of Aβ immunisation
Clive Holmes - BGS Spring 2009
Acknowledgments• Delphine Boche • David Wilkinson • Ghasem Yadegarfar • Vivienne Hopkins • Anthony Bayer • Roy W Jones • Roger Bullock • Seth Love • James W Neal • Elina Zotova • Roy Weller• James AR Nicoll
• Alzheimer’s Research Trust and Medical Research Council for funding this study
• Thanks to: – all patients and carers taking part
in the study.– Elan Pharmaceuticals for access to
phase 1 AN1792 treatment study data
– J Gifford; Helen Cartwright; Carol Hall and other clinical research staff at Southampton, Cardiff, Swindon and Bath.
– Neuropathology laboratory staff; staff of the HistochemistryResearch Unit and Biomedical Imaging Unit at Southampton General Hospital.
– M Esiri and C Joachim at Oxford University.
Clive Holmes - BGS Spring 2009