Neuroprotection in neurology: why is it so difficult? Speaker: Lorenz Hirt Univeristé de Lausanne

1. Neuroprotection
in neurology:
why is it so
difficult?
Swiss MS Society State of the Art
Symposium, Lucerne 2014
Lorenz Hirt

2. Neuroprotection
• Strategy to protect neurons
• To prevent them from dying
• To preserve their function

3. Neuronal death in Neurology
• Single damaging event
• Recurring damaging
events
• Continuous injury
Degeneration
• Stroke, TBI
• Recurrent stroke
Recurrent TBI
• Relapsing-remitt. MS
• Neurodegenerative
disorders
Primary progressive MS

4. Ischemic core and penumbra
Ischemic stroke, right middle cerebral artery territory
Perfusion-­‐CT,
2h
a2er
symptom
onset
CT,
2h
a2er
symptom
onset

5. ACA
MCA
PCA
ECA
MCA
PCA
ICA
BA
Mike O'Neill, Lilly
Middle cerebral artery occlusion (MCAO) model in the
mouse
Zoomof ÒVM H3-5Ó
25:0016:408:200
0
20
40
60
80
100
120

6. Mechanisms of cell death in
Ischemic penumbra
• Excitotoxicity
• Peri-infarct depolarisation
• Apoptosis
• Inflammation
– Numerous cellular mechanisms and
molecular pathways involved
Dirnagl
&
al
1999

7. Neuroprotection in cerebral
ischemia ?
• Can cell death mechanisms be targeted
directly ?
• Stroke: Restoring blood flow protects
• NINDS study / ECASS-3: rtPA i.v. within 4.5h
from symptom onset improves the functional
outcome at 3 months
• Indirect neuroprotection (effect on blood flow)
• Hypothermia protects the ischemic brain in
cardiac arrest (Holzer & al NEJM 2002; Bernard & al, NEJM 2002)
and neonatal hypoxic ischemic
encephalopathy (Jacobs & al 2007)

8. Strategies targeting cell death
mechanisms ?
• Not all patients qualify for thrombolysis /
recanalisation therapies (10%)
• Not all patients benefit sufficiently
• Time-window

9. Experimental approaches
• More than 1000 potential neuroprotective strategies tested
Dirnagl
&
al
1999
NEUROPROTECTION

10. STAIR recommendations
Stroke, 1999
• Stroke therapy academic industry roundtable
• Recommendations for preclinical trials
• Randomised & blinded
• Physiological parameters (CBF,
temperature, BP, blood gases,
adverse reactions)
• 2 models or more
• Both permanent and transient
ischemia
• 2 independent labs ore more
• 2 species or more including larger
animals
• Late time-points
• Morphology & functional
outcome as outcome measures
• Dose response curves
• Concentration in tissue
• Therapeutic window (delayed
administration)
• Treatment duration
• Both young and older animals
• Both male and female
• Drug combination, with TPA

11. Review of approaches 1957-2003
• O’Collins et al, Ann Neurol 2006
• 1026 experimental treatments
• Evaluation: Average score of 4.2 out of 10
according to STAIR recommendations
• Low score indicates that several problems
were identified in the studies
• 114 advanced into clinical trials

12. Decision to go into a clinical trial
• How was the decision taken ?
• No difference in score between treatments that
entered clinical trial and those that did not
• Other and yet unspecified criteria?
• Proprietary issues ?
• In half of the 114 compounds that were tested in
trials, negative trial results were published before
the preclinical data
O’Collins
et
al,
2006,
Moskowitz
2010

13. 1,026 Experimental treatments in acute stroke
Annals
of
Neurology
Volume
59,
Issue
3,
pages
467-­‐477,
1
FEB
2006
DOI:
10.1002/ana.20741
hQp://onlinelibrary.wiley.com/doi/10.1002/ana.20741/full#fig4
STAIR
score

14. NXY-059
• Traps free radicals
• Highly rated quality of preclinical data (maximum
STAIR score) and level of efficacy
• SAINT I & SAINT II trials
• 5028 patients enrolled
• Acute ischemic stroke
• treatment within 6h
• Primary endpoint: distribution of disability scores
at 3 months (mRS)
No difference in disability score distribution,
mortality, rates of haemorrhage.
Diener
&
al
Stroke
2008

15. NXY-059 in experimental stroke:
individual animal meta-analysis
• Data obtained from sponsor (AZ) or lead author
• Fifteen studies (26 conditions, 12 laboratories)
• 4 unpublished studies
• 544 rats, 9 mice, 32 marmosets
• Randomization (40%), blinding of surgeon (53%), outcome assessor
(63%)
Bath
et
al,
BJP
2009

16. Forrest plot
Bath
et
al,
BJP
2009

17. Funnel plot
Bath
et
al,
BJP
2009

18. NXY-059 in experimental stroke:
individual animal meta-analysis
• Data obtained from sponsor (AZ) or lead author
• Fifteen studies (26 conditions, 12 laboratories)
• 4 unpublished studies
• 544 rats, 9 mice, 32 marmosets
• Randomization (40%), blinding of surgeon (53%), outcome assessor
(63%)
• Efficacy in transient, permanent, thrombotic ischemia, up to 180min
post occlusion
• Conclusion: NXY-059 effective in experimental stroke although
efficacy was probably overestimated due to publication bias.
• Efficacy in young male animals is a poor predictor of clinical
outcome
Bath
et
al,
BJP
2009

19. Drug activity ?
• In most cases, there is a proposed
mechanism of action, tested in the
experimental setting (e.g. free radical
scavenging)
• In clinical trials however, the outcome
measure is mostly the neurological outcome
at 3 months
• No indication whether the proposed
mechanism of action does occur
• This is a major limitation to understand the
failure in clinical trials
Moskowitz
2010

20. Drug activity ?
• Drug activity is not tested in humans, we
don’t know if the failure of the
neuroprotection trials occurs because of
– Bad concept
– Poor target
– Bad drug
– Ineffective administration (e.g. timing, dosing)
Moskowitz
2010

21. Lack of back-testing
• Compounds that failed in clinical testing
were abandoned by the sponsors
• If a compound fails in a clinical trial, it
would be necessary to take it back to the
lab rather than to abandon it
Moskowitz,
Stroke
2010

22. Other concerns
• Clinical outcome measures are unrefined
and not appropriate for all lesion locations
• Differences in lesion volume perhaps not
sensitive enough: The measurement of the
volume of salvaged penumbra might be a
more suitable endpoint
Moskowitz,
Stroke
2010

23. JNK (c-Jun-N-terminal kinase)
Dirnagl
&
al
1999
-­‐ Selec[ve
inhibitor:
D-­‐JNKI1
Bonny
et
al,
2001

24. Borsello & al, Nature Med 2003
D-JNKI1: intra-cerebro-ventricular injection
30 min middle cerebral artery occlusion in the mouse
Lesion
volume
*
Good
therapeu[c
window

25. Permanent MCAO
• D-JNKI1/XG102
attenuates lesion
volume
• Improves the
behavioral outcome
• JNK is activated
after 1h
Hirt
&
al,
Stroke
2004

26. 30 min MCAO, i.v. injection at 6h
0
10
20
30
40
50
60
70
80
90
100
110
vehicle 0.00003 0.0003 0.003 0.03 0.3 1 3
XG102 (mg/kg)
Meanlesionvolume(mm3
)
n=18 n=6 n=5 n=5 n=5 n=5 n=3 n=5
**
**
*** ***
**
Wiegler
&
al,
CVD
2010

27. D-­‐JNKI1
i.v.
administra[on
Blinded
D-­‐JNKI1
0.1mg/kg
6h
a2er
30
min
ischemia
Wiegler
&
al,
2008
D-­‐JNKI1
(n=9)
0
50
100
150
-1 1 3 7 14 21 28
Time (days)
%initialperformance
XG102 1mg/kg
control
**
*
*
*
Performance
(ROTAROD)
-6.00
-1.00
4.00
9.00
14.00
19.00
24.00
29.00
34.00
vehicle (n=5) XG102 (n=5)
mm3
Atrophy
P=0.057
D-­‐JNKI1
1mg/kg
Control
D-­‐JNKI1
(n=5)

28. 0
20
40
60
80
100
vehicle (n=6) tPA (n=5) XG102 (n=6) tPA+XG102
(n=5)
mm3
***
***
***
*
***
tPA
&D-­‐JNKI1,
i.v.
Wiegler
&
al,
Cerebrovasc
Dis
2008
D-­‐JNKI1
(n=6)
D-­‐JNKI1

29. Mister
R,
66
y.o.
• Untreated
arterial
hypertension
• Sudden
headache,
falls
of
his
chair
in
café
• Admission
at
60min:
Le2-­‐sided
weakness
and
hemianopia
• Thrombolysis,
before
the
CT-­‐scan
?
CT
(75min)

30. Bacterial
collagenase
(0.1U)
Intracerebral
haemorrhage
model
in
mice:
the
JNK
pathway
200
µm
JNK
pathway
acIvaIon
Michel-­‐Monigadon
&
al,
Cerebrovasc
Dis
2010

31. • AQenuated
lesion
size
(œdema
at
2d)
• AQenuated
neurologic
deficit
(at
1d)
Michel-­‐Monigadon
&
al,
CVD
2010
D-­‐JNKI1
is
well
tolerated
in
intracerebral
haemorrhage
NaCl
D-­‐JNKI1

32. D-­‐JNKI1
and
stroke
o Promising
compound
o Tested
in
at
least
5
labs,
at
least
6
models,
at
least
2
species
o i.v.
administra[on
o Compa[ble
with
thrombolysis
(rTPA)
o Favourable
effect
in
intracerebral
haemorrhage
o Toxicity
studies
in
animals:
safe
o Phase
Ib
trial,
10
pa[ents,
CHUV:
safe
TRANSLATION
?
o Administra[on
to
healthy
volunteers
i.v.,
NCT01570205
o Clinical
trial
underway,
in
neurosensorial
deafness
(Auris
Medical,
AM-­‐111,
phase
II,
3
European
countries)

33. STAIR update (VII)
Albers & al, Stroke 2011
• Stroke therapy academic industry roundtable
• Failure of neuroprotection may relate
to
– Imperfect clinical trial design (delayed time
to treatment)
– Choice of agents with insufficient preclinical
data to support the clinical trial design
• The same time-window may exist as
for thrombolysis
• Multiple mechanisms
– Drug with multiple targets
– Combination of single target agents
• Hope in studying natural and induced
forms of tolerance
• Expansion of iv TPA requires that
neuroprotective agents be tested on
back-ground TPA
• Expansion of iv TPA requires further
efforts to study reperfusion injury in
patients
• Selective cerebral delivery (intra-
arterial catheters)
• Prehospital trials
– Early administration
– Require preclinical safety data in
hemorrhagic stroke
• Remote preconditioning
• Stroke is a systemic disease
– Activation of lymphoid organs with
mobilisation of monocytes and
lymphocytes to the brain

34. Endovascular
therapeu[c
hypothermia
for
acute
ischemic
stroke:
ICTuS
2/3
protocol
Lyden
&
al,
Int
J
Stroke
2014

35. Together !
• Collaboration between experimental stroke researchers
• Consensus on quality standards & endpoints, sharing and comparing
results (including neutral & negative results)
• Reciprocal audits, data monitoring, round robin tests
• Network could organize multicenter trials to replicate key-results, or phase
III trials
• Well-defined study protocols, robust sample size calculation
• Sufficiently large scale to detect small but relevant effects
• Stratified of factorial design (different strains, species, severities, with/out
comorbidities) leading to robust findings

36. Neuroprotection in stroke ?
• Proof of principle in numerous
experimental models
• No success so far in patients
• No strong argument that it can’t work
• Translation is very challenging

37. Acknowledgements
Stroke
lab,
DNC,
CHUV
Ximena
CasBllo
Tovar
Lara
Buscemi
Melanie
Price
Former
lab
members
Corinne
Benakis
Carole
Berthet
Wilfredo
Puentes
Yvo
Piazza
Maïté
Willaredt
Delphine
Michel
Jonathan
Thevenet
Osvaldo
Mirante
Karine
Wiegler
Marlise
de
Castro
Ribeiro
CrisBna
Granziera
Funding
FNS
3200-­‐68306.2;
FN
3100AO-­‐112484;
FN
310030_135617
CTI
7057.2
and
CTI
8909.1
Fonds
interdisciplinaire
FBM
/
Swissheart
/
NovarBs
FoundaBon
/FondaBon
Biaggi
Christophe
Bonny,
Didier
Coquoz,
ChrisBan
Pasquali,
Anne
Vaslin
XIGEN
Anne
Angelillo-­‐Scherrer,
Haematology,
CHUV
Jérôme
Badaut,
Loma
Linda
University,
USA
Peter
Clarke,
Tiziana
Borsello,
Paola
Bezzi,
Vanessa
Ginet,
Julien
Puyal
DNF,
UNIL
Denis
Monard,
F.M.I,
Basel
Hongxia
Lei,
Rolf
Grueger,
EPFL,
Lausanne
Pierre
Magistreh,
Igor
Allaman,
EPFL