Neuroprotection in neurology: why is it so difficult?

Swiss MS Society State of the Art Symposium, Lucerne 2014 Lorenz Hirt

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

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

Ischemic core and penumbra Ischemic stroke, right middle cerebral artery territory

Perfusion-­‐CT,  2h  a2er  symptom  onset  

CT,  2h  a2er  symptom  onset  

ACA

MCA

PCA

ECA

MCA

PCA

ICA

BA

Mike O'Neill, Lilly

Middle cerebral artery occlusion (MCAO) model in the mouse

Zoom of ÒVM H3-5 Ó

25 :0016 :408: 200

0

20

40

60

80

10 0

12 0

Mechanisms of cell death in Ischemic penumbra •  Excitotoxicity •  Peri-infarct depolarisation •  Apoptosis •  Inflammation

– Numerous cellular mechanisms and molecular pathways involved

Dirnagl  &  al  1999  

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)

Strategies targeting cell death mechanisms ?

•  Not all patients qualify for thrombolysis / recanalisation therapies (10%)

•  Not all patients benefit sufficiently •  Time-window

Experimental approaches

•  More than 1000 potential neuroprotective strategies tested

Dirnagl  &  al  1999  

NEUROPROTECTION    

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

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

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  

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  

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  

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  

Forrest plot

Bath  et  al,  BJP  2009  

Funnel plot

Bath  et  al,  BJP  2009  

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  

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  

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  

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  

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  

JNK (c-Jun-N-terminal kinase)

Dirnagl  &  al  1999  

-­‐  Selec[ve  inhibitor:  D-­‐JNKI1  Bonny  et  al,  2001  

 

Borsello & al, Nature Med 2003

D-JNKI1: intra-cerebro-ventricular injection 30 min middle cerebral artery occlusion in the mouse

Lesio

n  volume  

*  Good  therapeu[c  window  

Permanent MCAO

•  D-JNKI1/XG102 attenuates lesion volume

•  Improves the behavioral outcome

•  JNK is activated after 1h

Hirt  &  al,  Stroke  2004  

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)

Mea

n le

sion

vol

ume

(mm

3 )

n=18 n=6 n=5 n=5 n=5 n=5 n=3 n=5

**

** *** ***

**

Wiegler  &  al,  CVD  2010  

XG-102 iv, exploration

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)

% in

itial p

erfo

rman

ce

XG102 1mg/kgcontrol

**   *  *  *  

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)    

0

20

40

60

80

100

vehicle (n=6) tPA (n=5) XG102 (n=6) tPA+XG102 (n=5)

mm

3

***  ***  

***  

*  

***  

tPA  &D-­‐JNKI1,  i.v.    

Wiegler  &  al,  Cerebrovasc  Dis  2008  

D-­‐JNKI1  (n=6)               D-­‐JNKI1  

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)    

Bacterial  collagenase  (0.1U)    

Intracerebral  haemorrhage  model  in  mice:  the  JNK  pathway  

200  µm  

JNK  pathway  acIvaIon  

Michel-­‐Monigadon  &  al,  Cerebrovasc  Dis  2010  

•  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  

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)  

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

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

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

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

 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