TBI: Translational Issues and OpportunitiesJohn Povlishock PhD TBI Treatment Development Meeting February 19, 2015 State of the Science: Translational Issues and Opportunities Translational

TBI: Translational Issues and Opportunities

Alan I Faden MDJohn Povlishock PhD

TBI Treatment Development Meeting February 19, 2015

State of the Science: Translational Issues and Opportunities

Translational Issues: Failed Clinical Trials

- Animal Modeling Issues: injury response modifiers/confounders, injury model - Pathophysiology: multiple injury factors, temporal evolution- Pharmacological Issues: targets, dose, timing - Pathoanatomy and Therapeutic Targeting

Needs/Opportunities

- Improve Translation: Use of STAIR/ Transparent Reporting Criteria- Require Experimental Replication and/or Multi-Site Experimental Trials- Promote Use of Biomarkers and Advanced Imaging - Improve Methodology: Stratification; Common/Core Data Elements, Adaptive

Designs- New Therapeutic Targets & Multifunctional Strategies

TABLE I. Comparison of Pre-Clinical and Clinical Neuroprotective Studies for Selective Drug Classes

Stroke Head Injury Spinal Cord Injury

Pre-Clinical Clinical Pre-Clinical Clinical Pre-Clinical Clinical

Anti-Inflammatory + - + ND + ND

NMDA Antagonists +++ - +++ - +++ ND

AMPA Antagonists + - ++ ND ++ ND

Dexanabinol ++ - ++ - ND ND

Sodium Channel Blockers ++ - ++ ND + ND

TRH + ND +++ ND +++ +

Growth Factors ++ - ++ ND ++ ND

Glucocorticoids + - + - ++ +

Caffeinol +++ ND + ND ND ND

Opioid Antagonists + - ++ ND +++ +

Anti-Apoptosis ++ ND ++ ND + ND

Free Radical Scavengers ++ ± + - + ±

Erythropoetin ++ - ++ ND ++ ND

Calcium Channel Blockers + - + - ± ND

Magnesium Sulphate ++ - ++ - ++ ND

Statins ++ ± ++ ND ++ ND

Table I legend: + mild protection, ++ moderate protection, +++ strong protection, ± some studies showed no protection whereas others suggested

protection; ND - studies not done.


NEUROPROTECTION:MAJOR METHODOLOGICAL ISSUES

Relevance of model

Brain Pharmacokinetics and therapeutic window

Species, Strain, Gender

Anesthesia

Mechanisms Targeted: Cell death, Inflammation, Multiple

Outcomes: Histology, Behavior

Statistical: Power, Trial Design

HETEROGENEITY OF TRAUMATIC BRAIN INJURY

FOCAL

PENETRATING

PRE-MORBIDITIES

GENDER

GENETICS

COMPLICATIONS

DIFFUSE

CLOSED

CO-MORBIDITIES

AGE

EPIGENETICS

SEVERITY


Chronic neurodegeneration after TBI

Skardelly et. al., J. Neurotrauma, 2011Cazalis et. al., Frontiers in Neurotrauma, 2011

MULTIFUNCTIONAL TREATMENTS

QuickTime™ and a DV/DVCPRO - NTSC decompressor are needed to see this picture.

TRH & DIKETOPIPERAZINES

CELL CYCLE INHIBITORS

ERYTHROPOIETIN

PARP INHIBITORS

HSP70

STATINS

mGluR5 AGONISTS

CYCLOSPORIN A






NEW DAUGHTER CELL

MITOSIS (CELL DIVISION)

SYNTHESIS

(DOUBLING OF DNA

RESTRICTION POINT

(POINT OF NO RETURN)

BEGIN CYCLEGROWTH FACTORS,

ONCOGENES,

CYCLINS &CDKS

TUMOR SUPPRESSOR

GENES, CDK

INHIBITORS


Sham Vehicle CR80

25

50

75

100

**

++

**

Dis

cri

min

ati

on

In

de

x (

%)

Sham Vehicle CR80

25

50

75

100

Spatial Systematic Looping

Se

arc

h s

tra

teg

y

(%)

Sham Vehicle CR80

3

6

9

12

**

++

No

. o

f e

ntr

ies

into

th

e t

arg

et

qu

ad

ran

t

Sham Vehicle CR80

5

10

15

+

*

La

ten

cy

to

fir

st

en

try

into

th

e t

arg

et

qu

ad

ran

t

14 15 16 170

30

60

90Vehicle

CR8

Sham**

+

Post-injury days

Late

ncy t

o t

he p

latf

orm

(seco

nd

s)

A B C

D

Kabadi and Stoica et al., 2012 (Neurotherapeutics)

E

Systemic administration of Cell Cycle Inhibitor CR8 after mouse CCI

Upregulated Downregulated

BCl-2-related Cyclin L

Uncoupling protein 2 Cyclin D1

ApoE E2F5

Aquaporin 1 c-myc

Aquaporin 5 Rb

EST (similar to ubiquinine

oxidoreductase)

Calpain 6

mGluR7 Cyclin D1

HIF1 Cathepsin C precursor

HSP 70 Cathepsin H

BDNF Aquaporin 4

Genes

4 HRS

24 HRS

72 HRS

Diketopiperazine Mechanisms: Gene Regulation

Drug Structure Glutamate Maitotoxin FeSO4

Beta

Amyloid

In Vitro

Trauma

Trophic Factor

Removal

Oxygen/Glucose

Deprivation

35b + + — + + + ±

144a — NT NT — + + NT

606 + + + + + + +

807 — NT NT — + + NT

In Vitro Models

O

N

NH

O

O

N

NH

O

O

N

NH

O

H

OH

CH3

CH3

CH3

CH3 CH3

CH3

O

N

NH

O

Neuroprotective Drug Development: in vitro mechanism studies

0

2.5

5

7.5

10

Les

ion

Volu

me

(L

)

1

Groups

CCI+807

CCI+606

CCI+144

CCI+35b

CCI+Vehicle

Faden et al, Neuropharmacology 2005

Lesion Volume after CCI

***

****

**

CCI

CCI + 144

CCI + 35b

CCI + 606

CCI + 807

Diketopiperazine Treatment


Rapid Neuronal Cell Death(bioenergetic failure/necrosis)

Secondary injury (2nd Phase):Late Neuronal Cell Death

Inflammation (microglial-mediated neurotoxicity)Continuing and Expanding Tissue Damage

Delayed phase(hours to days )

Acute phase(seconds- minutes)

Chronic phase(months to years)

Primary injury: Direct mechanical damage

Secondary injury (1st Phase):Excitotoxicity

Mitochondrial dysfunctionInflammation

Delayed Cell Death (apoptosis)

TBI


Chronic microglial activation after TBI

Ramlackhansingh et al., Ann Neurol. 2011

Sham 7d TBI

Iba 1

1 1 5 12 52 520

5000

10000

15000

20000

25000

Cell

density

(cells

/mm

3)

****

** ++

Weeks post-injury1 1 5 12 52 52

0

3000

6000

9000

12000

15000

18000

21000

Cell

density

(cells

/mm

3)

TBISham

***

****** **

++^̂^̂ ^̂ ^

Weeks post-injury

Activated microglia

(hypertrophic/bushy)

Resting microglia

(ramified)

Loane et al., JNEN 73(1):14-29, 2014

Microglia remain activated in the cortex up to 1 year after experimental TBI

Also after repetitive mTBI in rodents:Aungst et al., JCBFM, 34(7):1223-32,2014Mouzon et al., Ann Neurol. 75(2):241-54 2014


Chronic Traumatic Inflammatory Encephalopathy:

New Neuroprotection Opportunity

Common occurrence after moderate/severe TBI; likely after multiple

mild TBI

Chronic neuroinflammation associated with up-regulation of NADPH

oxidase and oxidative stress

Persists for months to years, leading to progressive neurodegeneration,

cognitive decline and neuropsychiatric alterations

Highly delayed targeted therapies (pharmacologic and physical) effective

at limiting damage and improving outcome


mGluR5 Receptor ModulationByrnes et al, J Neuroinflammation 2012

1 3 7 14 21 280

10

20

30

40

50

Days post-injury

Fo

otfa

ults

Sham (Vehicle)

TBI (Vehicle)

TBI (VU0360172)

Sham (VU0360172)

TBI (MTEP + VU0360172)

+

******

*** *** *** ***

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

Lesio

n v

olu

me (

mm

3) Vehicle

VU0360172

MTEP+VU0360172*

Vehicle VU0360172 MTEP + VU0360172

CA1 0

400000

800000

1200000

Ne

uro

na

l de

nsity

(ce

lls/m

m3)

CA1

TBISham

***

*

***

+

^^^

mGluR5 PAM improves recovery and reduces neurodegeneration after TBI

mGluR5 stimulation repolarizes microglia towards an M2 phenotype after TBI

iNOST

BI (V

eh

icle

)T

BI

(VU

03

60

17

2)

Arg 1 CD11b

0.0

0.5

1.0

1.5

2.0

iNO

S+

/CD

11

b+

(Ma

nd

er's o

ve

rla

pco

effic

ien

t)

*

0.0

0.5

1.0

1.5

2.0

Arg

-1+

/CD

11

b+

(Man

de

r's o

ve

rla

pco

effic

ient)

TBI (Vehicle)

TBI (VU0360172)*

Delayed Exercise Initiation Reduces Lesion Volume

Sedentary TBI TBI + acEX TBI + deEX

Piao et al, Neurobiol Dis. 2012


Recommended Design Criteria for Pre-clinical Evaluation of Pharmacological Agents for TBI

Evaluate effects across injury severities

Randomize drug treatments and use blinding for all outcomes

Demonstrate specificity using structurally different modulators and parallel genetic modulation

Examine therapeutic window to include a clinically relevant time point (>8 h post TBI)

Evaluate both late histological and functional outcomes

Examine drug pharmacokinetics and brain concentrations associated with treatment efficacy

Include clinically relevant physiological monitoring

Evaluate the drug across gender and the age spectrum

Compare effects in multiple TBI models and species

Replicate the therapeutic effects across laboratories

Documents

TBI: Translational Issues and OpportunitiesJohn Povlishock PhD TBI Treatment Development Meeting February 19, 2015 State of the Science: Translational Issues and Opportunities Translational