Nuevos fenotipos e implicaciones terapéuticas en la ... · Nuevos fenotipos e implicaciones terapéuticas en la atrofia muscular espinal Eduardo Tizzano Director del Area Genetica

Nuevos fenotipos e implicaciones

terapéuticas en la atrofia muscular espinal

Eduardo Tizzano

Director del Area Genetica Clínica y Molecular

Unidad de Enfermedades Raras

Hospital Valle Hebron, Barcelona

XV Curso enfermedades neuromusculares infancia y

adolescencia

Grant support to conduct clinical trials on SMA from Ionis/Biogen; Serves

as a consultant to Biogen, AveXis, Roche,

Serves as a scientific/medical advisor for non profit organizations such

as

SMA Europe, TREAT-NMD, FUNDAME, FAME Chile, Familias SMA

Argentina and Famiglie SMA Italy.

www. enetMD.comE TIZZANO Hosp. V. Hebron Barcelona

Spain

Descripción de

la enfermedad

Diagnóstico clínico-

Clasificación

Diagnóstico genético

Investigación

translacional

Protocolos de

tratamiento

2000

1990-1999

1950-80

1850-1890

Conocimiento de la AME en los

últimos 150 años

???

Descubrimiento

del gen en

1995!

Birth

6 months

18 months

2-3 years

ADULT LIFE

TIPO II IntermediaTYPE II - Intermediate

TYPE III - Kugelberg -Welander

TYPE IV Adult

TYPE I - Werdnig-Hoffmann

TYPE 0 Congenital

SMA classification : Age at onset + motor

milestones

55

E TIZZANO Hosp. V. Hebron Barcelona

Spain

AGE

NORMAL

TYPE I

TYPE II

TYPE III

PRESYMPTOMATIC PHASE

SUBACUTE PHASE

CHRONIC PHASE

Neuromuscular milestones development

SIT WALK

BIRTH

E TIZZANO Hosp. V. Hebron Barcelona Spain

Cephalic Control

Modified from Swoboda et al., 2005)

AGE

NORMAL

TYPE I

TYPE II

TYPE III

PRESYMPTOMATIC PHASE

SUBACUTE PHASE

CHRONIC PHASE

Neuromuscular milestones development

SIT WALK

BIRTH


Cephalic Control

Modified from Swoboda et al., (2005)

Manifestaciones más comunes

• Debilidad proximal

• Hipotonía

• Fasciculaciones linguales

• Temblor manos

• Hipo-Arreflexia

• Trastornos deglución

•Escoliosis

• Problemas respiratorios

The most severe forms of type I SMA: arthrogryphosis, cardiacmalformation and digital necrosis

E TIZZANO Hosp. V. Hebron Barcelona

Spain

0

25

50

75

100

0 2 4 6 8 10 12 14 16 18 20 22 24

Natural History of SMA Type 1

“floppy baby” syndromemuscle weakness (legs more than arms)poor head controlbelly breathingbulbar muscle weakness (weak cry, difficulty swallowing, aspiration)

will never sit unsupported

% E

ve

nt-

Fre

e S

urv

iva

l*

Age (mos)

Finkel et al. Observational Study of Spinal Muscular Atrophy Type I and Implications for Clinical Trials. Neurology. August 2014.

* Survival = no death, or no need for ≥16-hr/day ventilation continuously for ≥ 2 weeks, in the absence of an acute reversible illness

n = 23 (2 copies of SMN2)75% survival*

8.1 mos

50% survival*

10.5 mos

25% survival*

13.6 mos

8% survival*

20 mos

Holds head

steady alone;

brings hands to

mouth

Rolls over in

both directions

Sits alone;

crawls

Cruises; may

stand alone

Walks alone; may run

and walk up stairs; eats

with a spoon

Climb furniture alone;

kicks and throws a ball

Onset of SMA Type 1 by 6 months

Symptoms may present

90% of SMA Type 1 patients will not survive to the age of 2

11

Milestone for a healthy infant

SMA Type 1 survival rates

Patients with type II are those who reach sitting status.

Some patients loss this capacity after (weak type II).

Some others reach standing and may perform some walk

with help (strong type II).

Patients are confined to wheelchair.

Material exclusivo para divulgación científica

Natural walking history type III

Zerres et al., J Neurol Sci. 1997;146: 67-72.

22.0%

70.3%,

AME tipo IIIb

AME tipo IIIa


Gen Determinante SMN1

Mutaciones en SMN1 (deleciones, mutaciones puntuales) se detectan en pacientes y confirman la enfermedad


Gen modificador SMN2

SMN2 es una copia homologa al SMN1 y está presente en TODOS los pacientes

AME y su numero de copias varía de 1 a 5


SMN 1

SMN 1SMN 2

SMN 2

SMN 2

SMN 2

SMN 1

SMN 1

SMN 1

SMN 2

SMN 2

90%

Portadores

2%

Afectados AME 1/6.000 -10.000 RN

5-10%

0%

Población general


LA ATROFIA MUSCULAR ESPINAL EN

NÚMEROS

• Incidencia aproximada 1/7000 recién nacidos.

• En España habría unos 60 casos nuevos por año (2 copias afectadas del gen SMN1) (400.000 por año)

• Frecuencia de portadores de 1/40-50 individuos de la población general (Alias et al., 2013).

• En España existirían casi 1 millón portadores (1 copiagen SMN1 alterada y 1 copia sana) (50 mill hab).

SMN 1

SMN 1

SMN 1

SMN 1

50% tipo I, 30% tipo II y 20% tipo III

8

8

STOP

AAAA

GGT TTT AGA

STOP

AAAA7

GGT TTC AGA

SMN2

SMN1

76

6~100%

50 - 90%

10 - 50%

SMN

SMN7

TTC or TTT codify for PHENYLALANINE

C>T transition in exon 7 makes this exon more prone to be excluded in mRNA

E TIZZANO Hosp Valle Hebron Barcelona Spain

SMN 7SMN2 6 7 8

UAGACAA

SMN1 6 7 8 SMN FL

CAGACAA

SF2/ASF

Kashima et Manley, Nat Genet 2003

EXONIC

SPLICING

ENHANCER

(ESE)

EXONIC

SPLICING

SILENCER

(ESS)

Material exclusivo para

divulgación científica

SMN mRNA and

protein in fetal

SPINAL CORD

(15 weeks)

FL SMN (COMPLETE)

delta 7 SMN (INCOMPLETE)

Control SMA

38kd

Ex7SMN1+SMN2 SMN2

SMN1+SMN2 SMN2

Una disminución de la proteína SMN

en la medula espinal provoca AME

SMN transcripts


Soler-Botija et al., JNEN, 2005

SMN 2

SMN 2

SMN 2

SMN 2

SMN 2

SMN 2

SMN2 copies in SMA patients

SMN 2

SMN 2

SMN 2

SMN 2


Typ

eI

Typ

eII

/ T

ype

III

Disease severity typically depends on the number of copies of the SMN2 gene

625 SMA from Spain

20

235

17

Type I SMA

24

162

Type II SMA

7

107

51

11

Type III SMA

1 SMN2 2 SMN2 3 SMN2 4 SMN2 5 SMN2 6 SMN2 Total

Type I SMA 20 235 17 0 0 0 272Type II SMA 0 24 162 0 0 0 186Type III SMA 0 7 107 51 1 1 167Total 20 266 286 51 1 1 625

Compiled from Bernal et al., EJHG 2009 17 vol 2 pp 344 and Calucho M, et al., submitted

n=272 n=186 n=167

100%

88%

6%

9%

57%

3%

37%

100% 100% 100%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

1 SMN2

copy

n=20

2 SMN2

copy

n=266

3 SMN2

copy

n=286

4 SMN2

copy

n=51

5 SMN2

copy

n=1

6 SMN2

copy

n=1

Type I Type II Type III

Prediction of SMA types according to the number of SMN2 copies

625 SMA from Spain

Compiled from Bernal et al., EJHG 2009 17 vol 2 pp 344 and Calucho M, et al., submitted.

Plus = age of onset, màximum motor milestone achieved

Manifestaciones AME

Copias SMN2/Cantidad de proteina SMN

Mas grave

Menosgrave

SMN1 ausente o mutado

1a 1b 1c 2a 2b 3a 3b 4 MM

Modificadores positivos

Modificadores negativos

Existe un espectro continuo de fenotipos de AME

Talbot and Tizzano, Gene Therapy (2017) 24:529-533

Terapia antisentido: Nusinersen

• Nusinersen o Spinraza es una moléculaque está formada por 18 pares de bases de material genético y que en forma de compuesto químico, se administra en solución a un paciente.

• Se lo conoce como una moléculaANTISENSE o ANTISENTIDO y como tiene pocos nucleótidos (18) es un oligonucleótido (ASO). Moleculaantisentido modificada

• Molecula antisentido modificada 2’-O-methoxyethyl (MOE)

6 7 8hnRNP A1

6 8∆-SMN2

pre-mRNA

mRNA

ISS-N16

7

8

hnRNP A1

6 8

7SMN-ASOs

FL-SMN2

ISS-N1

• 2’-O-methoxyethyl (MOE) modified antisense drug

• Displaces negative splicing factors on pre-mRNA,

promoting inclusion of mis-spliced exon 7

• Promotes synthesis of fully functional SMN protein

Intron 7

U1snRNP

hnRNP A1

hnRNP A2

hnRNP A1

hnRNP A2

GGUCGUAAUACUUUCACU

UAAGUCUGCCAGCAUUAUGAAAGUGAAU………………

Exon 7

UUAAAUUAAGGAG

Exon 8

AAUGCUGGCAU

28

Modulación del SMN2Por terapia antisentido

Change in HINE Motor Milestone Scores

Across Studies

Populations: NURTURE (232SM201) = interim efficacy set, CS3A = all dosed infants; ENDEAR (CS3B) = interim efficacy set. For each study, visits with n<5 are not plotted. aMaximum total milestone score = 26. bMedian (range) age at first dose: 19.0 (3–42) days. cMedian (range) age at enrolment: = 155 (36–210) days. dMedian (range) age at first

dose: 175.0 (30–262) days.

2

6

10

14

18

22

26

0

1

4

8

12

16

20

24

NURTURE (N=18)

CS3A (N=20)

29 64 92 183 302 394

Scheduled visit day

NURTURE

CS3A

CS3B-nusinersen

CS3B-control

505 568 631 694 757

Me

an

(±S

E)

tota

l m

ilesto

ne

sco

rea

18

20 20 19

73

37

18

19 18

66

30

16

17 17 14 15 13 14 11 11 10 7

59

23

11 9 5

36

16

26

11

ENDEAR (CS3B)-nusinersen (N=73)

ENDEAR (CS3B)-control (N=37)

NURTURE

(presymptomatic infantile-onset SMA; 2 or 3 SMA2 copies)b

CS3A

(infantile-onset SMA)c

Nusinersen vs.

Sham procedure control in ENDEAR final

analysis

(infantile-onset SMA; 2 SMN2 copies)d

Comienzo terapia a los 6

meses EC a los 2 meses

Gene therapy

– AAV9 cross blood brain barrier (BBB)

– Self Complementary allows rapid production of RNA and protein

(1-2 days) after administration

– Improves survival when administered very early to the SMA

mouse

– Efficacy was proved in a pig model and a protocol in phase I have

been approved in humans for type I disease.

AAV9

SMN1

E TIZZANO Hosp V. Hebron Barcelona Spain

Replacement or correction of SMN1 Gene Therapy

Avexis Program

Phase I/II clinical trial (2014-2017)

Nationwide Children’s Hospital in Columbus, Ohio

Systemic delivery of AVXS-101 (scAAV9-SMN)

Open-label, dose-escalation study

SMA type I before 6 months of age

Aims: safety and preliminary indications of efficacy

Enrollment completed:

Cohort 1 includes three patients dosed at (6.7 X1013 vg/kg), aged six to seven months at time of dosing

Cohort 2 includes 12 patients dosed at (2.0 X1014 vg/kg), aged one to eight months at time of dosing

Appears to be generally safe and well tolerated in the patients studied to date

Courtesy Dr. J. Mandell /B. Kaspar

SMA Type 1 treated at 2 mo and

picture 6 mo post GT

Courtesy Dr. J. Mandell /B. Kaspar 38

15 patients enrolled,

still alive after 15-24

months of injection

less nutrition and

respiratory

complications

improving motor

function.

Cohort 2 Achieved Motor Milestones Not Seen in the Natural History of SMA Type

1

3

9

Nusinersen AVXS-101

Type of therapy Antisense oligonucleotide

specific to ISSN1

ASO –ISSN1

Self complementary adeno

associated virus with

human SMN1

scAAV9.CB.SMN1

Intracellular place of

action

Pre-mRNA in nuclei to

include exon 7

Incorporates in nuclei as

episomes

Mechanism of action Increase amount of

complete SMN protein

from SMN2

Production of SMN protein

from SMN1

Administration route Intrathecally Intravenously

Dose and frequency of

administration

Dose escalation (12 mg

each) and maintenance

every 4 months

One dose of 2.0E14 vg/kg

Target Motor neurons and other

CNS cells

All non-dividing cells of the

organism

Pipelines Phase 3 trials completed Phase 1-2 trial completed

Type of SMA patients

treated

Type I and II and

presymptomatic

Type I

Number of patients

treated

to date

CT 243+ 21+20+21=305

EAP 549

15

Approval FDA (Dec 2016) EMA

(June 2017)

Pending of expanded CTs?

PS

Symptom Onset

I

SIT

WALK

Type I more survival-Better motor function

Onset

II Type II with less complications No scoliosis

Death

Onset

IIIType III permanent walker

Cure or minimal manifestations

NORMAL

A B

C

D

E

(Tizzano and Finkel NMD, 2017)

Genetic screening of SMN1 deletion (allows detection of

more than 90% of cases)

Parental Consent

Positive cases

SMN2 copies to estimate prognosis

Complete information to the family and psychological

support

Decision in treatment

Close Follow up and application of outcome measures

Neonatal screening for SMA


Seems reasonable to start therapy in patients with two SMN2 copies

Debate about patients with three SMN2 copies

Patients with four copies?

Evolution of prevention in SMA

Secondary prevention

Tertiary prevention

Primary prevention

Treat all patients with manifesting disease

Treat all presymptomatic cases detected by

screening

Perform Genetic Counselling in all carriers detected in a population

based screening

INCIDENCE

AND

PREVALENCE

OF THE

DISEASE

Serra-Juhe et al. under revision

+

-

Documents

Nuevos fenotipos e implicaciones terapéuticas en la ... · Nuevos fenotipos e implicaciones terapéuticas en la atrofia muscular espinal Eduardo Tizzano Director del Area Genetica