Post on 28-May-2020
transcript
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
E TIZZANO Hosp. V. Hebron Barcelona Spain
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
Material exclusivo para divulgación científica
Gen Determinante SMN1
Mutaciones en SMN1 (deleciones, mutaciones puntuales) se detectan en pacientes y confirman la enfermedad
Material exclusivo para divulgación científica
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
Material exclusivo para divulgación científica
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
E TIZZANO Hosp. V. Hebron Barcelona Spain
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
E TIZZANO Hosp Valle Hebron Barcelona Spain
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
E TIZZANO Hosp. V. Hebron Barcelona Spain
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
E TIZZANO Hosp Valle Hebron Barcelona Spain
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
+
-