Canadian Expert Patients in Health Technology Conference Nov 7 – 8, 2016: Day 1

1. Advances
in
gene
therapy
Eyal
Grunebaum
MD
Head,
Division
of
Immunology
and
Allergy
Senior
Scien<st,
Developmental
and
Stem
Cell
Biology
Hospital
for
Sick
Children,
Toronto
,
Ontario
Canadian
Expert
Pa<ents
in
Health
Technology
Conference
November
2016,
Toronto
1

2. Educational
objectives
• What
is
gene
therapy
(GT)
• Why
we
need
GT
(examples
from
immune
def.
pa<ents)
• How
we
do
GT
(outside
and
inside
the
body)
• When
do
we
now
use
GT
• What
innova<on
in
GT
are
expected
(CAR-­‐T,
CRISPER).
• Goal:
Empower
you
to
be
able
to
advocate
effec<vely
for
GT,
when
appropriate.
No
financial
“conflicts
of
interest”.
2

3. Gene
therapy:
De:inition
GT
is
the
introduc<on
of
gene<c
material
into
cells,
which
will
then
be
translated
by
the
cell’s
machinery
to
a
protein,
to
compensate
for
exis<ng
abnormal
gene
or
to
make
a
beneficial
change
to
a
gene.
3
Genes
in
the
DNA
are
the
codes
for
making
proteins.
Proteins
determine
the
various
traits
in
our
body.
Gene
Protein
Trait

4. “Bubbles”
temporary
protect
kids
with
severe
immune
defects
• Children
born
without
an
immune
system,
2nd
to
gene<c
defects.
• Prone
to
life
threatening
infec<ons.
• Without
appropriate
interven<on,
condi<on
fatal
in
1st
few
years.
• Previously,
total
isola<on
to
prevent
infec<ons
(“bubble
babies”)
.
David
Veer
(1971-­‐1983)
• Not
long
term
solu<on.
• Poor
quality
of
life,
significant
financial
&
mental
challenges.
4
Seinfeld,
1992,
“The
Bubble
Boy”
episode,
George
aacked
by
a
teenager
living
in
a
plas<c
bubble,
who
“losses
his
mind”.

5. Bone
marrow
transplantations
can
correct
severe
immune
defects
Transplan<ng
bone
marrow,
harvested
from
normal
donors,
to
restore
immunity
following
irradia<on,
chemo
or
immune
defects
(i.e.
“bubble
babies”).
Erythrocytes
Platelets
White
blood
cells
(immune
cells
to
fight
infec4ons)
Hematopoie<c
stem
cells
produce:
December
28th
1968
Bone
marrow
5

6. hp://chemosabe-­‐socks.blogspot.ca/2013/07/grae-­‐versus-­‐host-­‐disease.html
Defenseless
receiving
pa<ent
(host)
Ac<vated
immune
system
of
normal
donor
(grae),
primed
to
aack
You
must
be
new
here.
I
am
skin
A
major
complication
of
bone
marrow
transplants:
graft
vs
host
disease
6
Relocated
to
a
new
environment
Damage
to:
Skin
Liver
Gastro
Lungs
Joints
Etc

7. Graft
versus
host
response
has
major
impact
on
transplant
outcome.
Grunebaum
E,
Mazzolari
E,
Porta
F,
Dallera
D,
Atkinson
A,
Reid
B,
Notarangelo
LD,
Roifman
CM.
Bone
marrow
transplanta<on
for
severe
combined
immune
deficiency.
Journal
of
American
Medical
Associa<on.
2006.
In
North
America
d/t
small
families,
<20%
have
HLA
iden<cal
sibling
donor
Gene
therapy
with
pa<ents
own
“corrected”
cells
0
12
24
36
48
60
72
84
96
108
120
132
144
156
168
Months
after
bone
marrow
transplantation
100
50
10
60
70
80
90
Sibling
donors
with
identical
HLA
(92.3%)
Parents,
only
half
matched
HLA
(52.7%)
Survival
(%)
7
Example
from
pa<ents
with
severe
immune
defects
(12.5%
have
GvHD)
(61.4%
have
GvHD)

8. 1:
Gene
therapy
“outside
of
the
body”
How
is
it
done?
Cells
taken
from
pa<ent’s
BM
A
gene
of
interest
is
embedded
into
the
viruses’
DNA
“Altered”
viruses
are
mixed
with
the
pa<ent’s
cells
The
new
gene
integrates
into
the
cells’
DNA
and
is
expressed
as
a
protein
in
the
pa<ent’s
cells
Cells
injected
into
the
pa<ent
Altered
cells
expand
&
func<on
inside
the
body
8
In
the
lab,
viruses
(most
common
gene
delivery
tool)
altered
so
cannot
reproduce
or
cause
harm

9. Advantages
of
gene
therapy
vs
bone
marrow
transplants
include:
• Use
pa<ent’s
own
cells,
readily
available.
• No
“grae
versus
host”
response.
• No
risk
of
exposure
to
new
infec<ons
or
other
abnormali<es
donors
might
have
(and
not
know
about).
• Less
harm.
9

10. Gene
therapy
for
inherited
immune
defects.
• Pa<ents
with
adenosine
deaminase
deficiency,
type
of
inherited
severe
immune
deficiency,
were
the
1st
to
receive
gene
therapy
(1990),
followed
by
pa<ents
with
X-­‐linked
severe
combined
ID.
• Done
only
aeer
extensive
work
in
labs
(cells,
animals,
etc).
• Used
only
for
pa<ents
with
no
other
treatment
op<ons.
Decade
of
disappointments:
• Difficul<es
in
introducing
the
new
genes
into
the
cells.
• Difficul<es
in
geqng
genes
to
func<on
&
produce
proteins.
• Difficul<es
ensuring
only
2
gene
copies
entered
(normally
there
are
only
2
gene
copies
in
a
cell).
• Difficul<es
in
controlling
the
expression
of
the
new
genes.
• Viruses
integrated
randomly
in
the
cells’
DNA,
ac<va<ng
“cancer
genes”,
leading
to
leukemia.
10

11. Improvements
over
time
in
gene
therapy
:
• Learned
that
“gene
corrected”
cells
need
“head-­‐start”
to
overtake
pa<ent’s
exis<ng
cells
low
dose
chemotherapy
used
in
most
GT
protocols.
• Developed
beer
delivery
tools
with
improved
safety
and
efficacy.
• Beer
mechanisms
to
control
gene
expression,
using
endogenous
promoters
(“drivers”)
that
determine
expression.
• Enhanced
understanding
of
specific
disease
biology,
thereby
choosing
condi<ons
more
likely
to
benefit
from
GT.
• Earlier
iden<fica<on
of
pa<ents
through
newborn
screening,
enabling
therapy
of
kids
before
becoming
sick.
11

12. In
2006,
Parker
was
the
1st
Canadian
to
receive
“outside”
GT
(for
adenosine
deaminase
de:iciency)
through
the
“Milan”
GT
trial,
2016,
clinically
well,
normal
immunity.
Aug
2006
Aug
2016
12

13. Long-­‐term
follow-­‐up
of
gene
therapy
for
ADA
de:iciency
demonstrates
its
success
• All
18
ADA-­‐deficient
pa<ents
who
received
GT
in
the
Milan
trial
are
alive.
None
developed
any
malignancy.
• 90%
of
them
have
normal
immune
func<on.
• (Cicalese
MP,
et
al.
Update
on
the
safety
and
efficacy
of
retroviral
gene
therapy
for
immunodeficiency
due
to
ADA
deficiency.
Blood.
2016)
• May
2016:
“The
European
Marke<ng
Authoriza<on
Commiee”,
the
FDA
equivalent,
approved
commercial
use
of
GT
for
adenosine
deaminase
deficiency.
[1st
out-­‐of-­‐body
GT
licensed
in
Western
countries!]
• Clinical
trials
of
GT
for
ADA
deficiency
are
currently
being
done
in
Los
Angeles
and
London.
13

14. Current
status
of
gene
therapy
for
immune
defects
(outside
of
the
body)
Clinical
trials
• Adenosine
deaminase
def.
• IL2Rg
deficiency
• Chronic
granulomatous
disease
• Wisko
Aldrich
syndrome
Pre-­‐clinical
research
stages
• CD40
ligand
deficiency
• ZAP70
deficiency
• RAG1
deficiency
• RAG2
deficiency
• Artemis
deficiency
• Leukocyte
adhesion
defect
• Etc
Example:
We
have
been
working
on
GT
for
PNP
deficiency
for
a
decade,
and
have
at
least
5
years
<ll
clinical
trials.
(Liao
P,
Toro
A,
Min
W,
Lee
S,
Roifman
CM,
Grunebaum
E.
Len<virus
gene
therapy
for
purine
nucleoside
phosphorylase
deficiency.
J
Gene
Med.
2008)
14

15. Gene
therapy
for
immune
defects-­‐
remaining
challenges.
1. Life-­‐long
benefits
and
risks
are
not
known.
2. GT
needs
to
be
developed
separately
for
each
disease
(>300
genes
muta<ons
are
already
known
to
cause
immune
defects).
3. Each
of
these
condi<ons
requires
inves<ng
significant
resources
and
many
years
of
research.
4. Limited
access
in
USA,
not
(yet?)
in
Canada.
5. Pa<ents
and
families
need
to
travel
to
US/Europe.
6. Very
expensive
(US$250,000/pa<ent).
Support
by
MOH
appreciated,
however
non-­‐sustainable,
par<cularly
if
we
plan
to
increase
the
#
of
pa<ents
receiving
GT.
15

16. “Out
side
of
the
body”
GT
for
many
other
non-­‐immune
conditions
• Gene
therapy
where
bone
marrow
derived
cells
are
treated
with
virus
outside
of
the
body,
and
injected
back.
• Sickle
cell
anemia
• Fanconi
Anemia
• Thalassemia
• Metachroma<c
Leukodystrophy
• Adrenoleukodystrophy
For
addi<onal
condi<ons:
Clinical.Trails.gov
Storage
disorders
Hematological
diseases
16

17. • DNA
of
interest
delivered
directly
into
the
blood
or
<ssue/organ
using
viruses
(or
other
vehicles).
• Virus
inserts
itself,
and
the
DNA
of
interest,
into
the
cells
where
protein
is
expressed
by
the
cell’s
machinery.
17
2.
Gene
therapy
in
the
body

18. Gene
therapy
directly
in
the
body
• Advantages:
• No
need
to
remove
cells
from
the
pa<ent.
• When
disease
is
limited
to
specific
<ssue/organ,
the
gene
directly
delivered
to
<ssue/organ
(liver,
muscle,
brain,
tumor,
etc).
• More
delivery
methods
are
available
(viruses,
electricity,
lipids).
• These
“delivery
methods”
can
deliver
larger
genes.
• Easy
to
perform.
• Disadvantages:
• The
targeted
cells
usually
do
not
replicate
(nor
the
virus),
hence
effect
is
rela<vely
short,
oeen
necessita<ng
repeated
injec<ons.
• Repeated
injec<ons
might
cause
an
immune
response
against
the
virus,
thereby
jeopardizing
the
efficacy
of
gene
therapy.
• Might
“infect”
and
therefore
affect
neighboring
cells.
18
Because
of
rela<ve
ease,
became
very
popular

19. • Acute
Intermient
Porphyria
• Spinal
Muscular
Atrophy
1
• Duchenne
Muscular
Dystrophy
• Limb
girdle
muscular
dystrophy
• Amyotrophic
lateral
sclerosis-­‐
(HGF)
• Painful
diabe<c
neuropathy-­‐
(HGF)
• Leber's
Hereditary
Op<c
Neuropathy
• Choroideremia-­‐
done
in
Edmonton
• Rare:
Neuronal
Ceroid
Lipofuscinosis
• Common:
Parkinson’s
disease
• Very
common:
Myocardial
infarct-­‐
into
coronary
arteries
Direct
gene
delivery-­‐
commonly
used
19
Into
the
blood
Into
the
muscles
Into
the
brain
Into
the
eye

20. • Skin
melanoma
(delivers
a
tumor
suppressor
molecule).
• Recurrent
Prostate
Cancer
(increases
chemo
uptake).
• Advanced
stage
head
and
neck
malignancies
• Breast
cancer
(delivers
IL12)
• Advanced
Pancrea<c
Cancer
• For
addi<onal
condi<ons:
Clinical.Trails.gov
Direct
gene
therapy
very
promising
in
treating
20
Cancer!

21. Chimeric
antigen
receptor
(CAR)-­‐
T
cells
Treatment
of
B‑cell
malignancies
using
anF-­‐CD19
CAR
T
cells.
Nat.
Rev.
Clin.
Oncol
2014
T
cell
ac<va<on
T
cell
expansion
Refractory
lymphoma
Viral
delivery
of
an<-­‐CD19
CAR
“sensor”
CAR-­‐T
infusion
chemo-­‐
therapy
T
cell
Isola<on
21
“Arm”
pa<ents’
immune
cells,
outside
of
the
body,
with
an
engineered
“sensor”
that
searches
for
malignant
cells

22. Chimeric
antigen
receptor
(CAR)-­‐
T
cells
• Clinical
trials
of
CAR-­‐T
cells
to
leukemia,
lymphoma,
mul<ple
myeloma,
cervical
cancer,
and
many
more.
• Caveats:
• Some
pa<ents
do
not
have
enough
T
cells.
• Difficult
to
isolate
T
cells
and
insert
genes
into
them.
• T
cells
have
a
short
biological
half
life.
• Might
aack
“innocent
bystanders”
(similar
to
GvHD)
• Long-­‐term
benefits
not
known
yet.
• Accessibility,
as
very
expensive
(>$350,000/treatment).
22

23. Next
generation
gene
therapy
(1)
• Cells
source:
usage
of
“induced
pleuri-­‐potent
stem
cells”
such
as
pa<ent’s
skin
cells
that
are
“re-­‐programed”
into
bone
marrow
cells
or
T
cells,
and
then
are
corrected
by
gene
therapy
outside
of
the
body.
• Safer
delivery
tools,
including
“destruc<on
switch”
that
can
be
turned
on
if
cells
are
causing
uncontrollable
damage,
or
an
“insulator”
to
prevent
effects
on
neighboring
genes.
• More
efficient
viruses.

24. Next
generation
gene
therapy
(2)
• CRISPER/Cas9
is
revolu<onary
targeted
gene
edi<ng
technology.
• Instead
of
“adding”
an
exogenous
gene,
correct
the
defect
in
the
exis<ng
gene
(outside
of
the
body).
• Advantage:
use
the
cell’s
own
regulatory
mechanisms.
• No
need
to
worry
about
the
number
of
copies
inserted.
• However,
each
defect
in
each
gene
needs
to
be
corrected
independently
(hundreds
of
muta<ons
in
each
of
the
hundreds
of
affected
genes.
Very
promising
technology!!

25. Conclusions:
Gene
therapy
has
moved
from
vision
to
clinical
reality
• Early,
GT
was
impeded
by
adverse
effects
and
low
efficacy.
• Understanding
mechanisms
led
to
sophis<cated
tools
with
improved
safety
and
efficacy.
• In
recent
years,
there
has
been
promising
progress,
sugges<ng
that
GT
is
an
appropriate
treatment
approach.
• Further
improvements
are
expected
in
the
near
future,
par<cularly
in
controlling
gene
expression
and
protein
func<on,
making
gene
therapy
even
more
arac<ve
therapeu<c
op<on.
• Remaining
biological
limita<ons
&
financial
accessibility
will
need
to
be
addressed
by
scien<sts
and
the
community,
respec<vely.
25

26. Acknowledgments
• Suppor<ve
medical
community
(Hospital
for
Sick
Children,
The
Blood
&
Marrow
Transplant
unit,
Dr.
Roifman
&
SK
colleagues).
• Na<onal
and
Interna<onal
colleagues
(Aiu<-­‐
Milan,
Kohn-­‐
L.A.)
• Funding
agencies
(SK
Founda<on,
D
&
A
Campbell,
CIHR,
etc).
• Ontario
Ministry
of
Health
(“Out
of
Country”
sec<on).
• !!
Trus<ng
pa<ents
and
families
!!
26
3
of
our
recent
children
who
received
gene
therapy