First in human:Irv Weissman, Stanford University/media/Files/Activity Files/Research... · First in...
Transcript of First in human:Irv Weissman, Stanford University/media/Files/Activity Files/Research... · First in...
First in human:Irv Weissman,
Stanford University
The case for making human
mouse chimeras to understand
the function of human tissue stem
cells from normal or genetically
diseased donors
Blood-Forming Stem Cells
Ludwig Center at Stanford University
IN VIVO
VERITAS
1 Development
2 Maintenance
3 Malignant
transformation
Engraftment of human fetal blood-forming
tissues in the SCID mouse
Bruno Peault
Ethics and politics in 1986-88
, Mike McCune, Reiko Namikawa, Ann Tsukamoto Irv Weissman
Cancer Free Stem Cell Grafts
Improves Survival • Purified HSC show 3-fold higher survival vs non-purified MPB
• Stage 4 metastatic patients – failed all other therapies
~7%
~22%
~33%
Mueller,A. et al. 2011
ChemoRes
Stanford HSC
Stanford MPB
P< .02
P<.01
• Donor blood-forming and immune system
• Induce permanent transplant tolerance
• Reverse genetic autoimmune disease
Healthy Donor Transplant
Healthy Donor
Recipient
MPB or bone marrow
Pure stem cells
• Dependent on
Immunosuppressants
• Risk of Infections
(fungus, bacteria)
Recipient
Recipient
Recipient
T cells
Graft vs Host Disease Healthy
RADIATION DAMAGE OR THERAPY
GvH No GvH
Shizuru, Beilhack, Weissman
HSC Transplants In The Future
• Limited or no use of radiation or cytotoxic
drugs
• Targeted removal of host HSC, T cells,
and NK cells with Mabs
• In the far future [>5-10 years], ES or iPS
derived HSC will be cotransplanted with
other tissue stem cells from the same
donor line
02/16/99 1
Can Tissue Stem Cells Transdifferentiate?
Pluripotent stem cell
CNS-SC
Neurons Oligo-
dendrocytes
Astrocytes
HSC
Blood
PSC
Trans-differentiate
Differentiate
OR
Dedifferentiate
Cardiac
or
Skeletal
or
Lung
Trans-differentiate
NO! NO!
Human CNS-SC Neurosphere Cells Engrafted, Migrated &
Differentiated Into Neurons, Astrocytes and Oligodendrocytes
In Vitro Expansion
Transplantation
Dopaminergic
Neuron
Astrocytes Neurons Oligodendrocytes
Cerebellum
Cerebral Cortex
Immunodeficient mouse brain
Uchida et al
x
Human cells derived from HuCNS-SC transplant (brown)
RMS
Migrating as
chain of neuroblasts
b-tubulin III/ Human nuclei
Proliferation at neurogeneic site
SVZ
BrdU/Human Nuclei
Site appropriate differentiation
Into Granule Neurons in the olfactory bulb
HuCNS-SC Engraft, Migrate & Mature
SC121
Olig2
MBP
Animal Studies: Production of Function Myelin
MBP
Oligodendrocyte
differentiation – new
functional myelin
Myelin enhanced nerve
conduction
MRI used to detect human
myelination in animals
Uchida, et al. 2012
16-20 dense lines
• Progressive and fatal X-linked hypomyelination disorder due
to mutations of the proteolipid protein gene, PLP1
• No current therapy - regenerating oligodendrocyte
population alone could produce clinical benefit
• Recognized as appropriate human target for proof-of-
concept of donor-derived myelination in non-inflammatory
setting
• Diagnosis readily confirmed affording opportunity for early
intervention
• MRI measures of de novo myelination available as potential
surrogate markers of engraftment and function
Hypomyelination Disease:
Pelizaeus-Merzbacher Disease (PMD)
Well-tolerated intervention with a favorable safety profile
Signs of clinical changes detected suggest a departure from
the natural history of disease
MRI findings consistent with de novo myelination in the
transplanted frontal lobe regions in all four subjects
Phase I strongly supports a controlled Phase II trial in PMD
MRI data in a human hypomyelination disorder suggests
potential applicability to other myelination disorders, such as
select forms of cerebral palsy, spinal cord injury, transverse
myelitis, and multiple sclerosis
Phase I PMD: Summary of results
Pre 1 2 3 4 5 6 8 14 12
8
10
12
14
Weeks Post Injury
Open Field
BBB Score
(0-18)
* * * * *
HuCNS-SC (n=11)
Control (n=15)
Repeated Measures ANOVA p<0.01
* individual time points p<0.05
16
HuCNS-SC: Spinal Cord Injury Preclinical Efficacy
30day Delay DT
Treatment
Loss of
Gained
Function
Contusion site
A. Anderson UC, Irvine
Extensive engraftment with CNS SC,
local deposit with MSC; both DT sens
• Favorable interim safety and feasibility
• AIS A (n=3) cohort enrolled
• No adverse events attributed to HuCNS-SC
• Observed changes in light touch sensation support safety
• Quantitative Perception Testing shows segmental gains
• No evidence of electrophysiological loss
• AIS B cohort enrolling; AIS B dosed Sept 2012
Phase I/II SCI: Interim Results
Subject ASIA Grade ASIA Spinal
Level
Months Post
Txp
001 A T8 17
002 A T9 15
003 A T4 14
normal
impaired
absent
Subject 3:
Light touch examination
Jun 28 12 (6m Post-TX) Dec 12 11 (Pre-TX)
© StemCells, Inc. 2012
HuCNS-SC Clinical Trial Summary
Study N Cell Dose(s) Location Current Follow-up
Lysosomal
Storage
Disease (NCL) 6 500 to 1000 x 106
BRAIN:
Frontal lobe
Parietal lobe
Lateral ventricle
> 5 years
(n=3)
Myelin Disorder
(PMD) 4 300 x 106
BRAIN:
Frontal lobe > 2 years
(n=4)
Spinal Cord
Injury 4/12 20 x 106
SPINAL CORD
thoracic
intramedullary
AIS A > 1 year
(n=3)
AIS B 4 months (n=1)
Retinal
Degeneration
(dry AMD)
2/16 0.2 to 1 x 106 EYE:
subretinal space 2 to 4 months
(n=2)
Lessons learned to date • Choice of animal models on target
• Animal models have been very good predictors; to date
recapitulating in humans what we have seen in animal models
• Safety profile show no concerns to date
• Metric for calculating dose choices seem to be working
• Small uncontrolled studies on patients
• Preliminary evidence of HuCNS-SC biological activity in
transplanted patients reflect what we have seen in animal models
to date
• Accumulating long-term safety (1-5yrs), sustained biological
effects
It’s the cells, stu…
The human neuron-murine brain
mouse • Several mutations allow early neural precursors,
perhaps radial glia, to proliferate, but neuron
lineage progeny die or disappear: ligase 4 dko,
xrcc4 dko, etc.
• Will same stage human neural stem/progenitors
engraft in fetal life and make mouse or human
nervous systems, if they work at all?
• Bioethics: The American Journal of Bioethics,
2007.Thinking About the Human Neuron
Mouse.Henry T. Greely; Mildred K. Cho; Linda
F. Hogle; Debra M. Satz
WHICH OF THE FOLLOWING
NEURAL DISEASES DO YOU
NOT WANT TO CURE? • Lysosomal storage diseases(Battens,
Gauchers, etc)
• Brain cancers
• Spinal cord contusion with demyelination
• Stroke
• ALS
• Parkinsons
• Alzheimers
• Huntington’s
• Cerebral palsy
• Others I forgot since medical school
Single –cell
embryo ~ Day 6 ~ Day 3-4
Embryonic
Stem Cell
Totipotent
Epiblast
Stem Cell
Pluripotent
First tissue stem
cells
Embryo – Fetal Transition
Somatic / adult stem
cell Multipotent
Cord blood &
placenta
Hematopoietic (HSC)
&
Mesenchymal (MSC)
Other tissue
stem cells
Reprogrammed iPS Pluripotent
Phase I Study:
HuCNS-SC derived myelination
Diffusion MRI shows HuCNS-SC-derived myelination in all PMD subjects: 1
year post-transplant and 3 months post-withdrawal of immunosuppression
Gupta, et al. 2012
Control
ROIs
Transplant
ROI
Subject 3: EPT and dSSEP (T7 Left)
Dec 12 ‘11
Pre-txp Jun 28 ‘12
6m post-txp
© StemCells, Inc. 2012
• Purified, expandable & cryopreservable
• Self-renewing, non-tumorigenic
• Allogeneic – homologous use into
brain, spinal cord or eye
• In vivo – CNS restricted
• survive & migrate
• regulated by host
• differentiate site specific
• Mechanism-of-action: multi-faceted
• Cell replacement with proper type:
oligodendrocytes, neurons, astrocytes
• Neuroprotection of host cells: trophic
effects by secreted factors
HuCNS-SC cell attributes and clinical translation
Neurons Astrocytes Oligodendrocytes
Subject 1
(16m)
Tracheostomy and gastrostomy at baseline. Remained neurologically stable, but was noted to have reduced nightly
continuous positive airway pressure (CPAP) at 12 months. Increased FA by MRI.
Subject 2
(42m)
Developed improved truncal support and the ability to take steps with assistance.
Began speaking audible single words and the ability to follow two-step commands.
Increased FA by MRI.
Subject 3
(14m)
Tracheostomy and gastrostomy at baseline. Nightly CPAP dependency reduced.
Developed upper extremity antigravity strength and to take some solid foods by mouth.
Greatest increase in FA by MRI; but comparable to “control” regions.
Subject 4
(66m)
Developed improved truncal support; progressed from the use of a walker with significant support to walking with minimal assistance.
Developed the ability for self-feeding and to follow two-steps commands. Increased FA by MRI.
Clinical and Radiological Observations in PMD
Patients Post Transplant
Study Outcome
Animal
(thoracic SCI mice)
Locomotor improvement dependent on
presence of human cells
Remyelination & new neurons
Human – Phase I/II
Thoracic injury
chronic
12 mo. interim results: AIS-A
No safety concerns to date
Observed changes in light touch sensation
supporting safety
No evidence of electrophysiological loss
Clinical signs of sensory gains
Spinal Cord Injury
• Swissmedic authorized
• 12 patients with thoracic injury (tSCI)
• Injury level: T2-T11
• Chronic injury stage: 3-12 months post-injury
• Broad range of injuries: AIS A, B, C
• Significant cell dose: 20 million cells
• Safety and preliminary efficacy
• Clinical
• electrophysiological and
• QoL endpoints
Phase I/II Thoracic SCI Study
Study Outcome
Animal
(RCS rat)
Preservation of visual acuity
Neuroprotection of host cone photoreceptors
Human
Phase I/II
Dry AMD
TBD
Enrolling patients
Case Study: Retinal
Degeneration
Preservation of visual acuity
# c
on
es/1
00m
m
McGill et al,
2012
• Geographic Atrophy (dry) age-related macular degeneration
• Open-label; dose-escalation (200,000 and 1 million cells)
• Cohort I: 8 subject ≤ 20/400 – dosing in progress
• Cohort II: 8 subjects 20/100- 20/200
• Objectives: Safety and preliminary efficacy
Phase I/II AMD Study ClinicalTrials.gov Identifier: NCT01632527
Dry AMD Wet AMD
MRI: NCL Brain
Normal brain 6 year-old with NCL
Mouse Model that Mimics Human NCL
PPT 1-/-
CA1
Normal (NOD-scid)
CA1
NCL mouse brain: CA1 region only 8% of neurons were detected compare to normal
Neuroprotection Through Myelination
Oligodendrocyte Myelin sheath
with 20 continuous dense wrapping
Process
Myelinated Axons
Myelinating human MBP+
Olig2+ oligodendrocgtyes
in shiverer mouse brain
Olig2/SC121/MBP
Contused Spinal Cord Injury
Improved motor function
Remyelinated damaged axons
Axon
Axon
Immuno-EM: human myelin sheath
Human myelin sheath
with multi-layers dense wrapping
Oligodendrocyte death or
aberrant myelin
production leads to
myelin-associated
diseases
CNS-SC were
transplanted into: - oligodendroctye-mutant
shiverer mouse brain
- the injured spinal cord of
NOD-scid
HuCNS-SC Protects Neurons in Batten Mouse
Hippocampus
Not transplanted Low Dose
Transplanted
High Dose
Transplanted
% o
f N
orm
al
0
20
40
60
8 %
33 %
57 %
p<0.001 p<0.001
n=6 n=9 n=6
Capela, Uchida
HuCNS-SC Restores Motor
Function in Spinal Cord
Injured Mice
Pre 1 2 3 4 5 6 8 14 16 12 Post
DT
8
10
12
14
Weeks Post Injury
Open F
ield
BB
B S
core
(0
-18)
* * * * *
DT
Treatment
Restored
Motor
Function
Lost
HuCNS-SC (n=11)
Control (n=15)
Repeated Measures ANOVA p<0.01
* individual time points P<0.05
Aileen Anderson, Brian Cummings,Nobuko Uchida et al
Testing Biological Activity of Human Cells in Animal Models: Xenogenic Transplant
Immunodeficient mice: NOD-scid