2008-0471s1-4
DESCRIPTION
TRANSCRIPT
Human Embryonic Stem Cells: Considerations for
Therapeutic Development
Jane Lebkowski Ph.D.Geron Corporation
Cell, Tissue and Gene Therapy Advisory Committee MeetingApril 10, 2008
Human Embryonic Stem Cells
Blastocyst
Human Embryonic Stem Cells
Neural Cells
Spinal CordInjury
Parkinson’sDisease
Cardiomyocytes
Heart Failure
Islets
Diabetes
Osteoblasts
OsteoporosisAnd BoneFractures
Chondrocytes
Arthritis
Hepatocytes
Drug DiscoveryLiver Failure
Dendritic Cells
Tolerance InductionCancer Immunotherapy
Large Characterized cGMP Banks
Therapeutic Cells
hESCs: New Cell Type for Potential Broad Therapeutic Application
Simplify, Standardize, and Scale hESC Growth
Develop Reproducible Methods to Selectively Differentiate Cells
Develop Parameters to Characterize Differentiated Cell Populations
Define Efficacy, Potency, & Safety of Cell
Populations
Develop Methods to Deliver Cells to Target Tissue
Define Need for Immunosuppression
Demonstrate Safety & Efficacy in Clinical Trials
Develop Scaled Low Cost Production Methods
Necessary Technological Developments
Spinal Cord Injury: GRNOPC1 Transplantation
Differentiation Process
• Characterization of Materials• Starting Material• Adventitious Agents
• Characterization of Unit Operations• Cell Density• Culture Format• Timing of Induction
• Storage
• Release Testing
GRNOPC1 Manufacturing Process Flow Diagram: Differentiation
ST
AG
E I
I: D
IFF
ER
EN
TIA
TIO
N
CommentsAnalytical Methods
Unit OperationsMaterials
Cell Culture Vessel
uhESC Expansion
Passaging Enzyme
Glial Progenitor Medium (GPM)
Matrix Coated Vessels
Passaging Enzyme
Cell Count Enumeration
STAGE III: Harvest,
Formulation,Fill and Finish
Medium
Growth Factor
Supplement
Medium
Matrix Coated Vessels
GPM
GPM
GPM
D-PBS
Growth Factor
Growth Factor
Growth Factor
Growth Factor
Growth Factor
Growth Factor
GPM
Growth Factor
GPM
Growth Factor
= Analytical Method
Key = Off Page Reference
= Process FlowUnit Operation
Raw Material
= Manufacturing Stage
1 = Process Step
Prepare Embryoid Bodies8
Culture Embryoid Bodies in
Suspension9
Plate Embryoid Bodies10
Culture Cells11
Passage Cells12
Culture Cells13
Day Number Specified
Day Number Specified
Day Number Specified
Day Number Specified
GRNOPC1 Contains Oligodendroglial Progenitors
Lineage Marker
Neural Progenitors Nestin
Oligodendroglial Progenitors Olig 1
Oligodendroglial Progenitors NG2
Oligodendroglial Progenitors PDGFRa
Early Ectoderm Pax 6
Early Ectoderm Sox 10
Neurons TubIII
Astrocytes GFAP
Early Endoderm HNF3
Endoderm AFP
Early Mesoderm GATA4
Mesoderm MSA
Undifferentiated hESCs OCT4
Undifferentiated hESCs Tra-1-60
Phenotype Testing of Over 75 Lots
• Multiple Markers Required
• Lineage Specific Markers
• Specific Antibodies
• Detection and Quantitation Limits of Assays
• Potency Assays
Challenges
IdentityPurity
StrengthPotency
Considerations for Nonclinical Studies for hESC-Based Therapeutics
Final Product: What is the Product Designed to Do?What is the Target Site for Activity?
Final Product Production Scale:Does Scale Effect Composition?
Formulation:Cryopreserved Format?Selective Cell Survival?
Clinical Administration:Site of Administration?Effects on Performance and Potential Adverse Events?Need for Immunosuppression?Dose Required?
Pharmacology Studies9 mos GRNOPC1
hNucEC
1mm
100 m
9 mos vehiclehNucEC
1mm
100 m
In Vitro Activity• Protein and Gene Expression• Factor Production• Structural/ Metabolic Activity
In Vivo Survival• Survive Delivery• Immune Responses
Phenotype• In Vitro and In Vivo• Maturation Over Time• Proliferative Capacity
Activity in Disease Models• Clinical Efficacy• Histological Efficacy• Dose• Human Equivalent Dose• Delivery Site and Volume• Timing of Treatment
What Is the Activity of the Cells?
Where Do The Cells Go?
GRNOPC1 Migration within the Spinal Cord
0
2
4
6
8
10
12
14
16
18
20
2 day 2.4x10^5GRNOPC1
2 day 2.4x10^6GRNOPC1
14 day 2.4x10^5GRNOPC1
14 day 2.4x10^6GRNOPC1
180 day 2.4x10^5GRNOPC1
180 day 2.4x10^6GRNOPC1
Time Point and Dose
Ce
ll D
istr
ibu
tio
n (
mil
lim
ete
rs)
2 day 2.4x10^5 GRNOPC1
2 day 2.4x10^6 GRNOPC1
14 day 2.4x10^5 GRNOPC1
14 day 2.4x10^6 GRNOPC1
180 day 2.4x10^5 GRNOPC1
180 day 2.4x10^6 GRNOPC1
Safety and Efficacy Implications
• Sensitivity of Assay
• Site for Intended Activity
• Sufficient Cells at Site
• Distribution Outside Target Site
• Migration at Local Site
• Over Extended Time
Toxicology Studies
Toxicity of Delivery
• Doses of Product
• Tox Model
• Feasibility of Model
• Duration of Studies
• Duration of Human Cell Survival
GRNOPC1
• Toxicity of Delivery
• Animal Survival
• Clinical Observations
• Systemic Toxicity
• Hematological
• Coagulation Parameters
• Clinical Chemistries
• Macropathology
• Micropathology
• Allodynia
Considerations
Tumorigenicity Studies
• Teratomas
• Ectopic Tissues
• Local Injection Site
• Distal Sites
Challenges
• Human Dose
• Long-Term Cell Survival
• Large Numbers of Animals
• Mimic Human Setting
• Large Animals?
• Homologous ESC Systems?
GRNOPC1 Deliberately Spiked with hESCs
Tumorigenicity Studies: Lessons Learned
Important Factors In Teratoma Formation
• hESCs Cell Number
• Site of Implantation
• Cell Aggregation State
2 x 106 CellsIntraspinal Cord Injection
Assessment 12 mos.
Allogenicity Studies• Immunosuppression Required?
• Duration of Immunosuppression?
Challenges
• hESC-Based Products are Xenografts in All Animal Models
• Allogenicity of Maturing Cells In Vivo
• Humanized Models Challenging
• In Vitro Analyses
• Allogenicity In Vitro
• Inflammatory Site
• Remove Immunosuppression?
• Monitor Engraftment?
• Monitor Rejection?
• Effects of Rejection
Approaches
Cell Delivery in the Clinic
Considerations
• Local Delivery
• Delivery Site
• Intraoperative Delivery
• Rate of Delivery
• Skill Set Required for Delivery
• Effect of Delivery Device on Cells
• Training
Design of Clinical TrialsKey Consideration: Patient Safety
• Protocol
• Delivery
• Logistics of Trial
• Minimize Potential Risks
• Balance Risk with Potential Efficacy
• Define Adverse Events
• Monitor for Adverse Events
• Monitor Cell Survival
• Assess Outcome Measures
• Short and Long-Term Follow-up
• Steering Committee
• DMC
• Outcomes Committee
• Neurosurgeons
• Radiologists
• Investigators
• ESCRO Committee
Interactions with:
Phase 1 Multi-Center Trial
• Open Label Trial
• Subacute, Functionally Complete T3-T12 Lesions
• Transplant 7-14 Days Post Injury
• Temporary Immunosuppression
• Primary Endpoints: Safety Assessments
• Secondary Endpoints: Multiple Outcome Measurements
• Frequent Short and Long-Term MRIs
• Immunological Monitoring
Conclusions
• Numerous Considerations in Developing Cell Therapies
• Some Questions Common To All Cell Therapies
• Some Questions More Specific to hESC-Based Therapies
• Specific Nonclinical Study Designs Based on Clinical Considerations
• Clinical Trial Designs Require Interdisciplinary Input
• Frequent Monitoring Required