Introduc)on to Therapeu)c Strategies for Duchenne Sharon Hesterlee, Ph.D. Sr Director Research and Advocacy
DMD develops when dystrophin is missing or malformed
What does dystrophin do?
What happens when dystrophin is missing? calcium
Free radicals Inflamma)on Fibrosis (scarring) Muscle cell death no linkage
Strategies: How to fix the problem? Muscle Cell
Gene
RNA
Protein
Downstream funcFons Membrane integrity Cell health NO signaling
• Stem cells
• Gene repair
• Increase muscle growth
• Gene replace-‐ ment (gene therapy)
• Stop codon read-‐ through • PTC drugs to upregulate utrophin and IGF-‐1 and to block myostaFn
• Protein replacement
• Nitric oxide enhancers • Cell death inhibitors • Protein break-‐ down blockers • InflammaFon blockers
• Exon-‐skipping
From the “Bench” to the “Bedside”
Basic Research
Drug Screening Target IdenFficaFon
“Proof-‐of-‐Principle” TesFng in Animals
TranslaFonal Research “Preclinical Drug Development”
Clinical Research Including Trials
Cost of Projects Number of Projects
Pipeline Proof of concept
Preclinical
Human Trials Phase I
Gene Therapy: IM Gene Therapy: Regional PTC-‐124 Exon-‐skipping An)-‐fibro)c Therapy An)-‐inflamma)on Non-‐viral Gene Therapy Utrophin Protein Therapy Gene Correc)on Mesangioblast Stem Cells Bone Marrow Stem Cells Muscle Growth Embryonic Stem Cells Cord Blood Stem Cells Utrophin Upregula)on Dystrophin S)mula)on Growth Factors Exercise Cardiac Repair Myoblast Transplant Poloxamer therapy
Phase II
Strategies: How to fix the problem? Muscle Cell
Gene
RNA
Protein
Downstream funcFons Membrane integrity Cell health NO signaling
• Stem cells
• Gene repair
• Increase muscle growth
• Gene replace-‐ ment (gene therapy)
• Stop codon read-‐ through • PTC drugs to upregulate utrophin and IGF-‐1 and to block myostaFn
• Protein replacement
• Nitric oxide enhancers • Cell death inhibitors • Protein break-‐ down blockers • InflammaFon blockers
• Exon-‐skipping
TherapeuFc Strategies: Supplying healthy genes • Dystrophin • Utrophin • Agrin • Integrin • GalNac transferase • LARGE
[Illustra)ons from MDA’s Quest Magazine]
TherapeuFc Strategies: Supplying healthy genes Who
Phase
Gene
Vector
Delivery
Status
Plasmid study (Fardeau, et al) 2004
Phase I
Dystrophin
Plasmid
Intra-‐muscular injec)on
Complete: weak dystrophin in of 9 par)cipants
Asklepios Biopharmaceu)c als (Mendell and Samulski) 2010
Phase I
Micro-‐ Dystrophin
AAV 2.5
Intra-‐muscular injec)on
complete
Mendell-‐Wilton
Phase I
Alpha-‐ sarcoglycan (LGMD)
AAV 2
Intramuscular injec)on
complete
Mendell
Phase II
Alpha-‐ sarcoglycan (LGMD)
AAV8
Regional (whole limb)
enrolling
Samulski
Phase II
Micro-‐ Dystrophin
AAV8
Regional (whole limb)
Healthy volunteers
Mendell
Phase I
FollistaFn (BMD and IBM)
AAV1
Intra-‐muscular injecFon
2011
Chamberlain
Phase I
Micro-‐ dystrophin
Strategies: How to fix the problem? Muscle Cell
Gene
RNA
Protein
Downstream funcFons Membrane integrity Cell health NO signaling
• Stem cells
• Gene repair
• Increase muscle growth
• Gene replace-‐ ment (gene therapy)
• Stop codon read-‐ through • PTC drugs to upregulate utrophin and IGF-‐1 and to block myostaFn
• Protein replacement
• Nitric oxide enhancers • Cell death inhibitors • Protein break-‐ down blockers • InflammaFon blockers
• Exon-‐skipping
TherapeuFc Strategies: Exon-‐skipping
exon Intron
exon Intron
exon Intron
Intron “frameshiZ” mutaFon in dystrophin RNA leads to garbled protein
Blocking splice site with anFsense oligos leads to exclusion of exon with mutaFon; protein is shorter, but in frame
TherapeuFc Strategies: Exon-‐skipping
Exon 51 skipping for these deleFons: exons 45-‐50, exons 47-‐50, exons 48-‐50, exons 49-‐50, exon 52 and exons 52-‐63 Exon 50 skipping for these deleFons: Exon 51, exons 51-‐53, exons 51-‐55
Who
Where
Exon
Phase
Delivery
Prosensa
Europe
51 PRO051
Phase I
Intramuscular Complete
AVI
UK
51 AVI-‐4658
Phase I
Intramuscular Complete
GSK
Europe
51 GSK2402968
Phase I/IIa
Systemic
Complete
AVI
UK
51 AVI-‐4658
Phase II
Systemic
Final data analysis
50 AVI-‐5038
Preclinical
Not in humans
44
Phase I/IIa
Subcutaneous Ongoing injec)on
AVI
Prosensa
Europe
PRO044
Status
Therapeu)c Strategies: “Ignoring” muta)ons Dystrophin protein fragment STOP
STOP
Full-‐length dystrophin
STOP
STOP
Gentamicin/ PTC 124
Therapeu)c Strategies: “Ignoring” muta)ons Who
What
Phase
Delivery
Status
Jerry Mendell Gentamicin
Phase I/II
IV
Completed
PTC Therapeu)cs
Ataluren
Phase I
Oral
Completed
PTC Therapeu)cs
Ataluren
Phase IIa
Oral
Completed
PTC Therapeu)cs
Ataluren
Phase IIb
Oral
Halted
PTC Therapeu)cs
Ataluren
Non-‐ ambulatory study
Oral
Halted
Strategies: How to fix the problem? Muscle Cell
Gene
RNA
Protein
Downstream funcFons Membrane integrity Cell health NO signaling
• Stem cells
• Gene repair
• Increase muscle growth
• Gene replace-‐ ment (gene therapy)
• Stop codon read-‐ through • PTC drugs to upregulate utrophin and IGF-‐1 and to block myostaFn
• Protein replacement
• Nitric oxide enhancers • Cell death inhibitors • Protein break-‐ down blockers • InflammaFon blockers
• Exon-‐skipping
Muscle Build-‐up verses Muscle Break-‐down
• S)mulate muscle growth pathways
• Block protein break-‐down (proteasome inhibitors) • Block cell death (apoptosis inhibitors)
Muscle Build-‐up verses Muscle Break-‐down Who
What
Phase
Delivery
Wyeth
Myotas)n an)body
Phase I
Subcutaneous Completed
Phase I/II
Subcutaneous Completed
Iplex
Phase IIb
IV
Completed
Acceleron
ACE-‐031
Phase I
Injec)on
Completed
Acceleron
ACE-‐031
Phase II
Injec)on
Recrui)ng
Wyeth
Status
Therapeu)c Strategies: Supplying new cells
Stem Cells Derived from • Bone marrow • Muscle )ssue • Blood vessels • Embryos
Entering Muscle [illustra)on from MDA’s Quest Magazine]
Who
What
Where
Phase
Status
Guilio Cossu
Mesangioblast transplant
Italy
Phase I
Preclinical
An)-‐inflammatory/an)-‐fibro)c Strategies • Prednisone • NF-‐κB pathway • TGF-‐beta pathway
Who
What
Phase
Status
Ka)e Bushby: TREAT-‐ NMD
Prednisone
Approved
Recrui)ng within the next year
Catabasis
CAT-‐1904 (NF-‐κB )
Preclinical
No human studies
Validus
Anecortave (NF-‐κB)
Preclinical
No human studies
Dennis Gunridge
NBD ( NF-‐κB )
Proof-‐of-‐concept
No human studies
Jerry Mendell and Hugh Allen
Losartan (TGF-‐Beta)
Approved
Recrui)ng
Strategies: How to fix the problem? Muscle Cell
Gene
RNA
Protein
Downstream funcFons Membrane integrity Cell health NO signaling
• Stem cells
• Gene repair
• Increase muscle growth
• Gene replace-‐ ment (gene therapy)
• Stop codon read-‐ through • PTC drugs to upregulate utrophin and IGF-‐1 and to block myostaFn
• Protein replacement
• Nitric oxide enhancers • Cell death inhibitors • Protein break-‐ down blockers • InflammaFon blockers
• Exon-‐skipping
Other Approaches • Restoring Nitric Oxide (NO) ac)vity in the muscle • Patching holes in the membrane • Blocking calcium • Reducing oxida)ve stress • “Membrane stabilizing” proteins (utrophin, laminin 111, agrin, GalNac transferase)
Other Approaches Who
What
Phase
Status
Kathryn Wagner and Stan Froehner
Sildenafil (NO restora)on)
Approved
Recruitment this year
Phrixus
Carmaseal (poloxamer 188) for cardiomyopathy
Preclinical
Recruitment this year
Fred Sachs of SUNY Buffalo and Rose Pharmaceu)cals
GsMTx4 Mechano-‐sensi)ve pore blocker
Proof-‐of-‐concept
No human studies
Brian Tseng
Protandim (reducing oxida)ve stress)
Supplement
No humans studies in DMD
Prothelia
Laminin 111
Preclinical—Lead candidate
No human studies
Biomarin
Utrophin upregulator Phase I
Jim Ervas), University TAT-‐utrophin of Michigan PTC Therapeu)cs
In progress
Proof-‐of-‐concept
No human studies
Utrophin upregulator Preclinical—lead candidate
No human studies
Ques)ons? Sharon Hesterlee, Ph.D. Senior Director of Research and Advocacy Parent Project Muscular Dystrophy sharon@parentprojectmd.org (520) 444-‐4462