Overview of Duchenne Research Strategies

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