Exon skipping therapy for Duchenne muscular dystrophy It takes more than an an9sense oligonucleo9de

Transcription

1 Exon skipping therapy for Duchenne muscular dystrophy It takes more than an an9sense oligonucleo9de February 2018

2 Outline Duchenne and dystrophin Exon skipping approach Clinical development Lessons learnt Exon skipping for addi<onal diseases 2

3 Dystrophin protein Acts as shock absorber Connects cytoskelletal ac<n to extracellular matrix 3 ac9n binding domains 24 spectrin like repeat domains & 4 hinges Cystein rich domain C-terminal domain 3

4 Splicing

5 Dystrophin exons 5

6 Duchenne: reading frame disrupted 6

7 Exon dele<on Exon 46 Exon 47? Exon 51 Exon 52 Disrupted reading frame Protein transla<on truncated prematurely Dystrophin not func<onal 7

8 Becker: frame maintained 8

9 Becker: reading frame maintained Exon 46 Exon 47 Exon 52 Exon 53 Reading frame not disrupted Protein transla<on con<nues Dystrophin partly func<onal 9

10 Exon skipping to restore reading frame AON Exon 47 Intron 47/50 Exon 51 Intron 51 Exon 52 Intron 52 Reading frame restored Exon 46 Exon 47 Exon 52 Par<ally func<onal dystrophin 10

11 An9sense oligonucleo9des Small modified DNA or RNA Requirements for splice modula<ng AONs Nuclease resistant Should not induce RNase H Good pharmacokine<c proper<es Many chemistries available Used 2 -O-methyl phosphorothioate Stable Cheap Good PK proper<es 11 Aartsma-Rus Jan

12 Exon 51 skipping in Δ exon cells MANDYS1 MANDYS1 DYS2 12

13 Exon 44 skipping in Δ exon cells MANDYS1 MANDYS1 DYS2 13

14 Muta<on specific approach Dystroglycan domain hotspot 14 Exon All muta9ons Dele9ons 51 14% 21% % 13% % 12% % 11% % 5.6% % 4.5% 8 2.0% 2.9% Bladen et al, Hum Mut 2015

15 Clinical development 15

16 Clinical development 16

17 17 Annemieke Aartsma-Rus

18 Considera<ons for systemic delivery AONs very small (8-12 kda) Filtered out by kidney Phosphorothioate modifica<on Serum protein binding Less clearance by kidney Uptake by liver Uptake muscle poor 18

19 Mdx mouse model Spontaneous nonsense muta<on in exon 23 No dystrophin produc<on Dystrophic muscles Milder phenotype Needs exon 23 skipping 19

20 Systemic studies in mdx mice AON levels in muscle and Liver Gastrocn. WT Mice Mdx Mice 20

21 Systemic treatment AON Tissue Levels (ug/g)

22 22 TREAT-NMD BioBank Joint Research Standard Operating Procedures Website & Communications TACT Three year work plan Standards of Diagnosis & Care Patient Registries Care & Trial Site Registry Outcome Measures Outcome Pa9ent Care Joint EuroBioBank Standards Ac9on & Website Registries measures Trial research SOPs TACT Plan Site of & Diagnosis EU Communica9on funded Registry Network & Care Tests Standardized Unique TREAT-NMD Unified Regular to decide network gene<c experimental mee<ngs 3 year Advisory whether of plan 18 & to treatment clinical consolidate protocols core Extensive Commidee data improve efforts members for trial Interna<onal 2012 being onwards Informa<on website and the for recruitment about consensus tested in each Milestone-driven publica<on a comparability trial jointly is registered Alliance having tackle Therapeu<cs, of approach common studies Stores trial recommended any & site funded effect distributes kept in Interface 250,000 annual problems page hits 440,000 one loca<on through can standards vary Expert Drawn Maintains quality for mul<ple between mul<disciplinary up by a DNA, ease of care Vital to use the group network correct cell of countries streams whilst with of Topics independent 70,000 momentum based and visitors <ssue comparison s<ll global able outcome measure on researchers & necessity, establish annually to samples prove partners DMD-SMA-CMD-LGMD to share core body data (listed hos<ng if a in treatment & membership each to be new protocol) rotated works Addresses goals Independent Ethical Monthly & between governance newsleder organisa<onal and objec<ve partners sent best Working difficul<es Approx guidance to to Governance Family 40 3,500 of iden<fying guides harmonise sops on advancing recipients updated prac<ce the in appropriate 25 use Chair different of most Kevin sites languages appropriate Flannigan when Vice new therapies regularly for Proven transla<ons outcome >10,000 Chair selng communica<on DMD measures Jan up Kirschner verified pa<ents a trial for neuromuscular plaeorm diseases across Execu9ve different 30 countries diseases Printed booklets Commi`ee or Leads Leads - Marina Eric Hoffman Mora Annemieke Leads Supported - download Eugenio Jan Aartsma-Rus Verschuuren by academic Mercuri from advisory Secretariat Chair board Hugh Dominic Lucia - ( task Kate website Dawkins Monaco Bushby force ) Wells Filippo of Volker NMD Marco Buccella leaders Straub Crimi Funding Coordinated - Telethon by University & Parent Leads Medical Funding - Thomas Center - US - AFM (Dept & EC of Funding Funding Organiza9ons Sejersen Freiburg EC - Fondazione (opera9ng - COST (opera9ng Kathy Defense) grant) North Telethon grant)

23 Trials were ini<ated Subcutaneous delivery 2a: Dose escala<on (n=12) 2b: Dose regimen (n=51) 2b: Dose comparison (n=51) 3: Efficacy study (n=186) Open label extension study for each Primary endpoint: 6 minute walk test 23

24 Side effects observed Local injec<on reac<ons Known effect of subcutaneous delivery of PS AONs Intraveneous delivery: no injec<on reac<ons Proteinuria (reversible during treatment breaks) Thrombocytopenia in some pa<ents 24

25 Systemic trial 2OMePS (GSK/Prosensa) Pre-Treatment Dose * *Revertant Fiber Dystrophin (ManDys 106) Goemans et al, NEJM 2011, 364:

26 Open label study ater dose escala<on 26

27 Phase 2b. Dose regimen study 27

28 Phase 2b. Dose comparison 28

29 Phase 3. Efficacy study 29

30 What we know now Blue: below 7 Red: above 7 30

31 What we know now Green: baseline >350 m Orange: baseline <350 m 31

32 What happened then GSK dropped drisapersen Prosensa acquired by BioMarin! additional analyses Phase 3 population more advanced disease Younger subgroup shows response Older patients show response after longer treatment (open label) Applied for approval with FDA and EMA Approval denied by FDA Application withdrawn from EMA 32

33 And then 33

34 Lessons learned Interaction with regulators started too late Lack of outcome measures & natural history data Suboptimal trial design Now Ongoing dialogue academics, patients and regulators in EU Development new outcome measures Future trials will be better 34

35 PUL test: developed WITH pa<ents 35 Anna Mayhew

36 Let others benefit from your mistakes 36

37 Another exon 51 skipping drug is approved! Based on very minor increases in dystrophin (<1%) No func<onal efficacy shown yet Company needs to confirm func<onal effect by 2021 Based on drisapersen target sequence (IP LUMC) 37

38 What is clear There is room for improvement Currently working on Improved AON chemistries Muscle specific conjugates Beder animal models Improving muscle quality Improve understanding dystrophin splicing 38

39 Acknowledgements Exon Skip group Pietro Spitali Maaike van Puden Kayleigh Putker Silvana Jirka Svetlana Pasteuning Monika Hiller Davy van der Vijver Gido Gravesteijn Maurice Overzier Christa Tanganyika-de Winter Laura van Vliet Kevin Adamcek Nisha Verwey Ingrid Verhaart Gert-Jan van Ommen Department of Neurology/Radiology Erik Niks Jan verschuuren Hermien Kan Zaida Koeks Nathalie Doorenweerd BioMarin Nederland Judith van Deutekom Nicole Datson Peter de Visser 39

40 Other ways to do exon skipping Interna<onally: many! Reading frame restora<on Change alterna<ve splicing Reduce toxic protein forma<on Restore cryp<c splicing Exon inclusion: nusinersen for spinal muscular atrophy At LUMC PolyQ diseases (Willeke van Roon-Mom) CADASIL (Saskia Lesnik Oberstein) 40

41 Ataxin-3 exon skipping as a treatment strategy for SCA3 Lodewijk Toonen Departement of human gene<cs 41 Insert > Header & footer LUMC, The Netherlands 9-maa-18

42 CADASIL exon skipping Julie Ruden Departement of clinical gene<cs 42 Insert > Header & footer LUMC, The Netherlands 9-maa-18

43 Final conclusions An<sense mediated splicing modula<on has therapeu<c poten<al Focus on gene<c diseases Oten muta<on specific approach Approved drugs for DMD and SMA Many other approaches tested preclinically