Current and planned clinical research in DMD

1. Newcastle Collaborative work Dr Michelle Eagle Research Practitioner Physiotherapist Newcastle Muscle Centre Current and planned clinical research in DMD

2. Where do we need more evidence in DMD? Medicine cannot be ruled by anecdote • How do we best use the drugs we have already got? • Phase III clinical trials • Corticosteroids, cardioprotective medication • How do we test new compounds? • Phase I/II clinical trials • Antisense oligonucleotide treatment, PTC 124 etc • Myostatin inhibition?

3. Phase III clinical trials in DMD • FOR- DMD: international trial of steroid dosage regimens, seeking NIH funding • 300 patients, 14 different countries • 3 years + follow up (+2) • Three different steroid regimens • Continuous deflazacort or prednisolone • Intermittent predisolone • Which one gives the best functional gain and is most satisfactory to take? • What is the relative burden of side effects?

4. The ultimate test of the impact the natural course of the disease, and the burden of side effects, will be over a longer period. • The initial project will be embedded within a 10 year follow up study for which further funding will be sought in due course. • It will be possible to address issues concerning standards of care in DMD and the management of CS-associated side effects, • as well as develop a resource to study the pharmacogenetic response to CS treatment and the mode of action of CS in improving strength in DMD.

5. Belgium (for the Belgian network) Brussels: Peter van de Bergh (6) Canada Shannon Venance (3) Finland Helsinki: Helena Pihko (10) France Lyon: Carole Berard (5) Germany (for the German MD-Net) Rudolph Korinthberg (50) Italy (co-ordinator, C. Angelini) Bologna: Marcello Villanova (20) Messina: Guiseppe Vita (5) Naples: Giovanni Nigro (20) Padova: Corrado Angelini, Roberto Padoan (8) Pavia: Angela Berardinelli (3) Rome: Enzo Ricci, Enrico Bertini, Eugenio Mercuri (15) Netherlands (for the VSN network) Imelda de Groot, Anneke van der Kooi (20) Scandinavian network (for the Scandinavian network, co-ordinator Thomas Sejersen) Sweden/ Denmark/Norway Birgit Steffensen, Thomas Sejersen, Jas Rahbek, Magnhild Rasmussen (25) UK (North Star network) Birmingham: Helen Roper (8) Bristol: Phil Jardine (5) Cardiff (Welsh network): Louise Hartley, Cathy White, Jane Fenton-May (10) Dundee: Karen Naismith (3) Leeds: Anne- Marie Childs (12) London (Hammersmith): Francesco Muntoni, Adnan Manzur (20) Manchester: Imelda Hughes (8) Newcastle: Katharine Bushby, Volker Straub (6) Oswestry: Ros Quinlivan (6) Sheffield: Peter Baxter (4) Southampton: Neil Thomas (4) USA Baltimore: Kathryn Wagner (6) Boston: Basil Darras (6) New York City: Petra Kaufmann (17) Columbus: Jerry Mendell (20) Kansas City: Richard Barohn (10) New Mexico: Leslie Morrison (5) Oregon: Edward Cupler (8-10) Rochester: Richard Moxley, Emma Ciafaloni (5) Salt Lake City: Kevin Flanigan (20) San Antonio: Carlayne Jackson (6) Los Angeles: Melissa Spencer (20-25) Other investigators are committed to the project and will be called upon as necessary. Paris: Brigitte Estournet Spain (for the Spanish Neuropaediatric network)Jaume Colomer Switzerland (for the Swiss neuropaediatric network) Pierre Jeannet London (Guys):Heinz Jungbluth and Elizabeth Wraige Miami: Walter Bradley Philadelphia: Carsten Bonnemann Table 1 Participants in international DMD treatment trial

6. Why do we need this kind of trial? • Because there is great variation in practice of use of corticosteroids in DMD • Because there are no published long term controlled studies on the regimens in common use • Because steroid treatment in ambulant patients with DMD has become the “gold standard” against which other treatments will need to be tested

7. Steroids and non-ambulatory boys with DMD

8. Steroids and respiratory management Of boys aged 8.7 & 8.6 years mean FVC in the treated group was 1.5 litres (88% predicted) compared with 1.29litres (70% predicted) in the untreated group. % FVC was significantly greater in treated boys (p=0.0014) • Continuous steroids improve the FVC) in ambulant boys with DMD. In boys taking continuous DFZ FVC was preserved to over 1 litre aged 22.

9. Why is the FVC so important? Deteriorating FVC correlates with increasing Respiratory symptoms Need for ventilation Can be predicted by correlating symptoms and FVC

10. FVC Prognosis is improved the older the boy is when he reaches his peak FVC and the higher that peak is.

11. Non-ambulant steroid trialFunded by PPUK

12. Steroids are known to help improve strength in ambulant boys but what about those who are unable to walk? Aim • To evaluate the impact of steroids on forced vital capacity in ambulant and non-ambulant boys with Duchenne muscular dystrophy (DMD). • Improving the peak FVC and/or maintaining the FVC could delay the need for nocturnal ventilation and improve life expectancy. • Also wanted to see if there was any improvement in functional ability and muscle strength

13. Open label pilot study • prednisolone at 0.75mg/kg/day was prescribed for non ambulant boys. • A pre-treatment assessment period of three months was followed by 6 months treatment and then a further three months without treatment. • DEXA, ECHO, overnight oxymetry, manual muscle testing, functional testing, well being scales assessed 6 weekly

14. Patients • 48 not ventilated patients were identified from our clinic population • Two were excluded with severe cardiomyopathy, 4 patients approaching ventilation, 2 very obese and one diabetic were also excluded. • 39 patients were asked to participate and 12 agreed. One patient died suddenly after the first baseline assessment. • Data collection is unfinished in four patients

15. Preliminary Results • FVC deteriorated in all patients prior to starting steroids • FVC improved with treatment to more than the baseline level except those whose pre treatment FVC was below one litre (although they still improved) • FVC deteriorated to below the baseline when treatment was stopped

16. Muscle strength and Functional Ability Eight patients have completed 6 months on steroid Rx and five have requested to restart steroids. Reasons include deteriorating motor ability, weight loss, recurrence of hip pain and loss of ability to lift arms when steroids were stopped.

17. Summary • FVC improves over a 6 months period whilst taking steroids and deteriorates when steroids are stopped. • The peak FVC may not be reached within 6 months as some patients were still improving at the end of a 6 month trial. • Patients with an FVC below 1 litre do not show as much benefit as those with an initial FVC over 1 litre and may deteriorate rapidly when steroids are withdrawn. • There appears to be a stabilisation of strength over a 6 month period. • Functional improvement lags a little behind the stabilisation in power • Some non-ambulant patients benefited from increased weight but weight gain may be an undesired side effect. There were no reported behavioural or emotional disturbances over a 6 month period. Acne was a problem in 2 patients.

18. Preliminary Conclusions • Steroids should be considered for non-ambulant patients with DMD • Care should be taken if steroids are stopped as the FVC will deteriorate • Further research is required to determine optimum dose and side effect/efficacy balance

19. Heart protection in DMD

20. Scale & Implications of Cardiac Involvement Cardiomyopathy - dilated (segmenatal or global) - hypertrophic Electrical problems - ECG changes (‘electropathy’) - Ventricular arrhythmias

21. Prophylactic therapy of LV DysfunctionThe Evidence-base in DMD ? ♣ Detailed descriptions of progressive LV deterioration ♣ Extensive evidence of ACE & beta-blocker benefit in LV dysfunction and heart failure of other aetiologies. ♣ Anecdotes of improvements in DMD - in symptoms of LVF ♣ Newcastle clinic results of treating boys with progressive asymptomatic heart dysfunction

22. Cardiac involvement in DMD – when to intervene 100 80 60 Normal range LV Function 40 20 Onset of LVF symptoms 0 0 6 12 18 24 30 36 Age (years)

23. Effect of treating asymptomatic LV dysfunction Stabilising Effects of ACE & BB therapy LVEF% 70% 60% 50% 40% 30% 20% 10% 0% 13 14 15 16 17 18 19 20 21 22 23 24 25 Age (years)

24. ‘Effect of Perindopril on the Onset & Progression of Left Ventricular Dysfunction in Duchenne Muscular Dystrophy’ LV assessed: 6, 12, 18, 36 & 60 months End-points: Primary: LVEF (radionuclide) < 45% Secondary: Tolerability of perindopril Duboc et al - J Am Coll Cardiol - 2005, 45:855-7

25. The BHF-funded ‘DMD Heart-Protection Study’ - Aims ……to determine whether starting ♣ combination therapywith ACE-inhibitor & beta-blocker ♣ before the onset of echo-detectable LV dysfunction ♣ delays onset or slows cardiomyopathy progression rate ♣ five-UK-centre, double-blind, randomised, placebo-controlled trial ♣ over 5 years

26. The BHF-funded ‘DMD Heart-Protection Study’ Inclusion Criteria Aged 6-10 years ♣ LVEF > 60% (normal range = 63 + 5%) ♣ No global or regional wall motion abnormalities (echocardiogram) ♣ Informed consent from children & parents / guardians ♣ No contra-indication to perindopril or bisoprolol

27. The ‘DMD Heart-Protection Study’: Test schedule

28. The BHF funded ‘DMD Heart-Protection Study’ ♣ Primary end-point Change in LVEF% compared to baseline, after a minimum of two years of combination therapy or placebo ♣ Secondary end-points i) Death from any cause ii) Development of symptoms of cardiac failure iii) Sufficient objective deterioration in LV function, without symptoms, to make continuing placebo therapy unethical Progressive reduction in LVEF% over at least two assessments at least 3 months apart, resulting in LVEF < 35%

29. The BHF funded ‘DMD Heart-Protection Study’ Power Calculation ♣ The sample size is based on a composition of change in LVEF% over the 5 year term of the study. ♣ A difference of 5% between treatment groups was considered to be the smallest that would represent a clinically useful gain. ♣ The standard deviation of LVEF was taken to be 10% and this gives two groups of 64 subjects to yield a power of 80% at the 5% significance level & allowing for 10% withdrawal due to adverse effects Number of patients required = 140 - Start early 2006

30. Phase I/II trials in DMD • Antisense oligonucleotides • Myostatin inhibition • PCT 124 • ………….

31. Antisense oligonucleotides • Phase 1 clinical trials in the use antisense oligonucleotides are planned in UK for April 2006 • Newcastle and London collaborating in the UK consortium • European consortium (ENMC/Leiden) • Glaxo philanthropic initiative (Steve Wilton Aus) • Other centres around the world are also conducting trials using antisense technology

32. Concept of oligonucleotide therapy for DMD • Antisense oligoribonucleotides (AON) used to exclude specific exons by interference with splice sites or exon recognition sequences. • Estimated that 10 AONs would treat 70% of DMD cases (van Deutekom et al., 2001).

33. Concept of exon skipping is simple but there are challenges... • Must identify the mutation to tailor the treatment • Efficacy of exon skipping is influenced by • Genetic bandaid design • Nature of AO chemistry and modifications

34. Dystrophin expression : 6 weeks after injection of morpholino AO into TA of 11-day old mdx mouse 4x 10x inset 8% central nuclei 22% central nuclei

35. Morpholino with enhanced nuclear uptake: 10 daysaftersingle ip injection into mouse @ 10mg/kg (other tissues negative) slides from Steve Wilton Mdx diaphragm C57Bl 10diaphragm

36. Exon skipping and DMD • Exon skipping can not cure DMD • May reduce severity • some mutations should respond better than others • more efficient exon skipping • more functional protein being induced • Not applicable to all dystrophin mutations • large genomic deletions Dy--------N • loss of crucial binding domains Dystrophi

37. Clinical trials • Must demonstrate safety first • Intramuscular administration should demonstrate proof of principle but is unlikely to be a viable clinical option • AO administration must be achieved systemically • Must go with best AOs rather than addressing most common mutation to demonstrate efficacy • cocktail of AOs • multiple exon skipping strongly and consistently induced • would address more mutations than a single compound • provide additional sequence specific safety and toxicology information

38. How can we determine the impact of new treatments in DMD? • Clinical assessments previously used have not been rigorously evaluated for reliability, reproducibility • Functional assessments have reflected the ability of the untreated child and have not previously considered potential for improved ability • Biopsies to evaluate changes in muscle are unethical especially repeated and unwanted by children and parents • We are currently working on new techniques to evaluate muscle structure and collaborating in the development of clinical assessment

39. Assessment of muscle fibre damage in patients with Duchenne muscular dystrophy by MRI Penny Garood Volker Straub Michelle Eagle

40. Background • MRI routinely used to investigate muscle pathology • Late-stage appearance of DMD well characterised – fatty replacement and fibrosis • Less research on earlier stages, progression in distinct muscle groups and use of gadolinium contrast

41. Aims • To develop and evaluate MRI methods for measuring degree and distribution of muscle damage (response to treatment) • Definition of stages of muscle disease by MRI in DMD • 3 contrast-enhanced MRI scans over 2 years • Detection of exercise-related muscle changes by MRI • Step test (eccentric exercise) and MRI 4 days later

42. Eligible Boys • Boys aged ≥ 6 years • Independently ambulant (50m) and able to complete step test • Confirmed diagnosis of DMD • Possible cooperation with assessment • Written informed consent parent/guardian

43. Step Test • Eccentric exercise known to cause loss sarcolemmal integrity in normals  • rise in CK • MRI changes (peak day 4) • In DMD, common daily movements causing eccentric contractions may cause focal sarcolemmal disruptions • Does eccentric exercise produce changes on MRI ? • Study started September 05

44. Clinical Assessment • With the promise of future therapies comes a need for reliable evaluation of the clinical impact of treatment • We are collaborating in a national strategy to standardise clinical evaluation in the UK • North Star project • Aims to • To optimise and standardise the management and care of children with neuromuscular disease in paediatric centres throughout the UK

45. Project overview • Clinical network • National database DMD children – starting with those who are still ambulant and in 5-7 year old group • Data base will include specific detail of mutation so that when a treatment becomes available suitable children can be rapidly identified • Clinical audit • Standardised assessment • Equity of treatment across centres • Future links to clinical trials

46. Functional Testing • North Star Ambulatory Assessment • Timed 10m walk/run • Timed rise from floor • EK Scale (non-ambulant)

48. 2 -No evidence of Gowers’ manoeuvre 1A - Turns towards the floor and places hand/s on floor to start to rise, does not need to place hands on legs 1B- Turns towards the floor and places hand/s on floor to start to rise, one hand on leg 1C - Turns towards the floor and places hand/s on floor to start to rise, two hands on legs 0D - HAS to use furniture 0E - Unable Gower’s Manoeuvre

49. Other assessments • Need to monitor FVC &FEV1 absolute and percentage predicted for height • Myometry • Manual muscle testing Elaine Scott Research Physiotherapist / North Star Project Coordinator email e_scott@btopenworld.com 07795 227170

50. conclusions • New therapies are on the horizon for DMD • We need to be prepared for evaluation of these treatments by • Ensuring national and international collaboration • Setting up national data bases of patient populations • Developing and refining clinical assessments • Preparing therapists for an increasing role in clinical evaluation by high quality training with international standards • Finding alternatives to biopsy for evaluation of muscle structure/damage/repair