Safety and Dose Finding Study of NS-065/NCNP-01 in Boys With Duchenne Muscular Dystrophy (DMD)

Study Overview
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Brief Summary
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The main objective of this study is to evaluate the safety of a high (80mg/kg) and low (40mg/kg) dose of NS-065/NCNP-01 delivered as an intravenous infusion in patients with Duchenne Muscular Dystrophy (DMD) amendable to exon 53 skipping. Additional objectives include tolerability, muscle function and strength, pharmacokinetics and pharmacodynamics.

Detailed Description
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This is a Phase II, multiple center, 2-period, randomized, placebo-controlled, dose finding study of NS-065/NCNP-01 administered by infusion once weekly for 24 weeks to ambulant boys ages 4-<10 years with DMD. Two dose level cohorts will be enrolled. Period 1 of this study will be conducted in a double-blind fashion. Randomized patients will receive weekly IV infusions of NS-065/NCNP-01 or placebo for the first 4 weeks of their participation (Period 1) and NS-065/NCNP-01 by IV infusion for weeks 5-24 (20 weeks of active treatment - Period 2). Analysis of safety data from Period 1 of the 40mg/kg dose cohort will be completed prior to enrolling patients in the 80mg/kg dose cohort. Patients completing the 24-week study will be eligible for an open-label extension study. Clinical efficacy will be assessed at regularly scheduled study visits, including functional tests such as the six-minute walk test (6MWT), time to stand (TTSTAND), time to run/walk 10 meters (TTRW), time to climb 4 stairs (TTCLIMB) and quantitative muscle testing (QMT). All patients will undergo a muscle biopsy of the bicep at baseline and a second muscle biopsy at Week 24. Safety will be assessed through the collection of adverse events (AEs), blood and urine laboratory tests, electrocardiograms (ECGs), vital signs, and physical examinations throughout the study. Serial blood samples will be taken at four of the study visits to assess the pharmacokinetics of the study drug.

Official Title
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A Phase II, Dose Finding Study to Assess the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of NS-065/NCNP-01 in Boys With Duchenne Muscular Dystrophy (DMD)

Conditions
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Duchenne Muscular Dystrophy

Intervention / Treatment
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* Drug: NS-065/NCNP-01
* Drug: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male ≥ 4 years and <10 years of age Confirmed DMD mutation(s) in the dystrophin gene that is amenable to skipping of exon 53 to restore the dystrophin mRNA reading frame; Able to walk independently without assistive devices; Ability to complete the time to stand, time to run/walk and time to climb assessments; Stable dose of glucocorticoid for at least 3 months Exclusion Criteria: Acute illness within 4 weeks prior to the first dose of study medication; Evidence of symptomatic cardiomyopathy. [Note: Asymptomatic cardiac abnormality on investigation would not be exclusionary]; Severe allergy or hypersensitivity to medications; Severe behavioral or cognitive problems that preclude participation in the study, in the opinion of the Investigator; Previous or ongoing medical condition, medical history, physical findings or laboratory abnormalities that could affect safety, make it unlikely that treatment and follow-up will be correctly completed or impair the assessment of study results, in the opinion of the Investigator; Patient is taking any other investigational drug currently or within 3 months prior to the start of study treatment; or Patient has had surgery within the 3 months prior to the first anticipated administration of study medication or surgery is planned for anytime during the duration of the study; Patient has previously participated in this study or any other study during which NS-065/NCNP-01 was administered.

Ages Eligible for Study
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Minimum Age: 4 Years
Maximum Age: 9 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: NS-065/NCNP-01 40mg/kg<br>Six patients with confirmed DMD with genetic deletions amenable to exon 53 skipping will be administered an intravenous infusion of NS-065/NCNP-01 40mg/kg dose once a week for 24 weeks | Drug: NS-065/NCNP-01<br> <br> |
| Experimental: NS-065/NCNP-01 80mg/kg<br>Six patients with confirmed DMD with genetic deletions amenable to exon 53 skipping will be administered an intravenous infusion of NS-065/NCNP-01 80mg/kg once a week for 24 weeks | Drug: NS-065/NCNP-01<br> <br> |
| Placebo Comparator: Placebo<br>Two patients in each of the dose groups will be administered placebo as an intravenous infusion once a week for 4 weeks followed by 20 weeks of open label treatment | Drug: Placebo<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of Adverse Events as Assessed by CTCAE v4.0. | Treatment emergent adverse events (TEAEs) were summarized for Period 1 by comparing low dose to high dose to placebo and for Period 2 between the low dose cohort and the high dose cohort. TEAEs were summarized both at the patient level for number of TEAEs, highest severity, relationship, action and outcome and at the TEAE level (summarizing events) by organ system and preferred term TEAE as well as severity, relationship, action and outcome. The Medical Dictionary for Regulatory Activities (MedDRA) version 20.1 was used and the Common Terminology Criteria for Adverse Events (CTCAE) grading. | 24 weeks of treatment | 
| Dystrophin Production by Western Blot | Percentage normal dystrophin production in muscle biopsies from study participants at baseline and after 24 weeks treatment was measured by Western blot. To analyze dystrophin induction, biopsies were taken from a biceps muscle at baseline and the other biceps muscle after 24 weeks of treatment. Muscle samples were snap frozen and delivered to a central laboratory. All laboratory researchers remained blinded to sample identity. Dystrophin protein levels were assessed using standard curves on each gel (range from 0-25% of normal levels) generated by mixing 5 normal control samples with one DMD sample. | Baseline and 24 weeks of treatment | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Dystrophin Production by RT-PCR for mRNA - Percentage of Exons Skipped - Molarity | The alteration of mRNA splicing was measured by RT-PCR of dystrophin mRNA transcripts from a patient muscle biopsy at baseline and after 24 weeks treatment. To analyze dystrophin induction, biopsies were taken from a biceps muscle at baseline and the other biceps muscle after 24 weeks of treatment. Muscle samples were snap frozen and delivered to a central laboratory. All laboratory researchers remained blinded to sample identity. For RT-PCR, bands corresponding to specific versions of the spliced dystrophin mRNA were visualized by gel electrophoresis, and the amounts of different mRNA isoforms were compared. | Baseline and 24 weeks of treatment | 
| Dystrophin Production by Mass Spectrometry | The production of dystrophin protein was measured by stable isotope mass spectrometry methods from a patient muscle biopsy at baseline and after 24 weeks treatment. To analyze dystrophin induction, biopsies were taken from a biceps muscle at baseline and the other biceps muscle after 24 weeks of treatment. Muscle samples were snap frozen and delivered to a central laboratory. All laboratory researchers remained blinded to sample identity. Dystrophin peptides were identified and quantified using reversed-phase nanoflow high-performance liquid chromatography with high resolution Mass Spectrometry. | Baseline and 24 weeks of treatment | 
| Dystrophin Production by Immunofluorescence | The production of dystrophin protein was measured by immunofluorescence staining methods from a patient muscle biopsy at baseline and after 24 weeks treatment. To analyze dystrophin induction, biopsies were taken from a biceps muscle at baseline and the other biceps muscle after 24 weeks of treatment. Muscle samples were snap frozen and delivered to a central laboratory. All laboratory researchers remained blinded to sample identity. Immunofluorescence staining for dystrophin was performed on serial muscle biopsy sections in duplicate. | Baseline and 24 weeks of treatment | 
| Change From Baseline in Muscle Strength as Measured by Quantitative Muscle Testing (QMT). | A secondary efficacy endpoint was compared to Pre-Infusion Visit: quantitative muscle testing (QMT). | Baseline and 24 weeks of treatment | 
| Change From Baseline in Distance Traveled in the Six-Minute Walk Test (6MWT). | A secondary efficacy endpoint was compared to Pre-Infusion Visit: Six-Minute Walk Test (6MWT). | Baseline and 24 weeks of treatment | 
| Change From Baseline in Time to Climb 4 Stairs (TTCLIMB). | A secondary efficacy endpoint was compared to Pre-Infusion Visit: Time to Climb 4 Stairs (TTCLIMB). | Baseline and 24 weeks of treatment | 
| Change From Baseline in Time to Climb 4 Stairs (TTCLIMB) Velocity | A secondary efficacy endpoint was compared to Pre-Infusion Visit: Time to Run/Walk 10 meters (TTRW). The results were converted into velocity (meter/time). | Baseline and 24 weeks of treatment | 
| Change From Baseline in Time to Run/Walk 10 Meters (TTRW). | A secondary efficacy endpoint was compared to Pre-Infusion Visit: Time to Run/Walk 10 meters (TTRW). | Baseline and 24 weeks of treatment | 
| Change From Baseline in Time to Run/Walk 10 Meters (TTRW) Velocity. | A secondary efficacy endpoint was compared to Pre-Infusion Visit: Time to Run/Walk 10 meters (TTRW). The results were converted into velocity (meter/time). | Baseline and 24 weeks of treatment | 
| Change From Baseline in Time to Stand (TTSTAND) | A secondary efficacy endpoint was compared to Pre-Infusion Visit: Time to Stand (TTSTAND) | Baseline and 24 weeks of treatment | 
| Change From Baseline in Time to Stand (TTSTAND) Velocity | A secondary efficacy endpoint was compared to Pre-Infusion Visit: Time to Stand (TTSTAND).The results were converted into velocity (rise/time). | Baseline and 24 weeks of treatment | 
| Change From Baseline in North Star Ambulatory Assessment (NSAA) Score. | The NSAA is a functional scale devised for use in ambulant children with Duchenne muscular dystrophy (DMD). It consists of 17 activities graded 0 (unable to perform), 1 (performs with modifications), 2 (normal movement). It assesses abilities necessary to remain ambulant that have been found to progressively deteriorate in untreated DMD patients, as well as in other muscular dystrophies such as Becker Muscular Dystrophy. NSAA Total Score ranges from 0 to 34, with a score of 34 implying normal function. | Baseline and 24 weeks of treatment |