A Randomized, Double-Blind, Placebo-Controlled, Dose-Titration, Safety, Tolerability, and Pharmacokinetics Study Followed by an Open-Label Safety and Efficacy Evaluation of SRP-4045 in Advanced-Stage Patients With Duchenne Muscular Dystrophy Amenable to Exon 45 Skipping
Overview
- Phase
- Phase 1
- Intervention
- Placebo
- Conditions
- Duchenne Muscular Dystrophy
- Sponsor
- Sarepta Therapeutics, Inc.
- Enrollment
- 12
- Locations
- 3
- Primary Endpoint
- Number of Participants With Potentially Clinically Significant (PCS) Laboratory Abnormalities Reported as TEAEs
- Status
- Completed
- Last Updated
- 4 years ago
Overview
Brief Summary
This is a first-in-human dose-titration and open-label extension study to assess safety, tolerability, and pharmacokinetics of SRP-4045 in advanced-stage Duchenne muscular dystrophy (DMD) patients with deletions amenable to exon 45 skipping.
Detailed Description
This is a randomized, placebo-controlled dose-titration study to assess safety, tolerability, and pharmacokinetics of 4 dose levels of SRP-4045 in genotypically confirmed advanced-stage DMD patients with deletions amenable to exon 45 skipping. After completion of the dose-titration portion of the study and SRP-4045 is determined to be safe, all patients will be evaluated on open-label SRP-4045 for the duration of the study. Safety, including adverse event monitoring, routine laboratory assessments, and cardiac testing will be monitored through the duration of the dose-titration and open-label portions of the study. Clinical efficacy will be assessed at regularly scheduled study visits via quality of life questionnaires and tests of pulmonary and upper extremity function through the duration of the dose-titration and open-label portions of the trial.
Investigators
Eligibility Criteria
Inclusion Criteria
- •Genotypically confirmed DMD (amenable to exon 45 skipping).
- •Stable cardiac and pulmonary function.
- •Limited or no ambulation.
- •On a stable dose of oral corticosteroids for at least 24 weeks OR has not received corticosteroids for at least 24 weeks.
Exclusion Criteria
- •Current or previous treatment with the experimental agents SMT C1100 (BMN-195) or PRO
- •Other experimental treatment in the past 12 weeks.
- •If on cardiac medication, must be on a stable dose for the past 12 weeks.
- •Major surgery within the past 3 months.
- •Other inclusion/exclusion criteria apply.
Arms & Interventions
Placebo (double-blind dose titration)
Participants with genotypically confirmed Duchenne muscular dystrophy (DMD) characterized by deletions amenable to exon 45 skipping will receive placebo-matching to casimersen intravenous (IV) infusions, once weekly over approximately 12 weeks in the double-blind period.
Intervention: Placebo
SRP-4045 (double-blind dose titration)
Participants with genotypically confirmed DMD characterized by deletions amenable to exon 45 skipping will receive weekly IV infusions of casimersen at four escalating dose levels, each for at least 2 weeks: 4 milligrams per kilograms (mg/kg) during Week 1 to Week 2, followed by 10 mg/kg during Week 3 to Week 4, followed by 20 mg/kg during Week 5 to Week 6, followed by 30 mg/kg beginning at Week 7 and continue over approximately Week 12 in the double-blind period.
Intervention: SRP-4045
SRP-4045 (open label extension period)
All participants who completed double blind period will be enrolled to receive casimersen 30 mg/kg once weekly, for up to Week 144 in the open label extension period.
Intervention: SRP-4045
Outcomes
Primary Outcomes
Number of Participants With Potentially Clinically Significant (PCS) Laboratory Abnormalities Reported as TEAEs
Time Frame: Baseline up to Week 148
Laboratory parameters included serum chemistry (hepatic chemistry and renal chemistry), hematology, coagulation, and urinalysis. Number of participants with potentially clinically significant abnormal finding were reported as TEAEs. The Investigator determined whether abnormal assessment results were potentially clinically significant or not. Potentially clinical significance was defined as any variation in assessment results that had medical relevance resulting in an alteration in medical care.
Number of Participants With Potentially Clinically Significant Abnormalities in Echocardiograms (ECHO)
Time Frame: Baseline up to Week 148
Standard, 2-dimensional ECHOs were performed at a consistent time of day throughout the study.The ECHO was reviewed and interpreted by medically qualified personnel. Number of participants with potentially clinically significant abnormalities in ECHO were reported.
Number of Participants With Potentially Clinically Significant Abnormalities in Vital Signs Reported as TEAEs
Time Frame: Baseline up to Week 148
Vital sign parameters included systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), and body temperature. Number of participants with at least one potentially clinically significant abnormal vital signs findings were reported as TEAEs. The Investigator determined whether abnormal assessment results were potentially clinically significant or not. Potential clinical significance was defined as any variation in assessment results that had medical relevance resulting in an alteration in medical care.
Number of Participants With Potentially Clinically Significant Abnormalities in Electrocardiogram (ECG) Reported as TEAEs
Time Frame: Baseline up to Week 148
Twelve-lead ECGs were performed at a consistent time of day throughout the study. Electrocardiograms were performed only after the participant was in the supine position, resting, and quiet for a minimum of 15 minutes. The ECG was manually reviewed and interpreted by medically qualified personnel. Number of participants with potentially clinically significant abnormalities in ECG reported as TEAEs were presented here. The Investigator determined whether abnormal assessment results were potentially clinically significant or not.
Number of Participants With Treatment Emergent Adverse Events (TEAEs)
Time Frame: Baseline up to Week 148
Adverse event (AE) was any untoward medical occurrence in a clinical trial participant, which does not necessarily have a causal relationship with the investigational drug. AEs also included abnormal physical examination findings (Physical examination were conducted per protocol and any clinically significant abnormal findings were recorded in medical history if pre-existing or addressed as an AE if new or worsening). TEAEs was defined as AEs that started, worsened, or became serious on or after the start of first infusion through 148 weeks. Number of participants with TEAEs were reported.
Secondary Outcomes
- Area Under Concentration-time Curve From Time of Dosing to the Last Measurable Concentration (AUClast) of Casimersen in Plasma(Pre-infusion, 5 to 10 minutes, 1, 1.5, 2, 4, 6, 8, 12, 16, and 24 hours post-dose at Weeks 1 (for 4 mg/kg ), 3 (for 10 mg/kg arm), 5 (for 20 mg/kg arm), 7 (for 30 mg/kg arm) in DBP and Week 60 (for 30 mg/kg arm) in OLEP)
- Elimination Half-life (T1/2) of Casimersen(Pre-infusion, 5 to 10 minutes, 1, 1.5, 2, 4, 6, 8, 12, 16, and 24 hours post-dose at Weeks 1 (for 4 mg/kg ), 3 (for 10 mg/kg arm), 5 (for 20 mg/kg arm), 7 (for 30 mg/kg arm) in DBP and Week 60 (for 30 mg/kg arm) in OLEP)
- Total Clearance (CL) of Casimersen(Pre-infusion, 5 to 10 minutes, 1, 1.5, 2, 4, 6, 8, 12, 16, and 24 hours post-dose at Weeks 1 (for 4 mg/kg ), 3 (for 10 mg/kg arm), 5 (for 20 mg/kg arm), 7 (for 30 mg/kg arm) in DBP and Week 60 (for 30 mg/kg arm) in OLEP)
- Apparent Volume of Distribution at Steady State (Vss) of Casimersen(Pre-infusion, 5 to 10 minutes, 1, 1.5, 2, 4, 6, 8, 12, 16, and 24 hours post-dose at Weeks 1 (for 4 mg/kg ), 3 (for 10 mg/kg arm), 5 (for 20 mg/kg arm), 7 (for 30 mg/kg arm) in DBP and Week 60 (for 30 mg/kg arm) in OLEP)
- Time to Reach Maximum Plasma Concentration (Tmax) of Casimersen(Pre-infusion, 5 to 10 minutes, 1, 1.5, 2, 4, 6, 8, 12, 16, and 24 hours post-dose at Weeks 1 (for 4 mg/kg ), 3 (for 10 mg/kg arm), 5 (for 20 mg/kg arm), 7 (for 30 mg/kg arm) in DBP and Week 60 (for 30 mg/kg arm) in OLEP)
- Area Under Concentration-Time Curve From Time Zero Pre-dose to Twenty-Four Hours Post-dose (AUC0-24) of Casimersen in Plasma(Pre-infusion, 5 to 10 minutes, 1, 1.5, 2, 4, 6, 8, 12, 16, and 24 hours post-dose at Weeks 1 (for 4 mg/kg ), 3 (for 10 mg/kg arm), 5 (for 20 mg/kg arm), 7 (for 30 mg/kg arm) in DBP and Week 60 (for 30 mg/kg arm) in OLEP)
- Maximum Plasma Concentration (Cmax) of Casimersen(Pre-infusion, 5 to 10 minutes, 1, 1.5, 2, 4, 6, 8, 12, 16, and 24 hours post-dose at Weeks 1 (for 4 mg/kg ), 3 (for 10 mg/kg arm), 5 (for 20 mg/kg arm), 7 (for 30 mg/kg arm) in DBP and Week 60 (for 30 mg/kg arm) in OLEP)
- Area Under the Concentration-Time Curve From Time Zero Extrapolated to the Infinity (AUCinf) of Casimersen in Plasma(Pre-infusion, 5 to 10 minutes, 1, 1.5, 2, 4, 6, 8, 12, 16, and 24 hours post-dose at Weeks 1 (for 4 mg/kg ), 3 (for 10 mg/kg arm), 5 (for 20 mg/kg arm), 7 (for 30 mg/kg arm) in DBP and Week 60 (for 30 mg/kg arm) in OLEP)
- Mean Residence Time Extrapolated to Infinity (MRTinf) of Casimersen(Pre-infusion, 5 to 10 minutes, 1, 1.5, 2, 4, 6, 8, 12, 16, and 24 hours post-dose at Weeks 1 (for 4 mg/kg ), 3 (for 10 mg/kg arm), 5 (for 20 mg/kg arm), 7 (for 30 mg/kg arm) in DBP and Week 60 (for 30 mg/kg arm) in OLEP)
- Double-Blind Period: Renal Clearance (CLR) of Casimersen(0 to 4, 4 to 8, 8 to 12, and 12 to 24 hours post-dose at Weeks 1 (for 4 mg/kg ), 3 (for 10 mg/kg arm), 5 (for 20 mg/kg arm), 7 and 12 (for 30 mg/kg arm) in double-blind period)