The main objective of this study is to provide evidence of efficacy of eteplirsen (AVI-4658) in Duchenne muscular dystrophy (DMD) patients that are amenable to skipping exon 51. Additional objectives include evaluation of safety, biomarkers and the long-term effects of eteplirsen up to 96 weeks, followed by a safety extension (not to exceed 48 weeks).
This is an open-label, multi-center study to evaluate the efficacy and safety of eteplirsen in patients with genotypically confirmed Duchenne muscular dystrophy (DMD) with genetic deletions amenable to exon 51 skipping (treated group), with a concurrent control arm of DMD patients not amenable to exon 51 skipping (untreated group). Following primary efficacy endpoints, dosing will continue to week 144 to evaluate the long term effects of eteplirsen. Patients in the treated group will receive once weekly intravenous (IV) infusions of 30 mg/kg Eteplirsen for 96 weeks, followed by a safety extension (not to exceed 48 weeks). Patients in the untreated group will not receive treatment. Clinical efficacy will be assessed at regularly scheduled study visits, including functional tests such as the six minute walk test. Patients in the treated group will undergo a muscle biopsy at Baseline and a second muscle biopsy over the course of the study. Patients in the untreated group will not undergo muscle biopsy. Safety, including adverse event monitoring and routine laboratory assessments, will be continuously monitored for all patients.
Study Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
109
Eteplirsen 30 mg/kg will be administered as an IV infusion once a week for 96 weeks, followed by a safety extension (not to exceed 48 weeks).
Change From Baseline in the 6 Minute Walk Test (6MWT) Distance at Week 96
6MWT was performed by standardized procedures for all participants. Participants were asked to walk a set course of 25 meters for 6 minutes (timed), and the distance walked (in meters) was recorded. Change from baseline in 6MWT distance at Week 96 was reported.
Time frame: Baseline, Week 96
Change From Baseline in Dystrophin Protein Levels Determined by Western Blot at Week 96
Change from baseline in dystrophin protein levels (in muscle biopsy samples) were determined by Western blot. For each time point, 2 blocks of tissues were analyzed by Western blot, each with 2 replicates of gels to determine the dystrophin level as compared to a healthy individual (Percent Normal). The block average value from 2 replicate gels was computed. The overall average was calculated as the mean of the block average values. The overall average values were used for all analyses. In case only 1 gel was available for a block, then that value was used as the block average value.
Time frame: Baseline, Week 96
Number of Participants Having Ability to Rise Independently From the Floor Determined Based on North Star Ambulatory Assessment (NSAA) at Week 96
NSAA is a clinician-administered scale that rates participant performance on 17-items and included assessments of abilities such as 10-meter walk/run, rising from a sit to stand, standing on 1 leg, climbing a box step, descending a box step, rising from lying to sitting, rising from the floor, lifting the head, standing on heels, and jumping. For all activities, participants were graded as follows: 0 = unable to achieve goal independently; 1 = modified method but achieves goal independent of physical assistance from another and 2 = normal, no obvious modification of activity. Number of participants having ability to rise independently from the floor indicated by a NSAA Rise from floor sub score greater than 0 (unable to achieve goal independently) was reported.
Time frame: Week 96
Number of Participants Who Lost Ambulation (LOA) by Week 96
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
Neuromuscular Research Center
Phoenix, Arizona, United States
David Geffen School of Medicine at UCLA
Los Angeles, California, United States
University of California, Davis Medical Center
Sacramento, California, United States
Rady Children's Hospital, U.C. San Diego
San Diego, California, United States
Stanford University School of Medicine/Medical Center
Stanford, California, United States
Children's Hospital Colorado
Aurora, Colorado, United States
Connecticut Children's Medical Center
Hartford, Connecticut, United States
Children's National Health System
Washington D.C., District of Columbia, United States
The University of Florida, Powell Gene Therapy Center
Gainesville, Florida, United States
NW FL Clinical Research Group, LLC
Gulf Breeze, Florida, United States
...and 27 more locations
Number of participants who lost ambulation (LOA) by Week 96 was reported. Participant were considered non-ambulatory if each of the 3 conditions below were met: NSAA walk subscore was "0" (unable to achieve goal independently) on 2 consecutive days within a visit or NSAA was not done due to reason related to non-ambulation; 6MWT was not done with any reason related to permanent non-ambulation; and no later data showing this participant was still ambulatory. This was not required if non ambulatory status occurred at the time of early withdrawal or at the end of Week 96 assessment. NSAA is a 17-item scale to assess the participant's abilities; total score range from 0 (if all the activities are failed) to 34 (if all the activities are achieved) with higher scores indicating better performance on the assessment/ fully-independent function.
Time frame: Up to Week 96
Change From Baseline in Forced Vital Capacity Percent (FVC%) Predicted at Weeks 96
FVC is the total amount of air exhaled during the forced expiratory volume test that is measured during spirometry; and is the most important measurement of lung function. This test requires participant to breath into a tube connected to a machine that measures the amount of air that can be moved in and out of the lungs after taking an inhaled bronchodilator medicine which is used to dilate participant's bronchial (breathing) tubes. Percent of predicted FVC = (observed value) / (predicted value) \* 100%.
Time frame: Baseline, Week 96
Change From Baseline in North Star Ambulatory Assessment (NSAA) Total Scores at Week 96
NSAA is a clinician-administered scale that rates participant performance on 17-items and included assessments of abilities such as 10-meter walk/run, rising from a sit to stand, standing on 1 leg, climbing a box step, descending a box step, rising from lying to sitting, rising from the floor, lifting the head, standing on heels, and jumping. Participant were graded as follows: 0 = unable to achieve goal independently; 1 = modified method but achieves goal independent of physical assistance from another and 2 = normal, no obvious modification of activity. NSAA total score was derived by summing the scores for all the individual items and range from 0 (if all the activities are failed) to 34 (if all the activities are achieved) with higher scores indicating better performance on the assessment/ fully-independent function.
Time frame: Baseline, Week 96
Change From Baseline in Dystrophin Intensity Levels Determined by Immunohistochemistry (IHC) at Week 96
Change from baseline in dystrophin intensity levels (in muscle biopsy samples) was determined by Immunohistochemistry.
Time frame: Baseline, Week 96