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Study to Evaluate the Safety and Efficacy of PF-06939926 for the Treatment of Duchenne Muscular Dystrophy

Phase 3
Active, not recruiting
Conditions
Duchenne Muscular Dystrophy
Registration Number
NCT04281485
Lead Sponsor
Pfizer
Brief Summary

The study will evaluate the safety and efficacy of gene therapy in boys with DMD. It is a randomized, double-blind, placebo-controlled study with two thirds of participants assigned to gene therapy. The one third of participants who are randomized to the placebo arm will have an opportunity for treatment with gene therapy at the beginning of the second year.

Detailed Description

The study will assess the efficacy of PF-06939926 gene therapy on ambulatory function while also monitoring its safety. Approximately 99 boys with DMD will be enrolled and randomly assigned to one of two groups: approximately two thirds will be in Cohort 1 and receive gene therapy at the start of the study; approximately one third will be in Cohort 2 and receive placebo at the start of the study and receive gene therapy after one year, as long as it remains safe to do so. The treatment (PF-06939926 gene therapy or placebo) will be given as an intravenous infusion lasting up to 2 hours.

The study includes boys who are at least 4 years old and less than 8 years old (including 7 year olds up until their 8th birthday). All boys will need to be on a daily dose of glucocorticoids (prednisone, prednisolone, or deflazacort) for at least 3 months prior to enrolling and to stay on daily glucocorticoids for the first 2 years of the study. All boys will need to be negative for neutralizing antibodies against AAV9, as measured by the test done for the study as part of screening.

The primary outcome of the study will be assessed at 52 weeks. All participants will be followed in the study for 15 years after treatment with gene therapy. Participants who received fordadistrogene movaparvovec in Pfizer studies C3391001 and C3391008 or are currently enrolled in Pfizer study C3391011 will be allowed to roll over into the long-term safety follow-up period of this study and will be considered Cohort 3.

The study medication, all medical tests associated with the study, and the visits to the study sites are free of charge. Participants will also be supported for travel costs associated with study visits.

Recruitment & Eligibility

Status
ACTIVE_NOT_RECRUITING
Sex
Male
Target Recruitment
114
Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Primary Outcome Measures
NameTimeMethod
Change From Baseline in North Star Ambulatory Assessment (NSAA) Total Score at Week 52Baseline, Week 52

The NSAA was a 17-item test that graded performance of various functional skills using the following scale: 0 (unable to achieve independently), 1 (modified method but achieves goal independent of physical assistance from another), and 2 ("normal"- no obvious modification of activity). Total score was calculated as the sum of all 17 individual item responses and ranged from 0 (worst) to 34 (fully independent function) with higher scores indicating better function. Baseline NSAA total score is defined as the last non-missing NSAA total score collected prior to Year 1 drug administration.

Secondary Outcome Measures
NameTimeMethod
Least Square Mean of Proportion of Skills Either Improved or Maintained Based on the Individual Items of the NSAA at Week 52Baseline, Week 52

Proportion of skills either improved or maintained at Week 52 was expressed as a proportion of the number of items at Baseline that could be improved or maintained (numerator was the number of items on NSAA improved or maintained at Week 52 and denominator is number of items on NSAA which is 17). The NSAA was a 17-item test that graded performance of various functional skills using the following scale: 0 (unable to achieve independently), 1 (modified method but achieves goal independent of physical assistance from another), and 2 ("normal"- no obvious modification of activity). Total score was calculated as the sum of all 17 individual item responses and ranged from 0 (worst) to 34 (fully independent function) with higher scores indicating better function.

Change From Baseline in 10 Meter Run/Walk Velocity at Week 52Baseline, Week 52

Velocity was calculated based on the time it took to complete the 10-meter run/walk test.

Change From Baseline in Rise From Floor Velocity at Week 52Baseline, Week 52

Velocity was calculated based on the time it took to rise from floor.

Change From Baseline in Percent Normal Dystrophin Expression Level in Muscle Biopsies by Liquid Chromatography Mass Spectrometry (LC-MS) Based on LLQV Peptide at Week 52Baseline, Week 52

The LC-MS assay measured the LLQVAVEDR (LLQV) peptide that detected full-length endogenous dystrophin as well as the mini-dystrophin transgene protein.

Change From Baseline in Percent of Muscle Fibers Expressing Mini-Dystrophin in Muscle Biopsies by Immunofluorescence at Week 52Baseline, Week 52

Muscle fibers expressing mini-dystrophin transgene protein were evaluated by immunofluorescent staining using the mini-dystrophin specific antibody which only recognized the mini-dystrophin transgene protein.

Change From Baseline in Serum Creatine Kinase (CK) Concentration at Week 52Baseline, Week 52

The CK results were analyzed by the central laboratory.

Least Square Mean of Proportion of Skills Gained Based on the Individual Items of the NSAA at Week 52Baseline, Week 52

Proportion of skills gained at Week 52 were expressed as a proportion of the number of skills at Baseline that could be gained (numerator was number of items on NSAA gained at Week 52, with response 1 or 2 and denominator was number of items on NSAA with score 0 at baseline). The NSAA was a 17-item test that graded performance of various functional skills using the following scale: 0 (unable to achieve independently), 1 (modified method but achieves goal independent of physical assistance from another), and 2 ("normal"- no obvious modification of activity). Total score was calculated as the sum of all 17 individual item responses and ranged from 0 (worst) to 34 (fully independent function) with higher scores indicating better function.

Change From Baseline in Modified Pediatric Outcome Data Collection Instrument (PODCI)- Transfer and Basic Mobility Core Scale at Week 52Baseline, Week 52

Modified PODCI- transfer and basic mobility core scale (parent of pediatric participant) consisted of 11 items that assessed how caregivers of participants evaluated a participant's ability to walk, stand, and perform activities of daily living. The scale produced an independent, standardized score ranging from 0-100, with lower scores representing lower levels of function.

Change From Baseline in Modified PODCI- Sports and Physical Functioning Core Scale at Week 52Baseline, Week 52

Modified PODCI- sports and physical functioning core scale (parent of pediatric participant) consisted of 21 items that assessed how caregivers of participants evaluated a participant's ability to perform recreational activities. The scale produced an independent, standardized score ranging from 0-100, with lower scores representing lower levels of function.

Trial Locations

Locations (49)

Arkansas Children's Hospital

🇺🇸

Little Rock, Arkansas, United States

Arkansas Children's

🇺🇸

Little Rock, Arkansas, United States

University of Iowa Hospitals and Clinics

🇺🇸

Iowa City, Iowa, United States

KU Clinical Research Center - Clinical and Translational Science Unit (CTSU) - Fairway

🇺🇸

Fairway, Kansas, United States

KU Clinical Research Center - Clinical and Translational Science Unit (CTSU) - Rainbow

🇺🇸

Kansas City, Kansas, United States

University of Kansas Hospital - Investigational Pharmacy

🇺🇸

Kansas City, Kansas, United States

University of Kansas Hospital - Pediatric and Pediatric ICU - Operating Room

🇺🇸

Kansas City, Kansas, United States

University of Kansas Medical Center

🇺🇸

Kansas City, Kansas, United States

Pediatric Cardiology

🇺🇸

Prairie Village, Kansas, United States

Lenox Baker Children's Hospital

🇺🇸

Durham, North Carolina, United States

Scroll for more (39 remaining)
Arkansas Children's Hospital
🇺🇸Little Rock, Arkansas, United States

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