Study of Fordadistrogene Movaparvovec in Early Stage Duchenne Muscular Dystrophy

Overview

The study will evaluate the safety and dystrophin expression following gene therapy in boys with Duchenne Muscular Dystrophy (DMD). It is a single-arm, non-randomized, open-label study

Full Title of Study: “A PHASE 2, MULTICENTER, SINGLE-ARM STUDY TO EVALUATE THE SAFETY AND DYSTROPHIN EXPRESSION AFTER FORDADISTROGENE MOVAPARVOVEC (PF-06939926) ADMINISTRATION IN MALE PARTICIPANTS WITH EARLY STAGE DUCHENNE MUSCULAR DYSTROPHY”

Study Type

• Study Type: Interventional
• Study Design
  • Allocation: N/A
  • Intervention Model: Single Group Assignment
  • Primary Purpose: Treatment
  • Masking: None (Open Label)
• Study Primary Completion Date: July 17, 2024

Detailed Description

The study will assess the safety and tolerability of fordadistrogene movaparvovec gene therapy. Approximately 10 participants will be enrolled in the study and receive a single IV infusion of PF-06939926; there is no placebo arm. The study includes boys who are at least 2 years old and less than 4 years old (including 3 year olds up until their 4th birthday). 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 The primary analysis will occur when all participants have completed visits through Week 52 (or withdrawn from the study prior to Week 52). All participants will be followed in the study for 5 years after treatment with gene therapy.

Interventions

• Genetic: PF-06939926
  • All participants will receive a single dose of PF-06939926 on Day 1.

Arms, Groups and Cohorts

• Experimental: PF-06939926

Clinical Trial Outcome Measures

Primary Measures

• Incidence and severity of Treatment-Emergent Adverse Events and Serious Adverse Events
  • Time Frame: Through Week 52
• Number of participants with abnormal hematology test results
  • Time Frame: Through Week 52
  • Blood samples will be collected from subjects for the analysis of hematology
• Number of participants with abnormal biochemistry test results
  • Time Frame: Through Week 52
  • Blood samples will be collected from subjects for the analysis of biochemistry
• Number of participants with abnormal urine analysis
  • Time Frame: Through Week 52
  • Urine samples will be collected from subjects for the analysis of urine
• Number of participants with abnormal and clinically relevant changes in neurological examinations
  • Time Frame: Through Week 52
• Number of participants with abnormal and clinically relevant changes in body weight
  • Time Frame: Through Week 52
• Number of participants with abnormal and clinically relevant changes in vital signs
  • Time Frame: Through Week 52
• Number of participants with abnormal and clinically relevant changes on cardiac troponin I
  • Time Frame: Through Week 52
• Number of participants with abnormal and clinically relevant changes on electrocardiogram (ECG)
  • Time Frame: Through Week 52
• Number of participants with abnormal and clinically relevant changes on echocardiogram
  • Time Frame: Through Week 52

Secondary Measures

• Distribution of mini-dystrophin expression in muscle
  • Time Frame: At Week 9 and Week 52
  • Mini-dystrophin distribution from a muscle biopsy will be assessed by immunofluorescence
• Level of mini-dystrophin expression in muscle
  • Time Frame: At Week 9 and Week 52
  • Mini-dystrophin expression level from a muscle biopsy will be assessed by liquid chromatography mass spectrometry
• Incidence and severity of Treatment-Emergent Adverse Events and Serious Adverse Events
  • Time Frame: Through 5 years
• Number of participants with abnormal hematology test results
  • Time Frame: Through 5 years
  • Blood samples will be collected from subjects for the analysis of hematology
• Number of participants with abnormal biochemistry test results
  • Time Frame: Through 5 years
  • Blood samples will be collected from subjects for the analysis of biochemistry
• Number of participants with abnormal urine analysis
  • Time Frame: Through 5 years
  • Urine samples will be collected from subjects for the analysis of urine
• Number of participants with abnormal and clinically relevant changes in neurological examinations
  • Time Frame: Through 5 years
• Number of participants with abnormal and clinically relevant changes in body weight
  • Time Frame: Through 5 years
• Number of participants with abnormal and clinically relevant changes in vital signs
  • Time Frame: Through 5 years
• Number of participants with abnormal and clinically relevant changes on cardiac troponin I
  • Time Frame: Through 5 years
• Number of participants with abnormal and clinically relevant changes on electrocardiogram (ECG)
  • Time Frame: Through 5 years
• Number of participants with abnormal and clinically relevant changes on echocardiogram
  • Time Frame: Through 5 years

Participating in This Clinical Trial

Inclusion Criteria

• Confirmed diagnosis of DMD by prior genetic testing. Exclusion Criteria:

• Any of the following genetic abnormalities in the dystrophin gene: a. Any mutation (exon deletion, exon duplication, insertion, or point mutation) affecting any exon between exon 9 and exon 13, inclusive; OR b. A deletion that affects both exon 29 and exon 30; OR c. A deletion that affects any exons between 56-71, inclusive. – Positive test performed by Pfizer for neutralizing antibodies to AAV9. – Any prior treatment with gene therapy. – Any treatment designed to increase dystrophin expression within 6 months prior to screening (including, but not limited to, exon-skipping and nonsense read through). – Previous or current treatment with oral glucocorticoids or other immunosuppressive agents for the indication of DMD. – Abnormality in specified laboratory tests, including blood counts, liver and kidney function.

Gender Eligibility: Male

Male participants age ≥2 to <4 years, at Screening (Visit 1)

Minimum Age: 2 Years

Maximum Age: 3 Years

Are Healthy Volunteers Accepted: No

Investigator Details

• Lead Sponsor
  • Pfizer
• Provider of Information About this Clinical Study
  • Sponsor
• Overall Official(s)
  • Pfizer CT.gov Call Center, Study Director, Pfizer
• Overall Contact(s)
  • Pfizer CT.gov Call Center, 1-800-718-1021, ClinicalTrials.gov_Inquiries@pfizer.com