Phase 1b study of PF-06939926 Mini-Dystrophin Gene Therapy in people with Duchenne

A Study to Evaluate the Safety and Tolerability of PF-06939926 Gene Therapy in Duchenne

Questions and Answers

What stage is this research?

This is a Phase 1b, first-in-human/first-in-patient, multi-center, open-label, non-randomized, ascending dose, safety and tolerability study of a single intravenous (IV) infusion of PF-06939926 in ambulatory subjects with Duchenne muscular dystrophy.

Additional details about this study can be found at (Identifier: NCT#03362502).

Preliminary planning is underway in anticipation of a global, pivotal study of PF-06939926.

What is PF-06939926 Gene Therapy?

Duchenne is caused by an absence of dystrophin, a protein that helps keep muscle cells intact. In the absence of dystrophin, muscle cells deteriorate.

PF-06939926 is an investigational, recombinant adeno-associated virus, serotype 9 (AAV9) carrying a shortened version of the dystrophin gene (mini-dystrophin).

An AAV9 capsid was chosen for the delivery of this mini-dystrophin, because of its mild immune responses (safety) and its ability to enter muscle tissue when tested in pre-clinical studies.

Because the human dystrophin gene is too large to fit in the AAV9 capsid, a mini-dystrophin was developed that may help retain muscle function similar to that of a patient with a more mild disease, like Becker muscular dystrophy.

What is the goal or purpose of this study?

The goal of this study is to test how safe and tolerable a single infusion of PF-06939926 is in ambulatory boys with Duchenne.

Other objectives include measurement of dystrophin expression and distribution, and assessments of muscle strength, quality, and function.

Who is funding this study?

Pfizer Inc.

What are the requirements to be considered eligible to participate in this study?

  • Diagnosis of Duchenne confirmed by medical history and genetic testing;
  • Body weight between 15 and 50 kg;
  • Receipt of glucocorticoids for 6 months and a stable daily dose for at least 3 months prior to study entry;
  • Ability to walk independently and to rise from floor within seven (7) seconds;
  • Ability to tolerate magnetic resonance imaging (MRI) without sedation and with no contraindications to these procedures;
  • Ability to tolerate muscle biopsies under anesthesia with no contraindications to these procedures;
  • Negative test results at the start of this study for antibodies against AAV9 and for T-cell (immune) response to dystrophin.

What do I have to do if I decide to participate in this study?

This study is partitioned into 5 basic periods: Screening, Baseline evaluation, Treatment, First year Follow-up, and then Long-term Follow-up with annual visits for 4 years.

Participants will receive a single IV infusion of PF-06939926 over approximately a 2-hour period.

Participants will be required to remain in-patient at the clinical research site for at least 24 hours post-infusion.

Participants will be required to undergo safety tests, including MRI imaging, as well as assessments to measure muscle strength, quality and function. Muscle biopsies will also be collected to assess the presence of mini-dystrophin in the tissue. ➢ Some of the assessments required at a study visit may need to be completed across multiple days.

How long will this study last, and will I have access to the drug/treatment once the study has ended?

The anticipated length of participation in the study is approximately 5 years.

This study will seek to enroll 12 boys, with two cohorts of 6 boys each. Within each of the cohorts, the dosing interval between the first and second participant will be at least 6 weeks. If no safety concerns are identified 3 weeks after the second participant is infused, then dosing may proceed at 3-week intervals.

Participants in the study will receive a single IV infusion of PF-06939926 during the study.

No re-administration of the PF-06939926 mini-dystrophin gene therapy is currently being considered at any time before, during, or after the study.

Where does this study take place?

This study will be completed across approximately four clinical research sites in the United States only; Duke University Medical Center and University of Utah Hospital are currently active clinical research sites.

Please check, Identifier: NCT#03362502, for details regarding the status of these sites.

Will I get paid for participating in this study?

Participants will not be paid for taking part in this study.
Reasonable travel and accommodations will be provided or reimbursed.

Why should I consider participating in this study?

This is the first study of PF-06939926 in humans.

While no personal benefit can ever be guaranteed by participation in a clinical study, there are other benefits, including allowing participants to play an active role in their own health care (or that of their child), gaining access to new research treatments before they are widely available, having access to medical specialists that are normally not as accessible, and helping others by contributing to a better understanding of Duchenne.

Where can I learn more about this study?

You can learn more about this study at (NCT#03362502)

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