The CIFFREO clinical trial is researching an investigational gene therapy (fordadistrogene movaparvovec) in 4- to 7-year-old boys with Duchenne.

Duchenne is a neuromuscular disease that causes muscle degeneration. Although current treatments for the disease, such as steroids, can be beneficial for some patients, we hope that an investigational gene therapy (the study drug) will provide an option for the wider Duchenne population. We also hope that it will offer them even more protection against muscle degeneration.

Who may participate

Participating in research is an important and personal decision. Thank you for your interest in the CIFFREO clinical trial for 4- to 7-year-old boys with a prior genetic diagnosis of Duchenne.

In addition, each child must also be negative for neutralizing antibodies which we’ll check during the initial screening period. It’s okay if you don’t know this in advance. If you’re interested in your child participating, you’ll first review and sign an informed consent document before proceeding to the screening period.

There are other study criteria required to participate and these will be assessed by the study team to ensure the CIFFREO clinical trial is a good fit for your child. Only the study doctor can determine if your child is eligible to participate.




4 to 7 years old (before their 8th birthday)




Have been taking daily oral steroids for at least 3 months

Each clinical study has its own guidelines for who can participate, called eligibility criteria.  However, only the research study staff can determine if you qualify to enroll in the study based on the eligibility criteria.

Get started — See if you may qualify

A first step as you consider this study is to answer a 5‑minute questionnaire about your health and medical history either online or over the phone at
1-800-887-7002. If your answers show the study might be a good fit for you, you may choose to be referred to a study clinic that you select.

You will then be asked to provide your contact information for a study representative to contact you and discuss the next steps. If you’re interested, they will do a more detailed review of your medical history to see if you are able to participate. Only the study staff can determine if you meet the study’s eligibility criteria and are able to enroll in the study.

Your answers to these initial questions will only be linked to you if your responses indicate that you may be eligible to participate in this study and you choose to share your contact information with the study team. Pfizer study team members and our partners will have access to reports containing aggregated data that will not be directly linked back to you.

What to expect

If your child enrolls in the study, he will take part for up to five or six years, depending on which group he is randomly assigned to. During this time, you will both need to attend approximately 49 clinic visits (most planned visits will be outpatient and some may be completed at the patient’s home). Most of these visits will take place during the first 2 years of the study. During the follow-up period (the last 3 or 4 years of the study), you and your child will only be required to visit the study clinic once every six months. In addition, your child will need to stay in the hospital for at least seven days when receives the study drug/placebo. Once the study doctor decides your child can leave the hospital, you will be asked to stay close to the study site for at least seven more days.

Length of study participation

5 or 6 years

Number of study visits

About 49


Staying overnight (inpatient) for at least 7 days after receiving the infusion

Long-term follow up

1 visit, every 6 months for up to 4 years

More about the study

If enrolled, your child will be randomly placed into one of two study treatment groups:

  • Group 1 (2 in 3 participants) – Your child will receive a single dose of the study drug on the first day of the study treatment period and a single dose of the placebo* after approximately one year.
  • Group 2 (1 in 3 participants) – Your child will receive a single dose of the placebo* on the first day of the study treatment period and a single dose of the study drug after approximately one year, as long as it is still safe for your child to receive the study drug.

Both the study drug and the placebo are given as an intravenous (IV) infusion (a drip into the vein).

*A placebo looks like the study drug but contains no active ingredients.

Frequently asked questions

How does the investigational gene therapy work?

The gene therapy works by using a modified virus to deliver a shortened dystrophin gene to targets within the body. The virus is changed so that it cannot cause an infection. Once the new gene is within the body, it directs muscle cells to produce the shortened dystrophin protein.

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How is the investigational gene therapy given?

The investigational gene therapy will be given as a single intravenous (IV) infusion (a drip inserted into the vein through a needle). This usually takes about 2 to 4 hours.

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Will support be available?

The study drug and any study-related assessments will be provided free of charge. Travel support may be available and should be discussed with the study team.

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What is a caregiver required to do in this clinical research study?

As the caregiver, you will be required to provide consent for your child to take part in this study.

If you consent, you will need to complete questionnaires about your and your child’s health and well-being, Duchenne-related medical costs, as well as your child’s ability to complete certain activities. You will also need to attend study visits with your child and report any observed safety information to the study doctor and staff as appropriate.

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Can we leave the clinical research study if we change our minds?

As volunteers, you and/or your child can change your minds and leave the clinical trial at any time. Leaving the study will have no impact on your or your child’s regular healthcare. However, the long-term safety and assessment of the gene therapy is a key aspect of this clinical trial. Please think carefully about this commitment before agreeing to take part.

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