What is gene therapy?
Gene therapy is the transfer or addition of genetic material in cells to help treat a disease and is a type of genetic medicine.1,2 For rare genetic conditions like Duchenne, genetic medicine can be a way to treat the disease at the genetic level.3 This site focuses mainly on education of one type of genetic medicine—gene therapy.
Pfizer's gene therapy for Duchenne muscular dystrophy is being evaluated in clinical trials and is not approved by the FDA. If FDA approved, it may not be an appropriate treatment for all children with Duchenne.
![Young child playing violin with DNA strand stemming from their hand with their friend without Duchenne playing violin](./media_14a4f010129c4118bf30499e1f491b11a72d60463.png?width=750&format=png&optimize=medium)
Learn the basics of the different types
of genetic medicine approaches
/assets/videos/moa-video-compilation-1.mp4
Slide left and right to see types of genetic medicine
![Gene regulation with on and off switch](./media_180623c9d6c563b1940fa9ed110f884666bb0e962.png?width=750&format=png&optimize=medium)
Gene regulation
Changes how the gene
acts, which may include
turning it on or off1
![Gene therapy with vector](./media_15262cf501c487a79b3bc6d7ea4f428b7c813183e.png?width=750&format=png&optimize=medium)
Gene therapy
Transfers or adds part of a
functioning gene to work in place
of the gene that does not work1
![Gene editing with scissors](./media_1aec0c3e0e3732cf5e35b8b261d39211cb7e877ea.png?width=750&format=png&optimize=medium)
Gene editing
Removes or corrects
parts of a person’s gene1
Gene regulation, gene therapy (also known as gene transfer or gene addition), and gene editing are all being explored for Duchenne.4 This site focuses mainly on gene therapy education.
Gene therapy uses a shell called a vector, which carries a functional gene to the nucleus of the DMD gene.1,5 This process helps with the production of functional dystrophin protein.6
![Viral vector illustration with capsid and functional gene labeled](./media_155d43f942b0a3e2be6c7063e97781a7fb11ba330.png?width=750&format=png&optimize=medium)
Viral vectors are made to deliver functional genes5
Viral vectors are created from part of a virus in a lab.5 The outer shell of a virus (the capsid) helps it enter the body’s cells but does not cause a disease.5 Gene therapy uses the capsid but replaces what's inside with other parts, including a functional gene to treat the condition.5
Viral vectors are the most common way to deliver gene therapy.5
The adeno-associated virus (AAV)
The most common type of viral vector in gene therapy is the adeno-associated virus (AAV), which can be made to target certain types of cells.5 Over 20 years of research have shown that AAVs are able to deliver a functioning gene, but there is still more to learn about what this could mean for patients as research continues.7
AAVs do not cause disease and can be found in nature.5 When used in gene therapy, the viral DNA is removed from the AAVs and replaced with a functional copy of a gene; also known as transgene.6,8
It is possible for a child to already have come into contact with AAVs. As a result, the body may have developed neutralizing antibodies (NAbs).6,9 NAbs are found in the immune system and are designed to protect the body from diseases or anything unknown.6 If a child has certain NAbs, this may impact whether they would be a good candidate for gene therapy.
![AAV delivering a functioning gene in a cell illustration](./media_1245073b3d2162968a699e56220c8ffe20a76c3d7.png?width=750&format=png&optimize=medium)
How may gene therapy work for Duchenne?
Research is ongoing to learn more about Pfizer’s potential gene therapy for Duchenne. This includes safety considerations, immune reaction, how well the treatment may work, how long the treatment may last, and post-treatment considerations.4,10-13
If FDA approved, patients will be closely monitored in the short and long term following treatment as we continue to learn more.
Learn more about the potential gene therapy process
Understand how gene therapies may be administered, what treatment may look like, and get answers to some common questions.