Frequently asked questions about gene replacement therapy

1. What is gene replacement therapy?

Gene replacement therapy, a type of gene therapy, is a potential way to treat genetic diseases. Gene replacement therapy addresses the root or underlying cause of a disease by replacing a missing or faulty gene with a new, working copy of the gene. To learn more, download the facts about gene replacement therapy.

2. How does gene replacement therapy work?

Gene replacement therapy attempts to give the body a new, working copy of a missing or faulty gene. The new gene sits inside the nucleus, or control center, of cells and allows the cells to produce more of the missing proteins that are critical for the body to function.

3. Is gene replacement therapy safe? Does it work?

All therapies are required to undergo testing in clinical studies. All clinical studies, including the ones being conducted in gene replacement therapy, are monitored for safety and effectiveness of a treatment. The clinical study team works closely with the US Food and Drug Administration (FDA) to monitor potential risks both during and after its clinical studies.

4. Why are viruses used in gene replacement therapy?

Viruses are used in gene replacement therapy because of their natural ability to enter the body. In gene replacement therapy, scientists alter or reengineer a virus so it can be used as a vector, or delivery vehicle, without causing disease in humans. The vector acts like an envelope in that it holds the new, working copy of the gene and delivers it to where it needs to go in the body. Once the new gene has been delivered to cells, the rest of the vector, including the viral shell (the “envelope”), is broken down by the body.

5. Could gene replacement therapy help people with monogenic diseases?

A monogenic disease can be caused by one missing or faulty gene or gene pair. Since gene replacement therapy delivers a new, working gene to the body, it has the potential to help people with monogenic diseases. Learn more about some of the monogenic diseases that we believe may be an option for gene replacement therapy.