This brochure was developed to recruit patients with OTC, a rare genetic disease, for a clinical trial utilizing gene therapy. In the brochure, I explained how gene therapy works in a clear, easy-to-understand manner and also provided important details on the trial itself.

What is DTX 301?
DTX 301 is a type of gene transfer, an approach that attempts to treat diseases, like OTC deficiency, by providing the body with normal healthy genes.

• Genes have specific instructions like a cookbook recipe, for making important proteins in your body
• If something is wrong or missing in the “recipe” it can lead to serious disease
Patients with OTC deficiency have a genetic defect in the liver enzyme that causes ammonia to build up in the blood stream
• DTX 301 is designed to deliver a working copy of the OTC gene to your liver
• By introducing a normal, healthy OTC gene, DTX 301 may allow for adjustments in OTC medications and diet

How does DTX 301 work?
The working OTC gene is delivered to the liver via a vector, which is a kind of helper that enables genetic material to go directly into a cell. You can think of the vector as a car, and the gene as a passenger in the car. Vectors are often made from viruses, just as vaccines are made from viruses. Doctors use viruses to make vectors because they can easily enter cells. DTX uses a vector made from a virus called the adeno-associated virus (AAV). This virus has been changed so it can’t reproduce or cause infection in your body.