This study looks at how safe and effective a new treatment called AMT-191 is for people with Classic Fabry Disease (FD). Fabry Disease is a rare illness caused by a missing enzyme called α-galactosidase A. This study gives a single dose of AMT-191 to help create this enzyme in the body. AMT-191 uses a special virus, called a viral vector, to deliver the treatment directly to the liver through an IV infusion (a needle in a vein).

• The study needs men aged 18-50 with Classic Fabry Disease.
• Participants will keep taking their usual enzyme replacement therapy (ERT) during the study.
• Participants must agree to use condoms for up to 18 months to prevent transferring the treatment to others.

If you join, you will have to follow specific rules, such as no vaccinations around the time of treatment and no other experimental drugs. Risks include possible side effects from the treatment or its delivery method. Only consider joining if you meet the health conditions and requirements, and discuss it with your doctor.