In this episode of Health411, host Dr. Jonathan Karp and producer Daniel Geller discuss gene therapy. Specifically, a new treatment known as valactocogene roxaparvovec for hemophilia A. Valoctocogene roxaparvovec is a gene therapy that is designed to treat hemophilia A, a genetic disorder in which the blood does not clot properly. It is caused by a deficiency in a protein called factor VIII, which is needed for normal blood clotting. This new treatment works by introducing a functional copy of the gene that produces factor VIII into the patient's liver cells, which then produce the protein and release it into the bloodstream. This can help prevent bleeding episodes and reduce the need for other treatments such as factor replacement therapy. Valoctocogene roxaparvovec has shown promising results in clinical trials and has been approved by the FDA for use in patients with hemophilia A. However, like all gene therapies, there are still some potential risks and limitations that need to be considered. Dr. Karp and Mr. Geller discuss the science behind this treatment, its potential benefits and drawbacks, and what it could mean for the future of gene therapy and hemophilia treatment.