ABOVE: Illustration of adeno-associated virus
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A little more than a decade ago, seven patients with hemophilia B—a disease caused by a mutation on the F9 gene that prevents patients from forming crucial clotting proteins—volunteered to be the first humans to receive a gene therapy delivered using an adeno-associated virus as a vector. This particular treatment didn’t move past the Phase 1/2 trial because, while it was deemed safe, the patients did not sustain expression of the gene. But two other gene therapies based on an adeno-associated virus (AAV), Luxturna for rare forms of blindness and Zolgensma for spinal muscular atrophy, have since been approved by the US Food and Drug Administration (FDA), and several pharmaceutical companies are now pursuing regulatory approval of AAV-carried gene therapies for hemophilia B.
Recently, scientists followed up with four of those original patients. In a study published in Molecular Therapy in September, ...
