Hemophilia “A” gene therapy: Lost in translation

Successful gene therapy for hemophilia A had been considered as one of the “holy grails” in the gene therapy field. An important milestone toward realizing this goal had been achieved (https://www.ema.europa.eu/en/news/first-gene-therapy-treat-severe-haemophilia) following the first conditional marketing authorization approval in the European Union for an adeno-associated virus type 5 (AAV5)-based gene therapy strategy.1 Most of the treated patients remained off prophylaxis and bleed-free 2 years after dosing and up to 5 years in a supporting trial.