Gene therapy: a 2001 perspective

In the past year, three clinical trials of gene therapy for haemophilia hav e been initiated. Years of preclinical studies have culminated in translati on of research findings into the clinical arena. It is too early to predict which, if any, of these strategies will show efficacy. This paper will rev iew basic aspects of gene therapy for haemophilia and will briefly outline current clinical trials. The three clinical trials all share a dose escalat ion design. The ongoing trial for haemophilia B involves the intramuscular administration of an adenoassociated virus (AAV) vector expressing human fa ctor IX. In preclinical studies, this strategy has produced therapeutic lev els of circulating factor IX in haemophilic mice and dogs.