Gene therapy revisited

Since the death of Jesse Gelsinger 2 years ago during clinical trials at the University of Pennsylvania, gene therapy has maintained a low profile and receded from the public eye. But away from the headlines, researchers are, in fact, quietly making progress and are confident that, within the next decade, gene transfer will be elevated from its current experimental status to a therapeutic modality.At the recent Emerging Technologies in Gene/Drug Therapy and Molecular Biology meeting, sponsored by the Regulon company (Mountain View) and the International Society of Gene Therapy and Molecular Biology, a group of about 100 scientists gathered in Corfu, Greece, to discuss advances in bringing gene therapy to the clinic. They still face major challenges: targeting the right gene to the right location in the right cells and expressing it at the right time, all while minimising any adverse reactions. But the scientists presented data on the development of viral and non‐viral gene vectors, tissue‐ and disease‐specific gene delivery and cell cycle control that indicate that the clinical use of gene transfer is becoming a tangible possibility.Much research has concentrated on finding the best vector for a specific application. Eugene Redmond of Yale University (New Haven, CT) compared four viral vectors to determine which prolonged gene expression the most and which was the least destructive of brain tissue in treating neurological diseases: ‘A comparative study of viral vectors could be useful for evaluating vectors for human clinical use for somatic gene therapy, where long‐duration gene expression might be necessary, and inflammatory, demyelination and cytotoxicity is undesirable for diseases such as Parkinson's, Alzheimer's, or other diseases involving the brain’.Comparing lentiviral, adenoviral, adeno‐associated and retroviral vectors in primates, Redmond found that the adeno‐associated vector was the safest and most effective vector in producing long‐lasting gene expression when …