Gene therapy SCIDs

Last week's news that a patient in a French trial of gene therapy for the X-linked form of severe combined immune deficiency disease (XSCID) developed T cell lymphoproliferative disease renews concerns about the safety of the field which has yet to fully recover from the 1999 death of a patient caused by an experimental adenoviral-based therapy for ornithine transcarbamylase deficiency. The patient's hospitalization transforms concerns about the potential dangers of retroviral vectors from theory to reality.

And because early success in SCID has been held up as the model for the potential of gene therapy, it remains to be seen how heavy a blow the hospitalization will be to the field. Initial comments from Philip Noguchi, acting director of the office of cellular, tissue and gene therapies at FDA, indicate that the agency may not be ready to take drastic action. A meeting of the FDA's Biological Response Modifiers Committee scheduled for this Thursday may provide an answer. In the meantime, the FDA has placed three SCID gene therapy trials on hold, but has said other gene therapy trials may continue...