Gene therapy trial on hold

As the US Food and Drug Administration prepares to investigate the death of a patient in a phase I/II gene therapy trial for inflammatory arthritis, researchers in the field say the treatment's delivery vector, an adeno-associated virus (AAV), was unlikely to be the culprit."Vectors in this class have been used on hundreds of patients over the last 12 years, and are not associated with acute toxicity," said Terence Flotte of the University of Massachusetts Medical School in Worcester. Flotte has been a principal investigator in several clinical trials of AAV-based gene therapy, but is not associated with the trial in question. "I've never seen anything like this," he told The Scientist. "Whatever this is, it's unusual.""The AAV vectors in themselves are unlikely to cause inflammation or cell damage," agreed Theodore Friedmann of the University of California, San Diego, previous president of the American Society of Gene Therapy. Although...