Gene Therapy Death May Delay New Trials

Researchers hoping to test a novel nonviral gene therapy system in people next year are unsure of approval prospects, following the recent death of a young man who was treated with an experimental viral vector.¹ The man's health deteriorated rapidly a day after he was treated with an adenovirus carrying a therapeutic gene to treat ornithine transcarbamylase (OTC) deficiency.

R. Michael Blaese

Instead of taking the conventional gene therapy approach of delivering missing genes, the novel approach would use chimeraplasts--oligonucleotides containing both DNA and RNA that theoretically correct point mutations by initiating the cell's DNA mismatch repair machinery²--to treat Crigler-Najjar (C-N) syndrome. Children with C-N lack the complete protein necessary to break down toxic bilirubin in the liver and must spend 12-18 hours a day under a blue light to clear bilirubin. Even with that light therapy, their prospects to live into adulthood without a liver transplant...