In an ongoing clinical trial we are conducting in collaboration with Massachusetts General Hospital, a gene therapy to treat cerebral adrenoleukodystrophy (CALD) has halted the disease’s progression in 88 percent of patients. The first results of the trial, published in October 2017 in the New England Journal of Medicine, report that 15 of 17 patients have remained stable more than two years after receiving the gene therapy. The trial, sponsored by bluebird bio, is one of the largest gene therapy trials targeting a single-gene disease to be published to date.
Cerebral adrenoleukodystrophy (CALD) is a rare and progressive genetic disorder, usually diagnosed in boys, that affects the nervous system and the adrenal glands (small glands found on top of the kidneys). CALD is caused by a defective gene, called ABCD1, that normally produces an enzyme called ALD protein which breaks down fatty acids. Without a functional ABCD1 gene, fatty acids build up in the body and destroy the myelin of the brain’s neurons, causing devastating neurodegeneration which typically claims boys’ lives within 10 years of diagnosis. To perform the gene therapy, clinicians collect a patient’s blood stem cells, and then use a viral vector to insert a correct version of the faulty ABCD1 gene into the stem cells. After undergoing chemotherapy to make room for the genetically-altered blood stem cells in the bone marrow, the cells are given back to the patients intravenously.
In this video, David Williams, MD, President of Dana-Farber/Boston Children's, discusses the results of this clinical trial and what it means for patients and the future of gene therapy:
Children who meet the following criteria may be eligible to take part in our CALD gene therapy trial: