New Study Aims to Improve Transplant and Decrease Risk Through Gene Therapy.
Boys with Adrenoleukodystrophy (ALD), a rare x-linked disorder caused by mutations within the ABCD1 gene, are unable to metabolize very long chain fatty acids (VLCFA) leading to an accumulation of VLCFA in the blood, adrenal glands, testes and brain. In approximately 40 percent of boys with ALD, accumulation of VLCFA causes acute inflammatory demyelination, termed cerebral ALD (cALD). Most of the time, this occurs in boys between 4 and 10 years of age but may occur later. Boys with cALD develop normally until disease onset, which can be characterized by rapidly progressive loss of visual, auditory, motor and cognitive function. If left untreated, childhood onset cALD is generally fatal within a few years.
Currently the only effective treatment for childhood-onset cALD is allogeneic blood and marrow transplant (BMT) in which blood stem cells collected from a healthy donor are infused following a conditioning regimen of chemotherapy. Over the course of several months, the engrafted donor cells migrate to the CNS where they can stop progression of the disease. However, transplant carries a significant risk, including life-threatening infection, rejection of the donor cells leading to a failure of the transplant, or graft-versus-host disease, a condition in which the immune cells of the donor react to the body of the transplanted patient.
University of Minnesota has been chosen as one of only five sites worldwide to participate in an exciting new clinical trial investigating a method to provide the benefits of BMT without the associated risks of allogeneic transplantation. This new gene therapy approach will use an ex-vivo lenti-viral vector to introduce ABCD1 into a patient’s blood stem cells which had been previously harvested through apheresis. The patient then receives high-dose chemotherapy conditioning to eliminate his defective blood stem cells followed by infusion of the autologous, genetically modified cells. If successful, these genetically corrected blood stem cells would reconstitute the marrow. Because the patient’s blood stem cells are used for transplant, this gene therapy approach is expected to be better tolerated. The hope is that this approach will confer the benefits of transplant while carrying a lower risk profile.
Patients must have confirmed early-stage cerebral ALD to be eligible for the trial.
For more information about this clinical trial or other treatment options available at University of Minnesota Masonic Children’s Hopsital for patients with ALD, contact Paul Orchard, MD, Weston Miller, MD, Troy Lund, MD, or call Patty Kleinke with the BMT Program office at 612-273-0857 or 888-601-0787 (toll free).