Researchers in Calgary have launched the first gene therapy clinical trial in the world for Fabry disease, a rare inherited enzyme deficiency that can shorten the lifespan of people who have it by as much as 40 years.
Researchers will first remove a quantity of stem cells from a Fabry patient's blood. Then a working copy of a new gene will be inserted into the stem cells using a specially engineered virus. During the final phase of the trial, researchers hope to transplant these stem cells back into the donor patient and the new, working copy of the gene will make the missing enzyme.
The clinical trial has been prompted by promising gene therapy results in mice performed in the laboratory of Dr. Jeffrey Medin at the University Health Network in Toronto. Dr. Medin is the principal investigator of the pan-Canada team grant that is supporting this trial.
"We hope this will one day become a form of treatment that effectively cures Fabry disease," says Dr. Aneal Khan, a medical geneticist based at Alberta Children's Hospital, who is leading the Calgary segment of the national project.
"It could also help establish a platform on which we can create gene therapies for other illnesses and establish Calgary as a national leader in this experimental field of interventional genetics."
Although several gene therapies have been used in Canada for cancer, this study will be the first in the country to test a gene therapy for an inherited metabolic disorder.
People with Fabry disease have a change in a gene called GLA and can't make enough enzyme to break down a fatty substance called Gb3. The build-up of Gb3 can lead to problems in the kidneys, heart and brain. About 400 Canadians, including 25 Calgarians, have Fabry disease.
Although the project is headquartered in Toronto, physicians and scientists in Calgary will play a major role in the clinical trial. In particular, the lab at Foothills Medical Centre in Calgary has specialized expertise in the stem cell filtering process that will be used for the clinical trial.
"The trigger that's making all this possible is Calgary's expertise in isolating the specific blood stem cells we need," says Dr. Medin. "Without a sufficient quantity of those stem cells to work with, our likelihood of success would be greatly reduced."
In the Fabry trial, technologists led by Dr. Nicole Prokopishyn, director of the Calgary Laboratory Services Cellular Therapy Lab, processed the blood from a donor patient and isolated a specific type of stem cell called a CD34+ cell.
Christopher Armstrong, a 34-year-old Calgarian with Fabry disease, recently donated his blood for key initial experiments for the first phase of the trial. Nearly a billion of Christopher's CD34+ cells have been isolated and will be sent to Dr. Medin's lab in Toronto. Dr. Medin's team will take those cells and, using a modified virus, insert a working copy of the GLA gene into the stem cells.