Graft Versus Host Disease
Recently, we asked several of Canada’s leading stem cell scientists to tell us about what they think will be the next big thing in regenerative medicine.…
Recently, we asked several of Canada’s leading stem cell scientists to tell us about what they think will be the next big thing in regenerative medicine. Where do they see things going? What are they excited about? For today’s instalment, we interviewed Dr. Denis-Claude Roy, Director of the Centre de recherche de l’Hôpital Maisonneuve-Rosemont and a full professor at the Université de Montréal. Dr. Roy is Chief Executive Officer of CellCAN Regenerative Medicine and Cell Therapy Network. Asked about what he sees developing in the field of stem cells and regenerative medicine he provided the following highlights of his work and others.
In our work with blood-based cancers like leukemia and lymphoma, we have developed a protocol for stem cell transplantation for people who don’t have a matched donor. We are able to do mismatched stem cell transplants, or what’s called haploidentical stem cell transplantation. This means that in place of being fully compatible (with the donor cells), a patient can be 50% compatible and still get a transplant.
Normally (such a transplant) would kill the patient, but we’ve developed a strategy to eliminate the cells that cause Graft Versus Host Disease (GVHD) and attack the patient. GVHD is probably the biggest problem associated with stem cell transplantation. Instead of having the patient develop GVHD or treating the patient with drugs to prevent it from occurring, we treat the cells in the lab and eliminate those that cause GVHD. So, we’re able to do stem cell transplants without immune suppression and the patient won’t have to take immuno-suppressor drugs for the rest of their lives.
We’re very excited about this. Our first study included 19 patients and we have had extremely good results. The patients had few infections and low relapse rates. A second study on another 23 patients, part of an international study, is currently led by our centre. To date, patients are again doing very well.
We’re also starting a clinical trial using a molecule called UM171 that was developed by Dr. Guy Sauvageau (Université de Montréal) to expand umbilical cord blood stem cells while maintaining their properties. Right now, donated umbilical cords have too few cells to treat adults. One donation provides enough cells to treat a child, but not enough for a normal size adult. Currently for an adult, we have to use two donations and that presents immune issues and is very expensive. We want to ramp up the number of stem cells from umbilical cord donations for those patients that have a match but not enough cells. We can grow the cells in the lab to have enough for the transplant.
This will allow us to select from our larger pool of umbilical cord blood donations and therefore improve the match, which should result in decreasing the number of complications associated with transplants and make it possible for more people to get them. This could also accelerate engraftment, shortening the time for the cells to engraft, which would decrease risk associated with the procedure.
The the use of stem cells in cardiac treatments is also starting to gather momentum. Dr. Duncan Stewart (University of Ottawa) has a trial (using genetically modified stems to repair heart damage) that is going very well. I am also working with Dr. Nicolas Noiseux (Université de Montréal) on activating stem cells before they are infused into the heart. He is studying a number of molecules to activate the cells before they are injected. The idea is to repair the hearts of patients who have poor cardiac function.
We will also be starting a trial using cells from the immune system to target leukemia. They are specific, acting like missiles, which will select and kill leukemia cells. Dr Claude Perreault (Université de Montréal) is developing a series of new targets. A new clinical trial is likely to start in the Fall.