A molecule developed by Quebec researchers makes it possible to multiply the number of stem cells from umbilical cord blood, which offers new hope to certain patients who had exhausted all the options available to medicine until now.
The UM171 molecule makes it possible to multiply the number of stem cells taken from a donor or obtained using cord blood by 10 to 80 times.
“Our clinical trials show that this technology now allows us to cure people who, until now, seemed uncurable by transplant because their disease was too aggressive,” said Doctor Guy Sauvageau, of the Institute of research in immunology and oncology at the University of Montreal.
The UM171 molecule was tested, during phase II clinical trials, in 50 patients suffering from leukemia or myelodysplasia (a group of diseases characterized by insufficient production of healthy mature blood cells by the bone marrow) at high risk of relapse after a stem cell transplant.
70% of patients survived two years after their stem cell transplant amplified with the UM171 molecule, without any sign of disease recurrence.
These results are all the more promising given that approximately a third of the patients concerned had not obtained significant results following a first stem cell transplant without using the UM171 molecule.
In about 10% of cases of acute leukemia, Dr. Sauvageau said, doctors are unable to find a bone marrow donor who is compatible with the patient. And even though umbilical stem cells give caregivers greater flexibility, it is very often the case that the available cord is too small to meet the needs of a 70-kilogram adult.
“This molecule is literally the only example currently in the world of a molecule that can solve this problem for this 10% of patients,” summarized Doctor Sauvageau.
The use of the UM171 molecule, he added, not only makes it possible to obtain enough stem cells to maximize the chances of a successful transplant, but these cells also tend ― by their very nature ― to be more aggressive towards leukemia. “So you get the best of both worlds,” he said.
During their work, Dr. Sauvageau and his colleagues noted that the UM171 molecule appears to act on the basic mechanisms of blood stem cell rejuvenation. It may even have an impact on the basic mechanisms of human aging.
“The cell exposed to the UM171 molecule regains the characteristics of young cells,” said Dr. Sauvageau. In particular, these cells generate cells of the immune system which are much more active and which are much more numerous in the transplanted individual. »
The discovery of the UM171 molecule was first announced in the pages of the journal Science in 2014. The news caused a sensation and was even chosen as scientific news of the year in Quebec. The first clinical trials organized then gave very promising results.
“It still caused a “boom” in the media, but about five years ago, I told people, we’re heading into a dark period, you won’t hear from us for about five years because we have to do phases 2 and we have to recruit around a hundred patients,” recalled Doctor Sauvageau.
“But I said, you’re going to hear about us again one day. Well, the day has come. »
Researchers are currently in discussions with the United States Food and Drug Administration (FDA) and the European Medicines Agency for further clinical trials.
The most recent results were revealed during the 65e annual meeting of the American Society of Hematology.