Madrid, 26 February 2020. After more than 15 years of experience in autologous and allogeneic transplants, MD Anderson Cancer Madrid has launched a new Haematopoietic Transplant Unit with a view to enhancing and developing the transplant programme and offering CAR-T therapy. For the moment, as the main innovation, this new unit has incorporated a protocol for treatment with high doses of chemotherapy and autotransplantation of hematopoietic progenitors (autologous transplant) on a semi-ambulatory basis.
In addition to this innovation, a specific programme has been set up to facilitate this autologous transplant for people living outside Madrid. “We are working on the coordination of protocols with different centres that are not available to carry out this transplant,” explains Dr Adolfo de la Fuente, head of the Haematology Service in the MD Anderson Cancer Center Madrid – Hospiten.
“The aim is for patients to have to travel as little as possible, to be able to return home soon and for their progress to be monitored later by the same team that was treating them in their home town,” says this expert, who stresses patient comfort as the focus of the entire project.
In addition to systemic treatments and/or targeted therapies, both autologous and allogeneic haematological progenitor transplantation (commonly called bone marrow transplantation) continues today to be part of the treatment plan for many patients with various haematological diagnoses such as leukaemia, lymphoma and multiple myeloma.
El Autologous and allogeneic transplants are two totally different strategies, so they are offered or considered in different diagnoses and situations. “While in an autologous transplant there is no donor and the patient is the focus of the whole process, in an allogeneic transplant there is a donor and therefore compatibility studies must be carried out before starting the process,” explains the doctor.
Thus, in an autologous transplant, haematopoietic progenitors are taken from the patient; that is, "stem cells" just before they are differentiated into blood cells, for processing in the laboratory. Once prepared, the haematopoietic progenitors are infused back into the patient after an intensification process with high doses of chemotherapy. “After applying high doses of chemotherapy, we rescue the person with his or her own cells to repopulate his or her bone marrow and start the normal production of red blood cells, white blood cells and platelets again,” states the doctor.
For its part, an allogeneic transplant does not focus its curative intention on chemotherapy but on the contrary: here, chemotherapy serves to prepare the patient who will receive the cells from a donor and to help him/her nest these cells properly. “It is these donor cells that, once infused into the patient, will populate the bone marrow and rebuild the immune system, which is called the graft-versus-disease effect,” highlights this specialist.
The fundamental problem here is that the graft-versus-host effect, that is, the infused cells and the new immune system, reject the patient.
CAR-T cells versus haematopoietic stem cell transplantation
The success of results with CAR-T therapies in patients with various types of leukaemias and lymphomas have positioned this treatment as one of the great hopes in haematological tumours, but how exactly do these CAR-T therapies differ from autologous and allogeneic haematopoietic stem cell transplants?
Firstly, precisely these haematopoietic progenitors are key in autologous and allogeneic transplants, but not in CAR-T therapies. “In these therapies, what we need are T lymphocytes, which are processed in the laboratory and manipulated after their extraction so that they develop antitumoral activity against the disease suffered by each specific person,” explains Dr de la Fuente.
Once "trained" in the laboratory, those T-lymphocytes are infused back into the patient to identify and attack the tumour cells. Therefore, each type of transplant has a tool to act. “In autologous transplantation the tool is chemotherapy, in allogeneic transplantation it is the new immune system and in CAR-T cell therapy it is the patient's own re-educated T-lymphocytes,” concludes this expert.