CAR-T: Cancer treatment therapies
Can you imagine a therapy that can re-programme its own immune cells to attack cancer cells throughout the body? Well it does exist in Spain. It is called CAR-T, T-cell therapies with chimeric antigen receptors (chimeric antigen receptor, CAR). This new therapy treats several types of aggressive blood tumours, where the estimated survival does not reach seven months of life.
This new generation of so called ‘living therapies’ against cancer, referred to by the American Society of Clinical Oncology as the Advance of the Year in 2018, has a complex process to say the least.
T cells, which are a type of white blood cells that are part of the immune system, are first removed from the patient and taken to the laboratory where they undergo a genetic change to attack the cancer cells.
These T-cells with chimeric antigen receptors are grown in large amounts and then injected into the patient making it a programmed weapon to fight against cancer.
Hopeful results
There are currently two approved therapies that are already being applied in Spain.
The CAR-T is developed by Novartis and the pharmaceutical company Gilead. Both companies are aimed at treating various types of very aggressive Non-Hodgkin lymphoma.
For example, in the clinical trial conducted with the drug developed by Gilead, patients with aggressive B-cell Non-Hodgkin Lymphoma were treated with a single infusion of which 54 percent achieved a complete response to treatment, which meant they had no more cancer; and 74 percent of patients showed improvement with treatment. The trial followed up with patients for two years after treatment, most patients were still alive.
The clinical trial of Novartis therapy, targets children and young people with acute B-cell lymphoblastic Leukemia. After conducting the trial 83 percent of treated patients responded to treatment and in three out of four patients, the Leukemia had not yet returned after 6 months.
An expert tells us about CAR-T therapies
Jose María Moraleda Jiménez is coordinator of the Cellular Therapy Network of the Carlos III Health Institute and professor of Medicine at the University of Murcia. This is what he tells us:
The CAR-T therapies are a form of disruptive and innovative cell therapy that is framed in the so-called "Personalised Medicine". It consists of the transplantation of T lymphocytes, obtained from the patient himself, and modified in the laboratory using genetic engineering techniques so that they express on their surface an artificial ("chimeric") receptor directed against a specific ligand of a tumour cell. When the union between the receptor and the ligand occurs, the T lymphocyte is activated, multiplied logarithmically and destroys the tumour cell by releasing molecules that produce direct cell damage. Prior to transplantation, patients should receive treatment to facilitate the implantation and expansion of T-CARs.
Although they have serious side effects and their production is complex and expensive, CAR-T therapies are considered one of the greatest therapeutic advances of recent decades due to their excellent results in patients in the almost terminal stages of their disease. Children with acute leukemias of B lymphocytes that do not respond to chemotherapy get long-lasting responses of 50 to 70 percent, and adults with aggressive refractory B lymphocyte lymphoma of 40 to 60 percent. These therapies are being investigated for the treatment of solid tumours, autoimmune and infectious diseases, in what may be considered a new therapeutic revolution.
Article written by Marta Riesgo
