The results are in for the first set of clinical trials into a new cancer treatment that targets a specific type of blood cancer – and they’re very promising.
Named CAR T-cell therapy, the treatment involves genetically modifying patients’ T-cells. T-cells are part of a person’s immune system; they produce antibodies to attack foreign substances such as bacteria or viruses. In CAR T-cell therapy, these T-cells are genetically modified on a per-patient basis so that instead of destroying healthy cells, they target the patient’s tumor cells.
This type of cancer treatment is called ‘immunotherapy’, or ‘biologic therapy’. Immunotherapy involves using materials made by the body or in a laboratory to boost immune system function in order to treat a patient’s cancer.
Results from the cancer treatment trial
A trial recently took place on several dozen patients suffering from terminal blood cancers. In most cases, patients were typically expected to have a life expectancy of between 3 – 5 months. All patients involved in the study had previously undergone existing treatments for their specific types of blood cancer and treatment had failed in every case.
After the CAR T-cell therapy treatment, over 80% of patients saw response rates to the treatment and over half went in to complete cancer remission.
For patients with acute lymphoblastic leukemia (a specific type of blood cancer), symptoms vanished completely in an astonishing 94% of patients.
Side effects of CAR T-cell therapy
The study found that CAR T-cell therapy can cause some dangerous side effects. The most worrisome of these is cytokine-release syndrome. The modified T-cells produce chemical messengers called cytokines which “tell” the T-cells how to behave in the body. Cytokine-release syndrome is when a huge amount of cytokines are released into the bloodstream over a short amount of time. This can cause extremely high fevers and significant drops in blood pressure in the patient.
Whilst many patients in the trial only suffered mild side effects, seven were affected so badly that they required intensive care and a further two patients died from the condition.
Is CAR T-cell therapy the future of cancer treatment?
CAT T-cell therapy is designed purely for use on blood cancers such as leukemia. It is currently not suitable for treating “solid” cancer tumors. However, as the science around this treatment develops, it may one day be possible to use the knowledge gained from this study to help combat other types of cancers too.
The trial’s lead scientist Professor Stanley Riddell said during the annual meeting for the American Association for Science (AAAS): “Much like chemotherapy and radiotherapy, it’s not going to be a save-all. I think immunotherapy has finally made it to a pillar of cancer therapy.”
It’s important to remember that CAR T-cell cancer treatment is still at the very early stages of human trials. Many months (or years) of development and refinement will now follow to maximize the healing potential of the treatment and reduce the risk of side effects.