CAR-T stands for chimeric antigen receptor T-cell therapy. It’s a cutting-edge form of immunotherapy, which means it helps the body’s own immune system fight cancer. Our immune system normally relies on T cells – specialised white blood cells that act as the body’s soldiers – to search for and destroy abnormal cells. However, cancer cells are clever. They can disguise themselves and hide from normal T cells, allowing the disease to grow and spread. CAR-T therapy overcomes this problem by giving a patient’s T cells a new ‘target’ enabling them to recognise cancer cells more clearly and attack them with precision.
Why is it used?
CAR-T therapy is mainly used when standard treatments such as chemotherapy, radiotherapy or targeted drugs haven’t worked, or when the cancer has returned after a period of remission. Doctors call these situations relapsed (the cancer has come back) or refractory (the cancer hasn’t responded to treatment).
In some cases, CAR-T can be used after a bone marrow or stem cell transplant, and occasionally even before a transplant if other options are limited. For many families, this treatment represents hope when other therapies are no longer effective.
How does the treatment work?
CAR-T therapy is a multi-step process that usually takes several weeks and requires a hospital stay...
1) Collection: T cells are removed from the patient’s bloodstream through a process called apheresis. This is similar to a long blood donation, where blood is drawn from the body, the T cells are separated, and the remaining blood returned.
2) Modification: In a specialised laboratory, scientists insert a new gene into these T cells. This gene creates a receptor on the cell surface called a chimeric antigen receptor (CAR). The CAR acts like a sensor, enabling the T cells to recognise specific proteins found on the cancer cells.
3) Infusion: Once enough modified cells are produced, the patient is admitted to hospital. A short course of chemotherapy is given first to reduce existing immune cells and create space for the CAR-T cells. Finally, the engineered T cells are infused back into the bloodstream, where they multiply, hunt down, and destroy the cancer.
Are there any side effects?
Because CAR-T cells trigger a powerful immune response, there are some side effects –
• Cytokine release syndrome: A surge of immune chemicals can cause fever, low blood pressure, or breathing difficulties
• Neurotoxicity: Some patients may experience confusion, headaches, or seizures as the immune system affects the brain
These reactions can sound alarming, but treatment takes place in hospital under very close supervision, and doctors have effective medicines to manage them. Patients also experience the usual side effects of chemotherapy, such as fatigue or low blood counts.
Who can receive CAR-T therapy?
At present, CAR-T is approved in the UK for certain blood cancers, including specific types of leukaemia and lymphoma, particularly when other treatments have failed. Researchers are running clinical trials to see whether this approach can also help patients with solid tumours, such as brain tumours or sarcomas.
Where is it available for children and teenagers in the UK?
CAR-T therapy for young people is currently offered at four specialist centres:
- Great Ormond Street Hospital, London
- Royal Manchester Children’s Hospital
- University College London Hospital (UCLH)
- Great North Children’s Hospital, Newcastle
These centres have the expertise and facilities to deliver this highly specialised treatment safely.
From Contact magazine issue 109 | Winter 2025
