CAR T-cell therapy
CAR T-cell therapy is a type of immunotherapy. CAR stands for chimeric antigen receptor. You might also hear it called a type of adoptive cell transfer.
CAR T-cell therapy is a very complex and specialist treatment. You can only have this treatment in a registered CAR T-cell therapy hospital with healthcare professionals who have the expertise to look after you. Your doctor can tell you more about where you will be treated.
With this treatment, a specialist nurse collects your T cells. These are then sent to the laboratory where a change is made to the T cell to become CAR T-cells. After a few weeks, you have a drip containing these cells back into your bloodstream. The CAR T-cells then recognise and attack the cancer cells.
It is a possible treatment for children and adults with 
or B cell acute lymphoblastic leukaemia (ALL).
It is also a possible treatment for adults with relapsed or refractory:
- diffuse large B cell lymphoma (DLBCL)
- primary mediastinal large B cell lymphoma (PMBCL)
- mantle cell lymphoma (MCL)
People with other types of cancer might have it as part of a .
The European Society for Blood and Marrow Transplantation (EBMT) collects information on the different types of transplants and cellular therapies happening in Europe including CAR T-cell therapies. Although the treatment is relatively new, their latest report showed that in 2021 around 2,500 people had CAR T-cell therapy.
What are T cells?
To understand CAR T-cell therapy more, it helps to understand what T cells do.
Lymphocytes are a type of white blood cell. They play an important part in fighting infection and diseases, including cancer. There are different types of lymphocytes. T cells are one type.
T cells move around the body to find and destroy abnormal cells. When you come into contact with a new infection or disease, the body makes T cells to fight that specific infection or disease. It then keeps some in reserve so that if you come across the infection again your body can recognise it and attack it immediately.
What is CAR T-cell therapy?
As we know, T cells are good at fighting infection and disease like cancer. But it can be difficult for them to tell the difference between a cancer cell and a normal cell. So the cancer cells can hide away and not be recognised.
Scientists are trying to find ways to get T cells to recognise cancer cells. One possible way to do this is CAR T-cell therapy.
How does CAR T-cell work?
T cells are collected from the blood. This process is called apheresis.
In the laboratory, scientists change the T cells to become CAR T-cells. You might hear this called genetically engineering the T cell. They do this by adding a to the T cell that causes the cell to make proteins on their surface called chimeric antigen receptors (CARs). The CARs can recognise and target a specific protein on the surface of the cancer cells.
These changed T cells grow and multiply in the laboratory. Once there are enough CAR T-cells, you have a drip containing these cells back into your bloodstream. The aim is for the CAR T-cells to then recognise and attack the cancer cells.
The changes they make in the laboratory mean that they can stay in your body for long periods of time, recognising and attacking the specific cancer cells.
There are different types of CAR T-cell therapy made by different companies, these include:
- tisagenlecleucel (Kymriah)
- axicabtagene ciloleucel (Yescarta)
- brexucabtagene autoleucel (Tecartus)
Who can have CAR T-cell therapy?
CAR T-cell therapy is available for some children and adults with leukaemia. And for some adults with lymphoma.
The following is a summary of when you might have CAR T-cell therapy:
A CAR T-cell therapy called tisagenlecleucel is a possible treatment for children and young people up to 25 years old with a type of leukaemia called B cell acute lymphoblastic leukaemia (B cell ALL).
Brexucabtagene autoleucel is available for people 26 years of age and over who have B cell ALL.
Some people in England and Wales may also have brexucabtagene autoleucel CAR T-cell therapy for mantle cell lymphoma.
Axicabtagene ciloleucel is available for some adults with the following types of lymphoma:
- diffuse large B cell lymphoma (DLBCL)
- primary mediastinal B cell lymphoma
- transformed follicular lymphoma
It’s important to know the National CAR T Clinical Panel (NCCP) discusses each persons situation. The panel of specialists and patient advocates decide who can have CAR T-cell therapy. They look at many factors when deciding about this treatment.
Speak to your healthcare team if you think this treatment is right for you. They can explain how they can refer you and where you can have this treatment.
Having CAR T-cell therapy
Preparing for T cell collection
Before you have T cell collection your doctor might ask you to stop treatments such as steroids and chemotherapy. This is to help increase the number of T cells you have in your blood before they are collected. It also helps the T cells to be in good form.
You have several tests to make sure you are well enough to have your T cells removed.
Collecting your T cells
First you have a tube (cannula) put into a vein in each arm. You might need a special tube called a vascath or a if your veins in your arms aren’t big enough for the cannula.
One tube removes the blood and passes it into an apheresis machine. The machine separates the different parts of the blood.
For CAR T-cell therapy, the machine takes out your T cells. The rest of your blood cells and normal blood fluid go back into your body through the tube in your other arm.
It can take between 4 to 6 hours to collect your T cells.
The specialist nurse sends your T cells to the laboratory to make CAR T-cells. This can take several weeks. When they have enough CAR T-cells, they freeze them.
Before you have the CAR T-cells
Bridging treatment
While your CAR T-cells are being made some people might need treatment such as chemotherapy or radiotherapy. This is known as bridging treatment. This is to help keep the cancer under control until the CAR T-cells are ready.
Lymphodepletion
Immediately before you can have the CAR T-cells into your bloodstream you have chemotherapy over a few days. This starts about a week before the day you have them back. This lowers and kills the number of T cells in your blood and prepares your body for the CAR T-cells. Doctors call this lymphodepletion. You might also hear it called conditioning treatment.
Having the CAR T-cells
A specially trained nurse defrosts the CAR T-cells on the ward. They give you medicines into your vein to stop allergic reactions.
You then have the cells as a drip into your bloodstream. This usually takes less than 30 minutes.
You are closely monitored during and after the treatment.
Staying in hospital
The doctors and nurses need to monitor you closely for the first 2 weeks after CAR T-cell therapy.
If you’re well after 2 weeks, you may be able to go home if you live within one hour of the hospital. Or you may be able to stay in a hotel or other residence nearby, which the hospital pays for.
One of the requirements to be able to leave the ward if you’re well after 2 weeks is that you have someone with you 24 hours a day. If you don’t have someone that can be with you 24 hours a day, you must stay in hospital for the first month after the treatment.
If you are discharged after 2 weeks you are still closely monitored. This involves visiting the day care unit several times a week. This is also called an ambulatory clinic or Ambi-care. On the days you do not visit the ambulatory care unit you get a phone call to check how you are doing. You will also have the numbers of people to contact if you get any problems.
If you’re not well enough to be discharged after 2 weeks you will have to stay in hospital until your healthcare team think it is safe for you.
Your healthcare team asks that you stay within one hour of the hospital for up to 30 days after the treatment. Each CAR T-cell therapy hospital has slightly different advice. So it is important to follow the advice of the hospital you are under.
Side effects of having CAR T-cell therapy
All treatments have side effects. CAR T-cell therapy is still a relatively new treatment, so doctors might not know about all the possible side effects yet. The side effects can also depend on the type of CAR T-cell therapy you are having.
Some of the common side effects include:
- allergic reaction
- cytokine release syndrome
- changes in the brain (neurological side effects)
- increased risk of infection
- changes to the levels of chemicals in the blood due to breaking down of cancer cells quickly. This is called tumour lysis syndrome
Allergic reaction
You might have an allergic reaction to the CAR T-cells. Symptoms of an allergic reaction include high temperature (fever), chills, feeling or being sick and difficulty breathing.
Your nurse will give you medicines beforehand to try to prevent a reaction. Tell your nurse straight away if you have any symptoms of an allergic reaction. They will monitor you closely during and after the treatment.
Cytokine release syndrome
Cytokines are a group of proteins in the body that play an important part in boosting the . CAR T-cell therapy stimulates the immune system to make large amounts of cytokines. It causes symptoms such as:
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fever (high temperature)
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chills
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dizziness due to low blood pressure
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difficulty breathing
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headaches
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generally feeling unwell
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tiredness and weakness (fatigue)
Your doctors and nurses monitor you closely. Depending on how severe your symptoms are you might need treatment with a monoclonal antibody called tocilizumab to control it. You might also have .
Some people need to go to the Intensive Care Unit (ICU) if they get severely unwell with CRS. This syndrome might happen in the first couple of weeks after treatment.
Side effects affecting the brain (neurological side effects)
Sometimes CAR T-cells cause problems to the brain. Doctors call this neurotoxicity. This is also known as immune effector cell associated neurotoxicity syndrome (ICANS).
Symptoms of ICANS can be mild or severe. The symptoms might include:
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shaking (tremor)
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sudden confusion and agitation
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disorientation
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seeing things that aren’t there (hallucinations)
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headaches
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changes to how awake and aware you are
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changes in speech such as difficulty speaking or understanding
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seizures (fits)
Your healthcare team monitors you closely for any of these changes. The changes might go away on their own or you might need treatment, such as steroids.
Increased risk of infection
Some types of CAR T-cell therapy can increase your risk of infection. This is because CAR T-cells are designed to recognise a protein called CD19. CD19 is found on the surface of most B cells. B cells are a type of white blood cell and like T cells, they play an important part in fighting infection.
CAR T-cell therapy that targets the CD19 protein also destroys the B cells. It kills normal B cells as well as cancerous B cells. This can reduce the number of B cells or destroy them all so it makes it difficult for you to fight infections.
You might need treatment to help with this side effect. This treatment is called immunoglobulin therapy. It contains antibodies to help you fight infections.
Tumour lysis syndrome
This can happen when CAR T-cell therapy breaks down lots of cancer cells quickly. As the cancer cells break down, they release chemicals into the bloodstream. So the normal balance of chemicals circulating in your blood suddenly changes.
Chemicals such as potassium, sodium, phosphates and uric acid have to be kept within very tight limits in your bloodstream to keep you healthy. Abnormal levels of these chemicals can upset your heart rhythm and the way your kidneys work.
You have regular blood tests to check for this. If you develop tumour lysis syndrome you have fluids into your vein and medicine to help lower the levels of uric acid in your blood.
There are other side effects of CAR T-cell therapy. Your healthcare team will go through these with you.
Cancer News
Read about the latest news, analysis and opinions from Cancer Research UK. Use the search box to find out about the latest CAR T-cell therapy news.
Find out more about CAR T-cell therapy
Anthony Nolan runs one of the largest donor databases in the world. It has regional centres which are listed on its website. It also provides information about CAR T-cell therapy.
