A recently developed cancer treatment called chimeric antigen receptor T-cell therapy (CAR T-cell therapy, for short) offers hope to people whose diffuse large B-cell lymphoma (DLBCL) has proved hard to treat. First approved by the FDA in 2017, CAR T-cell therapy has the potential to cure your cancer. Here, we’ll walk you through the process you will undergo if your health care team determines you are a candidate for this treatment.
What Is CAR T-Cell Therapy?
CAR T-cell therapy is a type of cancer treatment called immunotherapy. It enables your body’s immune system to fight several kinds of blood cancers, including DLBCL. Doctors remove a type of white blood cell, called T cells, from your body and alter them in a laboratory. When they return them to your body, those T cells attack your cancer.
What Is DLBCL?
DLBCL is an aggressive but often treatable type of blood cancer. It affects B lymphocytes, which are a type of white blood cell that your immune system uses to fight infections. This cancer is the most common type of lymphoma. About 25,000 people receive a diagnosis of DLBCL every year.
What Are the Steps in CAR T-Cell Therapy?
Step One: Collecting your T cells
The first thing that your health care team will do is collect some of your T cells. This process is called apheresis (or leukapheresis), and it involves drawing blood to extract the T cells. There are two ways they may do this:
Intravenous. A technician will insert an IV into a vein into each of your arms. One of these will collect your blood. This blood will then pass through a machine that separates your white blood cells, including your T cells, from the rest of your blood. Once the white blood cells have been removed, the remaining blood will be returned to your body via the IV in your other arm.
Central venous catheter (central line). The technician inserts a small, thin tube called a catheter into a vein near your heart. It will be connected to two IV lines. One will draw blood, while the other line will return the remaining blood to your body.
There are two ways this may be done. One option is a tunneled chest catheter, in which the catheter is inserted into a large vein in your chest. The other method is called a peripherally inserted central catheter, or PICC line. The catheter is threaded through a vein in your arm to a vein near your heart.
This first step in the process takes several hours. Prior to this step, you’ll stop taking certain cancer treatments, such as chemotherapy drugs and steroids, in preparation for the removal of your T cells.
Step Two: Turning your T cells into cancer killers
The white blood cells are taken to a laboratory once they have been collected. There, they’re separated from the rest of the white blood cells. Specialists then genetically modify your T cells. Once that’s done, your T cells will produce a new protein on their surface. This protein, called a chimeric antigen receptor, will allow them to target the cancer cells in your body.
Step Three: Growing your army of T cells
Your T cells are now chimeric antigen receptor T cells, or cancer killers. But there aren’t enough of them yet to take on your cancer. During step three, scientists will grow millions more of them in the lab. This part of the process takes 2 to 4 weeks. When enough T cells have grown, the lab will freeze and prep them for transportation to your treatment site.
During this waiting period, you may need to have something called “bridging therapy.” Bridging therapy aims to keep your DLBCL from getting worse while your newly created T cells are being prepared to go to work. It involves cancer treatment, such as chemotherapy, radiation, and other therapies. Your health care team will decide what’s best for you based on your current health and how you have responded to past treatments. You may not need bridging therapy if your cancer is stable.
Another thing that will determine your need for bridging therapy is the wait time until your CAR T-cell therapy. Your health care team will decide if you can go without treatment for those 2 to 4 weeks or longer if necessary.
Step Four: Prepping for your CAR T-cell therapy
Three to 4 days before your CAR T-cell treatment, you will receive daily courses of chemotherapy. This is an outpatient procedure, so you won’t have to stay in the hospital. This process is called lymphodepletion or lymphodepleting chemotherapy.
Lymphodepletion suppresses your immune system. That’s important because it ensures that your body doesn’t reject the newly grown T cells that you will receive. Instead, they’ll grow and multiply, getting even more ready to attack your cancer cells.
Before you begin lymphodepletion, your doctor will confirm that you have no ongoing infections. If you do, that likely will delay the process until the infection clears up.
Step Five: Receiving your CAR T-cell therapy
The final step of the process is the infusion of the newly created CAR T cells. But first, you’ll have a final evaluation to be sure you’re ready. A few things could delay your treatment:
- Infection
- Irregular heartbeat (arrhythmia)
- Low blood pressure (hypotension)
- Worsening of your DLBCL
Once your doctor determines you’re ready for treatment, your CAR T cells will be thawed for infusion. You’ll get acetaminophen or diphenhydramine (Benadryl) to reduce the risk of allergic reactions to preservatives in the treatment. Then, you’ll receive your CAR T cells via a central venous catheter (central line) or an IV in a quick procedure. It should take less than half an hour.
After the procedure, you’ll either stay in the hospital or near the hospital so that your doctor can watch you for side effects of the treatment such as infections. If you’re not in the hospital, you’ll need a caregiver with you at all times to watch for signs of infection, fever, and neurological issues, such as confusion and speech problems. These are common and often temporary side effects. But they can be severe, even life-threatening, so you must report them to your health care team right away.
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Photo Credit: Sam Edwards / Getty Images
SOURCES:
Nature Reviews Drug Discovery: “FDA approves first CAR T therapy.”
American Cancer Society: “CAR T-cell Therapy and Its Side Effects.”
Lymphoma Research Foundation: “Diffuse Large B-Cell Lymphoma,” “CAR T Cell Therapy for Lymphoma.”
Leukemia and Lymphoma Society: “Diffuse Large B-Cell Lymphoma (DLBCL),” “Chimeric Antigen Receptor (CAR) T-Cell Therapy.”
St. Jude Children's Research Hospital: “Collecting cells for CAR T-cell therapy.”
Memorial Sloan Kettering Cancer Center: “CAR T Cell Therapy: A Guide for Adult Patients & Caregivers.”
Lymphoma Action: “CAR T-cell therapy.”
Frontiers in Oncology: “Radiation and CAR T-cell Therapy in Lymphoma: Future Frontiers and Potential Opportunities for Synergy.”
Annals of Oncology: “Management of adults and children receiving CAR T-cell therapy: 2021 best practice recommendations of the European Society for Blood and Marrow Transplantation (EBMT) and the Joint Accreditation Committee of ISCT and EBMT (JACIE) and the European Haematology Association (EHA).”
Dana-Farber Cancer Institute: “Frequently Asked Questions About CAR T-Cell Therapy.”