When it comes to treating cancer, the immune system can work wonders when it receives just the right level of support. Researchers recently used that guiding principle to expand on their ever-growing immunotherapy approaches with the development of CAR-T therapy. Although it’s a relatively new approach, this regenerative medicine practice has the potential to change how doctors treat cancer and give patients new hope at making a full recovery.
Wondering just how it works? Here’s a look at all you need to know about CAR-T therapy.
What is CAR-T Therapy?
Also known as chimeric antigen T-cell therapy, CAR-T therapy is a cancer-fighting immunotherapy treatment. Approved by the FDA in 2017, this therapy gets customized to the needs of each patient by reprogramming the cells in their immune system. The reprogrammed T-cells can then spot cancer cells in an instant and destroy them before they can multiply. The entire cell collection, engineering, and replacement process take several weeks to complete.
How CAR-T Therapy Works
CAR-T therapy works by equipping T-cells, or lymphocytes, with the ability to differentiate between cancer cells and normal, healthy cells. The body creates these white blood cells naturally whenever an infection or disease process starts in earnest.
Normally, they do not have the ability to identify cell types and just go on the offensive, destroying healthy cells along with the compromised ones. When that happens, the immune system takes a hit, making patients more susceptible to germs.
By modifying the T-cells, it’s possible for them to largely leave the healthy cells alone while going after the cancer cells. Their ability to destroy the cancer cells improves as a result, giving patients a better chance at making a full recovery.
Who Can Benefit from CAR-T Therapy?
CAR-T therapy is only authorized for the treatment of certain types of leukemia in children and lymphoma in adults. Not all cancer patients are eligible, however.
Patients age 25 and under may qualify for CAR-T therapy if they’ve been recently diagnosed with B cell ALL leukemia.
Patients may also be eligible if they’ve:
- Completed several failed treatments
- Relapsed two times or more
- Had the cancer come back after bone marrow or stem cell transplant procedures
In short, if other cancer treatments aren’t working to keep the cancer away, then it might be time to teach the T-cells how to fight back.
As for adults, they may only qualify if they’ve been diagnosed with:
- Primary Mediastinal B Cell Lymphoma
- Mantle Cell Lymphoma
- Diffuse Large B Cell Lymphoma
Like with pediatric patients, doctors may only suggest CAR-T therapy after other cancer treatments fail to work.
What to Expect During CAR-T Therapy
Once patients qualify for CAR-T therapy, their care team will complete the following steps.
Collecting T-Cells from the Patient
The first stage of CAR-T therapy is the collection of T-cells from the patient’s blood, which takes about five hours in total. The process starts with the insertion of a vascath or cannula tube into a vein on each arm. After that, the specialist switches on the apheresis machine that draws blood out of the vein in one arm and separates the T-cells out before cycling the blood back into the other arm.
Transforming T-Cells into CAR-T Cells
The collected T-cells end up at the lab next, so they can get transformed into the powerful CAR-T cells. The techniques and extension platforms used for that transformation depend on the patient’s unique treatment needs. The lab team may use recursive AAPC stimulation, GE bioreactors, or Miltenyi CliniMACS Prodigy system, for example, to fully transform the cells. The CAR-T cells take several weeks to make, and then they are frozen for later use.
Completing Chemotherapy Treatments
Patients must undergo a few days of chemotherapy before receiving the CAR-T cells. Called lymphodepletion, this process decreases T-cell numbers to make room for the newly transformed cancer-fighting cells.
Administering the CAR-T Cells
To prepare for the administration of the CAR-T cells, the specialist defrosts them and gives the patient a medication designed to prevent allergic reactions. Then, they set up a drip and let the CAR-T cells flow into the patient’s veins over a period of about 30 minutes.
Most patients need to stay in the hospital for about two weeks after their treatment, and then remain in the area for 28 more days for continued monitoring. Doctors complete a checkup at the three-month mark to see if the treatment worked.
The vast majority of patients respond favorably to the treatment, although there’s still a risk of side effects. Researchers are working hard to improve the therapy even more through additional trials, giving cancer patients even better chances at fully recovering.