Children's Hospital Colorado

The CAR-T Cell Therapy Process: What to Expect

Our top-ranked hematology, oncology, blood and marrow transplant and cellular therapy programs are national leaders in new and advanced treatments for pediatric cancers and blood diseases.

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Our team of pediatric experts will support you throughout your CAR-T cell therapy process. We've compiled these resources as a quick reference for before, during or after a CAR-T cell infusion.

What are CAR-T cells?

Chimeric antigen receptor (CAR) T cells are a recently approved therapy that uses a patient's own immune cells (called T cells) to attack their cancer cells. The cells that are used come from the patient, are genetically modified and then infused back into the patient to try to cure their cancer.

At Children's Hospital Colorado, we currently offer the commercially available FDA-approved KYMRIAH® product, as well as novel CAR-T cells that are part of clinical trials designed to improve CAR-T cell efficacy.

The main goal of the CAR-T cell infusion is to cure certain types of leukemia such as acute lymphoblastic leukemia. The CAR-T cells target a specific protein on the surface of acute lymphoblastic leukemia cells called CD19. Because this cell surface marker is also on normal B cells, both normal and the leukemic B cells are killed, but other normal tissues are not usually affected.

How does CAR-T cell therapy work?

During the procedure, blood is drawn from a patient, the immune cells are sorted and the immune cells (called T cells) are collected. Next, using a non-contagious virus, the T cells are genetically engineered to make a protein (i.e. the chimeric antigen receptor, or CAR) on the cell surface that recognizes certain types of cancer cells.

These engineered CAR-T cells are then infused back into the patient, where the CARs can recognize and attach to specific proteins on the surface of cancer cells. When the CAR attaches to the cancer cell, it triggers the T cells to kill the cancer cell.

How are blood T cells collected?

The T cells that are used to make CAR-T cells are collected from the patient's peripheral blood, a process called leukapheresis. The patient will have a large IV, a central line or a PICC line (a thin, flexible IV tube) placed in their arm or chest. Then, an apheresis machine collects the T cells and returns the other blood cells back into the body. This happens in the specialized stem cell apheresis center, the Blood Donor Center, as an outpatient visit and takes about 5 to 8 hours over the course of 1 to 5 days. The length of time depends on how many stem cells are needed and how easy it is to get that amount.

After all the cells are collected each day, they are sent to the laboratory where the T cells will be exposed to a non-contagious virus that causes the cells to make a protein that recognizes CD19 on leukemia cells.

The donor is awake and able to talk during the whole collection.

After the patient’s immune system and any short-term transplant complications are resolved, the patient will be followed in our HOPE Survivorship clinic.

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