By Mary Bolster
CAR T-cell therapy is an involved process. Patients undergo blood screening tests and must be clear of infections. They may be denied if they’ve had a recent treated or untreated cancer. Other restrictions may apply, says Dr. Ulane.
Once accepted into the trial, patients must have their white blood cells removed at a hospital through a process called leukapheresis, which extracts the white blood cells through a large catheter in the patients’ necks and separates them from red blood cells and plasma, which are returned to the body. The process takes two or three hours and can be uncomfortable, says Dr. Ulane.
The cells are then shipped to a company that modifies them using RNA or DNA so they can target specific or non-specific b-cells, depending on the disease. Patients remain on their regular treatment while waiting for the T-cells to be modified, which can take several weeks or a couple of months.
Once the modified T-cells are ready, the patient returns to the hospital for the infusion. If the T-cells have been modified using DNA, the patient must first have three days of immune-suppressing chemotherapy.
This improves the ability of the CAR T-cells to work. This step is not needed if the T-cells have been modified using RNA.
When the patient is ready, the infusion takes about 15 minutes. Those being infused with RNA-modified T-cells can return home that day. Patients being infused with DNA-modified T-cells must stay in the hospital for seven to 14 days, says Dr. Ulane.
“We’re looking for side effects such as cytokine release syndrome (CRS) or immune effector cell-associated neurotoxicity syndrome (ICANS). These can be addressed more quickly and aggressively in the hospital.”
CRS and ICANS are two of the more common side effects of CAR T-cell therapy. The former happens when the immune system releases too many cytokines into the bloodstream, causing widespread inflammation that can
damage organs and tissue. The latter, which can be life-threatening, happens when levels of cerebrospinal fluid cytokines increase and the blood/brain barrier is disrupted.