Study Looks at CAR T–Cell Long-Term Effects in Children
Logan likes to watch Spider-Man movies during immune globulin treatments.
Friday nights at Logan’s house are movie nights, complete with popcorn and candy. The 9-year-old, the youngest of the 3 siblings, usually picks the movie. It is often one with Spider-Man, Logan’s favorite superhero.
But these movie nights are different than most.
As his family watches the movie, Logan gets a medicine called immune globulin (IG) through small needles under the skin around his waistline. Logan’s mom, Holly, sets up the treatment and stays by her son’s side, sometimes missing part of the movie as she works. The treatment takes about 45 minutes.
To encourage her fun-loving son to sit still, Holly offers Logan candy, usually peanut M&Ms, his favorite. Holly keeps the treats beside the medicine, syringes, sterile wipes, gauze, and other items she has on hand for his care.
“Movie nights are a big thing with the family,” Holly says. “The kids ask: ‘Is it IG night?’”
Logan needs IG to replace infection-fighting antibodies. His body stopped making them after he had CAR T–cell therapy for leukemia in 2023. He got the treatment at St. Jude Children’s Research Hospital after chemotherapy did not keep his cancer in remission. CAR T–cell therapy successfully treated Logan’s leukemia, but it affected his immune system.
Holly wonders how long Logan will need IG treatment and if there will be other long-term effects of CAR T–cell therapy. Researchers are asking similar questions in a new study called CONQUER. It is one of the first studies to look at the long-term side effects of CAR T–cell therapy in childhood leukemia survivors. Logan is one of the patients taking part.
What is CAR T–cell therapy?
CAR T–cell therapy uses T cells, a type of immune cell, to help the body get rid of cancer cells.
The treatment was first successfully used in children in 2012 for difficult-to-treat cases of acute lymphoblastic leukemia (ALL), the most common form of childhood cancer. Overall, childhood ALL has a 5-year survival rate of more than 90% in the United States. But survival rates are much lower when ALL comes back (relapses) or does not respond to treatment.
This led researchers to look for new ways to treat ALL, including immunotherapy. CAR T–cell therapy helps the immune system find and destroy cancer cells. Chemotherapy can also kill cancer cells, but it may also damage healthy cells. Both treatments can have serious side effects.
How CAR T–cell therapy works
For Logan’s treatment, some of his T cells were removed from his blood and changed so that they could better find and destroy cancer cells. Logan then received these “amped up” T cells through an IV.
After the treatment, Logan had dizziness, nausea, and high fever. The strong immune response triggered by CAR T–cell therapy caused Logan’s immune cells to release large numbers of cytokines into the bloodstream. This can lead to problems throughout the body and can affect how organs work, a side effect called cytokine release syndrome.
“He looked pale white and would barely move. He had slight tremors,” Holly recalls. “This lasted about a week. It was stressful.”
CAR T–cell therapy got rid of Logan’s cancer cells, but it also killed healthy B cells, a type of immune cell that makes antibodies to help fight infections. This is an expected side effect of CAR T-cell therapy for ALL, but it can leave a patient vulnerable to infection.
“CAR T cell has worked wonders,” Holly says. “But the main drawback is that since he doesn’t have any B cells, he doesn’t make immune globulin, so he has to get infusions of it.”
Logan received CAR T-cell therapy in 2023. It successfully treated his leukemia, but he now needs regular immune globin treatments to provide antibodies his body stopped producing.
Studying CAR T–cell therapy long-term effects
The CONQUER study gives researchers the chance to examine CAR T–cell therapy’s long-term effects. The study brings patients to St. Jude from hospitals throughout the United States for detailed health checks over 3–4 days. Study participants have lab work, physical exams, and brain MRIs. Tests look at how CAR T–cell therapy may affect memory, sleep, physical abilities, hearing, vision, and immune health.
CONQUER involves the CARnation Consortium, a group of hospitals studying CAR T–cell therapy. One study goal is to start defining the long-term effects patients may have.
“The first aim is really ‘Can we do a study like this?’” says Aimee Talleur, MD, the study’s principal investigator. “The second aim is ‘Can we start to describe the side effects that we are seeing?’ CONQUER is setting the stage for a larger study.”
Because CAR T–cell therapy uses immune cells, both researchers and families wonder about its long-term effects on the immune system, particularly B cells. Talleur says scientists want to better understand CAR T–cell therapy to see if it can be used in more cases.
“We are also asking an important question: ‘If CAR T–cell therapy can replace some intensive chemotherapy, could it reduce the risk of long-term health problems?’” Talleur says. “It is possible, but more research is needed.”
Holly wonders if Logan’s body will start making B cells again and what that means for his future.
“What are the long-term effects of not having B cells?” Holly asks.
Right now, there is no clear answer for patients treated with CAR T cells.
“We’re living day to day, month to month, year to year, hoping Logan stays healthy,” Holly says. “But cancer is always at the back of your mind. You’re always waiting for the other shoe to drop. Will the B cells come back? Can they just come back to normal, and Logan can live a normal life?”
The CONQUER study is a first step toward finding answers.
