New Cancer Treatment Option At Cook Children’s Renewing Hope

A treatment now offered at Cook Children’s Medical Center is giving children with relapsed B-cell acute lymphoblastic leukemia (B-ALL)—the most common childhood cancer—a second chance for a cure. It’s called CAR T-cell therapy, or chimeric antigen receptor T-cell therapy. For kids who have lost hope for a cure through traditional chemotherapy or radiation, CAR T-cell therapy may eradicate their cancer.

Skylar Jones, 15, is the first patient to undergo CAR T-cell therapy at Cook Children’s. She was just 9 years old in 2014 when she was diagnosed with B-ALL. Despite undergoing intense chemotherapy, Skylar’s cancer relapsed in 2017 and again in March 2021.

CAR T-cell therapy was approved by the Food and Drug Administration (FDA) for use in refractory and relapsed B-ALL in 2017. Cook Children’s began offering the treatment for those who qualify in November 2020. For Skylar, the timing was perfect and meant she would not have to travel outside of Fort Worth and away from her long-time physicians at Cook Children’s to receive this potentially life-saving treatment.

“Had she relapsed six months earlier, we would have had to go out of town for this,” said Deby Jones, Skylar’s mother. “So for Cook Children’s to have this now and for families to not have to move to get this treatment for their kid, I mean, there’s tons of families that will benefit from this.”

Skylar’s necessary but difficult chemotherapy treatments wreaked havoc on her body. Mouth sores, headaches and rashes were common side effects. An infection required part of her lung to be removed, and the impact of chemotherapy on her bones and joints made it impossible for her to play basketball, her favorite sport.

When Skylar relapsed a second time in March, it was clear that chemotherapy was no longer the most effective course of treatment in her case. Her cancer required a different approach. This made her a good candidate for CAR T-cell therapy.

“CAR T-cell therapy is a treatment option for children with refractory B-ALL, meaning they haven’t responded to initial treatment, or kids whose cancer has relapsed,” said Holly Pacenta, M.D., a hematologist/oncologist with Cook Children’s Cellular Immunotherapy Program.

In this cell-based immunotherapy, the patient’s own T-cells, which help the body fight infection, are harvested from their blood and sent to a lab where they are reprogrammed into CAR T-cells to target their leukemia. The CAR T-cells are then reintroduced into the patient’s blood stream. From start to reinfusion, the process takes about four weeks.

The therapy begins with a procedure called leukapheresis where the healthy T-cells are removed from the patient’s blood. This takes about four to six hours and the patient is able to go home from the hospital the same day. Once the lab receives the cells, it takes a few weeks to reprogram them into CAR T-cells. Just before the CAR T-cells are reintroduced, the patient undergoes a short round of chemotherapy to lower the number of other T-cells in the body. This gives the CAR T-cells a better chance to activate inside the body to kill cancer cells. After chemotherapy, the patient returns to the hospital to be infused with their new CAR T-cells and is able to go home the same day.

Unlike chemotherapy and radiation, which affects the fast growing cells in the body, this treatment is a targeted approach that kills only the B-cells. The duration of treatment is shorter, too.

“B-ALL cells have specific markers that aren’t located on many other cells in the body, which is the part about it that’s unique,” Dr. Pacenta said. “The reason this has been so successful is because we are able to target one marker on leukemia cells to fight the disease.”

The remission rate after CAR T-cell therapy is 80%.

“Every patient is different, but we know that, in some children, this can be a long-term cure, meaning they don’t need to receive any additional treatment,” Dr. Pacenta said. “Some research studies have found that the CAR T-cells will persist in a patient’s body for as long as three and a half years, but it’s likely that the cells will be around for much longer.”

For Skylar, CAR T-cell therapy was as different from chemotherapy as night and day. She was fortunate to not experience any of the side effects associated with the therapy.

The side effects of CAR T-cell therapy include allergic reaction during and immediately following the infusion. In the weeks after, patients are closely monitored for neurotoxicity, as well as cytokine release syndrome, where the immune system becomes overactive due to the multiplying CAR T-cells releasing large amounts of chemicals called cytokines into the blood. These side effects can be very severe, with some patients requiring admission to the intensive care unit.

Now three months post infusion and Skylar's cancer is in remission. She will undergo more testing at six months post infusion, which will give her a better idea of her potential for long-term remission.

As for the possible impact of this type of cell-based immunotherapy on cancer, doctors are hopeful it could one day replace traditional treatments.

“I think there may be a day in the future where cellular therapy does replace chemotherapy, surgery and radiation for people with cancer,” Dr. Pacenta said. “But I think we are still a ways off. This therapy has been very successful initially but we still have a lot of work to do.”