Breakthroughs in childhood cancer

A new clinical trial takes CAR T-cell therapy to the next level

For the past two years, Children's Wisconsin has offered cutting edge therapies that harness a patient's own immune system to fight cancer. Children's is one of only about 40 pediatric hospitals in the country authorized to treat patients with relapsed or refractory B-cell acute lymphoblastic leukemia (ALL) using CAR T-cell immunotherapy Kymriah™ (tisagenlecleucel). While Kymriah uses a CD19-directed genetically modified autologous T-cell immunotherapy to treat patients, clinicians and researchers at Children's and The Medical College of Wisconsin have now developed their own CAR T-cell product targeting both the CD19 and the CD20 antigens.

"The thought is that by targeting both the CD19 and CD20, instead of just the CD19 like Kymriah does, hopefully, there is less chance of cancer cells escaping the therapy and returning," says Julie An M. Talano, MD, a pediatric bone marrow transplant and cellular therapy physician at Children's and professor at the Medical College of Wisconsin, who leads the bone marrow transplant clinical research team at Children's.

Children's new clinical trial, which was approved and launched in the fall of 2020, is open to patients with refractory leukemia that have failed traditional therapy and commercial products. Patients must be relatively stable, have adequate heart, oxygen and kidney function, and be under the age of 39.

One of the chief challenges with Kymriah, which led to the development of this new treatment, is the 50% relapse rate. "It also takes several weeks to manufacture the cells (at Novartis)," Dr. Talano says. "And these children are fragile and often quite ill, so there's a very small window of opportunity to help them."

The cells for Children's new CD19 and CD20 trial will be manufactured locally using the Prodigy system in the lymphocyte propagation laboratory at the Medical College under the direction of Bryon Johnson, PhD, and Tyce Kearl MD, PhD. This on-site manufacturing has shortened the turnaround time for cells from four-to-six weeks down to two weeks, which is critical for fragile patients. Plus, in the midst of a global COVID-19 pandemic, being able to treat patients locally gives them and their loved ones one less thing to worry about, adds Dr. Talano.

"Not only is this an exciting development for us and our patients, but it was a huge undertaking by multiple people across this campus — and we've also partnered with local scientists who will be studying these samples to learn more about the immune system as well," Dr. Talano says. "These efforts position Children's on the cutting edge of cellular therapy treatments."

Possible side effects

One of the greatest risks with any CAR T-cell immunotherapy treatment is cytokine release syndrome (CRS), in which the large, rapid release of cytokines into the blood from the modified immune cells leads to fever, nausea, headache, rash, rapid heartbeat, low blood pressure and respiratory problems. Neurologic side effects may also occur, including encephalopathy.

"We mandate that the patients be monitored very closely for 30 days after the cells are infused. And we closely monitor them throughout the trial," Dr. Talano says.

Dr. Talano and her team have also worked closely with the emergency room and intensive care unit staff to educate them about the treatment and the early signs of CRS and other complications.

For information and eligibility requirements on the CD19 and CD20 clinical trial, visit clinicaltrials.gov  (CAR-20/19-T Cells in Pediatric and Young Adult Patients With Relapsed/Refractory B Cell ALL - Full Text View - ClinicalTrials.gov NCT04049383).