A cutting-edge immunotherapy could help kids fight — and even banish — brain tumors, the leading cause of cancer-related deaths in children.
The new treatment falls under a category called T-cell therapy, which trains the immune system to identify and attack cancer on its own.
T-cell therapy has already proven effective against blood cancers like leukemias, but it has rarely succeeded against solid tumors.
This trial was groundbreaking because it showed the new T-cell therapy could teach kids’ immune systems to find and fight brain tumors. Some patients even remained disease-free years after treatment.
Why brain tumors are hard to treat
Brain tumors are difficult to treat for several reasons.
The body has a natural blood brain barrier that protects the brain but can also keep out treatments like chemotherapy. To get around this, doctors sometimes administer drugs directly into the brain or fluid surrounding it.
Brain tumors are also made up of many different types of cells. A treatment may kill some while leave others behind, allowing the cancer to return.
The children in the trial had aggressive cancers like diffuse intrinsic pontine glioma and relapsed central nervous system tumors.
“Pediatric tumors are one of the greatest challenges in cancer research, with children still facing extremely limited treatment options, and existing treatments often causing severe side effects,” said David Scott, director of Cancer Grand Challenges, which helped fund the research into CAR T-cell therapy.
This new treatment teaches the immune system to attack multiple targets at once, killing more cancer cells and reducing the chances the disease will return.
Those targets are three proteins commonly found in pediatric brain tumors: WT1, PRAME and Survivin.
“We were excited to see that we could preserve safety and quality of life while generating anti-tumor responses by attacking three targets at once,” said Eugene Hwang, MD, chief of oncology at Children’s National hospital in Washington, DC, and co-senior author of the study.
What is T-cell therapy?
Because the body can recognize and respond to cancer cells on its own, T-cell therapy is often called “living medicine” and could pave the way for long-term remission.
It’s also a shorter, less aggressive treatment than chemotherapy, which kills many healthy cells along with cancer cells.
CAR T-cell therapy begins by extracting some of a patient’s T-cells — a type of white blood cell — from their blood. The cells are then sent to a specialized facility, where they’re trained to recognize and kill cancer.
Scientists do this by introducing a deactivated virus that delivers new genetic instructions, effectively reprogramming the T-cells to recognize cancer. This transforms them into CAR T-cells.
Once they’re engineered, the CAR T-cells are grown until they reach a therapeutic dose, often millions or even billions of cells.
They are then shipped back to the patient and infused through an IV, a process that takes less than an hour.
The study at Children’s National marks the first time this therapy has been tested in humans for these pediatric brain tumors.
Researchers have established a feasible manufacturing process for the T-cell therapy, identified a maximum tolerated dose and defined an early safety profile.
Next, they hope to move the treatment into a Phase 2 trial, bringing it one step closer to FDA approval and making it available to kids in need.
