May 6, 2020

New treatment for recurrent pediatric brain cancer enters clinical testing

Dr. Michael Taylor
Dr. Michael Taylor

OICR-supported study helps move promising CAR-T cell therapy into a first-in-child clinical trial

Recurrent brain tumours are some of the most difficult cancers to treat, with no approved targeted therapies available and only a few potential therapies in clinical trials. Developing new drug treatments for these tumours is challenging in part because the drugs must overcome the blood-brain barrier and specifically target cancer cells while sparing the surrounding critical regions of the brain. Scientists at The Hospital for Sick Children (SickKids) have discovered a new solution.

In a study, recently published in Nature Medicine, a SickKids-led research team describes a novel treatment approach that delivers chimeric antigen receptor T (CAR-T) cell therapy directly into the cerebrospinal fluid that surrounds the tumour. Their findings show that the approach was effective in treating ependymoma and medulloblastoma, two common types of brain tumours, in experimental mouse models of human disease.

“The vast majority of children with recurrent metastatic medulloblastoma or ependymoma currently have a deadly prognosis, so it is very exciting to think we have identified a novel approach to treat this underserved patient population,” says senior author Dr. Michael Taylor, Neurosurgeon, Senior Scientist in the Developmental and Stem Cell Biology program and Garron Family Chair in Cancer Research at SickKids and Co-lead of OICR’s Brain Cancer Translational Research Initiative.

CAR-T cell therapies, which use genetically engineered immune cells to attack cancer cells, are remarkably effective in treating certain types of lymphomas and leukemias. Whereas CAR-T therapies are typically delivered through the blood stream, the research team discovered that delivering their engineered T cells directly into the cerebrospinal fluid provided a better chance for the therapy to reach and eliminate brain tumours.

The team performed in-depth molecular studies to design CAR-T cells that can recognize specific molecules on the surface of brain tumour cells. They also found that the use of a complementary approved cancer medication, azactyidine, boosts the efficacy of their approach.

Now, building on these findings, collaborators at Texas Children’s Hospital have launched a first-in-child clinical trial to test the safety and anti-tumour efficacy of their new strategy.

“This work was possible thanks to the concerted collaboration of our Pediatric Cancer Dream Team, which brought together scientists studying tumor genomics and tumor immunotherapy around the world to enable the design of more effective therapies for children with incurable and hard to treat cancers,” says corresponding author Dr. Nabil Ahmed, associate professor of pediatrics and immunology, section of hematology-oncology at Baylor and Texas Children’s Hospital.

This research was supported in part by OICR through OICR’s Brain Cancer Translational Research Intitiative and funding provided to the Stand Up to Cancer (SU2C) Canada Cancer Stem Cell Dream Team.

Read SickKids news release.