New research claims first response of nervous system tumour to CAR T therapy

Researchers at a General Hospital in Massachusetts has reported what they claim is the first response of a central nervous tumour to chimeric antigen receptor T-cell (CAR-T) cancer therapy.

Researchers claimed first response of a nervous system tumour to CAR-T cancer therapy.

CAR-T therapy works by taking the patient’s own T cells and genetically engineering them to target and bind to specific antigens on cancer cells – in this case, the CD19 protein. The trial, sponsored by Juno Therapeutics, investigated the effects of JCAR017 on a 68-year-old patient’s lymphoma.

It was discovered that the treatment was able to induce complete remission of the patient’s brain metastasis of diffuse large B-cell lymphoma (DLBCL) after it became resistant to chemotherapy and did not respond to stem-cell transplant. Two months passed since the treatment, and when a biopsy was performed as a result of the tumour’s re-emergence, the CAR T-cells spontaneously re-expanded it was forced back into remission; blood testing also revealed that the number of CD19-targeted CAR T-cells had grown as the brain metastasis regressed.

Although the patient unfortunately died as a result of the disease over a year later, the tumour never recurred from the time of treatment until she passed away. This is the first reported case of central nervous system lymphoma responding to CAR T-cell treatment, and although CAR T-cell re-expansion has been documented in response to another immunotherapy, this is the first time it has been noted in response to a biopsy.

"Brain involvement in DLBCL carries a grave prognosis, and the ability to induce a complete and durable response with conventional therapies is rare," explained lead author Jeremy Abramson of the MGH Cancer Center. "In addition, all available CAR T-cell trials have excluded patients with central nervous system involvement. This result has implications not only for secondary DLBCL like this case but also for primary central nervous system lymphoma, for which treatment options are similarly limited after relapse and few patents are cured.

"Typically the drugs we use to fight cancer and other diseases wear off over time," he continued. "This spontaneous re-expansion after biopsy highlights this therapy as something entirely different, a 'living drug' that can re-expand and proliferate in response to biologic stimuli."