Immunotherapy shows promise in treating brain cancer

Combining standard chemotherapy treatment with immunotherapy may buy some time for patients with recurrent glioblastoma multiforme (GBM).

The study, led by Professor Rajiv Khanna at the QIMR Berghofer Medical Research Institute, treated patients with their own (autologous) T cells specific to cytomegalovirus (CMV). The results showed the treatment was safe and effective - most study participants lived much longer than the median survival of less than six months for patients with recurrent GBM. And some patients showed no signs of disease progression.

“It is early days, but this is exciting,” Professor Khanna said of the phase I study. “Survival rates for this aggressive cancer have barely changed in decades. There is an urgent clinical need for new treatments.”

GBM is one of the most malignant human brain tumours. It is diagnosed in about 800 Australians every year and prognosis is poor, with less than 10% of patients surviving beyond 5 years.

Current treatment includes surgery, radiotherapy and chemotherapy, but GBM inevitably recurs after initial therapy.

The study builds on previous research that found many brain tumours carry CMV.

A common viral infection, CMV is usually without symptoms in healthy people. Although not classified as an oncogenic virus, CMV can increase cellular proliferation, angiogenesis and immune evasion - some of the hallmarks of cancer.

Professor Khanna developed a technique to modify and expand a patient’s CD8+ T-cells in the lab. When returned to the patient, these T cells targeted the virus and at the same time destroyed the cancer.

“It’s becoming increasingly clear that immunotherapy - manipulating a person’s own immune system - is a rich new frontier for cancer treatment,” Professor Khanna said.

Molecular profiling of the CMV-specific T cells from these patients revealed distinct gene expression patterns which correlated with a patient’s clinical response.

The research team is planning to begin trials involving patients at an earlier stage of the cancer’s development in the hope that the treatment will be more effective if given at an earlier stage of the disease.

The study has been published online in Cancer Research.