Engineering the immune system to tackle glioblastoma

Each year, roughly 15,000 Americans are diagnosed with Glioblastoma Multiforme (GBM), the most common malignant primary brain tumor in adults, and also the most lethal. Surgery, radiation, and chemotherapy can help slow the tumor’s growth, but the disease remains incurable. Recurrence occurs in almost every case.

x-ray of a brain tumor

While the median survival rate is counted in months, there are survivors who have lived in remission for years, some for more than a decade.

While all treatments help improve outcomes, immunotherapy is potentially a “game changer,” says Donald O’Rourke,  director of the GBM Translational Center of Excellence at the Abramson Cancer Center.

“We need an approach that goes places where surgeons can’t … the deeply invasive portions of the tumor,” he continues. “We need to harness and engineer the patient’s immune system.”

Glioblastomas are particularly difficult to treat, partly because of their location. A natural blood-brain barrier prevents poisons and toxins from getting into the brain. In addition, the GBM tumor has many ways of making itself invisible to the immune system. The tumor’s ecosystem also presents a challenge. The body’s immune system has safety checkpoints that prevent T cells from destroying healthy cells. However, cancer cells can co-opt these checkpoints to turn the T cells off, thus preventing them from destroying the cancer cells.

Still, although the challenges remain great, the mechanisms behind them are becoming much better understood. 

Read more at Penn Medicine News.