Researchers have found a new way to help immunotherapy work better for patients with aggressive, recurrent high-grade astrocytoma, a serious type of brain cancer.
One of the biggest challenges in treating brain tumors is the blood-brain barrier. This natural protective barrier prevents many drugs and immune cells from entering the brain, including treatments designed to help the immune system attack cancer. Because of this, patients with recurrent astrocytoma usually survive only about four to five months.
In this study, researchers combined a minimally invasive laser procedure called Laser Interstitial Thermal Therapy (LITT) with the immunotherapy drug pembrolizumab. LITT uses heat from a laser to destroy tumor tissue. An important effect of this heat is that it temporarily opens the blood-brain barrier for several weeks.
This temporary opening allows immune cells activated by pembrolizumab to enter the brain more easily, recognize the tumor, and attack it.
The results of the Phase 1/2b trial were striking. Nearly half of the patients who received LITT plus pembrolizumab were still alive 18 months later, while none of the patients who had standard surgery with the same drug survived that long. In addition, more than one-third of patients treated with LITT lived longer than three years, far exceeding typical survival expectations for this disease.