New drug that blocks recurring growth of brain tumors identified

An international team of scientists has identified a drug that blocks the growth of the most aggressive brain tumor and how to most accurately identify which tumor will respond to the drug.

When a non-metastatic brain tumor - meningioma - recurs after surgery and radiation treatment, a patient is out of options. No drugs are approved for these aggressive tumors, which occur in up to 20 percent of cases and can lead to patient disability or even death.

But the new drug called abemaciclib, detailed in the journal Nature Genetics, is a cell cycle inhibitor, meaning it blocks the cell division cycle and inhibits tumor growth.

The scientists at the universities of Northwestern, California, and Hong Kong demonstrated the effectiveness of the drug in select patients, mouse models, a 3D living tissue brain tumor (organoids), and cell cultures.

Investigators discovered that meningiomas can be divided into molecular subgroups with different clinical outcomes and recurrence rates. This new method of classifying tumors allows scientists to predict recurrence more accurately than the current method of classifying the tumor.

Currently, after surgery, doctors examine a specimen of a tumor under a microscope and grade it one, two, or three in its aggressiveness. But the grade is only about 70 percent accurate, meaning some tumors will behave in a way that doesn't fit with how it appears under the microscope.

"Our study identifies which patients we should treat with this drug because their tumors will likely respond to it," said Dr. Stephen Magill, Assistant Professor of neurological surgery at Northwestern's Feinberg School of Medicine.

"We now have the potential to give them options and hope for a longer, symptom-free life."

The team found that mice with meningiomas treated with the medication lived longer and their tumors didn't grow as rapidly.

The drug was also used off-label for compassionate use in several patients whose tumors decreased in size and whose symptoms improved, suggesting the drug should be considered for clinical trials, Magill said.

"Eventually we hope to tailor medical therapy to the genetic changes within each person's meningioma," Magill said.

Meningiomas are the most common primary (non-metastatic) tumor in the central nervous system. The symptoms are headaches, seizures, or neurological deficits (weakness, vision loss, double vision, or sensory changes). (AA/IANS)