Pilot Trial of Perampanel on Peritumoral Hyperexcitability in Newly Diagnosed High-grade Glioma

Glutamatergic neuron-glioma synaptogenesis and peritumoral hyperexcitability promote glioma growth in a positive feedback loop. The objective of this study was to evaluate the feasibility and estimated effect sizes of the targeted AMPA receptor antagonist perampanel on peritumoral hyperexcitability.

An open-label trial was performed comparing perampanel with standard of care (SOC) in patients undergoing resection of newly diagnosed radiologic high-grade glioma. Perampanel was administered as a preoperative loading dose followed by maintenance therapy until progressive disease or up to 12 months. SOC treatment involved levetiracetam for 7 days or as clinically indicated. The primary outcome of hyperexcitability was defined by intraoperative electrocorticography high-frequency oscillation (HFO) rates. Seizure freedom and overall survival were estimated by the Kaplan-Meier method. Tissue concentrations of perampanel, levetiracetam, and correlative biomarkers were measured by mass spectrometry.

HFO rates were similar between patients treated with perampanel and levetiracetam. The trial was terminated early after a planned interim analysis, and outcomes assessed in 11 patients (seven perampanel treated; four treated with SOC). Over a median 281 days of postenrollment follow-up, 27% of patients had seizures, including 14% maintained on perampanel and 50% treated with SOC. Overall survival in perampanel-treated patients was similar to that in a glioblastoma reference cohort. Glutamate concentrations in surface biopsies were positively correlated with HFO rates in adjacent electrode contacts and were not significantly associated with treatment assignment or drug concentrations.

Glioma peritumoral glutamate concentrations correlated with high-gamma oscillation rates. Targeting glutamatergic activity with perampanel achieved similar electrocorticographic hyperexcitability levels as in levetiracetam-treated patients.