Main study endpoint
high-grade glioma, midline glioma, glioma
GLIOMA
To evaluate safety and feasibility of intratumoral microdialysis placement post high-grade glioma resection or midline glioma biopsyTo evaluate safety and feasibility of brain interstitial dialysate sampling in glioma participants post abemaciclib administrationTo measure intratumoral vs. systemic concentrations of abemaciclib in glioma participants post abemaciclib administration