Initial therapy
cortical high-grade glioma, PD, midline glioma
DISEASE, PATHOLOGY, RECURRENT DISEASE
All participants will take abemaciclib pre-operatively for 4.5 days (9 total doses of abemaciclib) at twice daily dosing. A maximally safe surgical resection for cortical high-grade glioma or stereotactic needle biopsy for midline glioma will be performed in the operating room. Intraoperative pathology will confirm recurrent disease in order to proceed with microdialysis placement. Microdialysis insertion (based on participant safety, surgical feasibility and pathology confirmation of disease) will be performed post-biopsy in the operating room and placement will be verified by brain CT. Continuous microdialysis sampling will be obtained over the course of the next 48 hours, with subsequent removal of the catheter at the bedside. After discharge from NIH inpatient, PK and PD findings will assist in determination of whether the participant will continue to receive abemaciclib therapy. If intratumoral or PK brain dialysate sampling concentrations are >10nmol/L, or PD findings suggest CDK inhibition (decreased expression of Rb and/or topoIIα), then abemaciclib therapy will be resumed in combination with temozolomide for maintenance therapy post resection or biopsy.