We are doing this study to find out the safety and effectiveness of Tumor Treating Fields (TTFields, 200 kHz) delivered by the Optune® device. We want to know if this experimental procedure can improve results for people who are being treated for GBM. We will compare how well this procedure works when it is given along with 2 different types of drug therapies.

Newly Diagnosed Glioblastoma (GBM)

Adults ages 18+ who:

• Are diagnosed with GBM
• Have recovered from maximal debulking surgery (gross total resection, partial resection and biopsy-only patients are all acceptable)
• Have completed standard adjuvant chemoradiotherapy
• Have not received previous therapy with an anti-PD-1, anti-PD-L1, or anti PD L2 agent or with an agent directed to another stimulatory or co-inhibitory T-cell receptor (e.g., CTLA-4, OX 40, CD137)

For more information, contact the study team at 919-684-5301.

If you choose to join this study, you will get a random assignment (by chance) to 1 of 2 groups:

• The Treatment Group: If you are assigned to this group, you will get Optune® in combination with the drugs temozolomide (TMZ) and pembrolizumab, which is an immunotherapy drug.
• The Control Group: If you are assigned to this group, you will get Optune® in combination with TMZ and a placebo, which is an inactive substance that looks the same as and is given the same way as pembrolizumab.

Study participants will have a 2-in-3 chance of being assigned to the treatment group and a 1-in-3 chance of being assigned to the control group.

Patients who are randomly assigned to the treatment group will receive pembrolizumab, which will be given intravenously (injection in the vein) at the hospital or outpatient clinic. For patients who are randomly assigned to the control group, a placebo (normal saline solution) will be administered the same way as pembrolizumab.