Neoadjuvant Chemoimmunotherapy in Recurrent Glioblastoma

Participants will undergo screening tests to determine if they are eligible to participate. This will involve a complete history and physical examination, vital signs, blood tests including complete blood count (CBC), and serum chemistry (CMP).

Participants will receive one cycle of Temozolomide and Pembrolizumab prior to removing recurrent tumor, followed by three weekly cycles of treatment until progression.

Participants will take Temozolomide pills at home at a dose determined by body weight. They will take the pills for five days every 3 weeks. It will be dispensed by the pharmacy and must be stored in a closed container at room temperature, away from heat, moisture, and direct light and kept from freezing. It will be kept out of the reach of children. Outdated medicine or medicine no longer needed will be returned to the Brown Cancer Center pharmacy for disposal.

Drug: Pembrolizumab and Temozolomide

Characterize the safety and immunologic/genomic/metabolomic effects of neoadjuvant Pembrolizumab and Temozolomide in recurrent glioblastoma.

Other Name: Pembro and Temodar

Experimental: Pembrolizumab

Pembrolizumab will be administered at a dose of 200 mg as an IV infusion through a freely flowing IV. The diluted solution will be administered intravenously over 30 minutes through an intravenous line containing a sterile, non-pyrogenic, low-protein binding 0.2 micron to 5 micron in-line or add-on filter. Other drugs will not be co-administered through the same infusion line. Pembrolizumab doses will be repeated every three weeks.