Association of Peripheral Blood Immunologic Response to Therapeutic Response to Adjuvant Treatment With Immune Checkpoint Inhibition (ICI) in Patients With Newly Diagnosed Glioblastoma or Gliosarcoma

Background: Glioblastoma (GBM) represents an aggressive malignancy with limited therapeutic options. The immunosuppressive nature of GBM may be reversible with immune checkpoint inhibitor (ICI) treatment, however, initial studies have yet to demonstrate this. It is postulated that trafficking of peripherally activated lymphocytes may play a role in generating a robust intracranial immune response. Therefore, a blood-based assay to identify peripheral blood response may both predict response and better identify the ideal patient populations for future ICI clinical trials. Objectives: Determine if the outcomes, as measured by overall survival, is improved in patients with newly diagnosed glioblastoma when treatment with immune checkpoint inhibitors result in an immune response in peripheral blood T lymphocytes. Eligibility: Histologically confirmed, newly diagnosed primary glioblastoma or gliosarcoma; Age greater than or equal to 18 years; Adequate organ function; Karnofsky performance score greater than or equal to 70; Subjects must recently complete resection and chemoradiation; Subjects must not have prior immunotherapy, other current investigational agents, or corticosteroid treatment \> 30mg cortisone-equivalents per day. Design: Open-label, investigator-initiated exploratory study of newly-diagnosed GBM who have completed resection and chemoradiation. Participants will be randomized to be treated in Arm 1 or 2, consistent of adjuvant chemotherapy (temozolomide (TMZ)) and immunotherapy (nivolumab + ipilimumab): TMZ (150-200 mg/m2 PO on days 1-5 q28 days for cycles 1-6) Arm 1: Nivolumab (1 mg/kg IV q2weeks for cycles 1-4, then 480 mg IV q4weeks for cycles 5-16) + ipilimumab (1 mg/kg IV q4 weeks for cycles 1-4) Arm 2: Nivolumab (1 mg/kg IV q2weeks for cycles 1-4, then 480 mg IV q4weeks for cycles 5-16) + ipilimumab (3 mg/kg IV q4 weeks for cycles 1-4) For the primary objective, serial examination of peripheral blood, including comprehensive flow cytometric analysis of leukocyte populations and cytokines, and Interferon- \>= (IFN- \>=) ELISPOT functional analysis of CD4+/8+ response to common recall antigens will be used to determine systemic response to ICI treatment. For the secondary objectives, correlative studies assess peripheral blood T cells' ability to respond to an in vitro stimulation paradigm, including nivolumab and ipilimumab, in a microbead-based model. The T cell response to pretreatment in vitro stimulation would be compared to post-treatment in vivo stimulation to determine if this in vitro model can predict in vivo response. Additional exploratory studies are planned to characterize the in vivo immune response to adjuvant chemotherapy and immunotherapy, including but not limited to: Phospho-flow functional analysis of NK cell response to IFN/IL-15 stimulation.