Phase Ii Study To Evaluate The Clinical Efficacy And Safety Of Medi4736 In Patients With Glioblastoma (Gbm).

TPS2077 Background: Programmed cell death ligand-1 (PD-L1) is widely expressed on antigen presenting cells (APC) and other immune cells. PD-L1 binds two important regulatory receptors on T-cells: programmed cell death-1 (PD-1) and CD80/B7. Targeting Programmed Death-1 (PD-1) and its ligand, PD-L1, have demonstrated promising anti-tumor activity among other challenging solid tumors and growing data implicates PD-1/PD-L1 signaling as a significant contributor to immunosuppression in glioblastoma (GBM). PD-1 is expressed by many GBM infiltrating lymphocytes while PD-L1 is expressed by 61-100% of GBM tumors. Furthermore, loss of the PTEN tumor suppressor gene, which occurs in 40-50% of GBM tumors, leads to increased transcription and expression of PD-L1 in GBM. These findings indicate that PD-L1 is an attractive and important therapeutic target in GBM. MEDI4736 (M), a human IgG1κ blocking monoclonal antibody against PD-L1, represents a compelling immune-mediated anti-tumor treatment for GBM. Methods: Phase II...