SRA

Glioblastoma is the most common primary malignant brain tumor in adults and associated with poor survival. Standard-of-care chemotherapy and radiation confer a median overall survival of under two years. The Ivy Foundation Early Phase Clinical Trials Consortium conducted a randomized, multi institution clinical trial to evaluate immune responses and survival following neoadjuvant and/or adjuvant therapy with pembrolizumab, a programmed cell death protein 1 (PD-1) monoclonal antibody, in 35 patients with recurrent, surgically resectable glioblastoma. Patients who were randomized to receive neoadjuvant pembrolizumab, with continued adjuvant therapy following surgery, had significantly extended overall survival compared to patients that were randomized to receive adjuvant, post-surgical PD-1 blockade alone (hazard ratio = 0.39; P = 0.04, log-rank test). Neoadjuvant PD-1 blockade was associated with upregulation of T cell and interferon-?-related genes, but downregulation of cell cycle related genes within the tumor, which was not seen in patients that received adjuvant therapy alone. Focal induction of programmed death-ligand 1 (PD-L1) in the tumor microenvironment was observed more frequently in the neoadjuvant group than in tumors obtained from patients treated only in the adjuvant setting. Similarly, neoadjuvant pembrolizumab was associated with clonal T cell expansion and the overlap of T cell receptors between tumor and blood, decreased PD-1 expression in T cells and a decreasing peripheral monocytic population. These findings suggest that the neoadjuvant administration of PD-1 blockade enhances the local and systemic anti-tumor immune response and may represent a more efficacious approach to the treatment of this uniformly lethal brain tumor. This trial was registered with ClinicalTrials.gov under the identifier NCT02852655 (https://clinicaltrials.gov/ct2/show/NCT02852655). Overall design: This dataset contains the transcriptomes of recurrent glioblastoma with either neoadjuvant (1 dose) or adjuvant pembrolizumab treatment