This is an open-label, Phase IV study of Pembrolizumab employed in neoadjuvant and adjuvant setting on top of standard therapy to evaluate the short-term and long-term safety, tolerability and efficacy in disease control in Glioblastoma Multiforme (GBM) patients. The control arm will be a group of patients treated in accordance with Standard of Care (SoC).~The study will include 3 treatment arms (up to n=12 evaluable patients per arm) and will be conducted at single site in Poland.~Patients with GBM will be randomly assigned in 1:1:1 ratio into one of 3 treatment arms:~Treatment arm 1 - n=12 evaluable patients - neoadjuvant Pembrolizumab (2 doses, 200mg each) plus adjuvant Pembrolizumab (16 cycles q3w, 200mg each) on top of standard chemo-radiotherapy (Stupp protocol: radiotherapy 60Gy over 6 weeks, 2 Gy per daily fraction Mo-Fri setting plus Temozolomide 75mg/m2 BSA daily during radiotherapy and six cycles post-radiotherapy of 150-200mg/m2 BSA for 5 days in each 28-day cycle)~Treatment arm 2 - n=12 evaluable patients - neoadjuvant Pembrolizumab (2 doses, 200mg each) on top of standard chemo-radiotherapy (Stupp protocol: radiotherapy 60Gy over 6 weeks, 2 Gy per daily fraction Mo-Fri setting plus Temozolomide 75mg/m2 BSA daily during radiotherapy and six cycles post-radiotherapy of 150-200mg/m2 BSA for 5 days in each 28-day cycle)~Treatment arm 3 - n=12 evaluable patients - standard chemo-radiotherapy (Stupp protocol: radiotherapy 60Gy over 6 weeks, 2 Gy per daily fraction Mo-Fri setting plus Temozolomide 75mg/m2 BSA daily during radiotherapy and six cycles post-radiotherapy of 150-200mg/m2 BSA for 5 days in each 28-day cycle) A pre-screening period will identify potential candidates for enrollment. Once qualified to the study patients will be randomized to one of the treatment arms. Then patients randomized to treatment arm 1 and 2 will receive first dose of neoadjuvant Pembrolizumab on day 4 and day 18 (200mg each). An immuno-PET scan for these arm 1 and 2 patients will be performed on day 29 and 30. Up to 72 hours after last immuno-PET scan all patients will undergo tumor resection. After surgery all patients will be treated in accordance with standard of care (Stupp protocol) with combined radio- and chemotherapy. Radiotherapy will consist of 60Gy over 6 weeks in daily fraction of 2Gy in Mo-Fri setting and parallel chemotherapy with Temozolomide of 75mg/m2 of BSA on a daily basis. After completion of radiotherapy the chemotherapy will continue for six cycles of 28 days with 150-200mg/m2 Temozolomide on days 1-5 of each cycle. In addition, patients randomized to arm 1 will receive 16 cycles of 21 days with Pembrolizumab treatment in adjuvant setting of 200mg/cycle.~During treatment period all patients will be assessed every three months and MRI will be performed in order to evaluate disease status/response.~After EOT patient's follow up period will continue for up to 3 years from initial resection with MRI assessment every 3 months.~If progression/relapse is identified, patients will undergo a tumor resection or biopsy within 48 hours thereafter.~All patients will then stay in follow up until the end of three years follow up period or death from any cause.~The evaluation of safety, tolerability, and quality-of-life (QoL) will be based on adverse event reporting criteria (Common Terminology Criteria for Adverse Events - CTCAE/WHO Classification of Diseases - ICD10), ECOG status assessment, KPS assessment, EORTC - QLQ-C30 and EORTC-QLQ-BN20 scale.~Clinical assessment will be based on Response Assessment in Neuro-Oncology (RANO). For patients treated with immunotherapy beyond onset of objective disease progression, the iRANO scale will be used within first 6 months of immunotherapy.~Due to a significant risk of identifying other pathology than GBM (i.e. metastasic tumor) in post-surgery histopathology it is anticipated that up to additional 6 patients may be recruited in order to achieve planned number of evaluable patients.
To evaluate the short-term and longer-term safety, tolerability, and effectiveness of neoadjuvant and adjuvant Pembrolizumab on top of standard therapy (Stupp protocol) in patients with Glioblastoma Multiforme (GBM).~Randomized comparison of safety, tolerability, and clinical efficacy of (1) neoadjuvant and adjuvant Pembrolizumab (on top of Stupp protocol, n=12 patients), (2) neoadjuvant Pembrolizumab (on top of Stupp protocol, n=12 patients), and (3) standard of care (Stupp protocol only, n=12 patients). Immuno-PET examination will be performed before and after surgery in all patients.