The study for each participant consists of a Screening period, a Treatment period and a 12-month Follow-up period.~During the screening period of up to 6 weeks before starting GBM treatment, each participant will be assessed for somatostatin receptor (SSTR) expression by [68Ga]Ga-DOTA-TATE imaging PET/scan.~Eligible participants with newly diagnosed glioblastoma will be assigned to Group 1 or Group 2 depending on O-6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status:~Participants in Group 1 (concomitant radiotherapy + temozolomide and temozolomide maintenance) will receive treatment with [177Lu]Lu-DOTA-TATE every 4 weeks +/- 2 days, up to 6 administrations. Radiotherapy and temozolomide will be administered 7 to 10 days after the first administration of [177Lu]Lu-DOTA-TATE. Temozolomide will be administered orally at a dose of 75 mg/m2/day during the concomitant period, concurrently with radiotherapy. Radiotherapy will be delivered at a dose of 2 Gray (Gy)/day, 5 days per week followed by 2 days of rest, for 6 consecutive weeks with a total dose of 60 Gy (without interruption). During the maintenance period, there is an intra-patient dose escalation in temozolomide treatment. The dosage of temozolomide is 150 mg/m2 in Cycle 1 of maintenance period, and then to 200 mg/m2 in Cycle 2 and beyond in the maintenance period, if 150 mg/m2 temozolomide treatment is well tolerated in Cycle 1.~Participants in Group 2 will receive treatment with [177Lu]Lu-DOTA-TATE every 4 weeks +/- 2 days for the first 3 doses (during the radiotherapy period) followed by every 3 weeks +/- 2 days as single agent, up to a total of 6 administrations. Radiotherapy will be initiated 7 to 10 days after the first administration of [177Lu]Lu-DOTA-TATE and will be delivered at a dose of 2 Gy/day, 5 days per week followed by 2 days of rest, for 6 consecutive weeks.~Eligible participants with recurrent glioblastoma will be assigned to Group 3 and will receive [177Lu]Lu-DOTA-TATE as single agent treatment every 3 weeks +/- 2 days.~An infusion of sterile 2.5% Lysine - Arginine amino acid (AA) solution will be co-administered with each [177Lu]Lu-DOTA-TATE dose for renal protection.
This study aims to establish the recommended dose of [177Lu]Lu-DOTA-TATE in combination with the standard of care or as single agent in three different groups of participants with Glioblastoma. In addition, this study will investigate the safety of [68Ga]Ga-DOTA-TATE and describe its uptake characteristics in participants with Glioblastoma.