Glutamate Inhibitors in Glioblastoma

Prior treatment

• Scheduled for hypofractionated radiotherapy
• Other clinically significant concomitant disease states (e.g., renal failure, hepatic dysfunction, cardiovascular disease),
• Known or suspected non-compliance, drug or alcohol abuse,
• Participation in another study with investigational drug within the 30 days preceding and during the present study,
• Previous enrolment into the current study,
• Any prior radiotherapy of the brain or radiotherapy with potential overlap of the irradiation fields,
• Previous intolerance reactions to one of the study drugs,
• Concomitant therapy with digoxin, cyclosporin, methotrexate,

Other illness

• Inability to follow the procedures of the study, e.g. due to language problems, psychological disorders, dementia, etc. of the participant,
• Active malignancy that may interfere with the study treatment,
• History of exfoliative dermatitis, Stevens-Johnson-Syndrome, toxic epidermal necrolysis, DRESS (Drug Rash with Eosinophilia and Systemic Symptoms) syndrome or renal tubular acidosis.

Lab values

• Abnormal ECG with QTc \>450 ms,
• Known glucose-6-phosphate dehydrogenase deficiency,

Other

• Women who are pregnant or breast feeding,
• Intention to become pregnant during the course of the study or intention to father a child,
• Lack of safe contraception, defined as: Female participants of childbearing potential, not using and not willing to continue using a medically reliable method of contraception for the entire study duration, such as oral, injectable, or implantable contraceptives, or intrauterine contraceptive devices, or who are not using any other method considered sufficiently reliable by the investigator in individual cases. Female participants who are surgically sterilised / hysterectomised or post-menopausal for longer than 2 years are not considered as being of child bearing potential.
• Being an investigator, his/her family members, employees and other dependent persons,
• Contraindication for Gadolinium-enhanced MRI,
• Intolerance reactions to sulfonamides or salicylates,
• Acute intermittend porphyria,

• Diagnosis: Newly diagnosed supratentorial glioblastoma according to the 2021 World Health Organization (WHO) Classification of Central Nervous System Tumors
• Signed informed consent
• Age \>18 years
• Eligible for standard chemoradiotherapy with temozolomide (TMZ/RT-\>TMZ, hypofractionated RT regimen not allowed)
• KPS 70 or more
• Ability to judge per local investigator estimate (at least oriented to time, place and situation)
• Paraffin-embedded tissue for central pathology review
• Adequate heamatological, liver and renal function