Clinical trial Recruiting at 1 site Phase1; Phase2 Interventional Ages 18 and up

Using glutamate inhibitors to treat glioblastoma

Official title: A Phase Ib/II Randomized, Open Label Drug Repurposing Trial of Glutamate Signaling Inhibitors in Combination With Chemoradiotherapy in Patients With Newly Diagnosed Glioblastoma

Run by University of Zurich · NCT05664464 · Data updated 2026-11-12

This study is testing if adding certain medications that block glutamate can help improve treatment outcomes for people with newly diagnosed glioblastoma when used with standard chemotherapy and radiation.

More Glioblastoma trials

Quick facts

PhasePhase1; Phase2
Study typeInterventional
Ages18 Years and up
SexAll
Enrollment120 (estimated)
SponsorUniversity of Zurich
Academic / other
Drugs / interventionsmethotrexate
Locations1 site (Zurich, Canton of Zurich)
StatusRecruiting
StartedJanuary 1, 2023
Main results expectedJune 2026
Study endsDecember 2026
Registry record updatedMay 10, 2024
Trial IDNCT05664464 on ClinicalTrials.gov

Is this trial a fit for you?

Likely a good fit

Ideal candidates are adults over 18 with newly diagnosed supratentorial glioblastoma eligible for standard chemoradiotherapy.

Probably not a fit

Patients scheduled for hypofractionated radiotherapy or those who are pregnant or breastfeeding may not benefit from this study.

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This clinical trial investigates the effectiveness of adding anti-glutamatergic drugs—gabapentin, sulfasalazine, and memantine—to standard chemoradiotherapy with temozolomide in patients with newly diagnosed glioblastoma. The study is designed as a 1:1 randomized, multi-center, open-label phase Ib/II trial. The rationale behind this approach is based on the role of glutamate in glioblastoma progression and the potential of these drugs to inhibit glutamate synthesis and signaling, which may improve patient outcomes. Participants will receive standard treatment alongside these additional medications to assess their combined efficacy.

Why it matters

Potential benefit: If successful, this approach could significantly improve survival rates and quality of life for patients with glioblastoma.

How similar studies have gone: While there is limited commercial interest, the rationale for this combined anti-glutamatergic approach is based on existing knowledge, though it remains largely untested in this specific context.

Who can join: the full rules

Show full inclusion / exclusion criteria
Inclusion criteria

* 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

Exclusion criteria

* Scheduled for hypofractionated radiotherapy
* 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.
* Other clinically significant concomitant disease states (e.g., renal failure, hepatic dysfunction, cardiovascular disease),
* Known or suspected non-compliance, drug or alcohol abuse,
* Inability to follow the procedures of the study, e.g. due to language problems, psychological disorders, dementia, etc. of the participant,
* Participation in another study with investigational drug within the 30 days preceding and during the present study,
* Previous enrolment into the current study,
* Being an investigator, his/her family members, employees and other dependent persons,
* Any prior radiotherapy of the brain or radiotherapy with potential overlap of the irradiation fields,
* Active malignancy that may interfere with the study treatment,
* Abnormal ECG with QTc \>450 ms,
* Contraindication for Gadolinium-enhanced MRI,
* Previous intolerance reactions to one of the study drugs,
* Intolerance reactions to sulfonamides or salicylates,
* Acute intermittend porphyria,
* Known glucose-6-phosphate dehydrogenase deficiency,
* Concomitant therapy with digoxin, cyclosporin, methotrexate,
* History of exfoliative dermatitis, Stevens-Johnson-Syndrome, toxic epidermal necrolysis, DRESS (Drug Rash with Eosinophilia and Systemic Symptoms) syndrome or renal tubular acidosis.

Where it's running

  • University Hospital Zurich
    Zurich, Canton of Zurich, Switzerland
    Recruiting

Study contacts

  • Principal investigator: Hans-Georg Wirsching, MD — University Hospital and University of Zurich
  • Study coordinator: Hans-Georg Wirsching, MD
  • Email: hans-georg.wirsching@usz.ch
  • Phone: +41432532928

Similar studies

Other studies for the same condition or treatment. Recruiting studies are listed first.

How to take part

  1. Review the eligibility criteria above with your treating physician.
  2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
  3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.
Last reviewed 2026-11-14 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.