A Phase 1/2 interventional study of Zedoresertib and Temozolomide in Glioblastoma IDH (Isocitrate Dehydrogenase) Wildtype and Astrocytoma, Grade III, sponsored by Debiopharm International SA. Recruiting at 16 sites in 3 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-28.
Sponsored by Debiopharm International SA (part of Debiopharm) · Phase 1/2, Interventional, and Treatment
The primary purpose of the Phase 1 (Dose Escalation) of this study is to identify the dose-limiting toxicities (DLTs) of zedoresertib combined with temozolomide (TMZ) (Arm A) and with TMZ and radiotherapy (RT) (Arms B and C) and to characterize the safety and tolerability of these combinations in adult participants with glioblastoma (GBM). Arm B which was previously added to the protocol, has been permanently halted per the safety monitoring committees' decision on the safety findings of this arm.
The primary purpose of Phase 1 (Dose expansion) of the study is to assess the doses studied under Phase 1 (Dose Escalation) Arm A and identify the recommended dose (RD) for further development.
The Phase 2 will start once the RD Phase 1 has been defined. The primary objective of Phase 2 is to assess the efficacy of zedoresertib at the RD for further development in combination with TMZ, compared to the standard of care (SOC) in adult participants with GBM.
2,132 studies on the registry are indexed under Glioblastoma; 464 are open to participants now.
This study's planned enrollment of 116 is above the median of 36 across 1,753 interventional studies indexed under Glioblastoma.
Browse Glioblastoma studies →Debiopharm International SA is the lead sponsor of 51 studies on the registry; 6 are open to participants now.
Of its 9 completed or terminated interventional studies of FDA-regulated products, 6 (67%) have results posted.
Compared within Glioblastoma, this study's primary condition as ClinicalTrials.gg classifies it; the registry's first condition term is Astrocytoma. The counts are of registry records indexed under each term, refreshed daily. How we classify →
The criteria were revised on the registry on Oct 28, 2026. See what changed
Screening Inclusion Criteria for Phase 1 and Phase 2:
Additional specific inclusion criteria for Phase 1 and Phase 2:
Note: Only 1 prior line of systemic therapy is allowed; combination therapy with TMZ and RT with or without subsequent TMZ maintenance treatment is considered as 1 systemic line. Prior surgery, radiation, or localized delivery of therapeutic agents (i.e., carmustine-containing wafers [GLIADEL®]) for first recurrence is allowed.
Additional specific inclusion criteria for Phase 1 Arm A:
Additional specific inclusion criteria for Phase 1 Arm B and C:
Additional specific inclusion criteria for Phase 1 dose expansion and Phase 2:
Additional specific exclusion criteria for Phase 1 Arm A • Prior treatment with more than 2 lines of therapy for GBM, IDH-wildtype, Grade 4, or for astrocytoma, IDH-mutant, Grade 3
Additional specific exclusion criteria for Phase 1 and Phase 2
Additional specific exclusion criteria for Phase 1 Arm B and C:
Additional specific exclusion criteria for Phase 1 dose expansion and Phase 2
[Note: Other inclusion/exclusion criteria mentioned in the protocol may apply.]
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
The amount of disease can be tracked with a defined measurement, so the study can see whether it shrinks or grows. It might be a tumour measured on a scan or, in some blood cancers such as myeloma, a marker measured in blood or urine.
The criteria or the study team say which measurement counts — having no tumour visible on a scan does not by itself rule you out.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
A line of therapy is one course of treatment, which may combine several drugs. First-line is the first course given; second-line follows when that stops working or is not tolerated.
“Two prior lines” means two courses that count separately under the study’s rules — not simply two drugs. Ask the study team if you are unsure how yours are counted.
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
A 0–100 scale of how well someone can carry out everyday activities. 100 is no complaints and no signs of illness; 70 is able to look after yourself but not to work or keep up normal activity; 50 is needing considerable help and frequent medical care.
Studies often ask for 60 or 70 and above. Your doctor gives the score.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Life expectancy
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Measurable disease
The amount of disease can be tracked with a defined measurement, so the study can see whether it shrinks or grows. It might be a tumour measured on a scan or, in some blood cancers such as myeloma, a marker measured in blood or urine.
The criteria or the study team say which measurement counts — having no tumour visible on a scan does not by itself rule you out.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Line of therapy
A line of therapy is one course of treatment, which may combine several drugs. First-line is the first course given; second-line follows when that stops working or is not tolerated.
“Two prior lines” means two courses that count separately under the study’s rules — not simply two drugs. Ask the study team if you are unsure how yours are counted.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Biopsy and archival tissue
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Karnofsky performance status (KPS)
A 0–100 scale of how well someone can carry out everyday activities. 100 is no complaints and no signs of illness; 70 is able to look after yourself but not to work or keep up normal activity; 50 is needing considerable help and frequent medical care.
Studies often ask for 60 or 70 and above. Your doctor gives the score.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Excipients
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
LVEF (left ventricular ejection fraction)
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants will receive intermittent zedoresertib, escalating doses along with temozolomide (TMZ) in each 28-day cycle for up to 2 years.
Drug: Zedoresertib · Drug: Temozolomide
Participants will receive intermittent zedoresertib, escalating doses along with TMZ and concomitant administration of radiotherapy (RT) for up to 6 weeks. As per Protocol \_V4.0 Arm B has been permanently halted.
Drug: Zedoresertib · Drug: Temozolomide · Radiation: Radiotherapy
Participants will receive intermittent zedoresertib, escalating doses along with TMZ and concomitant administration of radiotherapy (RT) for up to 6 weeks.
Drug: Zedoresertib · Drug: Temozolomide · Radiation: Radiotherapy
Participants will receive zedoresertib, escalating doses along with temozolomide (TMZ) in each 28-day cycle for up to 2 years. Participants will receive one of the 2 selected doses for further investigation.
Drug: Zedoresertib · Drug: Temozolomide
Participants will receive intermittent zedoresertib RD along with TMZ in each 28-day cycle for up to 2 years.
Drug: Zedoresertib · Drug: Temozolomide
Administered as capsules.
Also known as: Debio 0123
Administered as capsules.
Administered in accordance with the local clinical practice and applicable Radiation Therapy Oncology Group (RTOG) or the European Organization for Research and Treatment of Cancer (EORTC) guidelines.
Phase 1 (Dose Escalation): Number of Participants Experiencing Dose-limiting Toxicities (DLTs)
Time frame: Phase 1: Arm A: Cycle 1 (Cycle=28 days); Arms B and C: Up to approximately 1.8 months
Phase 1 (Dose Escalation): Number of Participants With At Least One Treatment-emergent Adverse Event (TEAE)
Time frame: Up to 30 days after the end of treatment (Arm A: Up to approximately 26 months and Arms B and C: Up to approximately 3.5 months)
Phase 1 (Dose Escalation): Number of Participants With Clinically Significant Abnormalities in Laboratory, Vital Signs, Electrocardiogram (ECG), and Echocardiogram (ECHO) Parameters
Time frame: Up to 30 days after the end of treatment (Arm A: Up to approximately 26 months and Arms B and C: Up to approximately 3.5 months)
Phase 1 (Dose Escalation): Change From Baseline in Karnofsky Performance Status (KPS) Score
KPS is an assessment tool for functional impairment. It is a standard way of measuring the ability of participants with cancer to perform ordinary tasks. The KPS scores range from 0 (death) to 100 (no evidence of disease). A higher score means the participant is better able to carry out daily activities.
Time frame: Until disease progression or end of study (approximately 66 months)
Phase 1 (Dose Expansion): Number of Participants With At Least One Treatment-emergent Adverse Event (TEAE)
Time frame: Up to approximately 26 months
Phase 1 (Dose Expansion): Change from Baseline in Tumor Size Assessed by Objective Response (OR) as per Response Assessment in Neuro-oncology (RANO) Criteria
Time frame: From the start of study treatment until disease progression or end of study (up to approximately 66 months)
Phase 1 (Dose Expansion): Plasma Concentration of Zedoresertib and its Metabolite
Time frame: Predose and at multiple timepoints up to 6 hours post dose up to Day 15 of Cycle 1 (Cycle=28 days)
Phase 1 (Dose Expansion): Pharmacodynamic(s) PDy, Change from baseline in Phosphorylated Cell Division Cycle (pCDC2)
Time frame: Predose and 4 to 6 hours post dose on Day 10 of Cycle 1 (Cycle=28 days)
Phase 2: Overall Survival (OS)
Time frame: From the start of study treatment until death from any cause or end of study (up to approximately 66 months)
Phase 1 (Dose Expansion): OS
Time frame: From the start of study treatment until death from any cause or end of study (up to approximately 66 months)
Phase 1 (Dose Escalation): Plasma Concentration of Temozolomide
The PK of temozolomide will be evaluated in plasma.
Time frame: Phase 1: Predose and at multiple timepoints up to 7 hours post dose up to Day 5 of Cycle 1 (Arm A) and up to Day 29 (Arm B and C)
Phase 1 (Dose Expansion): Number of Participants With Clinically Significant Abnormalities In Laboratory, Vital Signs, ECG, and (ECHO Parameters)
Time frame: Up to 30 days after the end of treatment (up to approximately 26 months)
Phase 1 (Dose Expansion): Number of Participants With At Least one TEAE
Time frame: Up to 30 days after the end of treatment (up to approximately 26 months)
Phase 1 (Dose Expansion): Change From Baseline in KPS Score
KPS is an assessment tool for functional impairment. It is a standard way of measuring the ability of participants with cancer to perform ordinary tasks. The KPS scores range from 0 (death) to 100 (no evidence of disease). A higher score means the participant is better able to carry out daily activities.
Time frame: Until disease progression or end of study (approximately 66 months)
Phase 2: Change From Baseline in KPS Score
KPS is an assessment tool for functional impairment. It is a standard way of measuring the ability of participants with cancer to perform ordinary tasks. The KPS scores range from 0 (death) to 100 (no evidence of disease). A higher score means the participant is better able to carry out daily activities.
Time frame: Until disease progression or end of study (approximately 66 months)
Phase 2: Number of Participants With Clinically Significant Abnormalities in Laboratory, Vital Signs, and ECG Parameters
Time frame: Up to 30 days after the end of treatment (up to approximately 26 months)
Phase 2: Number of Participants With At Least One TEAE
Time frame: Up to 30 days after the end of treatment (up to approximately 26 months)
Phases 1 and 2: Plasma Concentration of Zedoresertib and its Metabolite
The pharmacokinetics (PK) of zedoresertib and its metabolite will be evaluated in plasma.
Time frame: Phase1(Dose Escalation):Predose, multiple timepoints upto 8hours postdose upto Day 15 of Cycle 1(Arm A) and upto Day 29(Arms B and C);Phase1(Dose expansion)andPhase2: Predose, multiple timepoints upto 4hours postdose upto Day 15 of Cycle1(Cycle=28 days)
Phases 1 and 2: Percentage of Participants With Best Overall Response (BOR) Assessed As Per Response Assessment in Neuro-oncology (RANO) Criteria
Time frame: From the start of study treatment until disease progression or end of study (up to approximately 66 months)
Phases 1 and 2: Percentage of Participants with Objective Response (OR) Assessed As Per RANO Criteria
Time frame: Up to end of study (approximately 66 months)
Phases 1 and 2: Percentage of Participants With Disease Control (DC) Assessed As Per RANO Criteria
Time frame: From the start of study treatment until disease progression or end of study (up to approximately 66 months)
Phases 1 and 2: Duration of Response (DOR) Assessed As Per RANO Criteria
Time frame: Up to disease progression or end of study (up to approximately 66 months)
Phases 1 and 2: Progression Free Survival (PFS) Assessed As Per RANO Criteria
Time frame: From the start of study treatment until disease progression or death or end of study (up to approximately 66 months)
Plan to share: No
No publications or documents are linked to this record.
Started May 2023 (actual). Primary completion is estimated for Sep 2028, 64 months after the start.
Of 53 industry-sponsored phase 1/2 interventional studies under Glioblastoma, half reached primary completion within 55 months of starting (the median), counting those still running; a quarter within 39 and three quarters within 75. This study's planned 64 months is above that.
Counting every sponsor, half of 137 studies reached it within 66 months; a quarter within 45 and three quarters within 100.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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Studies of the drugs tested here: Zedoresertib · Temozolomide