A Phase 1 interventional study of Biospecimen Collection and Magnetic Resonance Imaging in Glioblastoma, Gliosarcoma and MGMT-Unmethylated Glioblastoma, sponsored by National Cancer Institute (NCI). Terminated at 11 sites in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-11-13.
Sponsored by National Cancer Institute (NCI) · Phase 1, Interventional, and Treatment
This phase I trial studies the side effects and best dose of navtemadlin in treating patients with glioblastoma (brain cancer) that is newly diagnosed or has come back (recurrent). Navtemadlin may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth.
PRIMARY OBJECTIVES:
I. Determine the concentration and variability in concentration of navtemadlin (AMG 232 [KRT 232]) in brain and brain-associated tissue in patients with recurrent glioblastoma (GBM). (Part 1) II. Determine the maximum tolerated dose (MTD) of AMG 232 (KRT 232) given in combination with standard radiation following surgery for patients with newly diagnosed GBM harboring unmethylated MGMT promoters and wild-type TP53. (Part 2)
SECONDARY OBJECTIVES:
I. Determine the safety and toxicity of AMG 232 (KRT 232) in patients with recurrent GBM. (Part 1) II. Assess the variability of AMG 232 (KRT 232) concentration in tumor enhancing versus (vs.) infiltrative tissue. (Part 1) III. Assess the pharmacodynamic effect of AMG 232 (KRT 232) on p21 elevation. (Part 1) IV. Determine the safety of AMG 232 (KRT 232) given concurrently with radiation therapy (RT) and adjuvantly as monotherapy for patients with newly diagnosed GBM harboring unmethylated MGMT promoters and wild-type TP53. (Part 2) V. Assess AMG 232 (KRT 232) exposure and correlations with pharmacodynamic (PD) effect on p21 elevation. (Part 2) VI. Assess PD effect on MIC-1 elevation in serum. (Part 2)
OUTLINE: This is a phase 0, intratumoral pharmacokinetic (PK)/PD study of navtemadlin followed by a phase I dose-escalation study.
PART I: Patients with recurrent glioblastoma receive navtemadlin (KRT-232) orally (PO) once daily (QD) for 2 days. Within 3-6 hours of the last dose, patients undergo standard-of-care surgery. Upon recovery (within 45 days), patients with TP53 wild-type tumors continue to receive navtemadlin (KRT-232) PO QD on days 1-7. Cycles repeat every 21 days in the absence of disease progression or unacceptable toxicity. Patients also undergo magnetic resonance imaging (MRI) at baseline as well as on study and/or end of treatment and collection of blood and tissue samples at baseline and on study.
PART II: Within 6 weeks of standard-of-care surgery, patients with newly diagnosed glioblastoma undergo radiation therapy daily during weeks 1-6. Patients also receive navtemadlin (KRT-232) PO 1 time weekly (day 2), 2 times weekly (days 2, 4), 3 times weekly (days 2, 3, 5), 4 times weekly (days 2, 3, 4, 5), or 5 times weekly (days 1-5) for 6 weeks during radiation therapy. Patients also undergo MRI at baseline and end of treatment and collection of blood samples at baseline and on study.
PART II (EXPANSION COHORT): Patients receive navtemadlin (KRT-232) PO QD on days 1-7. Cycles repeat every 21 days in the absence of disease progression or unacceptable toxicity. Patients also undergo MRI at baseline, on study, and end of treatment.
After completion of study treatment, patients are followed every 2 months for the first two years from the off-treatment date, and then every 6 months until 5 years.
2,132 studies on the registry are indexed under Glioblastoma; 464 are open to participants now.
This study's enrollment of 32 is below the median of 36 across 1,753 interventional studies indexed under Glioblastoma.
Browse Glioblastoma studies →National Cancer Institute (NCI) is the lead sponsor of 3,556 studies on the registry; 336 are open to participants now.
Of its 411 completed or terminated interventional studies of FDA-regulated products, 373 (91%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Part 1 patients must have recovered from severe toxicity of prior therapy; the following intervals from previous treatments are required to be eligible:
Exclusion Criteria:
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.
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.
The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.
It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (µL). Each lab has its own reference range.
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
How quickly the kidneys clear creatinine, a waste product, from the blood. A study may estimate it from a blood test with age, weight and sex (often by the Cockcroft–Gault formula), or measure it using blood and urine collected over a set time. Given in mL/min; higher is better.
Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.
Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.
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.
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.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
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.
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 diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).
Your pathology report is the document that shows this.
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.
The US National Cancer Institute’s scale of how severe an adverse event is — any unwanted medical event during a study, such as a symptom, an illness or an abnormal test result, whether or not a treatment caused it. Whether it did is judged separately.
“Side effects of earlier treatment resolved to grade 1 or less” means they have settled to mild or gone.
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.
CYP3A is a group of enzymes, mainly CYP3A4, in the liver and gut that break down many medicines. Some medicines, supplements and foods (grapefruit, St John’s wort) slow them down or speed them up, which changes how much of a study drug stays in the body.
Studies list them so they can be avoided or switched; bring a list of everything you take, including supplements.
On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.
The study may name a correction formula and a limit in milliseconds, often around 450–480.
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
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.
Absolute neutrophil count (ANC)
The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.
It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (µL). Each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hemoglobin (Hb)
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Bilirubin
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Creatinine clearance (CrCl)
How quickly the kidneys clear creatinine, a waste product, from the blood. A study may estimate it from a blood test with age, weight and sex (often by the Cockcroft–Gault formula), or measure it using blood and urine collected over a set time. Given in mL/min; higher is better.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
INR, PT and aPTT (clotting tests)
Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.
Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
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.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
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.
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.
Histologically or cytologically confirmed
The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).
Your pathology report is the document that shows this.
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.
CTCAE grade
The US National Cancer Institute’s scale of how severe an adverse event is — any unwanted medical event during a study, such as a symptom, an illness or an abnormal test result, whether or not a treatment caused it. Whether it did is judged separately.
“Side effects of earlier treatment resolved to grade 1 or less” means they have settled to mild or gone.
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.
CYP3A (CYP3A4) inhibitors and inducers
CYP3A is a group of enzymes, mainly CYP3A4, in the liver and gut that break down many medicines. Some medicines, supplements and foods (grapefruit, St John’s wort) slow them down or speed them up, which changes how much of a study drug stays in the body.
Studies list them so they can be avoided or switched; bring a list of everything you take, including supplements.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
QT and QTc
On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.
The study may name a correction formula and a limit in milliseconds, often around 450–480.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
NYHA class (heart failure)
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis C tests
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
See Detailed Description
Procedure: Biospecimen Collection · Procedure: Magnetic Resonance Imaging · Drug: Navtemadlin · Radiation: Radiation Therapy
Undergo collection of blood and tissue samples
Also known as: Biological Sample Collection, Biospecimen Collected, Specimen Collection
Undergo MRI
Also known as: Magnetic Resonance, Magnetic Resonance Imaging (MRI), Magnetic resonance imaging (procedure), Magnetic Resonance Imaging Scan, Medical Imaging, Magnetic Resonance / Nuclear Magnetic Resonance, MR, MR Imaging, MRI, MRI Scan, MRIs, NMR Imaging, NMRI, Nuclear Magnetic Resonance Imaging, sMRI, Structural MRI
Given PO
Also known as: (3R,5R,6S)-5-(3-Chlorophenyl)-6-(4-chlorophenyl)-3-methyl-1-((1S)-2-methyl-1-(((1-methylethyl)sulfonyl)methyl)propyl)-2-oxo-3-piperidineacetic Acid, AMG 232, AMG-232, KRT 232, KRT-232, KRT232, MDM2 Inhibitor KRT-232
Undergo radiation therapy
Also known as: Cancer Radiotherapy, Energy Type, ENERGY_TYPE, Irradiate, Irradiated, Irradiation, Radiation, Radiation Therapy, NOS, Radiotherapeutics, Radiotherapy, RT, Therapy, Radiation
Pharmacokinetics (PK) parameters with target inter-tumor drug concentration at >= 25 nm (Part 1)
Part 2 of the trial will proceed only if at least one of the doses yielded a 50% PK response rate. If both doses reached 50% PK response rate, both doses will be studied in Part 2 of the trial.
Time frame: Up to 5 years
Maximum tolerated dose (MTD) of MDM2 inhibitor AMG 232 (KRT-232) when combined with concomitant radiation therapy (Part 2)
MTD will be determined according to dose-limiting toxicities graded by National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0 (Beginning April 1, 2018 version 5.0 will be utilized for adverse event reporting). The target dose-limiting toxicity (DLT) rate is 33%. If the MTD is not reached among the pre-specified doses, the dose for the expanded cohort will be the highest dose studied for which the DLT rate is less than 33%.
Time frame: Up to 16 weeks
Incidence of adverse events (Part 1)
Assessed by Common Terminology Criteria for Adverse Events (CTCAE) version 4.0 (Beginning April 1, 2018 version 5.0 will be utilized for adverse event reporting). Will be used for scoring toxicity and adverse events. The severity and frequency of toxicity will be tabulated by the tested dose or doses, or combination regimens using descriptive statistics. The proportion of patients who experienced grade 3 or above toxicities will be estimated along with 95% confidence intervals by each type of toxicity.
Time frame: Up to 30 days following the last dose of study drug
Variability of MDM2 inhibitor AMG 232 (KRT-232) concentration in tumor enhancing versus infiltrative tissue (Part 1)
Will be summarized using descriptive statistics.
Time frame: Up to 5 years
p21 elevation in tissue (Part 1)
Will be coded as binary outcome either elevated or not elevated compared to a reference value from archived tumor tissues in matched patient population. A proportion of patients with elevated p21 will be estimated using a binomial distribution along with 95% confidence interval.
Time frame: Up to 5 years
Incidence of adverse events (Part 2)
Assessed by CTCAE version 4.0 (Beginning April 1, 2018 version 5.0 will be utilized for adverse event reporting). Will be used for scoring toxicity and adverse events. The severity and frequency of toxicity will be tabulated by the tested dose or doses, or combination regimens using descriptive statistics. The proportion of patients who experienced grade 3 or above toxicities will be estimated along with 95% confidence intervals by each type of toxicity.
Time frame: Up to 10 weeks
MIC-1 elevation in serum (Part 2)
The PK variables and changes in MIC-1 will be tabulated and descriptive statistics (e.g., geometric means and coefficients of variation) calculated for each dose level. PK parameters and MIC-1 changes will be compared across dose level using non-parametric statistical testing techniques.
Time frame: Up to 5 years
MDM2 inhibitor AMG 232 (KRT-232) exposure (Part 2)
Assessed by liquid chromatography/tandem mass spectrometry. A full pharmacokinetic profile of AMG 232 (KRT 232) will be proposed in this study to assess exposure-response relationships with various pharmacodynamic (PD) endpoints (i.e., MIC-1 changes, toxicity, and efficacy). Correlation with PD effect on p21 elevation will be determined.
Time frame: Up to 5 years
PDFs hosted by the registry, ClinicalTrials.gov.
Plan to share: Yes — NCI is committed to sharing data in accordance with NIH policy. For more details on how clinical trial data is shared, access the link to the NIH data sharing policy page
Data sharing details ↗ · grants.nih.gov
Ran from Jul 2018 to primary completion in Aug 2025, 85 months.
How these figures are worked out, and which studies are left out of them.
This study is terminated, as verified in Nov 2025. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Navtemadlin
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