A Phase 1/2 interventional study of Mirdametinib in Pediatric Low-grade Glioma, sponsored by St. Justine's Hospital. Recruiting at 10 sites in Canada. Open to participants aged 2 Years to 25 Years. Per ClinicalTrials.gov, last updated 2026-10-16.
Sponsored by St. Justine's Hospital · Phase 1/2, Interventional, and Treatment
This is a 3-part open-label study (feasibility phase, treatment phase and follow-up phase) of orally administered mirdametinib in combination with intravenous vinblastine chemotherapy in patients with PLGG with activation of MAPK pathway.
Feasibility Phase:
The maximum tolerated/recommended phase 2 dose (MTD/RP2D) of the mirdametinib plus vinblastine combination will be assessed using a modified Rolling-6 design.
Treatment Phase:
Patients will receive mirdametinib twice daily (continuously) at a fixed dose (2mg/m2 po BID up to 4 mg BID) for a total of 13 cycles (28 days cycle). Weekly intravenous vinblastine at MTD will be given for a total of 17 cycles. If adverse events occur, two dose reductions are allowed.
Follow-up Phase:
Following the end of treatment, patients will be scheduled for a follow-up visit every 6 months for 36 months to evaluate PFS, TTP and OS.
This is a phase 1/2, open label, interventional clinical trial that will study the response rate of newly diagnosed pediatric low-grade glioma (PLGG) to oral administration of mirdametinib in combination with weekly vinblastine. Patients meeting all inclusion criteria for a given study group will receive mirdametinib twice daily (continuous) at a fixed dose (2 mg/m2 po BID up to 4 mg BID) for a total of 13 cycles (28 days cycle). Weekly intravenous vinblastine at MTD will be given for a total of 17 cycles.
The lead-in feasibility phase will be conducted to establish the maximum tolerated/recommended phase 2 dose (MTD/RP2D) of vinblastine in combination with mirdametinib combination using a modified Rolling-6 design. The established RP2D for mirdametinib (2 mg/m2 po BID up to 4 mg BID) will be used on this study. Mirdametinib will be administered on a continuous dosing schedule and de-escalated as necessary to an intermittent (3 weeks on, 1 week off) dosing schedule. Vinblastine will be escalated (or de-escalated) as necessary. Since these classes of agents do not have overlapping toxicities, the starting dose (i.e., Dose Level 0) for vinblastine is 4 mg/m2/week, which is 20% lower than the recommended single agent dose of vinblastine of 5 mg/m2/week. Dose Level 1 for vinblastine is 5 mg/m2/week and Dose Level -1 for vinblastine is 3 mg/m2/week.
Following the end of treatment, patients will be scheduled for a follow-up visit every 6 months for 36 months to evaluate PFS, TTP and OS. A total of 50 patients will be recruited as part of this clinical study.
Patients aged between 2 and 25 years old will be eligible, in order to include a maximum of patients affected by glioma. This study includes PLGG patients with neurofibromatosis type 1 (NF1) with a KIAA1549-BRAF fusion and patients with activation of the MAPK pathway with the exception of patients with a BRAFV600E mutation.
Response to treatment will be evaluated using the modified Response Assessment in Pediatric Neuro-Oncology (RAPNO), Response Assessment in Pediatric Neuro-Oncology (RANO) 1. Evaluation of quality of life will be measured using the Pediatric Quality of Life inventory (PedsQL) (Generic/Brain tumor modules).
This study will explore the genetic and epigenetic landscape of PLGG. Our biological study may include SNP array, nanoString studies, methylation array and RNAseq.
St. Justine's Hospital is the lead sponsor of 156 studies on the registry; 27 are open to participants now.
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.
Participants must have PLGG with NF1 gene mutation (based on clinical NIH criteria, germline NF1 mutation or molecular analysis of the tumor) or PLGG with KIAA1549-BRAF fusion (based on molecular analysis of the tumor) or PLGG with evidence of MAPK pathway alteration with the exception of patients with BRAF V600E mutation (based on molecular analysis of the tumor).
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.
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.
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.
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.
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.
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.
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.
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 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.
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.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
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.
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.
Patients will receive oral mirdametinib twice daily (continuous) at a fixed dose (2mg/m2 PO BID, rounded to the nearest 1mg, up to a maximum of 4 mg BID) for a total of 13 cycles. Each cycle will last 28 days.
Drug: Mirdametinib
Participants will receive orally administered mirdametinib in combination with intravenous vinblastine chemotherapy
Also known as: Vinblastine
Determine maximum tolerated dose of Mirdametinib plus Vinblastine.
The maximum tolerated/recommended phase 2 dose (MTD/RP2D) of the mirdametinib plus vinblastine combination using a modified Rolling-6 design.
Time frame: 3 years
Determine the objective response rate of mirdametinib plus vinblastine for PLGG with Mitogen-activated Protein Kinase (MAPK) pathway activation in treatment naïve patients.
The proportion of patients with complete (CR), major (MaR), partial (PR) and minor response (MiR) as the best response on study based on RAPNO criteria. Response = MiR+PR+MaR+CR
Time frame: 5 years
Efficacy outcome measures: Overall Survival.
Overall Survival (OS) is defined as the time from starting mirdametinib (C1D1) to death due to any cause, or censored at date last known alive. OS will be evaluated from starting mirdametinib up to the end of the 3-year follow-up. Estimated using Kaplan-Meier methods.
Time frame: Up to 3 years following completion of treatment.
Efficacy outcome measures: Progression-Free Survival.
Progression-Free Survival (PFS): the time from starting mirdametinib (C1D1) to the date of first observation of radiological progression or death due to any cause. Participants alive without disease progression or death are censored at date of last disease evaluation. Estimated using Kaplan-Meier methods.
Time frame: Up to 3 years following completion of treatment.
Efficacy outcome measures: Time to Progression.
Time to Progression (TTP) is defined as the time from starting mirdametinib (C1D1) to radiological progression, or censored at date of last disease evaluation for those without progression reported. Estimated using Kaplan-Meier methods.
Time frame: Up to 3 years following completion of treatment.
Efficacy outcome measures: Objective Response Rate.
Objective response rate (ORR) is defined as the percentage of patients experiencing their best response on study as CR or PR or MR or SD.
Time frame: Up to 3 years following completion of treatment.
Determine the safety and tolerability of the combination of mirdametinib plus vinblastine.
Adverse events (AE) and severe adverse events (SAE).
Time frame: 5 years
Determine neurological changes in patients during active treatment and after completion of therapy.
Changes in neurological status will be evaluated. Standardized global assessment including motor function will be evaluated by local investigators at baseline, every six months during treatment phase and after completion of treatment. This evaluation will include assessment of weakness, coordination, and balance.
Time frame: 5 years
Evaluate the quality of life during treatment.
Evaluations of quality of daily life at inclusion and every six months PedsQL (Generic/Brain tumor modules).
Time frame: 5 years
Evaluate the response rate based on the tumor volume.
Accurate quantification of tumor volumes using a semi-automated volumetric method.
Time frame: 5 years
To investigate and correlate biological features to tumor response.
Exploratory biology studies may include, but are not limited to: tumor molecular profiling, gene expression, methylation profiling and DNA sequencing to explore possible associations between candidate molecular predictors and clinical outcome. Descriptive statistics may be used to visualize biological feature results and compare to measures of efficacy.
Time frame: 5 years
Plan to share: Yes — Data will be share with researchers upon request following publication of data analysis of trial via scientific articles.
Supporting information: Clinical study report
Time frame: 2030-2040
Access criteria: Upon request to the sponsor and study chair
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 drug tested here: Mirdametinib