A Phase 1/2 interventional study of MT-125 in Glioblastoma, sponsored by Myosin Therapeutics Inc.. Not yet recruiting at 3 sites in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-05-22.
Sponsored by Myosin Therapeutics Inc. · Phase 1/2, Interventional, and Treatment
This is a Phase 1, single-arm MT-125 dose escalation study followed by a Phase 2, randomized parallel design dose expansion phase, to determine the safety and tolerability of MT-125 administered 5 consecutive days a week with 2 days off for the 6 weeks of outpatient treatment of Radiotherapy (RT) plus TMZ. Participants with newly diagnosed histologically or molecularly confirmed IDH wild type and MGMT methylated GBM will be eligible to enroll. The dose-limiting toxicity (DLT) observation window will be 6 weeks, starting with the first dose of MT-125 administration and chemoradiation. A Bayesian Optimal Interval (BOIN) adaptive trial design will be used to efficiently evaluate up to four dose levels. Secondary endpoints for this Phase 1/2 study will include determination of the MTD, the systemic PK of MT-125, and the RP2D of MT-125. Once the MTD is defined, additional participants will be enrolled as part of an expansion cohort, with a randomized parallel design, which will include up to 2 dose levels which are expected to be MTD and one dose below the MTD. Up to 36 participants will be enrolled in the study (up to 24 participants in the dose escalation phase and up to a total of 12 participants maximum per dose level for the two expansion cohorts).
MT-125 is a potent, selective, and central nervous system (CNS) permeable dual small molecule inhibitor of the non-muscle myosin II (NMII) paralogs, IIA and IIB. MT-125 is being developed by Myosin Therapeutics Inc. as a potential treatment for glioblastoma (GBM). NMIIs are molecular motor ATPases that act directly on actin to regulate the cytoskeleton's control of cellular processes such as movement, division, signaling and mitochondrial biology. As a result, simultaneous inhibition of NMIIA and IIB with MT-125 interferes with tumor cell proliferation, invasion and metastasis, while also generating reactive oxygen species (ROS) in tumor cells. The latter is due to the role of NMII in mitochondrial quality control and underlies the synergistic survival benefit observed in preclinical studies when MT-125 and radiation therapy (RT) are combined. Additionally, NMIIA is upregulated in several types of cancer, including GBM, speaking to its importance in cancer physiology and making these tumor cells highly sensitive to its inhibition. The focus of this clinical study is GBM.
Patients with GBM have a poor prognosis, and there have been no new Food and Drug Administration (FDA) approved drugs for these patients since 2008, when bevacizumab was approved. The current well-known standard of care for newly diagnosed GBM is maximal safe surgical resection followed by concurrent RT with temozolomide (TMZ). O6-methylguanine- DNA methyltransferase (MGMT) promoter methylation status is the most predictive biomarker for TMZ responsiveness, where patients with unmethylated MGMT do not respond to TMZ.
MT-125 significantly prolongs survival as a monotherapy in animal models and is synergistic with both RT and with FDA-approved oncogenic kinase inhibitors to further enhance survival. The Sponsor is currently evaluating MT-125 as a monotherapy in a first-in-human (FIH) trial (STAR-GBM) with standard of care RT in newly diagnosed isocitrate dehydrogenase (IDH) wildtype / MGMT unmethylated GBM. Due to the poor response of MGMT unmethylated tumors to TMZ, the chemotherapeutic is excluded in the STAR-GBM trial. Here we will evaluate MT-125 as a monotherapy in a Phase 1/2 trial (NOVA-GBM) in newly diagnosed IDH wildtype / MGMT methylated GBM with standard of care RT and TMZ, following the standard chemoradiation treatment regimen.
In the pivotal 28-day nonclinical safety studies of MT-125, no dose-limiting toxicities (DLT) or adverse effects (AE) were noted in any of the parameters evaluated (clinical observations, functional endpoints, clinical pathology, macroscopic and histologic tissue assessments) at doses up to the NOAELs, 20 mg/kg/day and 30 mg/kg/day in dogs and rats, respectively, which yielded systemic MT-125 exposures 10- to 16-fold greater than efficacious exposures in pharmacodynamic in vivo models. As the NOAELs in both studies were below the STD10 (rats) and HNSTD (dogs), the calculated safety margins are conservative.
The goal of this Phase 1/2, MT-125 dose escalation and expansion study is to evaluate the safety and tolerability of MT-125 administered 5 consecutive days per week with 2 days off for the 6 weeks of outpatient RT plus TMZ. Participants with newly diagnosed GBM with histologically or molecularly confirmed IDH wildtype and MGMT methylation will be eligible to enroll. The DLT observation window will be 6 weeks following first treatment administration, and a Bayesian Optimal Interval (BOIN) trial design will be used to efficiently evaluate up to four dose levels. Secondary endpoints for this Phase 1/2 study will include determining the maximum tolerated dose (MTD), which will contribute to the selection of the recommended phase 2 dose (RP2D) and evaluating the systemic pharmacokinetics (PK) of MT-125.
Once the MTD is determined, additional participants will be enrolled into a randomized, parallel dose expansion cohort, consisting of up to 2 potential doses of MT-125. The dose levels for the expansion cohort will be selected as the MTD and the dose below the MTD. Overall response rate (ORR) in those participants with measurable disease, progression-free survival (PFS6) in all participants, and Overall Survival (OS) in all participants are included as exploratory endpoints
If no MTD is identified within the initially defined dose range and all tested doses are deemed well-tolerated based on the observed DLTs, the study may be paused temporarily to allow consideration of dose levels beyond those originally planned.
1,920 studies on the registry are indexed under Glioblastoma; 450 are open to participants now.
This study's planned enrollment of 36 is close to the median of 36 across 1,618 interventional studies indexed under Glioblastoma.
Browse Glioblastoma studies →Myosin Therapeutics Inc. is the lead sponsor of 2 studies on the registry; 2 are open to participants now.
Counted across the registry records on this site, refreshed daily.
The following laboratory values obtained ≤15 days prior to registration:
Negative serum pregnancy test done ≤7 days prior to first dose of MT-125 administration, for persons of childbearing potential only.
a. If >7 days between last test and first dose of study treatment, the serum pregnancy test will be repeated.
Exclusion Criteria:
Any of the following because this study involves an investigational agent, the genotoxic, mutagenic, and teratogenic effects of which on the developing fetus and newborn are unknown:
Up to 6 participants will receive 25 mg of MT-125 for 5 days then off for 2 days for a total of 6 weeks in combination of RT plus TMZ
Drug: MT-125
Up to 6 participants will receive 50 mg of MT-125 for 5 days then off for 2 days for a total of 6 weeks in combination of RT plus TMZ
Drug: MT-125
Up to 6 participants will receive 83.5 mg of MT-125 for 5 days then off for 2 days for a total of 6 weeks in combination of RT plus TMZ
Drug: MT-125
Up to 6 participants will receive 100 mg of MT-125 for 5 days then off for 2 days for a total of 6 weeks in combination of RT plus TMZ
Drug: MT-125
Participants will be randomized to receive either MTD or one dose lower than MTD for 5 days, then off 2 days for a total of 6 weeks in combination with RT plus TMZ
Drug: MT-125
This is an investigational new drug under IND 170975.
Dose Limiting Toxicity Measurement
The dose escalation portion of this study will follow a BOIN design with cohorts containing a min of 3 DLT evaluable participants. If the observed DLT rate at the current dose is ≤0.236, then the decision will be to escalate the dose to the next higher dose level; if the observed DLT rate at the current dose is \>0.359, then the decision will be to deescalate the dose to the next lower dose level; otherwise, the decision will be to stay at the current dose level.
Time frame: Day 1 through 6 weeks of treatment
Incidence and Severity of AEs
Incidence and Severity, attribution, grade and type of AE will be assessed based on the NCI CTCAE v5.
Time frame: Day 1 through 6 weeks of treatment
Maximum Tolerated Dose
To determine the maximum tolerated dose (MTD) of MT-125
Time frame: Day 1 through Day 40
PK Parameters- Cmax
The time it takes for a drug to reach a maximum concentration after administration.
Time frame: Completed on study days; Day 1, Day 2, Day 5, Day 19, Day 33 and Day 40
PK Parameters-AUC 0-24hr
Area under the plasma concentration-time curve over the last 24 hour dosing interval.
Time frame: Completed on study days; Day 1, Day 2, Day 5, Day 19, Day 33 and Day 40
PK Parameters - T1/2
Time required for plasma concentrations of a drug to decrease by 50%
Time frame: Completed on study days; Day 1, Day 2, Day 5, Day 19, Day 33 and Day 40
PK Parameters - CL
CL will quantify the body's efficiency in eliminating MT-125
Time frame: Completed on study days; Day 1, Day 2, Day 5, Day 19, Day 33 and Day 40
PK Parameters - Vss
The steady state volume of distribution that describes how MT-125 distributes throughout the body once it has reached a state of equilibrium.
Time frame: Completed on study days; Day 1, Day 2, Day 5, Day 19, Day 33 and Day 40
Determine the phase 2 dose
To determine the Recommended Phase 2 Dose (RP2D) of MT-125
Time frame: Day 1 through 6 weeks of treatment
To obtain preliminary data on clinical efficacy measurements such as ORR
Overall Response Rate in those with Measurable disease
Time frame: Day 1 though on average one year following completion of treatment
Exploratory Analysis to obtain preliminary data on clinical efficacy
6 month Progression Free survival (PFS6) based on MRI imaging
Time frame: Up to 1 year following completion of treatment
To obtain preliminary data on clinical efficacy
Overall Survival (OS)
Time frame: Day 1 though on average one year following completion of treatment.
Plan to share: No
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Myosin Therapeutics Inc.