MT-125 for Glioblastoma

(STAR-GBM Trial)

Not yet recruiting at 2 trial locations

Age: 18+

Sex: Any

Trial Phase: Phase 1

Sponsor: Myosin Therapeutics Inc.

Must be taking: Steroids

Must not be taking: Investigational agents

Disqualifiers: Pregnancy, Nursing, Severe disease, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: Unknown

Duration: 6 weeks

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests a new treatment, MT-125, for individuals recently diagnosed with glioblastoma, a type of brain tumor. The goal is to identify the safest dose of MT-125 when combined with standard radiation therapy and to assess its effectiveness in enhancing treatment. Participants will receive varying doses of MT-125 to determine the highest dose they can safely tolerate. The trial seeks individuals with glioblastoma who have not experienced certain genetic changes that affect treatment. Participants should maintain a stable daily routine on their current medication for at least two weeks before joining the trial. As a Phase 1 trial, this research aims to understand how MT-125 works in people, offering participants the opportunity to be among the first to receive this new treatment.

Do I need to stop my current medications to join the trial?

The trial information does not specify if you need to stop taking your current medications. However, you must be on a stable dose of steroids for at least 2 weeks before joining. It's best to discuss your specific medications with the Study Doctor.

Is there any evidence suggesting that MT-125 is likely to be safe for humans?

Research has shown that MT-125 has potential based on early animal studies. It was safe for mice, successfully reaching the brain and stopping the growth of glioblastoma, a type of brain cancer. These studies found that MT-125 did not cause serious side effects in animals.

Currently, MT-125 is being tested in humans for the first time, so limited information exists about its safety in people. The main goal of the current research is to determine the best dose that people can take without problems. While the treatment is designed to be safe, its effects on humans are still under investigation. Participants in this trial are helping researchers learn how well it can be tolerated when used with standard radiotherapy. ^{1 2 3 4 5}

Why do researchers think this study treatment might be promising for glioblastoma?

Researchers are excited about MT-125 for glioblastoma because it introduces a novel approach compared to the standard treatments like temozolomide and radiation therapy. Unlike these existing options, MT-125 is designed to be administered in varying doses alongside radiation, potentially enhancing the therapy's effectiveness without increasing toxicity. Its unique feature is the ability to tailor doses from 25 mg to 100 mg, including the maximum tolerated dose (MTD), which may improve treatment outcomes by finding the optimal balance between efficacy and safety. This adaptability could potentially offer a more personalized treatment strategy for patients with glioblastoma.

What evidence suggests that MT-125 might be an effective treatment for glioblastoma?

Research has shown that MT-125 could be promising for treating glioblastoma, a type of brain cancer. Studies in mice found that MT-125 can extend their lifespan by inhibiting certain proteins in cancer cells and increasing stress on these cells, leading to their death. MT-125 also helps prevent the cancer from growing and spreading. These findings suggest that MT-125 might enhance the effectiveness of radiotherapy in humans. However, this treatment remains new, and its effectiveness in people is not yet confirmed. Participants in this trial will receive different dosages of MT-125 combined with radiation therapy to evaluate its potential benefits. ^{1 3 5 6 7}

Are You a Good Fit for This Trial?

This trial is for adults with a new diagnosis of glioblastoma, which is an aggressive type of brain tumor. Participants must have specific genetic features in their tumors (IDH wild-type, MGMT-unmethylated) and be able to undergo standard radiotherapy. People who don't meet the genetic criteria or can't complete necessary tests won't qualify.

Inclusion Criteria

Negative serum pregnancy test done ≤7 days prior to first dose of MT-125 administration, for persons of childbearing potential only

Has provided written informed consent

Willing to return to enrolling institution for follow-up (during the Active Monitoring Phase of the study)

Exclusion Criteria

Nursing persons

Co-morbid systemic illnesses or other severe concurrent disease

Receiving any other investigational agent

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive MT-125 in combination with radiation therapy for 6 weeks, with 5 consecutive days of treatment followed by 2 days off each week.

6 weeks

Weekly visits for treatment administration

Dose Escalation

Evaluation of safety and tolerability of MT-125 with dose escalation to determine the maximum tolerated dose (MTD).

6 weeks

Follow-up

Participants are monitored for safety and effectiveness after treatment, including assessment of adverse events and pharmacokinetics.

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• MT-125

Trial Overview The study is testing MT-125, a new treatment given alongside standard radiotherapy for glioblastoma. The goal is to find the highest dose patients can tolerate without severe side effects by starting with lower doses and increasing gradually among different groups.

How Is the Trial Designed?

Group I: MT-125 at MTD and one dose lower than MTD Experimental Treatment 1 Intervention

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 radiation therapy.

Group II: MT-125 at 83.5mg Experimental Treatment 1 Intervention

Up to 6 participants will receive 83.5 mg of MT-125 for 5 days, then off 2 days for a total of 6 weeks in combination with radiation therapy.

Group III: MT-125 at 50 mg Experimental Treatment 1 Intervention

Up to 6 participants will receive 50 mg of MT-125 for 5 days, then off 2 days for a total of 6 weeks in combination with radiation therapy.

Group IV: MT-125 at 25 mg Experimental Treatment 1 Intervention

Up to 6 participants will receive 25 mg of MT-125 for 5 days, then off 2 days for a total of 6 weeks in combination with radiation therapy.

Group V: MT-125 at 100 mg Experimental Treatment 1 Intervention

Up to 6 participants will receive 100 mg of MT-125 for 5 days, then off 2 days for a total of 6 weeks in combination with radiation therapy.

Who Is Running the Clinical Trial?

Myosin Therapeutics Inc.

Lead Sponsor

Mayo Clinic

Collaborator

Trials

3,427

Recruited

3,221,000+

Citations

1. cell.com cell.com/cell/fulltext/S0092-8674(25)00569-0

MT-125 inhibits non-muscle myosin IIA and IIB and ... MT-125 increases ROS, induces ferroptosis, and prolongs survival in murine GBM. •. MT-125 stimulates oncogenic kinase signaling through a ROS-driven mechanism.

2. clinicaltrials.gov clinicaltrials.gov/study/NCT07185880

A Phase 1 Study of the Safety and Tolerability of MT-125 in ... MT-125 inhibits non-muscle myosin IIA and IIB and prolongs survival in glioblastoma. Cell. 2025 Aug 21;188(17):4622-4639.e19. doi: 10.1016/j.cell.2025.05 ...

3. cancernetwork.com cancernetwork.com/view/fda-grants-fast-track-designation-to-mt-125-in-glioblastoma

FDA Grants Fast Track Designation to MT-125 in ... The evaluation of MT-125's safety and preliminary activity in glioblastoma is underway in a phase 1/2 trial.

4. reporter.nih.gov reporter.nih.gov/project-details/10697940

MT-125 for the Therapeutic Treatment of Glioblastoma Preclinical in vitro and in vivo studies show that MT-125 blocks the Go and Grow phenotypes and extends survival.

5. sciencedirect.com sciencedirect.com/science/article/abs/pii/S3050562325001515

MT-125: A glimpse of hope for glioblastoma patients MT-125 with its remarkable brain retention and in vivo tolerance impedes GBM invasion and extends the lifespan of murine GBM models through ...

6. sciencedirect.com sciencedirect.com/science/article/pii/S0092867425005690

MT-125 inhibits non-muscle myosin IIA and IIB ... MT-125 has high brain penetrance and an excellent safety profile, blocks GBM invasion and cytokinesis, and prolongs survival in murine GBM ...

7. cell.com cell.com/cell-biomaterials/fulltext/S3050-5623(25)00151-5

MT-125: A glimpse of hope for glioblastoma patients MT-125 with its remarkable brain retention and in vivo tolerance impedes GBM invasion and extends the lifespan of murine GBM models through ...