MRM-3379 for Fragile X Syndrome

Recruiting at 3 trial locations

Age: < 65

Sex: Male

Trial Phase: Phase 2

Sponsor: Mirum Pharmaceuticals, Inc.

Disqualifiers: Other medical conditions, others

Prior Safety Data This treatment has passed at least one previous human trial

Compensation: Varies

Number of Visits: Unknown

Duration: 12 weeks

60 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests a new medicine, MRM-3379, to determine its effectiveness in alleviating symptoms of Fragile X Syndrome (FXS), a genetic condition that can cause learning and behavior challenges. The study primarily targets males aged 16 to 45, comparing three different doses against a placebo (a pill with no active medicine) to assess safety and effectiveness. Additionally, a group of younger males, aged 13 to under 16, will receive a low dose of MRM-3379 without a placebo. Men diagnosed with FXS who have a reliable caregiver are suitable candidates for this trial. As a Phase 2 trial, this research measures the treatment's effectiveness in an initial, smaller group of participants.

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

The trial information does not specify whether you need to stop taking your current medications. It's best to discuss this with the trial coordinators or your doctor.

Is there any evidence suggesting that MRM-3379 is likely to be safe for humans?

Research shows that MRM-3379 is being tested for safety and tolerance in people with Fragile X Syndrome. Previous studies have found that MRM-3379 is generally well-tolerated. Although specific side effects are not listed, ongoing trials focus on closely monitoring and managing any unwanted side effects.

This trial is in Phase 2, indicating that earlier safety tests have been completed and the treatment is considered safe enough for people with the condition. Participants should report any side effects to the study team, who are there to help manage and address them. ^{1 2 3 4 5}

Why do researchers think this study treatment might be promising for Fragile X Syndrome?

Researchers are excited about MRM-3379 for Fragile X Syndrome because it offers a potential new approach to treating this genetic condition. Unlike current treatments, which often focus on managing symptoms through behavioral therapy and medications like antipsychotics or antidepressants, MRM-3379 targets the underlying mechanisms associated with Fragile X. Specifically, MRM-3379 is designed to address the protein synthesis issues caused by the genetic mutation in Fragile X Syndrome, which could lead to more effective symptom management. Additionally, the trial explores different dosages, including an open-label low dose for younger participants, providing valuable insights into its effectiveness across age groups. This innovative approach holds promise for improving the quality of life for those affected by this condition.

What evidence suggests that MRM-3379 might be an effective treatment for Fragile X Syndrome?

Research has shown that MRM-3379, a type of medication, holds potential for treating Fragile X Syndrome (FXS), particularly in animal studies. In experiments with a specific type of mice used to study FXS, those given MRM-3379 demonstrated noticeable improvements in behavior, such as better nest-building skills, compared to those not receiving the treatment. Additionally, MRM-3379 reaches higher levels in the brain than in the blood, suggesting it could effectively target brain-related symptoms of FXS. Although no treatments for FXS are currently approved, these findings offer hope that MRM-3379 might help improve symptoms in people. ^{1 4 6 7 8}

Are You a Good Fit for This Trial?

This trial is for male participants aged 16 to 45 with Fragile X Syndrome. A separate group aged 13 to less than 16 will also be included in an open-label part of the study. Participants must commit to a 12-week treatment period.

Inclusion Criteria

I can sign the consent form myself or have someone legally authorized to do so on my behalf.

I can swallow pills.

I am a male between 13 and 45 years old.

Exclusion Criteria

I don't have any health conditions that would make this study risky for me.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive 12 weeks of treatment with MRM-3379 or placebo, with a parallel open-label cohort for younger participants

12 weeks

Follow-up

Participants are monitored for safety and effectiveness after treatment

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• MRM-3379

Trial Overview The safety and effectiveness of three different doses of MRM-3379 compared to a placebo are being tested over a period of 12 weeks. The goal is to see if MRM-3379 can improve symptoms associated with Fragile X Syndrome.

How Is the Trial Designed?

Group I: Arm 5: Low dose of MRM-3379 Open-Label Experimental Treatment 1 Intervention

Participants 13 to \< 16 years of age will receive the low dose of MRM-3370 Open-Label

Group II: Arm 3: High dose of MRM-3379 Experimental Treatment 1 Intervention

Participants 16-45 years of age randomized to this arm will receive the high dose of MRM-3379

Group III: Arm 2: Middle dose of MRM-3379 Experimental Treatment 1 Intervention

Participants 16-45 years of age randomized to this arm will receive the middle dose of MRM-3379

Group IV: Arm 1: Low Dose of MRM-3379 Experimental Treatment 1 Intervention

Participants 16-45 years of age randomized to this arm will receive the low dose of MRM-3379

Group V: Arm 4 :Placebo Placebo Group 1 Intervention

Participants 16-45 years of age randomized to this arm will receive Placebo

Who Is Running the Clinical Trial?

Mirum Pharmaceuticals, Inc.

Lead Sponsor

Trials

32

Recruited

102,000+

Citations

1. clinicaltrials.gov clinicaltrials.gov/study/NCT07209462

Study of MRM-3379 in Male Participants With Fragile X ... The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome ...

2. mirumpharma.com mirumpharma.com/wp-content/uploads/2025/09/FXS-NDD-2025-Mouse-Model-Poster_FINAL.pdf

Evaluation of MRM-3379, a PDE4D Inhibitor, in a Mouse ... Fmr1 KO2 mice treated with MRM-3379 (both doses) had higher nest quality scores compared with those treated with vehicle (both P<0.0001); ...

3. fragilexnewstoday.com fragilexnewstoday.com/news/mirum-plans-2025-phase-2-trial-testing-fragile-x-treatment/

Mirum plans 2025 Phase 2 trial testing fragile X treatment Previous studies have shown that treatment with MRM-3379 results in drug levels that are about five times higher in the brain than in the blood, ...

4. theglobeandmail.com theglobeandmail.com/investing/markets/stocks/MIRM/pressreleases/35745205/mirum-pharmaceuticals-advances-in-fragile-x-syndrome-treatment-study/

Mirum Pharmaceuticals Advances in Fragile X Syndrome ... ' The study aims to evaluate the safety and tolerability of MRM-3379 in males aged 16 to 45 with Fragile X Syndrome (FXS), with a parallel ...

5. trial.medpath.com trial.medpath.com/news/75a4df3a21dbf5f0/mirum-plans-2025-phase-2-trial-testing-fragile-x-treatment

Mirum Pharmaceuticals to Launch Phase 2 Trial of MRM-3379 ... Fragile X syndrome affects approximately 50,000 males in the U.S. and EU, and currently has no approved treatments.

6. ctv.veeva.com ctv.veeva.com/study/phase-2-study-of-mrm-3379-in-male-participants-with-fragile-x-syndrome

Study of MRM-3379 in Male Participants With Fragile X ... This study is a multicenter, double-blind, randomized, placebo-controlled study to assess the safety and tolerability of 3 doses of MRM-3379 ...

7. mirumpharma.com mirumpharma.com/our-science/pipeline/

Our Discoveries - Mirum Pharma Fragile X Syndrome (FXS) Phase 2 Study — Enrolling. Evaluating the safety and tolerability of MRM-3379 in male patients with Fragile X syndrome. View full ...

8. withpower.com withpower.com/trial/phase-2-fragile-x-syndrome-11-2025-5b2b9

MRM-3379 for Fragile X Syndrome This study is a multicenter, double-blind, randomized, placebo-controlled study to assess the safety and tolerability of 3 doses of MRM-3379 in male ...