NCT07209462 · Mirum Pharmaceuticals, Inc.
Study of MRM-3379 in Male Participants With Fragile X Syndrome (BLOOM)
What this study is about
This study is a conducted at multiple hospitals, where neither patients nor doctors know which treatment is given, randomly assigned, compared against an inactive treatment study to assess the safety and how well patients handle the treatment of 3 doses of MRM-3379 in male participants with Fragile X Syndrome ages 16 to 45 (inclusive).
View original scientific description
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 participants with Fragile X Syndrome ages 16 to 45 (inclusive). In addition, a parallel cohort of participants ages 13 to \<16 will receive open-label MRM-3379. All participants will participate for 12 weeks of treatment.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Willing and able to provide signed informed consent/assent. Where local regulations permit inclusion of participants deemed unable to provide informed consent, a legally authorized representative must provide informed consent on the participant's behalf, and the participant must provide assent if applicable.
- Male, 13-45 years of age (inclusive)
- Weight ≥30 kg and BMI between 18 and 36 kg/m2 (inclusive) at the screening visit
- Diagnosis of FXS with a molecular genetic ≥200 CGG repetitions .
- Able to perform the PVT and ORRT of the NIH-TCB
- Have a consistent caregiver(s) who is willing and able to be present regularly and reliably with the participant
- Able to swallow tablets or capsules
Exclusion criteria
- History of or current medical condition other than FXS and related issues that would place the participant at higher risk from study participation
Where
- Phoenix, Arizona
- Irvine, California
- Orange, California
- Sacramento, California
- Aurora, Colorado
- Miami, Florida
- Atlanta, Georgia
- Chicago, Illinois
- Baltimore, Maryland
- Boston, Massachusetts
- Worcester, Massachusetts
- Minneapolis, Minnesota
And 3 more locations — see the full list below.
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jun 15, 2026 · Source of record for eligibility and locations