Study of MRM-3379 in Male Participants With Fragile X Syndrome (BLOOM)

Inclusion Criteria:

• Willing and able to provide signed informed consent/assent. Where local regulationspermit inclusion of participants deemed unable to provide informed consent, alegally authorized representative must provide informed consent on the participant'sbehalf, 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 andreliably 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