A Phase 2, Randomized, Double-Blind, Placebo-Controlled Study to Evaluate the Safety and Tolerability of MRM-3379 in Male Participants with Fragile X Syndrome

The primary objective of this study is to evaluate the safety and tolerability of MRM-3379 in male participants with Fragile X Syndrome. Assessment is based on the incidence and severity of treatment-emergent adverse events and the frequency of withdrawal due to adverse events.

The secondary objectives include:

• Evaluation of preliminary efficacy through changes from baseline in the NIH-TCB Crystallized Cognition: Composite score, comprising the Picture Vocabulary Test and the Oral Reading Recognition Test, as well as the Clinician Global Impression-Change score.
• Characterization of pharmacokinetic properties by measuring steady-state plasma concentrations of MRM-3379 and its metabolites.

This clinical trial involves 54 male participants diagnosed with Fragile X Syndrome. The study population consists of individuals aged 13 to 45 years. Inclusion requires a molecular genetic diagnosis characterized by CGG repetitions of 200 or more. Eligible participants must have a body mass index between 18 and 36 kg/m² and a weight of at least 30 kg. Additionally, subjects must demonstrate the ability to swallow oral dosage forms and have a consistent caregiver available for regular attendance. The study population is classified as a vulnerable population.

This Phase 2 randomized, double-blind, placebo-controlled study is designed to evaluate the safety and tolerability of MRM-3379 in male participants diagnosed with Fragile X Syndrome. The primary objectives include assessing the incidence and severity of treatment-emergent adverse events and the frequency of withdrawal due to adverse events. Secondary endpoints involve evaluating preliminary efficacy via the NIH-TCB Crystallized Cognition Composite and the Clinician Global Impression-Change score, as well as characterizing pharmacokinetic properties through steady-state plasma concentrations. The investigation utilizes an oral administration route of hard capsules. Participants must meet specific inclusion criteria, including a male sex, an age range of 13 to 45 years, a body mass index between 18 and 36 kg/m2, and a molecular genetic diagnosis of the condition with ≥200 CGG repetitions.

The experimental treatment consists of MRM-3379, which is administered in a hard capsule pharmaceutical form. The route of administration is oral use.

The control group receives a placebo corresponding to MRM-3379.

The assessment of preliminary efficacy in male participants with Fragile X syndrome involves several secondary endpoints. The key secondary endpoint is the change from baseline on the NIH-TCB Crystallized Cognition Composite (CCC), which is composed of change-sensitive scores from the Picture Vocabulary Test (PVT) and the Oral Reading Recognition Test (ORRT).

Additional efficacy evaluations include the Clinician Global Impression-Change (CGI-C) score. Furthermore, the pharmacokinetic properties of MRM-3379 are characterized by measuring steady-state plasma concentrations of MRM-3379 and its metabolite.