To Study the Efficacy & Safety of Oral NA-921 (Bionetide) in Girls and Women with Rett Syndrome

A Randomized, Double-Blind, Placebo-Controlled, Phase 2/3 Study of NA-921 (Bionetide) for the Treatment of Girls and Women with Rett Syndrome Primary Objective • To investigate the efficacy and safety of treatment with oral NA-921 (Bionetide) versus placebo in girls and women with Rett syndrome Key Secondary Objective • To investigate the efficacy of treatment with oral NA-921 (Bionetide) versus placebo on ability to communicate in girls and women with Rett syndrome Co-Primary Endpoints * Rett Syndrome Behavior Questionnaire (RSBQ) total score - Change from Baseline to Week 12 * Clinical Global Impression-Improvement (CGI-I) Score at Week 12 Key Secondary Endpoint Change from Baseline to Week 12 in: • Communication and Symbolic Behavior Scales Developmental Profile™ Infant-Toddler Checklist- Social Composite Score (CSBS-DP-IT Social)