This study is designed to assess oral ketamine for the treatment of Rett Syndrome and consists of up to 4 ascending dose cohorts, each assessing 1 dose level of ketamine vs placebo. Patients will receive in either order, a 5-day BID regimen of both placebo and the cohort-specified dose level of oral ketamine. Patients may only participate in 1 cohort. Safety and tolerability will be assessed via patient disposition, vital signs, physical examination, adverse events and concomitant medication use. Efficacy will be assessed via physician and caregiver questionnaires and assessments, and continuous, wearable, at-home biosensor data collection. An independent safety committee will review safety data from each cohort to determine if the subsequent ascending dose cohort is warranted. A total of 12 patients per cohort is anticipated at approximately 7 sites. The screening period will last between 2 and 4 weeks, the cross-over treatment period will last 4 weeks, and the safety follow-up period will last 2 weeks. Total patient participation is approximately 8-10 weeks.
