A Study of RO5186582 in Down Syndrome Among Children 6 to 11 Years of Age

A Randomized, Double-Blind, Placebo-Controlled, Parallel Group 26-Week Dose-Investigating Study to Explore the Pharmacokinetics, Pharmacodynamic Effects, Efficacy, Safety and Tolerability of RO5186582 in Children With Down Syndrome Aged 6-11 Years

This study will evaluate the safety, tolerability, efficacy, and pharmacokinetic and pharmacodynamic activity of 3 different dosages of RO5186582 compared with placebo. A total of approximately 46 participants will be enrolled, in order to have at least 32 evaluable, and will be randomly assigned to 1 of 4 treatments in a 1:1:1:1 ratio, with 9 children per treatment arm. The target ratio between 6-8 years and 9-11 years age groups is approximately 1:1 in each treatment arm, with a minimum of 3 children per age group in each treatment arm.

Inclusion Criteria:

• Diagnosis of Down syndrome, except for mosaic Down syndrome
• Available parent or caregiver to attend clinic visits and provide information about the participant's behavior and symptoms

Exclusion Criteria:

• Any primary psychiatric comorbid disorder
• History of infantile spasms, West syndrome, Lennox-Gastaut syndrome, early infantile epileptic encephalopathy, treatment-refractory epilepsy with cognitive/developmental regression, severe head trauma, or central nervous system (CNS) infection
• Seizure event of any type within 12 months prior to Screening or relevant changes in anti-epileptic drugs 6 weeks prior to enrollment
• Significant sleep disruption
• Significant gastrointestinal, renal, hepatic, endocrine, or cardiovascular disease
• New-onset or ongoing hematologic/oncologic disorder
• Severe lactose intolerance
• Participation in another clinical study within 1 month or 6 half-lives prior to first dose, or any extent of participation in Study BP29589 (NCT02451657)