Parent-Reported Outcome Measures for Individuals with Fragile X Syndrome: Clinically Meaningful Change Thresholds.

Estimating meaningful change thresholds (MCT) on clinical outcome assessments is an important consideration when evaluating treatments. In fragile X syndrome (FXS) research, there has been no consensus on how to define MCT's on several commonly used outcome measures. The purpose of the current study was to determine clinically relevant MCT's of caregiver-rated assessments using data from a phase 3 clinical trials of arbaclofen (Berry-Kravis et al.

Adaptive behavior in autism: Minimal clinically important differences on the Vineland-II.

Unlabelled: Autism Spectrum Disorder (ASD) is associated with persistent impairments in adaptive abilities across multiple domains. These social, personal, and communicative impairments become increasingly pronounced with development, and are present regardless of IQ. The Vineland Adaptive Behavior Scales, Second Edition (Vineland-II) is the most commonly used instrument for quantifying these impairments, but minimal clinically important differences (MCIDs) on Vineland-II scores have not been rigorously established in ASD.

Arbaclofen in fragile X syndrome: results of phase 3 trials.

Background: Arbaclofen improved multiple abnormal phenotypes in animal models of fragile X syndrome (FXS) and showed promising results in a phase 2 clinical study. The objective of the study is to determine safety and efficacy of arbaclofen for social avoidance in FXS.

Methods: Two phase 3 placebo-controlled trials were conducted, a flexible dose trial in subjects age 12-50 (209FX301, adolescent/adult study) and a fixed dose trial in subjects age 5-11 (209FX302, child study).

Arbaclofen in Children and Adolescents with Autism Spectrum Disorder: A Randomized, Controlled, Phase 2 Trial.

Several lines of emerging data point to an imbalance between neuronal excitation and inhibition in at least a subgroup of individuals with autism spectrum disorder (ASD), including in those with fragile X syndrome (FXS), one of the most common genetic syndromes within ASD. In animal models of FXS and of ASD, GABA-B agonists have improved both brain and behavioral phenotypes, including social behavior. A phase 2 randomized, placebo-controlled, crossover trial found that the GABA-B agonist arbaclofen improved social avoidance symptoms in FXS.

STX209 (arbaclofen) for autism spectrum disorders: an 8-week open-label study.

STX209 (arbaclofen), a selective GABA-B agonist, is hypothesized to modulate the balance of excitatory to inhibitory neurotransmission, and has shown preliminary evidence of benefit in fragile X syndrome. We evaluated its safety, tolerability, and efficacy in non-syndromic autism spectrum disorders, in an 8-week open-label trial enrolling 32 children and adolescents with either Autistic Disorder or Pervasive Developmental Disorder-Not Otherwise Specified, and a score ≥17 on the Aberrant Behavior Checklist (ABC)-Irritability subscale. STX209 was generally well-tolerated.