title: STX209 (arbaclofen) for autism spectrum disorders: an 8-week open-label study.
abstract: 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. The most common adverse events were agitation and irritability, which typically resolved without dose changes, and were often felt to represent spontaneous variation in underlying symptoms. Improvements were observed on several outcome measures in this exploratory trial, including the ABC-Irritability (the primary endpoint) and the Lethargy/Social Withdrawal subscales, the Social Responsiveness Scale, the CY-BOCS-PDD, and clinical global impression scales. Placebo-controlled study of STX209 is warranted.
authors.affiliation: Division of Child and Adolescent Psychiatry, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
authors.forename: Craig A
authors.initials: CA
authors.lastname: Erickson
authors.forename: Jeremy M
authors.initials: JM
authors.lastname: Veenstra-Vanderweele
authors.forename: Raun D
authors.initials: RD
authors.lastname: Melmed
authors.forename: James T
authors.initials: JT
authors.lastname: McCracken
authors.forename: Lawrence D
authors.initials: LD
authors.lastname: Ginsberg
authors.forename: Linmarie
authors.initials: L
authors.lastname: Sikich
authors.forename: Lawrence
authors.initials: L
authors.lastname: Scahill
authors.forename: Maryann
authors.initials: M
authors.lastname: Cherubini
authors.forename: Peter
authors.initials: P
authors.lastname: Zarevics
authors.forename: Karen
authors.initials: K
authors.lastname: Walton-Bowen
authors.forename: Randall L
authors.initials: RL
authors.lastname: Carpenter
authors.forename: Mark F
authors.initials: MF
authors.lastname: Bear
authors.forename: Paul P
authors.initials: PP
authors.lastname: Wang
authors.forename: Bryan H
authors.initials: BH
authors.lastname: King
mesh_terms: D000293:Adolescent; D017109:Akathisia, Drug-Induced / Q000175:diagnosis; D001418:Baclofen / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use; D002648:Child; D002659:Child Development Disorders, Pervasive / Q000188:drug therapy*; D005260:Female; D058786:GABA-B Receptor Agonists / Q000009:adverse effects / Q000627:therapeutic use*; D006801:Humans; D007508:Irritable Mood / Q000187:drug effects; D008297:Male; D016896:Treatment Outcome
chemical_list: D058786:GABA-B Receptor Agonists; D001418:Baclofen; C543531:arbaclofen placarbil