Seaside 209AS208

Study Name: Seaside 209AS208 - A Randomized, Double-Blind, Placebo-Controlled Study of the Efficacy, Safety, and Tolerability of STX209 (Arbaclofen) Administered for the Treatment of Social Withdrawal in Subjects with Autism Spectrum Disorders

IRB # 11-0925

PI: Linmarie Sikich, MD

Sponsor: Seaside Therapeutics

Contact person: Lindsey Hazzard

Phone: 1-800-708-0048



Brief Description

Purpose:  To explore the efficacy, safety and tolerability of STX209 (arbaclofen) administered for the treatment of social withdrawal in subjects with autism spectrum disorders (ASD)

Participants:  This study aims to randomize up to 150 male and female subjects 5 - 21 years of age
(inclusive) with autism spectrum disorders to receive either STX209 or placebo in the Treatment Period
within 2 age brackets: 5 – 11 and 12 – 21. Up to 30 study sites in North America will be participating in
this study.  This site will consent up to 16 subjects for screening in order to randomize up to 12 subjects total.

Procedures (methods):  All subjects will receive 12 weeks of treatment with STX209 or placebo in a double-blind, placebo-controlled, parallel group study design.  There will be 4 study periods: Screening (up to 14 days in length), the Treatment Period (12 weeks, including 28 days of up-titration followed by stable dosing), the Withdrawal Period (up to 28 days), and Follow-up Period (up to 31 days).  Subjects who complete the entire study may be eligible to enroll in a subsequent open-label study.  

Subject Payment

Subjects will be compensated $50 for each study visit [Screening, Visit 1 (Day 1), Visit 2 (Day 15), Visit 3 (Day 29), Visit 4 (Day 57), Visit 5 (Day 85), and Visit 6 (Day 113)] for a total payment of up to $350. This amount is intended to cover costs of the entire family’s time spent in the study and travel to the study site.  Parking vouchers may be provided for subjects who park in the UNC parking garage.  Payments will typically be made in individual checks for each visit or may be made in cash in cases where checks are not immediately available.  UNC-Dept of Psychiatry business office typically requires 2-3 weeks for checks to be cut.   Subjects will not be given additional compensation for visits that subjects opt to split multiple visits. There will be no additional compensation for time spent on phone calls.  

Inclusion Criteria

Subjects are eligible for the study if they fulfill all the inclusion criteria specified below:
1.    Male or female subjects 5 to 21 years of age, inclusive.
2.    Diagnosis of an Autism Spectrum Disorder according to the DSM-IV-TR criteria, including Autism, Pervasive Developmental Disorder – Not Otherwise Specified (PDD-NOS), and Asperger’s Syndrome, but excluding Childhood Disintegrative Disorder and Rett’s Disorder.
3.    CGI-S rating for aberrant behavior of moderate or higher at Screening and at Visit 1 (Day 1).
4.    An ABC-C Lethargy/Social Withdrawal Subscale score ≥8 at Screening and at Visit 1 (Day 1).
5.    Current pharmacological treatment regimen has been stable for at least 4 weeks prior to Screening.
6.    Subjects with a history of seizure disorder must currently be receiving treatment with antiepileptics and must have been seizure free for 6 months prior to Screening, or must be seizure free for 3 years prior to Screening if not currently receiving antiepileptics.  If currently receiving treatment with antiepileptics that are typically monitored by serum concentration (e.g., valproic acid, carbamazepine, or phenytoin), serum concentrations of the antiepileptic drugs must be tested and confirmed to be within the therapeutic range at Screening.
7.    If the subject is already receiving stable non-pharmacologic educational, behavioral, and/or dietary interventions, participation in these programs must have been continuous during the 2 months prior to screening and subjects or their parent/caregiver/LAR may not electively initiate new or modify ongoing interventions for the duration of the study.  Typical school vacations are not considered modifications of stable programming.
8.    Prior to the conduct of any study-specific procedures, the subject must provide verbal assent to participate in the study (if developmentally appropriate), and the parent/caregiver/LAR must provide written informed consent.  If the caregiver attending the clinic visits is not the parent or LAR, written consent must be obtained from the parent or LAR for the caregiver’s participation in the study.
9.    The subject’s parent/caregiver/LAR must be able to speak and understand English sufficiently to understand the nature of the study and to allow for the completion of all study assessments. The same parent/caregiver/LAR must be capable of providing reliable information about the subject’s condition, agree to oversee the administration of study drug, and accompany the subject to all clinic visits.
10.    Negative pregnancy test for females of childbearing potential (subject has experienced onset of menses and is not postmenopausal).  Females of childbearing potential who are sexually active must agree to use an accepted form of contraception (i.e., surgical sterilization, intrauterine contraceptive device, oral contraceptive, diaphragm, or condom in combination with contraceptive cream, jelly, or foam, or abstinence).

Exclusion Criteria

Subjects are to be excluded from the study if any one of the following is fulfilled:
1.    Subjects with known genetic disorders associated with ASD such as FXS, Rett’s disorder, phenylketonuria, tuberous sclerosis, etc.
2.    Subjects with any condition that might interfere with the conduct of the study, confound interpretation of the study results, or endanger their own well-being.  This includes, but is not limited to impairment of renal function, evidence or history of malignancy or any significant hematological, endocrine, respiratory, hepatic, cardiovascular or gastrointestinal disease, including any clinically significant abnormalities on ECG.
3.    Subjects who are currently engaged in illicit drug use or alcohol abuse.
4.    Subjects who are currently receiving treatment with racemic baclofen, vigabatrin, tiagabine, or riluzole.
5.    Subjects currently treated with antipsychotic medication(s).
6.    Subjects currently treated with more than 2 psychoactive medications. Psychoactive medications must be FDA-approved for use for the condition or symptom being treated. Antiepileptic medications for seizure control are permitted.
7.    Subjects who are currently receiving pharmacologic treatment with agents having anxiolytic properties such as serotonin re-uptake inhibitors, tricyclic anti-depressants, venlafaxine, buspirone, or propranolol. However, benzodiazepines that are administered on a regular schedule are not permitted. Benzodiazepines administered prn for procedures are permitted. Melatonin, diphepnhydramine, and other medications administered regularly for insomnia are permitted.
8.    Subjects who plan to initiate or change pharmacologic or non-pharmacologic interventions during the course of the study.  
9.    Subjects who have taken another investigational drug within the last 30 days.
10.    Subjects who are not able to take oral medications.
11.    Subjects who have a history of hypersensitivity to racemic baclofen.
12.    Subjects who have previously participated in a clinical trial of STX209 (arbaclofen).
13.    Subjects who, in the Investigator’s opinion, might not be suitable for the study.

Site of study

UNC Neurosciences Hospital

Target enrollment

Enrollment will continue until 150 subjects have been randomized into the trial at up to 30 sites in North America.  Subjects will be randomized to treatment only if they meet all the inclusion criteria and none of the exclusion criteria. We plan to consent up to16 patients to allow for up to 12 to be randomized at our site.

Date enrollment closes