The purpose of this study is to evaluate safety, tolerability and preliminary efficacy of SD-809 in the treatment of motor and phonic tics of Tourette Syndrome and to evaluate the pharmacokinetic of SD-809 and its metabolites.

Inclusion Criteria:

• 12 to 18 years of age, inclusive, at Screening.

• Patient has a Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-V) diagnosis of Tourette Syndrome and has manifested motor and phonic tics within 3 months before the Screening visit

• Patient has total tic score of ≥19 on the YGTSS

• Tic severity and frequency has been stable for at least 2 weeks before the Screening visit

• Willing to adhere to medication regimen and to comply with all procedures

• Patient is in good general health, as indicated by medical and psychiatric history and physical examination

• Patient and parent/guardian have provided written, informed consent (and written assent, as appropriate)

• Female patients of childbearing potential agree to use an acceptable method of contraception

  • Additional criteria apply, please contact the investigator for more information

Exclusion Criteria:

• Patient has a serious untreated or undertreated psychiatric illness

• Patient has a history of suicidal ideation or behavior

• Patient has received tetrabenazine, neuroleptics, benzodiazepines, topiramate, dopamine receptor antagonists within 14 days of Screening or Baseline; or botulinum toxin within 3 months of Screening or Baseline

• Patient is being treated with deep brain stimulation for control of tics

• Patient has a progressive or degenerative neurological disorder or a structural disorder of the brain

• Patient has participated in an investigational drug or device trial within 30 days of Screening

• Patient is pregnant or breastfeeding at Screening or Baseline

• Patient has a history of alcohol or substance abuse in the previous 12 months, as defined in the DSM-V

  • Additional criteria apply, please contact the investigator for more information