['tourette syndrome', 'chronic motor tic disorder']
['abx-1431', 'placebo comparator', 'abx-1431']

        Principal Inclusion Criteria:

          -  Patient is a male or female between the age of 18 and 65 years of age at the Screening
             Visit.

          -  Patient has a diagnosis of Tourette Syndrome OR chronic motor tic disorder as defined
             by the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5)
             criteria.

          -  Patient's Yale Global Tic Severity Scale (YGTSS) total tic sub-scale (TTS) results
             must be ≥ 18 (Range 0-50) at the Screening Visit.

          -  Patients taking daily medications for symptoms of Tourette Syndrome [e.g. neuroleptics
             (e.g. aripiprazole, risperidone) or selective serotonin reuptake inhibitors (e.g.
             fluoxetine)] must be on a stable dose of medication for at least 30 days before the
             Screening Visit and must be expected to remain on a stable dose during this study.

        Principal Exclusion Criteria:

          -  Patient is taking potent cytochrome P450 3A4/5 inducers [e.g. carbamazepine,
             oxcarbazine, rifampin, St. John's Wort (Hypericum perforatum), or phenytoin]. Patient
             is taking strong P450 3A4/5 inhibitors including atazanavir, bocepravir,
             clarithromycin, grapefruit juice, indinavir, itraconazole, ketoconazole, nefazodone,
             nelfinavir, posaconazole, ritonavir, saquinavir, telithromycin, or voriconazole.

          -  Patients with a diagnosis of any psychiatric comorbidity (obsessive compulsive
             disorder, attention deficit hyperactivity disorder) OR generalized anxiety disorder,
             depression or post-traumatic stress disorder that is unstable or requires alteration
             in therapy are excluded. Patients with a past history of psychosis or schizophrenia at
             any time are excluded. Patients with stable OCD or ADHD requiring no alteration in
             therapy may be enrolled.
      