A Phase 2 Trial Evaluating SNC-102 in Drug-Induced Tardive Dyskinesia

Inclusion Criteria:

1. Males and females 18-75 years of age.

2. Diagnosis, at least 3 months prior to the Screening Visit, of drug-induced TD

1. AIMS ≥3 (moderate or worse) for ≥1 body area, or AIMS = 2 (mild) for ≥2 body
areas; and

2. >3 months exposure to antipsychotic drug or metoclopramide; and

3. Other causes of dyskinesia have been ruled out.

3. AIMS score is confirmed at the Screening Visit by the Principal Investigator and the
Trial Reading Center, and at the Baseline Visit at least 1 week later by the
Principal Investigator.

4. If using antipsychotic medication or metoclopramide, dose has been stable for at
least 60 days prior to the Baseline Visit and is expected to remain stable through
the course of the trial.

5. If using opioid medication, dose has been stable for at least 14 days prior to the
Baseline Visit and is expected to remain stable through the course of the trial.

6. If using vitamin or dietary supplements, dose and type has been stable for at least
14 days prior to the Baseline Visit and is expected to remain stable through the
course of the trial.

7. If using alcohol, willingness to limit intake to no more than 2 drinks/day through
the course of participation in the trial, and to abstain for at least 12 hours prior
to any assessment visit.

Exclusion Criteria:

1. Unstable psychiatric status, as indicated by any change in psychotropic medication
(unless approved by the Sponsor), or by hospitalization, within 60 days prior to the
Screening Visit.

2. Active drug or alcohol dependence or abuse.

3. Current use of cocaine, amphetamine, phencyclidine (PCP), or ketamine, documented
either by history or by urinary drug screening at Screening and Baseline Visits.
Drugs used to treat attention deficit-hyperactivity disorder are allowed if stable
for at least 14 days prior to the Baseline Visit and are expected to remain stable
through the course of the trial.

4. Risk of significant medication non-adherence, based on the judgment of the Principal
Investigator.

5. Neurologic or psychiatric disorder that could interfere with the attribution of
observed involuntary movements to TD, such as a primary movement disorder unrelated
to medication.

6. History of neuroleptic malignant syndrome.

7. Significant risk, in the judgment of the Principal Investigator, of suicidal or
violent behavior.

8. Receipt of new medication for the treatment of TD within 4 weeks prior to the
Baseline Visit or anticipated while participating in the trial.

9. Initiation of oral contraceptive medication, or change in dose, within 30 days prior
to the Screening Visit, or anticipated while participating in the trial.

10. Gastrointestinal disease such as short-bowel or other malabsorption syndrome which,
in the judgment of the Principal Investigator, could interfere with absorption of
orally-administered medication.