Reducing Involuntary Movements in Tardive Dyskinesia

Inclusion Criteria:

- History of using a dopamine receptor antagonist for at least 3 months

- Clinical diagnosis of tardive dyskinesia and has had symptoms for at least 3 months
prior to screening

- Subject has successfully completed a controlled study of SD-809 for treatment of
moderate to severe tardive dyskinesia

- Subjects with underlying psychiatric diagnosis are stable and have no change in
psychoactive medications

- Have a mental health provider and does not anticipate any changes to treatment regimen
in the next 3 months

- History of being compliant with prescribed medications

- Able to swallow study drug whole

- Be in good general health and is expected to attend all study visits and complete
study assessments

- Female subjects must not be pregnant and agree to an acceptable method of
contraception

Exclusion Criteria:

- Currently receiving medication for the treatment of tardive dyskinesia

- Have a neurological condition other than tardive dyskinesia that may interfere with
assessing the severity of dyskinesias

- Have a serious untreated or undertreated psychiatric illness

- Have recent history or presence of violent behavior

- Have unstable or serious medical illness

- Have evidence of hepatic impairment

- Have evidence of renal impairment

- Have known allergy to any component of SD-809 or tetrabenazine

- Has participated in an investigational drug or device trial and received study drug
within 30 days

- Have acknowledged use of illicit drugs

- Have a history of alcohol or substance abuse in the previous 12 months