Inclusion Criteria:

• Key Inclusion Criteria:

  1. DSM-IV diagnosis of bipolar I disorder, most recent episode manic or mixed.
  2. A lifetime history of bipolar disorder symptoms for at least 2 months.
  3. YMRS score greater than or equal to 16.
  4. CGI-S score greater than or equal to 4.
  5. Male or female outpatient aged between 10-17 years old inclusive at the time of consent.
  6. Functioning at an age-appropriate level intellectually, as deemed by the Investigator.
  7. The subject has no co-morbid illness that could affect efficacy, safety, or tolerability or in any way interfere with the subject's participation in the study.
  8. Must have a satisfactory medical assessment with no clinically significant and relevant abnormalities.

Exclusion Criteria:

• Key Exclusion Criteria:

  1. Current controlled or uncontrolled, co-morbid psychiatric diagnosis that could interfere with clinical assessments or study conduct.
  2. A history of lack of therapeutic response or hypersensitivity to the study drug.
  3. A greater than or equal to 50% reduction in YMRS between Screening and Baseline.
  4. Acutely at risk for suicidal or violent behavior or a history of suicide attempts requiring medical intervention.
  5. A history of aplastic anemia, agranulocytosis or bone marrow depression.
  6. A history of seizure disorder, other than a single childhood febrile seizure.
  7. A history of severe, unstable asthma.
  8. Current hospitalization for psychiatric symptoms.
  9. History of alcohol or other substance abuse or dependence.
  10. Pregnant or lactating females.
  11. Body weight less than or equal to 25 kg.