Clinical Study of Lamotrigine to Treat Newly Diagnosed Typical Absence Seizure in Children and Adolescents

Inclusion Criteria:

1. Target disease: Subjects with newly diagnosed and untreated typical absence seizurewhich is classifiable by the International Classification of Seizures.

2. Diagnosis of typical absence seizures is established by at least one of two 4-minutehyperventilation tests as supported by clinical signs and EEG findings. The following criteria will be used to define a typical absence seizure on the EEG: adischarge of generalized spike-and-wave or multiple spike-and-wave activity lasting ≥3seconds during the awake state. The frequency of the spike-and-wave should be between 2.5-4.5 Hz.

3. Age (at the time of obtaining consent):

• 2 to 15 years of age in Japan

• 2 to 12 years of age in South Korea

4. Subjects must weigh at least 7 kg

5. Outpatients

6. Parent/guardian must have given written informed consent. Subjects who areintellectually able to understand the concepts and procedures of the protocol mustgive assent by also signing the consent.

7. Gender: Male or female

8. QTc<450 millisecond (msec) or <480msec for subjects with Bundle Branch Block - valuesbased on either single ECG values or triplicate ECG averaged QTc values obtained overa brief recording period.

Exclusion Criteria:

1. Subjects with partial seizure or generalized seizures other than typical absence.

2. Subjects with a history of rash associated with other treatment.

3. Subjects with any clinically significant chronic cardiac, renal, or hepatic medicalcondition. Any patient with these conditions will be excluded from the study even ifthese conditions are being controlled with chronic therapy.

4. Subjects with an acute or chronic illness likely to impair drug absorption,distribution, metabolism or excretion or with any unstable physical symptoms likely torequire hospitalization during participation in the study.

5. Subjects with a psychiatric disorder requiring medication, or who had psychiatricconditions in the past that was both judged to be severe and required hospitalization.

6. Subjects with an acute or progressive neurological disorder or an organic disease.

7. Subjects with currently taking any psychoactive drugs to treat hyperactivity disorderor attention deficit disorder.

8. Subjects with an unstable liver disease (as defined by the presence of ascites,encephalopathy, coagulopathy, hypoalbuminaemia, oesophageal or gastric varices orpersistent jaundice), cirrhosis, known biliary abnormalities (with the exception ofGilbert's syndrome or asymptomatic gallstones).

9. Female subjects who are pregnant or lactating, who may be pregnant, or who plan forpregnancy during the study.

10. Children in foster care: A child who has been placed under the control or protectionof an agency, organisation, institution or entity by the courts, the government or agovernment body, acting in accordance with powers conferred on them by law orregulation. This can include a child cared for by foster parents or living in a carehome or institution, provided that the arrangement falls within the definition above.The definition of a child in care does not include a child who is adopted or who hasan appointed legal guardian.

11. Subjects taking inducers of lamotrigine glucuronidation (i.e., rifampicin,lopinavir/ritonavir), atazanavir/ritonavir, risperidone, oral contraceptives orhormone drug which includes estrogen.

12. Subjects having participated in other clinical study in the past 3 months before thestart of investigational product.

13. Subjects who have active suicidal plan/intent or have had active suicidal thoughts inthe past 3 months before the start of investigational product or who have history ofsuicide attempt in the last 1 year before the start of investigational product or morethan 1 lifetime suicide attempt.

14. Subjects whom the investigator (or subinvestigator) considers ineligible for thestudy.