Efficacy and Safety Study of Eltrombopag in Pediatric Patients With Thrombocytopenia From Chronic Idiopathic Thrombocytopenic Purpura (ITP)

Inclusion Criteria:

- Subjects between 1 year and <18 years of age at Day 1.

- Written informed consent from subject's guardian and accompanying informed assent from
subject (for children over 6 years old).

- Confirmed diagnosis of chronic ITP, according to the American Society of Hematology /
British Committee for Standards in Haematology (ASH/BCSH) guidelines [George, 1996;
BCSH, 2003]. In addition, a peripheral blood smear or bone marrow examination should
support the diagnosis of ITP with no evidence of other causes of thrombocytopenia.

- Subjects who are refractory or have relapsed after at least one prior ITP therapy or
are not eligible, for a medical reason, for other treatments.

- Day 1 (or within 48 hours prior) platelet count <30 Gi/L.

- Previous therapy for ITP with immunoglobulins (IVIg and anti-D) must have been
completed at least 2 weeks prior to Day 1 or have been clearly ineffective.

- Subjects treated with concomitant ITP medication (e.g. corticosteroids or
azathioprine) must be receiving a dose that has been stable for at least 4 weeks prior
to Day 1.

- Previous treatment for ITP with splenectomy, rituximab and cyclophosphamide must have
been completed at least 4 weeks prior to Day 1 or have clearly been ineffective.

- Subjects must have prothrombin time (PT/INR) and activated partial thromboplastin time
(aPTT) within 80 to 120% of the normal range.

- Subjects must have a complete blood count (CBC) not suggestive of another
hematological disorder.

- The following clinical chemistries for the subjects MUST NOT exceed the upper limit of
normal (ULN) reference range by more than 20%: creatinine, alanine aminotransferase
(ALT), aspartate aminotransferase (AST), total bilirubin, and alkaline phosphatase. In
addition, total albumin must not be below the lower limit of normal (LLN) by more than
10%.

- For subjects of child-bearing potential (after menarche): subject must not be sexually
active or is practicing an acceptable method of contraception (documented in chart).
Female subjects (or female partners of male subjects) must use one of the following
highly effective methods of contraception (i.e., Pearl Index <1.0%) from two weeks
prior to administration of study medication, throughout the study, and 28 days after
completion or premature discontinuation from the study:

- Complete abstinence from intercourse;

- Intrauterine device (IUD);

- Two forms of barrier contraception (diaphragm plus spermicide, and for males condom
plus spermicide);

- Systemic contraceptives (combined or progesterone only).

Exclusion Criteria:

- Any clinically relevant abnormality, other than ITP, identified on the screening
examination or any other medical condition or circumstance, which in the opinion of
the investigator makes the subject unsuitable for participation in the study or
suggests another primary diagnosis (e.g. thrombocytopenia is secondary to another
disease).

- Concurrent or past malignant disease, including myeloproliferative disorder.

- Subjects who are not suitable for continuation of their current therapy for at least 7
additional additional weeks.

- Treatment with an investigational drug within 30 days or 5 half-lives (whichever is
longer) preceding Day 1.

- History of platelet agglutination abnormality that prevents reliable measurement of
platelet counts.

- Diagnosis of secondary immune thrombocytopenia, including those with laboratory or
clinical evidence of HIV infection, anti-phospholipid antibody syndrome, chronic
hepatitis B infection, hepatitis C virus infection, or any evidence of active
hepatitis at the time of subject screening.

- Subject with Evans syndrome (autoimmune thrombocytopenia and autoimmune hemolysis).

- Subjects with known inherited thrombocytopenia (e.g. MYH-9 disorders)

- Subjects treated with drugs that affect platelet function (including but not limited
to aspirin, clopidogrel and/or NSAIDs) or anti-coagulants for >3 consecutive days
within 2 weeks of Day 1.

- Subjects who have previously received eltrombopag or any other thrombopoietin receptor
agonist.

- For female subjects who have reached menarche status, an inability or unwillingness to
provide a blood or urine specimen for pregnancy testing.

- Female subjects who are pregnant or lactating.