Study of a New Medication for Childhood Chronic Immune Thrombocytopenia (ITP), a Blood Disorder of Low Platelet Counts That Can Lead to Bruising Easily, Bleeding Gums, and/or Bleeding Inside the Body.

Inclusion Criteria:

• Written informed consent must be obtained from the patient's guardian and accompanyinginformed assent from the patient (for children over 6 years old)

• Patients must be between 1 year and <18 years of age at Day 1

• Patients will have a confirmed diagnosis of chronic ITP for at least 1 year, atscreening, according to the guidelines published in the International Working GroupReport

• A peripheral blood smear or bone marrow examination will support the diagnosis of ITPwith no evidence of other causes of thrombocytopenia.

• Patients must be refractory or have relapsed after at least one prior ITP therapy, orpatients must be unable, for a medical reason, to continue other ITP treatments.

• Patients must have a Day 1 (or within 48 hours prior) platelet count <30 Gi/L.

• Previous therapy for ITP with immunoglobulins (IVIg and anti-D) must have beencompleted at least 2 weeks prior to Day 1, or these therapies must have been completedat least 1 week prior to Day 1 and have been clearly ineffective.

• Previous treatment for ITP with splenectomy, rituximab and cyclophosphamide must havebeen completed at least 4 weeks prior to Day 1.

• Patients treated with concomitant ITP medication (e.g. corticosteroids orazathioprine) must be receiving a dose that has been stable for at least 4 weeks priorto Day 1.

• Patients must have a complete blood count (CBC) not suggestive of anotherhematological disorder.

• Patients must have the following laboratory results:

• prothrombin time international normalized ratio (INR) and activated partialthromboplastin time (aPTT) within 80 to 120% of the normal range.

• clinical chemistries that do NOT exceed the upper limit of normal reference range bymore than 20% for the following: creatinine, ALT, AST, total bilirubin, and alkalinephosphatase.

• total albumin that is not below the lower limit of normal by more than 10%.

• Female patients of child-bearing potential (after menarche) must:

• have a negative pregnancy test within 24 hours of first dose of study treatment,

• agree and be able to provide a blood or urine specimen for pregnancy testing duringthe study,

• agree to use effective contraception during the study and for 28 days following thelast dose of study treatment, and not be lactating.

• Male patients with a female partner of childbearing potential must agree to useeffective contraception from 2 weeks prior to administration of the first dose ofstudy treatment until 3 months after the last dose of study treatment.

• In France, a patient will be eligible for inclusion in this study only if eitheraffiliated to or a beneficiary of a social security category.

Exclusion Criteria:

• Patients with any clinically relevant abnormality, other than ITP, identified on thescreening examination or any other medical condition or circumstance, which in theopinion of the investigator makes the patient unsuitable for participation in thestudy or suggests another primary diagnosis (e.g. Thrombocytopenia is secondary toanother disease).

• Patients with concurrent or past malignant disease, including myeloproliferativedisorder.

• Patients expected not to be suitable for continuation of their current therapy for atleast 13 additional weeks.

• Patients with a history of platelet agglutination abnormality that prevents reliablemeasurement of platelet counts.

• Patients with a diagnosis of secondary immune thrombocytopenia, including those withlaboratory or clinical evidence of HIV infection, anti-phospholipid antibody syndrome,chronic hepatitis B infection, hepatitis c virus infection, or any evidence of activehepatitis at the time of subject screening.

• Patients with Evans syndrome (autoimmune thrombocytopenia and autoimmune hemolysis).

• Patients with known inherited thrombocytopenia (e.g. MYH9 disorders).

• Patients treated with any medication that affects platelet function (including but notlimited to aspirin, clopidogrel and/or NSAIDS) or anti-coagulants for >3 consecutivedays within 2 weeks of Day 1.

• Patients who have received treatment with an investigational drug within 30 days or 5half-lives (whichever is longer) preceding Day 1.

• Patients who have previously received eltrombopag or any other thrombopoietin receptoragonist.

• Any patient considered to be a child in care, defined as one who has been placed underthe control or protection of an agency, organization, institution or entity by thecourts, the government or a government body, acting in accordance with powersconferred on them by law or regulation. This can include a child cared for by fosterparents or living in a care home or institution, provided that the arrangement fallswithin the definition above. The definition of a child in care does not include achild who is adopted or who has an appointed legal guardian.

• Patients who have a known immediate or delayed hypersensitivity reaction oridiosyncrasy to drugs chemically related to eltrombopag or excipients thatcontraindicates their participation.

• Any serious and/or unstable pre-existing medical, psychiatric disorder, or otherconditions that could interfere with the patient's safety or compliance to the studyprocedures.