Eltrombopag in Second Line Adult Primary Immune Thrombosytopenia

Inclusion Criteria: 1. Diagnosis of primary ITP; 2. Age ≥ 18 years; 3. Patients are in the new diagnosis or persistent phase of disease (i.e. within month 12 from diagnosis); 4. Patients not responsive or in relapse after a full course of steroid therapy (prednisone 1 mg/kg/d for at least 28 days or 3 cycles of dexamethasone 40 mg/day for consecutive 4 days, according to the GIMEMA ITP0207 trial) ± IVIG; 5. Patients have a platelet count \< 10 x 109/L documented in a single blood cell count; 6. Patients have bleeding symptoms and a platelet count \> 10 \< 30 x 109/L documented in a single blood cell count; 7. Patients have no bleeding symptoms and a platelet count \>10 \< 30 x 109/L in at least 2 blood cell counts at 3 days interval in the week preceding the enrollment with the last count at the day of enrollment; 8. Patients have corticosteroids or IVIG dependence (the need for ongoing or repeated doses administration of corticosteroids or IVIG to maintain a platelet count ≥ 30 x 109/L and/or to avoid bleeding; 9. Written informed consent obtained from the subject; 10. Men with a female partner of childbearing potential must have either had a prior vasectomy or agree to use effective contraception from time of enrollment until 6 months after the last dose of study treatment; 11. Female subjects of non-childbearing potential may be enrolled in the study; for this study population, non-childbearing potential is defined as current tubal ligation, hysterectomy, ovariectomy or post-menopause; OR 12. Female subjects of childbearing potential may be enrolled in the study, if the subject has practiced adequate contraception for 30 days prior to start of Eltrombopag, has a negative pregnancy test within 14 days of first dose of Eltrombopag, and has agreed to continue adequate contraception during the entire treatment period and for 6 months after completion of the treatment. Exclusion Criteria: 1. Diagnosis of secondary ITP. As far as patients with immune thrombocytopenia and antiphospholipid antibodies positivity, individuals without a previous thromboembolic event are excluded only if lupus anticoagulant (LAC) is associated with the presence of anticardiolipin (aCL) and aβ2-Glycoprotein I (aβ2GPI) antibodies; 2. Previous treatment with other anti-ITP second line therapies (i.e. Rituximab, Azathioprine, Cyclosporin-A or other); only patients with a previous full course of steroid (see inclusion criteria for definition) ± IVIG are admitted to the study; 3. Previous treatment with any TPO-R agonists; 4. Patients have life threatening bleeding complications; 5. Patients had deep venous thrombosis (DVT) or arterial thrombosis in the 3 months preceding the enrollment; 6. Patients are HIV, HCV, HBsAg positive; 7. Patients with hepatic impairment (i.e. mild, moderate or severe hepatic impairment (Child-Pugh score \> 6); 8. Patients have a well established liver disease that represents a contraindication for the use of Eltrombopag; 9. Patients are unable to respect the 4-hour interval between Eltrombopag and other medications (e.g. antacids), calcium-rich foods (e.g. dairy products and calcium fortified juices), or supplements containing polyvalent cations such as iron, calcium, aluminium, magnesium, selenium, and zinc; 10. Patients are unable to stop medications that are known to cause a drug-drug interaction with Eltrombopag; 11. Subjects meeting any of the following criteria must not be enrolled in an Eltrombopag study: * Lactating female. * History of another malignancy. Exception: subjects who have been disease-free for 5 years, or subjects with a history of completely resected non-melanoma skin cancer or successfully treated in situ carcinoma are eligible. * Any serious and/or unstable pre-existing medical, psychiatric disorder, or other conditions that could interfere with subject's safety, obtaining informed consent or compliance with the study procedures. * Hormone replacement therapy. Subjects must discontinue hormone replacement therapy prior to study enrollment due to the potential for inhibition of Cytochrome P450 (CYP) enzymes that metabolize estrogens and progestins. * Administration of an investigational drug within 30 days or 5 half-lives, whichever is longer, preceding the first dose of study treatment. * Have a known immediate or delayed hypersensitivity reaction or idiosyncrasy to drugs chemically related to Eltrombopag or excipients that contraindicate their participation.