An Open-label Safety Study of Lusutrombopag (S-888711) in Adults With Chronic Immune Thrombocytopenia (ITP)

Inclusion Criteria: * Subjects who previously participated in Study 0913M0621 (NCT01054443) and who completed treatment or discontinued treatment due to a platelet count \> 400,000/μL and continued to meet all inclusion criteria of the previous study, listed below, including platelet counts \< 50,000/μL were eligible for study participation. For the purpose of this study, initial screening visit and all prestudy time period refer to Study 0913M0621. * A signed and dated written informed consent * Males and females ≥ 18 years of age * All subjects must agree to use barrier contraception * Diagnosis of ITP * Subjects \> 60 years must have had a diagnostic bone marrow aspiration * Relapsed persistent or chronic ITP status, with or without prior splenectomy * Subjects receiving steroid therapy must be on a stable dose for at least 2 weeks prior to Screening * Prothrombin time (PT) and activated partial thromboplastin time (aPTT) within 20% of the upper limit of normal (ULN) at Screening * Subjects receiving stable dosages of cyclosporine A, mycophenolate mofetil, azathioprine, or danazol are allowed Exclusion Criteria: * History of clinically important hemorrhagic clotting disorder * Females who are pregnant, lactating, or taking oral contraceptives * History of alcohol/drug abuse or dependence within 1 year * Use of the following drugs or treatment prior to Visit 1 (Day 1): * Within 1 week - Rho(D) immune globulin or intravenous immunoglobulin; * Within 2 weeks - plasmap…