Romiplostim (AMG 531) Versus Medical Standard of Care for Immune (Idiopathic) Thrombocytopenic Purpura

A Randomized, Controlled, Open-label Study Evaluating the Efficacy and Tolerability of AMG 531 Versus Medical Standard of Care as Chronic Therapy for Non-splenectomized Subjects With Immune (Idiopathic) Thrombocytopenic Purpura

This is a phase 3b, multi-center, randomized, Standard of Care (SOC)-controlled, open-label, 52-week treatment study to compare romiplostim to medical SOC for Idiopathic Thrombocytopenia Purpura (ITP), with a 6-month Safety Follow-up. Patients randomized to romiplostim must complete the taper or discontinuation of medical SOC for ITP as soon as medically feasible after the initiation of romiplostim. After the completion or discontinuation of the study treatment period, any participant who does not transfer in to another romiplostim study will complete a 6-month Safety Follow-up period.

Inclusion Criteria:

• Subject is ≥ 18 years of age
• Subject has a diagnosis of Idiopathic Thrombocytopenia Purpura (ITP) according to the American Society of Hematology (ASH) guidelines
• If subject is > 60 years of age, subject has a written bone marrow biopsy report confirming the diagnosis of ITP
• Subject has received at least 1 prior therapy for ITP
• Subject has a platelet count < 50,000 or their platelet count falls to < 50,000 during or after a clinically-indicated taper or discontinuation of current ITP therapy
• Before any study-specific procedure, the appropriate written informed consent must be obtained

Exclusion Criteria:

• Subject has had a splenectomy for any reason
• Subject has an active malignancy
• Subject has a history of cancer, other than basal cell carcinoma or cervical carcinoma in situ, with treatment or active disease within 5 years
• Subject has a known history of bone marrow stem cell disorder
• Subject has participated in any study evaluating polyethylene glycol-conjugated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF), recombinant human thrombopoietin (rHuTPO), AMG 531, or a thrombopoietic protein
• Subject is receiving other investigational agents or procedures
• Subject is currently enrolled in, or has completed within the last 30 days, another investigational device or drug study
• Subject is pregnant or breast feeding
• Subject is not using adequate contraceptive precautions
• Subject has known sensitivity to any recombinant E. coli-derived product
• Subject has any kind of disorder that compromises the ability of the subject to give written informed consent and does not have a legally acceptable representative
• Subject has any kind of disorder that compromises the ability of the subject to comply with study procedures