Amgen Megakaryopoiesis Protein 2 (AMG 531) in Thrombocytopenic Subjects With Immune Thrombocytopenic Purpura (ITP)

An Open-label, Unit Dose-finding Study Evaluating the Safety and Efficacy of Amgen Megakaryopoiesis Protein 2 (AMG 531) in Thrombocytopenic Subjects With Immune Thrombocytopenic Purpura (ITP)

The purpose of this study is to assess the safety and tolerability of AMG 531 (romiplostim), a novel thrombopoiesis-stimulating peptibody, and its effect on platelet counts in adults with immune thrombocytopenic purpura.

Inclusion Criteria:

• Greater than or equal to 3 months history of ITP, regardless of splenectomy status, and completion of at least 1 prior treatment for ITP
• 2 of 3 pretreatment platelet counts that were less than 30 x 10^9/L (if not currently on ITP therapy) or less than 50 x 10^9/L (if currently receiving corticosteroids for ITP therapy)
• Ability to give informed consent

Exclusion Criteria:

• Known history of arterial thrombosis, active malignancy, or bone marrow stem cell disorder