A Phase 2 Study to Evaluate the Efficacy and Safety of AMG531 in Aplastic Anemia

A Phase 2, Randomized, Open-Label, Parallel, Comparative, Dose-Finding Study to Evaluate the Efficacy and Safety of AMG531 in Aplastic Anemia Subjects With Thrombocytopenia Refractory to Immunosuppressive Therapy

The present study will be conducted to evaluate the efficacy and safety of AMG531 and to determine the recommended initial dose of AMG531 on the basis of its efficacy and safety when it is administered subcutaneously (SC) to the Aplastic Anemia (AA) patients with immunosuppressive-therapy refractory thrombocytopenia and also to assess the pharmacokinetics of this product. Its efficacy and safety during the extension period beyond one year will also be evaluated.

Inclusion Criteria:

• Patient who is diagnosed as AA and refractory to immunosuppressive therapy
• Platelet ≤ 30,000/μL

Exclusion Criteria:

• Concurrent active infection not adequately responding to appropriate therapy
• HIV positivity
• Bone marrow reticulin grade of > 1
• Clinically significant cardiac disease
• Arterial or venous thrombosis within the last 1 year before enrollment
• Other cause of thrombocytopenia
• AA with hemolytic predominant paroxysmal nocturnal hemoglobinuria (PNH)
• Uncontrolled diabetes
• Receiving any agent used to treat AA, including antithymocyte globulin (ATG) or ATG + cyclosporine within 6 months before starting study treatment and/or cyclosporine or anabolic hormone within 6 weeks before starting the study treatment
• History of PEG-rHuMGDF, recombinant human thrombopoietin, AMG531, and other thrombopoietin (TPO)-receptor agonist
• Who plans to conduct hematopoietic stem cell transplantation within 1 year