Evaluating the Safety of Long Term Dosing of Romiplostim (Formerly AMG 531) in Thrombocytopenic Subjects With Myelodysplastic Syndromes (MDS)

"Subjects will begin the study at an initial dose of 750 µg.~Except for:~* Subject whose doses were escalated to doses higher than 750 µg AMG 531 weekly, and maintained a response per IWG guidelines for platelet response.~* Subjects who were stable at a lower dose of AMG 531 on the previous study. Doses will be adjusted throughout the study based on individual subject's platelet count."