Immune (Idiopathic) Thrombocytopenic Purpura (ITP) Clinical Trial
Official title:
An Open Label Extension Study Evaluating the Safety and Efficacy of Long Term Dosing of AMG 531 in Thrombocytopenic Japanese Subjects With Immune (Idiopathic) Thrombocytopenic Purpura
The purpose of this study is to assess the safety and efficacy of long term dosing of AMG 531
in thrombocytopenic Japanese subjects with ITP.
It is anticipated that AMG 531 will be a safe and well tolerated in long term treatment and
that AMG 531 will effectively raise and maintain platelet counts to a desired therapeutic
range, when individual dose adjustments based on platelet counts are permitted.
This study is available to subjects who have completed any previous AMG 531 ITP study in
Japan and meet the eligibility criteria of this study.
Romiplostim was administered by subcutaneous (SC) injection once per week. If subjects entered the extension study within 12 weeks from the last investigational product administration in the previous study and had shown an increase in platelet counts ≥ 20 x 109/L from baseline at least once during the 13-week treatment period (excluding 4 weeks after receiving rescue medication), they were treated with romiplostim at the same weekly dose (last dose on study) received in the previous study. Otherwise, subjects were treated with romiplostim at a starting dose of 3 μg/kg. Dose adjustment based on platelet counts was allowed throughout the treatment period to allow subjects to maintain platelet counts in the target range of ≥ 50 to ≤ 200 x 109/L, up to a maximum permitted dose of 10 μg/kg. ;