Amgen’s romiplostim Phase III study meets primary endpoints

Additionally, romiplostim-treated patients taking concurrent immune thrombocytopenic purpura (ITP) medications such as corticosteroids were able to reduce or discontinue these medications.

Efficacy and safety data from another pivotal Phase III study evaluating romiplostim (AMG 531) in non-splenectomized chronic ITP patients as well as interim results from a long-term extension study in chronic adult ITP indicate that primary endpoint was met with 38.1% of romiplostim-treated patients achieving durable platelet response compared to none of the patients receiving placebo. Additionally, no rescue medications (defined as any additional ITP medicine needed to increase platelet counts) were administered at any time during the study to patients achieving durable platelet response.

Overall platelet response was 78.6% in romiplostim-treated patients compared to no response in the placebo group. Overall platelet response was defined as either transient platelet response (more than or equal to four weekly platelet responses, separated by more than eight weeks from administration of any rescue medication) or durable platelet response. The mean number of weeks with a platelet response was significantly greater in romiplostim-treated patients than in the placebo group (12.3 weeks vs. 0.2 week).