Possible Association Between Acute Myelogenous Leukemia and Thrombopoietin Receptor Agonist in Immune Thrombocytopenia Patients: A Preliminary Signal Report

Abstract 3541 Background One of the concerns of potential adverse reactions of thrombopoietin receptor (MPL) agonists (romiplostim and eltrombopag) is development of myeloid malignancies. Progression from myelodysplastic syndrome to acute myelogenous leukemia (AML) has been reported in romiplostim. However, development of AML in immune thrombocytopenia (ITP) patients has not been reported. The objective of this study is to clarify whether the concern of AML in MPL agonists in patients with ITP is worth further investigation. Method We performed a disproportionality analysis on patients with ITP registered in an adverse event database, AERS between 2002 and 2011. We compared characteristics between AML case and others. Results Total of 4,821 subjects were identified as ITP and 62 AML cases among them in the AERS. The proportion of AML reporting in romiplostim and eltrombopag were 1.73% (95%CI; 1.30–2.26%) and 1.35% (0.62–2.54%), respectively. It should be noted that all AML was reported with one or more MPL agonist(s). Other factors associated with AML were male gender (OR 2.01; 95%CI 1.03–3.91) and age between 60 and 69 (OR 2.22; 95%CI 1.16–4.24). Conclusion We reported possible association between AML and MPL agonist use in ITP subjects. Due to limitations of spontaneous reporting, further studies are warranted to determine whether the detected signal is real risk or not. Prescribing physicians should not alter their prescribing behaviors based on only this preliminary analysis. Disclosures: Tojo: Novartis Pharma K.K.: Research Funding; Bristol-Myers Squibb Company: Research Funding; Chugai Pharmaceutical Co., Ltd.: Research Funding; Otsuka Pharmaceutical Co., Ltd.: Research Funding; Dainippon Sumitomo Pharma Co., Ltd.: Research Funding; Celgene K.K.: Consultancy. Yasuo:sanofi-aventis K.K.: Employment.