OBJECTIVES: Immune thrombocytopenia (ITP) is a rare autoimmune disorder characterised by low platelet counts resulting in symptoms that are usually minor, e.g. petechiae. However, patients with very low platelet counts face the risk of serious, but rare, bleeds, e.g. intracranial haemorrhage. The study objective was to estimate the cost-effectiveness of treating two groups of chronic adult ITP patients (refractory to splenectomy and where splenectomy is contraindicted) with oral eltrombopag versus romiplostim or rituximab from an Irish healthcare payer perspective.METHODS: A Markov model with a four week model cycle, two year time horizon and seven health states was used. In one arm, patients were treated with eltrombopag and in the other romiplostim or rituximab. Patients began in either the ‘controlled platelet’ or ‘uncontrolled platelet’ health states. Response rates from clinical trials (eltrombopag and romiplostim) and a published literature review (rituximab) determined whether patients were controlled or not. Controlled patients experienced a higher level of utility and lower risk of transitioning to bleed health states. Utilities (using the SF-36v2) for controlled/uncontrolled platelet levels were from the eltrombopag pivotal trial, RAISE. Utility for bleeds and costs were taken from the literature. Costs and benefits were discounted by 4%.RESULTS: The model estimated that eltrombopag dominates romiplostim, i.e. cost savings of €13,000 and €18,000 with an incremental QALY of 0.1 and 0.03 for patients who are refractory to splenectomy and where splenectomy is contraindicated respectively. This result was driven by the fact that eltrombopag is less expensive, does not incur wastage or administration costs and has slightly better durable response rates compared to romiplostim. Eltrombopag is not cost-effective compared to rituximab for both groups of patients because rituximab is significantly less costly than eltrombopag with comparable response rates. CONCLUSIONS: The economic model showed that eltrombopag dominates romiplostim but is not cost-effective versus rituximab.