Comparative Net Cost Impact of the Utilization of Romiplostim and Intravenous Immunoglobulin for the Treatment of Patients with Immune Thrombocytopenia in Quebec,

Immune thrombocytopenia (ITP) is an autoimmune disorder characterized by increased platelet destruction and suboptimal platelet production, which results in low platelet counts and mild to severe bleeding. Bleeding events may range from petechiae and purpura to severe intracranial and gastrointestinal haemorrhage. Approximately 5% of adult ITP patients suffer from a fatal bleeding event. However, the risk of severe, fatal bleeding is significantly higher for patients who are unresponsive or intolerant to current therapies, over the age of 60 years, or refractory to splenectomy. The prevalence of diagnosed cases of chronic ITP in the overall population in Canada is reported to be 20.3 per 100,000; thus, it is estimated that there are about 160,000 people in Quebec with chronic ITP.

Therapeutic management of ITP include the use of corticosteroids, immunosuppressive agents, and intravenous immunoglobulins (IVIg). IVIg is an expensive and occasionally scarce blood product. Surgical management includes splenectomy. Most recently, thrombopoietin (TPO) mimetic agents such as romiplostim and eltrombopag have been used to treat ITP.

Romiplostim is indicated in Canada to increase the platelet levels in adult patients with chronic immune (idiopathic) thrombocytopenic purpura: •Who are non splenectomized and have had an inadequate response or are intolerant to corticosteroids and/or immunoglobulin; •Who are splenectomized and have had an inadequate response to splenectomy.

Romiplostim does not have public reimbursement in the province of Quebec. Although the public drug program expert review acknowledged the benefit of romiplostim in substantially reducing the use of IVIg, the reviewers did not recognize the use of IVIg as a maintenance therapy. The objective of this study was to conduct a net cost analysis to determine if using romiplostim instead of IVIg can result in savings to the provincial health care budget in Quebec.

A net cost impact model was developed to provide a detailed analysis of the cost implications of romiplostim utilization compared with IVIg, including the drug treatment costs, costs related to the preparation and administration of medications, monitoring costs, and indirect costs such as patients' time away from usual activities or work. Expert consultation with physicians, pharmacists and nurses in Quebec was used to define treatment algorithms including all health resource utilization required when using romiplostim and IVIg. Costs were assigned to direct (e.g., drugs, medical supplies, laboratory testing, healthcare professionals' time) and indirect (e.g., productivity) healthcare resources.

Based on the median weekly dose (3mcg/kg) observed in the pivotal romiplostim clinical trial in splenectomised patients, the annual cost of romiplostim per patient was $47,244. The annual per patient cost of IVIg was $114,548 based on an average dose suggested by a clinical expert (1g/kg every 4 weeks and average administration time of 3.5 hours). Lower costs for drug preparation and administration ($284 vs. $1355) and less time lost from work (valued at $447 vs. $2141) were attributed to romiplostim compared to IVIg. The time attributed to monitoring was the same for both romiplostim and IVIg ($115). The total average annual per patient costs including medication, drug administration, monitoring and lost productivity for romiplostim vs. IVIg were, respectively, $48,090 and $118,159. The use of romiplostim would save, on average, about $70,069 per patient per year.

From a societal perspective, treating ITP patients with romiplostim can provide a lower cost alternative to IVIg for the overall provincial healthcare budget. Compared with IVIg, the use of romiplostim results in lower direct costs, reduced health care resource utilization and less indirect costs. As a precious commodity, blood products must be used wisely. As stated by the expert review committee in Quebec, IVIg should remain a last resort option to treat ITP. Romiplostim can allow for improved healthcare resource allocation by reserving IVIg for use in other areas of greater need while also providing cost savings. Romiplostim also potentially improves patients' quality of life by reducing the time required for drug infusion and avoids the risks associated with IV administration.

Pettigrew:Amgen Canada Inc.: Consultancy. Deuson:Amgen: Employment, Equity Ownership. Garces:Amgen Canada: Employment, Equity Ownership.