Cost-effectiveness analysis of eltrombopag, hetrombopag and romiplostim for second-line treatment of primary immune thrombocytopenia in China

Background: Primary immune thrombocytopenia (ITP) is a chronic autoimmune bleeding disorder requiring long-term second-line treatment in patients refractory to corticosteroids and immunoglobulins. In China, eltrombopag, hetrombopag, and romiplostim are all available after national reimbursement negotiations, but comparative economic evidence to inform optimal therapeutic selection remains limited. This study aimed to evaluate the cost-effectiveness of eltrombopag, hetrombopag, and romiplostim as second-line treatments for primary ITP in China from the healthcare system perspective. Methods: A lifetime Markov model was developed to estimate costs and quality-adjusted life-years (QALYs) associated with each treatment strategy. Clinical inputs were derived from phase III randomized controlled trials in Chinese populations and supplemented with indirect treatment comparisons where head-to-head evidence was unavailable. Long-term disease progression and relapse were extrapolated using published literature and clinical assumptions consistent with ITP disease course. Costs were obtained from domestic medical databases, and utility values were sourced from published studies. Both deterministic and probabilistic sensitivity analyses were conducted to assess parameter uncertainty. Scenario analyses were performed to explore the impact of different time horizons on model outcomes. Results: Compared with eltrombopag, hetrombopag and romiplostim yielded incremental health gains of 0.02 QALYs and 0.05 QALYs with incremental costs of 41,329.52 CNY and 99,009.66 CNY, generating ICERs of 2,484,284.17 CNY/QALY and 2,077,773.05 CNY/QALY, respectively. When compared with hetrombopag, romiplostim was associated with an ICER of 1,859,724.27 CNY/QALY. Deterministic sensitivity analysis identified treatment response rates, drug acquisition costs and discount rate as key drivers of model outcomes. Probability sensitivity analysis revealed that at a willingness-to-pay threshold of 2 times GDP per capita, eltrombopag regimen demonstrated the highest probability of being cost-effective among the three strategies. Results of scenario analyses verified the robustness of base-case results. Conclusion: Eltrombopag was likely to be the most cost-effective second-line treatment option for ITP compared with hetrombopag and romiplostim. Our findings provide economic evidence to support decision-making regarding the use of TPO-RAs in China.