Hughes Avery, Marshall John K, Moretti Myla E, Ungar Wendy J
Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada.
Program of Child Health Evaluative Sciences, The Hospital for Sick Children Research Institute, Toronto, Ontario, Canada.
J Can Assoc Gastroenterol. 2020 Feb 11;4(1):48. doi: 10.1093/jcag/gwz045. eCollection 2021 Feb.
Lower-cost biosimilar infliximab may address affordability concerns in the treatment of adults with Crohn's disease (CD), however, evidence regarding the cost-effectiveness of switching from reference to biosimilar is warranted. The aim of this research was to assess the incremental cost of switching from treatment with reference infliximab to biosimilar compared with maintaining reference infliximab in adults with CD per quality-adjusted life year (QALY) gained.
A probabilistic cohort Markov model with 8-week cycle lengths was constructed to estimate the incremental costs and effects of switching over a 5-year time horizon from a public payer perspective. Base-case clinical inputs were obtained from NOR-SWITCH subgroup analyses and other published trials. Costs were obtained from Canadian sources. A total of 10,000 simulations were run. Sensitivity analysis was used to test the robustness of the results to variations in uncertain parameters.
Switching to biosimilar infliximab was less costly but also less effective with incremental savings of $46,194 (95% confidence interval [CI]: $42,420, $50,455) and a loss in QALYs of -0.13 (95% CI: -0.16, -0.07). Eighty-three per cent of the simulations demonstrated incremental cost savings and an incremental loss of effectiveness. The model was sensitive to differences in rates of disease worsening between reference and biosimilar infliximab.
While biosimilar infliximab is associated with incremental savings for patients on maintenance therapy who are switched from reference infliximab, funding decision makers must decide whether a small loss of effectiveness is justified. Further evidence will help to inform reimbursement policy.
低成本的英夫利昔单抗生物类似药可能解决成人克罗恩病（CD）治疗中的可负担性问题，然而，关于从参比制剂转换为生物类似药的成本效益的证据仍很有必要。本研究的目的是评估在成人CD患者中，与维持使用参比英夫利昔单抗相比，转换为生物类似药英夫利昔单抗每获得一个质量调整生命年（QALY）的增量成本。
构建了一个周期长度为8周的概率性队列马尔可夫模型，从公共支付方的角度估计5年时间跨度内转换治疗的增量成本和效果。基础病例的临床数据来自NOR - SWITCH亚组分析和其他已发表的试验。成本数据来自加拿大。共进行了10,000次模拟。采用敏感性分析来检验结果对不确定参数变化的稳健性。
转换为生物类似药英夫利昔单抗成本更低，但效果也更差，增量节省成本46,194美元（95%置信区间[CI]：42,420美元，50,455美元），QALY损失为 - 0.13（95% CI： - 0.16， - 0.07）。83%的模拟显示有增量成本节省但效果有增量损失。该模型对参比制剂和生物类似药英夫利昔单抗之间疾病恶化率的差异敏感。
虽然生物类似药英夫利昔单抗对于从参比制剂转换过来的维持治疗患者可带来增量成本节省，但资助决策者必须决定有效性的小幅损失是否合理。更多证据将有助于为报销政策提供信息。
