Socal Mariana P, Ezebilo Ijeamaka, Bai Ge, Anderson Gerard F
Department of Health Policy and Management, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
Am J Health Syst Pharm. 2021 Jan 22;78(3):216-221. doi: 10.1093/ajhp/zxaa376.
Biosimilars can generate competition and provide cost savings over reference biologics for the Medicare program and beneficiaries. The extent to which these benefits can be realized in the Medicare Part D program depends on how biosimilars and biologics are placed in the formulary. We conducted a study to examine Medicare formulary placement of the first biologic to have 2 biosimilars on the market-infliximab and its biosimilars infliximab-dyyb and infliximab-abda.
All standalone and Medicare Advantage (MA) prescription drug plans (PDPs) offered in Medicare Part D were examined between September 2016 (ie, at the end of the last quarter before the launch of the first infliximab biosimilar) and September 2018, at which time a second biosimilar had been on the market for about 14 months. When PDPs covered both the reference biologic and a biosimilar, we compared the cost-sharing tier and the frequency of prior authorization and step therapy requirements for each drug.
Nearly all PDPs covered infliximab throughout the study period. By September 2018, 31.7% of MA plans and 14.9% of standalone PDPs were covering a biosimilar on the market. Nearly all plans that covered a biosimilar also covered the reference product. Most plans (98% of standalone PDPs and 89% of MA plans) had placed prior authorization restrictions on both the biologic and the biosimilar. All plans covering both products placed them in the same cost-sharing tier. No plan required step therapy for either product.
Formulary placement of infliximab biologic and biosimilars in Medicare Part D is not optimized to generate cost savings for the Medicare program and beneficiaries, whose cost sharing is often based on the drug's list price. The Medicare program should provide incentives for PDPs to expand biosimilar coverage.
生物类似药能够带来竞争，并为医疗保险计划及其受益人节省相对于参照生物制剂的成本。这些益处能在医疗保险D部分计划中实现的程度，取决于生物类似药和生物制剂在药品处方集里的安排方式。我们开展了一项研究，以考察市场上有两种生物类似药的首个生物制剂——英夫利昔单抗及其生物类似药英夫利昔单抗-dyyb和英夫利昔单抗-abda在医疗保险药品处方集中的安排情况。
对2016年9月（即首个英夫利昔单抗生物类似药上市前最后一个季度末）至2018年9月期间医疗保险D部分提供的所有独立及医疗保险优势（MA）处方药计划（PDP）进行了考察，此时第二种生物类似药已上市约14个月。当PDP同时涵盖参照生物制剂和一种生物类似药时，我们比较了每种药物的费用分摊层级以及预先授权和逐步治疗要求的频率。
在整个研究期间，几乎所有PDP都涵盖英夫利昔单抗。到2018年9月，31.7%的MA计划和14.9%的独立PDP涵盖了市场上的一种生物类似药。几乎所有涵盖生物类似药的计划也都涵盖了参照产品。大多数计划（98%的独立PDP和89%的MA计划）对生物制剂和生物类似药都设置了预先授权限制。所有同时涵盖这两种产品的计划都将它们置于相同的费用分摊层级。没有计划对任何一种产品要求逐步治疗。
医疗保险D部分中英夫利昔单抗生物制剂和生物类似药在药品处方集中的安排并未优化，无法为医疗保险计划及其受益人节省成本，他们的费用分摊通常基于药品的标价。医疗保险计划应激励PDP扩大生物类似药的覆盖范围。
