Faculty of Law and Faculty of Medicine, University of Zurich, Zurich, Switzerland.
Epidemiology, Biostatistics, and Prevention Institute, University of Zurich, Zurich, Switzerland.
JAMA Health Forum. 2024 Aug 2;5(8):e242530. doi: 10.1001/jamahealthforum.2024.2530.
Understanding how patent expirations affect drug prices is crucial because price changes directly inform accurate cost-effectiveness assessments. This study investigates the association between patent expirations and drug prices in 8 high-income countries and evaluates how the changes affect cost-effectiveness assessments.
To analyze how the expiration of drug patents is associated with drug price changes and to assess the implications of these price changes for cost-effectiveness evaluations.
DESIGN, SETTING, AND PARTICIPANTS: This cohort study performed an event study design using data from 8 high-income countries to assess the association between patent expiration and drug prices, and created a simulation model to understand the implications for cost-effectiveness analyses. The simulation cost-effectiveness model analyzed the implications of including or ignoring postpatent price dynamics.
Drug patent expiration.
Change in drug prices and differences in incremental cost-effectiveness ratios when considering vs ignoring postpatent price dynamics.
The sample comprised 505 drugs undergoing patent expiration in Australia, Canada, France, Germany, Japan, Switzerland, UK, and US. Price decreases were statistically significant over the 8 years after patent expiration, with the fastest price declines observed in the US: 32% (95% CI, 24%-39%) in year 1 after patent expiration and 82% (95% CI, 71%-89%) in the 8 years after patent expiration. Estimates for other nations ranged from a decrease of 64% in Australia to 18% in Switzerland in the 8 years after expiration. The cost-effectiveness simulation model indicated that not accounting for generic entry into the market may produce biased incremental cost-effectiveness ratios of 40% to -40%, depending on the scenario.
The findings of this cohort study demonstrate that drug prices were reduced substantially after patent expirations in high-income countries. Therefore, incorporating information on patent status and pricing dynamics in cost-effectiveness assessment analyses is necessary for producing accurate economic evaluations of new drugs.
了解专利到期如何影响药品价格至关重要，因为价格变化直接影响准确的成本效益评估。本研究调查了 8 个高收入国家专利到期与药品价格之间的关联，并评估了这些价格变化对成本效益评估的影响。
分析药品专利到期与药品价格变化之间的关系，并评估这些价格变化对成本效益评估的影响。
设计、设置和参与者：本队列研究采用事件研究设计，使用来自 8 个高收入国家的数据，评估专利到期与药品价格之间的关系，并建立模拟模型，以了解对成本效益分析的影响。模拟成本效益模型分析了包含或忽略专利后价格动态的影响。
药品专利到期。
专利到期后药品价格变化和考虑与忽略专利后价格动态时增量成本效益比的差异。
该样本包括在澳大利亚、加拿大、法国、德国、日本、瑞士、英国和美国专利到期的 505 种药物。专利到期后 8 年内，药品价格呈下降趋势，在美国观察到最快的价格下降：专利到期后第 1 年下降 32%（95%CI，24%-39%），8 年后下降 82%（95%CI，71%-89%）。其他国家的估计值从澳大利亚的下降 64%到瑞士的下降 18%不等。成本效益模拟模型表明，如果不考虑仿制药进入市场，可能会导致增量成本效益比产生 40%至-40%的偏差，具体取决于情况。
本队列研究的结果表明，高收入国家专利到期后药品价格大幅下降。因此，在成本效益评估分析中纳入专利状况和定价动态信息对于新药品的准确经济评估是必要的。
