Salt Lake City Veterans Affairs Medical Center and Department of Internal Medicine, University of Utah, Salt Lake City, UT.
Puget Sound Veterans Affairs Medical Center, Seattle, WA.
Medicine (Baltimore). 2024 Sep 13;103(37):e39476. doi: 10.1097/MD.0000000000039476.
The Veterans Health Administration (VHA) listed the infliximab (IFX) biosimilar, IFX-dyyb (Inflectra), on the Veterans Affairs National Formulary (VANF) in May 2017. In September 2018, biosimilar IFX-abda (Renflexis) became the VANF IFX product. The recommended formulary changes from one IFX biosimilar to another provided a unique opportunity to study IFX utilization patterns in IFX-naïve Veterans with Inflammatory Bowel Disease (IBD). This study aimed to describe IFX and healthcare utilization during the 365 days after initiation with IFX reference product (RP) or biosimilars IFX-dyyb and IFX-adba. This descriptive study was performed using the VHA Corporate Data Warehouse. All Veterans initiated on IFX-RP (Remicade) or biosimilars IFX-dyyb and IFX-adba between September 1, 2016 and December 30, 2019 were included and followed for 365 days. Veterans enrolled in the VHA for at least 365 days with no evidence of IFX before their index date were considered IFX-naïve. Continuous data on IFX use, laboratory measurements, and healthcare utilization were reported with means, 95% confidence interval (CI), medians, and interquartile ranges. Frequency, proportions, and 95% CIs were presented for categorical variables. Statistical tests included ANOVA and Kruskal-Wallis for continuous outcomes, Poisson regression for count-based outcomes (i.e., healthcare utilization visits), and Chi-square for dichotomous outcomes. The study identified 1763 IFX-naïve patients with IBD, and 785, 441, and 537 was indexed to RP, IFX-dyyb, and IFX-adba, respectively. Statistical differences were observed in IFX utilization measures related to dosing, adherence, and persistence. The proportion of days covered (PDC) during the 365-day follow-up period varied among the IFX groups: IFX-RP at 66%, IFX-dyyb at 60%, and IFX-abda at 69% (P value < .001). Persistence with the index IFX product during the 365-day follow-up period also varied: IFX-RP at 43%, IFX-dyyb at 32%, and IFX-abda at 51% (P value < .001). Healthcare utilization and laboratory findings were similar among the IFX groups. IFX utilization and laboratory patterns were clinically similar among the IFX biosimilars and RP groups, suggesting that providers did not modify their practice with biosimilars. Statistically significant differences in IFX utilization patterns are explained by formulary dynamics when the VANF product switched from IFX-dyyb to IFX-abda.
退伍军人健康管理局 (VHA) 于 2017 年 5 月将英夫利昔单抗 (IFX) 的生物类似药 IFX-dyyb (Inflectra) 列入退伍军人事务部国家处方集 (VANF)。2018 年 9 月，生物类似药 IFX-abda (Renflexis) 成为 VANF 的 IFX 产品。从一种 IFX 生物类似药到另一种 IFX 生物类似药的推荐处方变化为研究 IFX 利用模式提供了一个独特的机会，这些模式适用于患有炎症性肠病 (IBD) 的 IFX 初治退伍军人。本研究旨在描述在开始使用 IFX 参比产品 (RP) 或生物类似药 IFX-dyyb 和 IFX-abda 后的 365 天内 IFX 和医疗保健的利用情况。这项描述性研究使用了 VHA 公司数据仓库。2016 年 9 月 1 日至 2019 年 12 月 30 日期间，所有开始使用 IFX-RP (Remicade) 或生物类似药 IFX-dyyb 和 IFX-abda 的退伍军人都被纳入研究，并随访 365 天。在指数日期之前至少有 365 天在 VHA 登记且没有 IFX 证据的退伍军人被认为是 IFX 初治患者。报告了 IFX 使用、实验室测量和医疗保健利用的连续数据，包括平均值、95%置信区间 (CI)、中位数和四分位距。对分类变量报告了频率、比例和 95%CI。连续结果的统计检验包括 ANOVA 和 Kruskal-Wallis，计数结果（即医疗保健利用就诊次数）的统计检验采用泊松回归，二项结果的统计检验采用卡方检验。该研究确定了 1763 名患有 IBD 的 IFX 初治患者，分别有 785、441 和 537 名患者被分配到 RP、IFX-dyyb 和 IFX-abda。与剂量、依从性和持久性相关的 IFX 利用措施存在统计学差异。在 365 天的随访期间，各组的覆盖天数比例 (PDC) 不同：IFX-RP 为 66%，IFX-dyyb 为 60%，IFX-abda 为 69%（P 值<0.001）。在 365 天的随访期间，对指数 IFX 产品的持久性也存在差异：IFX-RP 为 43%，IFX-dyyb 为 32%，IFX-abda 为 51%（P 值<0.001）。IFX 组的医疗保健利用和实验室发现相似。IFX 生物类似药和 RP 组的 IFX 利用和实验室模式具有临床相似性，这表明提供者在使用生物类似药时没有改变其治疗方法。当 VANF 产品从 IFX-dyyb 切换到 IFX-abda 时，IFX 利用模式的统计学显著差异可通过处方动态来解释。
