Keith Michael S, Wilson Rosamund J, Preston Peter, Copley J Brian
Shire, Wayne, Pennsylvania, USA.
Spica Consultants, Marlborough, Wiltshire, United Kingdom.
Clin Ther. 2014 Sep 1;36(9):1276-86. doi: 10.1016/j.clinthera.2014.06.036. Epub 2014 Jul 26.
Sevelamer hydrochloride (SH) and lanthanum carbonate (LC) are calcium-free phosphate binders used in the clinical management of hyperphosphatemia in patients with end-stage renal disease (ESRD). The objective of this analysis was to assess the cost-effectiveness of LC monotherapy compared with SH monotherapy in US patients with ESRD in a clinical practice setting.
This was a post hoc assessment of phosphate binder costs among US patients with ESRD who converted from SH to LC monotherapy in a previously published, 16-week, Phase IV, real-world study. Calculations of drug costs used both average wholesale price (AWP) and wholesale acquisition cost (WAC).
There were 953 patients with available baseline SH dose data; 950 also had a recorded LC dose >0 mg at baseline, and 691 had dose data available for both SH at baseline and LC at week 16 (post hoc analysis population). Baseline demographic characteristics were similar in excluded patients and the post hoc analysis population. Mean (SD) serum phosphate levels were 5.91 (1.66) mg/dL at baseline and 5.93 (1.85) mg/dL after conversion to LC monotherapy for 16 weeks. Mean AWP costs were US$35.72 (16.89) per day at baseline and US$24.69 (8.28) per day at week 16, yielding an overall mean cost change (defined as LC cost - SH cost) of -US$11.03 (16.37) per day in favor of LC. The overall mean WAC cost change was -US$9.17 (13.64) per day. Within baseline SH dose subgroups 2400 to 4800, >4800 to 7200, >7200 to 9600, and >9600 mg/d, the mean AWP cost change ranged from US$2.78 (9.26) per day in favor of SH for the 2400- to 4800-mg/d subgroup to -US$33.15 (12.58) per day in favor of LC for the >9600-mg/d subgroup. Mean WAC cost changes showed a similar trend, ranging from US$2.33 (7.72) per day to -US$27.59 (10.48) per day. Linear regression analyses revealed that the inflection SH doses corresponding to a mean cost change of zero were 4905 mg/d (AWP) and 4908 mg/d (WAC). For the 455 (66%) patients in the post hoc analysis population who had baseline SH doses at least as high (≥ 5600 mg/d) as these point estimates, the mean SH:LC tablet ratio was ≥ 3.7, indicating a mean reduction in the tablet burden after conversion to LC of ≥ 73%.
This real-world assessment of comparative phosphate binder drug costs between SH and LC among US patients with ESRD indicates that average cost savings with LC use increased with increasing SH doses. Conversion to LC from SH ≥ 5600 mg/d reduced drug costs and tablet burden while maintaining serum phosphate levels.
碳酸司维拉姆（SH）和碳酸镧（LC）是用于终末期肾病（ESRD）患者高磷血症临床管理的无钙磷结合剂。本分析的目的是在临床实践环境中评估LC单药治疗与SH单药治疗相比，对美国ESRD患者的成本效益。
这是一项对美国ESRD患者中从SH转换为LC单药治疗的磷结合剂成本的事后评估，该数据来自之前发表的一项为期16周的IV期真实世界研究。药物成本计算使用了平均批发价（AWP）和批发采购成本（WAC）。
有953例患者有可用的基线SH剂量数据；950例患者在基线时也记录了LC剂量>0mg，691例患者在基线时的SH剂量数据和第16周时的LC剂量数据均可用（事后分析人群）。排除患者和事后分析人群的基线人口统计学特征相似。基线时血清磷平均（标准差）水平为5.91（1.66）mg/dL，转换为LC单药治疗16周后为5.93（1.85）mg/dL。基线时平均AWP成本为每天35.72（16.89）美元，第16周时为每天24.69（8.28）美元，总体平均成本变化（定义为LC成本 - SH成本）为每天 - 11.03（16.37）美元，有利于LC。总体平均WAC成本变化为每天 - 9.17（13.64）美元。在基线SH剂量亚组2400至4800、>4800至7200、>7200至9600和>9600mg/d中，平均AWP成本变化范围从2400至4800mg/d亚组中有利于SH的每天2.78（9.26）美元到>9600mg/d亚组中有利于LC的每天 - 33.15（12.58）美元。平均WAC成本变化显示出类似趋势，范围从每天2.33（7.72）美元到每天 - 27.59（10.48）美元。线性回归分析显示，对应平均成本变化为零的拐点SH剂量分别为4905mg/d（AWP）和4908mg/d（WAC）。在事后分析人群中，455例（66%）基线SH剂量至少与这些点估计值一样高（≥5600mg/d）的患者中，平均SH:LC片剂比例≥3.7，表明转换为LC后片剂负担平均降低≥73%。
这项对美国ESRD患者中SH和LC之间比较磷结合剂药物成本的真实世界评估表明，使用LC的平均成本节约随着SH剂量的增加而增加。从SH≥5600mg/d转换为LC可降低药物成本和片剂负担，同时维持血清磷水平。
