Cost-minimization analysis of lanthanum carbonate versus sevelamer hydrochloride in US patients with end-stage renal disease.
PURPOSE
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.


METHODS
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).


FINDINGS
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%.


IMPLICATIONS
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.