OBJECTIVES

: Eculizumab is the first FDA/EMA approved therapy for atypical hemolytic uremic syndrome (aHUS). This study investigated the impact of eculizumab treatment on hospitalization in patients with aHUS/thrombotic microangiopathy (TMA).

METHODS

: This retrospective study included patients in the Optum^® Clinformatics^® Data Mart commercial and the Medicare Advantage claims databases, from January 2007 to March 2019, who met inclusion criteria for aHUS/TMA as defined by diagnostic codes or laboratory criteria and/or end-organ involvement. The index date was defined by the date of aHUS/TMA diagnosis or first eculizumab prescription. Only patients with continuous enrollment of ≥12 months pre- and ≥18 months post-index date were included. All-cause hospitalizations and hospital length of stay were qualitatively described for patients treated with and without eculizumab.

RESULTS

: Of the 431 patients who met the inclusion criteria, 16 (3.7%) received eculizumab. Comparing 0–6 months pre- and 13‒18 months post-index date, the change in mean number of hospitalizations per patient was –1.0 (from 3.0 to 2.0) and +0.2 (from 1.8 to 2.0) in patients treated with and without eculizumab, respectively. Over the same period, the change in mean hospital length of stay decreased by 7.9 days (from 11.7 to 3.8 days) and 0.5 days (from 9.0 to 8.5 days) in patients treated with and without eculizumab, respectively.

CONCLUSIONS

: These data suggest that eculizumab may reduce the number and duration of hospitalizations potentially resulting in long-term decreases in health resource utilization and medical expenditure in patients with aHUS/TMA. Sample sizes were too small for statistical comparisons, and variable treatment patterns, disease severity and comorbid conditions in patients precluded direct comparison. Further studies are required to support these observations.