61 Economic Burden of Neutropenia Among Patients Treated for HR+/HER2– and Triple-Negative Metastatic Breast Cancer in the United States: A Retrospective Claims Analysis

Background

Neutropenia is a common adverse event associated with metastatic breast cancer (mBC) treatments. Little is known about the economic burden of neutropenia in mBC to US health systems. The goal of this research is to evaluate all-cause and neutropenia-related costs and health care resource utilization (HCRU) among patients with hormone receptor (HR)–positive/HER2-negative and triple-negative mBC.

Materials and Methods

Patients with greater than or equal to 1 ICD-10 diagnosis code for mBC were identified in IQVIA PharMetrics Plus claims database from September 2019 to June 2024. Selection criteria included continuous enrollment 6 months before and greater than or equal to 3 months after the index (diagnosis of mBC) date, receipt of mBC treatment post index, and no diagnosis codes for other cancers less than or equal to 15 months preindex. Study patients were categorized into HR-positive/HER2-negative mBC or metastatic triple-negative breast cancer (mTNBC) cohorts based on mBC treatment post index using treatment-based proxies. All-cause and neutropenia-related HCRU and costs per patient per month (PPPM) were reported by treatment category across the duration of any line of mBC treatment.

Results

Among HR-positive/HER2-negative patients with mBC (n=4650; 98.1% female; mean age, 55 years; 94.0% NCI comorbidity index<1), neutropenia was experienced by 48.5%, 32.4%, 24.8%, and 8.8% of patients over the duration of sacituzumab govitecan (SG; n=68), chemotherapy (CT; n=4507), other targeted therapy (TT; n=1690), and endocrine therapy (ET; n=3325) regimens, respectively. Among patients with mTNBC (n=1409; 99.4% female; mean age, 56 years; 91.1% NCI comorbidity index<1), neutropenia was experienced by 43.9%, 36.1%, and 39.4% of patients over the duration of SG (n=246), CT (n=482), and TT (n=1299) regimens. All-cause (and neutropenia-related, %) costs PPPM were $44,921 ($8046, 18%), $13,386 ($1502, 11%), $19,299 ($232, 1%), and $6110 ($75, 1%) during receipt of SG, CT, TT, and ET regimens, respectively, for patients with HR-positive/HER2-negative mBC and $44,568 ($7720, 17%), $13,892 ($2294, 17%), and $25,980 ($1825, 8%) over the duration of SG, CT, and TT regimens for patients with mTNBC (Table). The proportion of patients making a neutropenia-related inpatient and outpatient visit was 18% and 35%, 5% and 31%, 2% and 24%, and 0% and 9% during receipt of SG, CT, TT, and ET regimens, respectively, for patients with HR-positive/HER2-negative mBC and 9% and 40%, 8% and 34%, and 10% and 36% during receipt of SG, CT, and TT regimens for patients with mTNBC.

Conclusions

Neutropenia is a common adverse event with substantial impact to the overall economic burden among patients with mBC. An unmet need exists for treatments that balance costs of care with clinical benefit for these patients.