Cost of disease progression among US patients with human epidermal growth factor receptor 2-positive metastatic breast cancer.

Aim: The objectives were to investigate the differences in per patient per month (PPPM) healthcare resource utilization (HCRU) and costs among commercially insured and Medicare Advantage patients with human epidermal growth factor receptor 2 positive (HER2+) metastatic breast cancer (mBC) who experience disease progression in 12 months compared with those who don't investigate the impact of progression timing on cumulative healthcare costs. Patients & methods: This claims-based study included patients diagnosed with mBC between 1 January 2013 and 30 April 2020 and received HER2-targeted therapy. Patients were categorized as progressed or nonprogressed. For objective one, monthly HCRU and costs were assessed for up to two lines of therapy (LOTs). Data were summarized descriptively and compared using a generalized linear model (GLM). For objective two, patients with at least 6 months of follow-up were assessed and cumulative healthcare costs were estimated in the 3 years following the start of LOT1 or LOT2 using a GLM and Kaplan-Meier weighting. Results: Among the 4113 patients in the study sample, 3406 had at least 12 months of follow-up (or less if due to death). Compared with nonprogressed patients, progressed patients had higher mean PPPM healthcare costs (LOT1: $22,014 vs $18,372, p < 0.001; LOT2: $19,643 vs $16,863, p = 0.001), and HCRU, including number of emergency room visits and inpatient stays (both p < 0.001) in the 12 months following LOT start. Progressed patients had higher 3-year mean cumulative healthcare costs than nonprogressed patients following LOT1 and LOT2 and this difference was greater for patients who progressed earlier. Conclusion: Disease progression was associated with significant increases in HCRU and costs. Delays in progression were associated with lower cumulative healthcare costs. Earlier use of more clinically effective treatments to delay progression may reduce the economic burden among these patients.