OBJECTIVES: To estimate the clinical events and healthcare resource utilization (HRU) among a cohort of ER+/HER2-/ESR1-mutated advanced or metastatic breast cancer patients treated with SOC versus elacestrant.

METHODS: A decision analytic model estimated the clinical events and HRU offsets resulting from treating patients with elacestrant over a 3-year time horizon. The analysis took a community oncology facility-level perspective and estimated the average number of patients with ER+, HER2-, ESR1-mutated advanced or metastatic breast cancer with disease progression following at least one line of endocrine therapy treated at a facility each year. Clinical, epidemiological, HRU, and indirect inputs were based on clinical trials and published literature. Outcomes included the number of deaths avoided, adverse events avoided, patients requiring subsequent treatment, fulvestrant administrations avoided, reduction in emergency room-, inpatient-, and outpatient visits, and the number of hours of missed work and impaired activity avoided. The model analyzed a scenario in which the current treatment mix of eligible patients converted to elacestrant.

RESULTS: Among an average of 223 breast cancer patients per facility, nineteen patients were estimated to be eligible for treatment each year, totaling 56 patients over the modeled time horizon. Based on the model, elacestrant led to a reduction in the number of clinical events with 3 deaths and 23 Grade ≥3 adverse events avoided. Reductions in HRU were observed with 113 less hospital days, 684 less fulvestrant administrations, and a reduction in 1,277 outpatient visits, 195 inpatient visits, and 49 emergency room visits. The number of hours of missed work avoided and activity impairment avoided were estimated to be 5,068 hours and 5,265 hours, respectively.

CONCLUSIONS: The model showed that among the explored patient population, treating patients with elacestrant resulted in a meaningful reduction of clinical events and HRU while showing improvements in work productivity and activities of daily living.