Use of a blood-based biomarker assay for patients with metastatic breast cancer reduced the utilization of traditional monitoring and resulted in net savings three times the spend on the assay itself, according to a study presented at the 2021 San Antonio Breast Cancer Symposium.

“Management of postmenopausal women with [HR-positive metastatic breast cancer] includes monitoring with tumor markers, CT scans, and bone scans. DiviTum® TKa is a blood-based biomarker assay developed to monitor and predict treatment response in [HR-positive] metastatic breast cancer,” explained Gregory F. Guzauskas, PhD, University of Washington, Seattle, and colleagues.

“Uptake of DiviTum® TKa monitoring may decrease usage of traditional monitoring technologies and potentially avoid prolongation of futile treatments,” they continued.

This study aimed to estimate the budget impact of the blood-based biomarker assay on monitoring utilization and cancer treatment among patients with postmenopausal HR-positive metastatic breast cancer in a 1-million-member US health plan.

Researchers developed a budget impact model which included a population of postmenopausal women with HR-positive metastatic breast cancer who received first-line treatment with CDK4/6 inhibitors plus an aromatase inhibitor. The model compared the inclusion of DiviTum® TKa to standard monitoring practices vs standard monitoring practices alone.

Two scenarios were explored: (1) the uptake of DiviTum® TKa reduces the frequency of traditional metastatic breast cancer monitoring tools and (2) in addition to scenario 1, DiviTum® TKa predicts treatment futility 1 month in advance of radiological disease progression.

Researchers assumed adherence to DiviTum® TKa and traditional monitoring schedule was 100%, based on clinical guidelines and expert opinion. The impact of DiviTum® TKa on therapy utilization was based on public literature and expert opinion.

Modeled costs included DiviTum® TKa, NCCN-recommended treatments, imaging, biomarker testing, and adverse events. Unit costs were based on CMS fee schedules and wholesale acquisition costs. SEER and publicly available data were used to estimate annual rates of incident and recurrent postmenopausal HR-positive metastatic breast cancer. Total and per-member per-month (PMPM) costs were calculated with a 3-year time horizon.

The model found that 17 women who progressed to metastatic breast cancer and 4 who developed de novo metastatic breast cancer received first-line treatment with CDK4/6 inhibitors plus an aromatase inhibitor each year. In scenario 1, the addition of 404 DiviTum® TKa assays led to 203 fewer CT scans, 93 fewer bone scans, and 60 fewer biomarker tests over the 3-year time horizon. In scenario 2, the mean time on treatment with CDK4/6 inhibitors plus an aromatase inhibitor was 28 months without DiviTum® TKa and 27 months with DiviTum® TKa.

Total spend on DiviTum® TKa testing was $161,600. In scenario 1, accounting for test costs only resulted in incremental cost of $38,000 and a PMPM cost of $.001. In scenario 2, accounting for time spent on futile therapy resulted in incremental cost savings of $465,600 and a PMPM cost-savings of $.013.

“In this analysis, use of DiviTum® TKa reduced use of a substantial proportion of traditional monitoring. If use of DiviTum® TKa can also predict lack of benefit from costly CDK4/6i therapy and clinicians act on that information in a timely fashion, this can result in substantial cost savings to patients and health plans,” Dr Guzauskas and colleagues concluded.

Guzauskas GF, Calrson JJ, Dann RA, et al. The budget impact of the DiviTum® TKa assay in postmenopausal women with hormone receptor positive metastatic breast cancer. Presented at: 2021 San Antonio Breast Cancer Symposium; December 7-10, 2021; virtual. Abstract P3-03-05.