Abstract P3-03-05: The budget impact of the DiviTum®TKa assay in postmenopausal women with hormone receptor positive metastatic breast cancer
Authors: Guzauskas Gregory F. , Carlson Josh J. , Dann Robert A. , Ramsey Scott D. 
Published: March 2022

Abstract
Background. Management of postmenopausal women with HR+ mBC 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 hormone receptor positive metastatic breast cancer (HR+ mBC). Uptake of DiviTum®TKa monitoring may decrease usage of traditional monitoring technologies and potentially avoid prolongation of futile treatments. Our objective was to estimate budget impacts of the assay on monitoring utilization and cancer treatment on a postmenopausal HR+ mBC population in a 1,000,000 member U.S. health plan. Methods. We developed a budget impact model comparing inclusion of DiviTum®TKa to standard monitoring practices vs. standard monitoring practices alone. The modeled population was post-menopausal women with HR+ mBC who receive 1st-line treatment with CDK4/6 inhibitors (CDK4/6i) + an aromatase inhibitor (AI). We explored two scenarios: (1) uptake of DiviTum®TKa reduces the frequency of traditional mBC monitoring tools, and 2) in addition to scenario 1, DiviTum®TKa predicts treatment futility 1 month in advance of radiological disease progression. We assumed patients were 100% adherent to DiviTum®TKa and traditional monitoring schedules, which were based on clinical guidelines and expert opinion. DiviTum®TKa’s impact on therapy utilization was based on published 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. Annual rates of incident and recurrent post-menopausal HR+ mBC were estimated from SEER and publicly available data. We calculated total and per-member per-month (PMPM) costs with a 3-year time horizon. Results. Each year, 17 women who progressed to mBC and 4 who developed de novo mBC were treated 1st-line with CDK4/6i+AI. In scenario 1 (monitoring only), addition of 404 DiviTum®TKa assays led to 203 fewer CT scans, 93 fewer bone scans, and 60 fewer biomarker tests over 3 years. In scenario 2 (impact on therapy), mean time on treatment with CDK 4/6i + AI therapy was 28 months without DiviTum®TKa testing; with DiviTum®TKa, 27 months; this led to treatment-related cost savings due to avoidance of time on futile therapy. Spend on DiviTum®TKa testing was $161,600. Accounting only for test costs (Scenario 1) resulted in incremental cost of $38,000 and a PMPM of $0.001. Accounting for time spent on futile therapy (Scenario 2) resulted in incremental cost savings of $465,600 and a PMPM cost-savings of $0.013. In one-way sensitivity analysis, results were most sensitive to DiviTum®TKa and CT scan costs, the proportion of mBC patients treated with CDK4/6i+AI, and CDK4/6i costs. Conclusions. 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. In this 2nd scenario, net savings on adding a new test to care were ~3X the spend on the test itself. Following approval and commercial introduction of DiviTum®TKa, future research on practice patterns will be necessary to validate our analysis.
Scenario 1WithoutDiviTum®TKaWithDiviTum®TKaDifferenceDifferencePMPMTotal Cost$14,518,998$14,556,984$37,986$0.001Monitoring$284,680$322,666$37,986$0.001Treatment$13,703,867$13,703,867$0$0.000Adverse Events$530,451$530,451$0$0.000Scenario 2WithoutDiviTum®TKaWithDiviTum®TKaDifferenceDifferencePMPMTotal Cost$14,518,998$14,053,431-$465,567-$0.013Monitoring$284,680$311,179$26,500$0.001Treatment$13,703,867$13,209,240-$494,627-$0.014Adverse Events$530,451$533,013$2,561$0.000
Citation Format: Gregory F. Guzauskas, Josh J. Carlson, Robert A. Dann, Scott D. Ramsey. The budget impact of the DiviTum®TKa assay in postmenopausal women with hormone receptor positive metastatic breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-03-05.