462P - Health outcomes of treatment sequences with eribulin or other single agents’ chemotherapy for treating relapsed metastatic HER2-negative breast cancer

Background

Treatment of HER2- metastatic breast cancer (MBC) is driven by biomarker status (HR+ vs. triple negative [TNBC]). Single agent chemotherapy (ChT) is recommended for patients relapsing on targeted therapies including endocrine therapy or immunotherapies, with ChTs optimal sequence not yet established. The study objective was to compare the health outcomes (life years [LYs], quality adjusted LYs [QALYs]) in sequences starting ChT with eribulin (ERI), capecitabine (CAP) or treatment of physician choice (TPC), in second-line (2L) to fourth-line (4L) settings.

Methods

A stochastic microsimulation was developed tracking a MBC cohort through 2L-4L, with patients starting the next line of therapy due to progression or serious adverse events (SAEs) discontinuation. After each line, patients could receive another active therapy or best supportive care. Treatment sequences across three treatment pathways, capturing ChT initiation in 2L, 3L or 4L (the table), were based on clinical guidelines, real-world data and clinical interviews. Clinical inputs were stratified by biomarker and treatment line, with QALYs driven by progression status, response rates and SAEs. The analysis time horizon was 20 years, with outcomes discounted at 3.5%.

Results

In the HR+ subgroup, sequences with ERI used earlier than CAP/TPC led to higher LYs (1.62 - 2.24 vs. 1.57 - 2.22) and QALYs (0.75 -1.28 vs. 0.69 – 1.27), across the three pathways, driven by improved ERI efficacy and safety profile vs. CAP/TPC. Similarly, in the TNBC subgroup, earlier use of ERI vs. CAP/TPC led to higher LYs (1.19 - 1.64 vs. 1.16 - 1.63) and QALYs (0.55 - 0.86 vs. 0.49 - 0.85) when used in 2L or 4L, while 3L ERI vs. 3L TPC led to higher QALYs (0.70 vs. 0.67 - 0.68), but comparable LYs (1.40). The results were consistent across the sensitivity analyses conducted. Table: 462P

CDK = cyclin-dependent kinase; FUL = fulvestrant; PAC = paclitaxel; PAL = palbociclib; SAC = sacituzumab. Note: TPC includes vinorelbine, gemcitabine, capecitabine, taxanes, anthracyclines and hormonal therapy.

Conclusions

Starting single agent ChT with ERI vs. CAP or TPC is associated with improved health outcomes for 2L-4L HER2- MBC management.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Eisai.

Disclosure

S. Rivolo: Other, Institutional, Research Funding, Simone Rivolo is employed by Evidera, a part of Thermo Fisher Scientific, which received consulting fees for research activities from Eisai.: Eisai. K. Ndirangu: Financial Interests, Institutional, Full or part-time Employment, Kerigo Ndirangu is an employee of Eisai Inc.: Eisai. D. Teloian: Other, Institutional, Research Funding, Diana Teloian is employed by Evidera, a part of Thermo Fisher Scientific, which received consulting fees for research activities from Eisai.: Eisai. A. Ambavane: Other, Institutional, Research Funding, Apoorva Ambavane is employed by Evidera, a part of Thermo Fisher Scientific, which received consulting fees for research activities from Eisai.: Eisai. C. Jackisch: Financial Interests, Personal, Invited Speaker: Roche, Exact Sciences, Gilead, Molecular Health; Financial Interests, Personal, Advisory Board: AstraZeneca, Novartis, Daiichi Sankyo, Pfizer. P.S. Hall: Financial Interests, Institutional, Research Funding: Lilly, Eisai, Novartis, Merk, Gilead, Sanofi, Roche, SeaGen.