Abstract OT3-07-01: Real-World Data on First-line Treatment of HR-positive, HER2-negative, Metastatic Breast Cancer in Brazil (BRAVE Study/LACOG 0221)

Abstract

Background: It is estimated that 50 thousand patients live with metastatic breast cancer (MBC) in Brazil. A recent Brazilian registry (LACOG 0312) on MBC demonstrated a median overall survival (OS) by breast subtype of 15 months for triple negative, 23 months for HER2 positive, and 42 months for Luminal tumors, which are very similar to developed countries except the HER2 positive group which have limited access to targeted agents in the public health system. Recently, CDK 4/6 inhibitors were approved for the treatment of HR+ HER2-negative MBC with an improvement in progression-free survival (PFS) and ribociclib and abemaciclib demonstrating benefit in OS over endocrine therapy alone, establishing the standard of care in first-line setting for this BC subtype. In Brazil, disparities exist in the incorporation of novel anticancer agents between public and private health systems limiting treatment options for patients with HR+ HER2- negative MBC in the public system, which covers most of the population. The BRAVE study aims to describe the patient journey and current patterns of care for HR+ HER2-negative MBC to identify possible gaps and how health insurance type influences treatment patterns in Brazil. Trial Design: This is an observational, retrospective cohort study. All patients diagnosed with mBC (either de novo or recurrent) in the period of January 2018 to December 2020 at participating centers will be included. Data will be collected from medical records. No interventions are proposed. Enrollment of a total of 300 patients (150 patients from public health care system and 150 patients from private health care system) is planned. ClinicalTrials.gov identifier: NCT05034393. Eligibility: Inclusion criteria: women ≥18 years old; histologically confirmed HR-positive HER2-negative invasive breast cancer; HR-positive, defined as 1% to 100% of tumor nuclei positive for ER and/or PgR as per ASCO/CAP Guideline 2020 or Allred score of ≥3; HER2-negative, defined as IHC result is 0/1+ or 2+ with ISH negative as per ASCO/CAP Guideline 2018; diagnosed with de novo or recurrent metastatic breast cancer between January 2018 and December 2020. Exclusion criteria: male BC; first-line treatment for mBC received through clinical trial. Specific Aims: Primary objective is to describe the first-line (1L) treatment of HR-positive, HER2-negative mBC in Brazil. Secondary objectives are to describe progression-free survival (PFS) in the 1L setting until month 24; describe and compare the 1L treatment of HR-positive, HER2-negative mBC and PFS until month 24 according to the health care coverage (public vs. private); describe timelines from symptoms, histopathological diagnosis, molecular test, and treatment; describe the mBC pathological characterization; describe frequency of diagnostic tests to define breast cancer molecular subtypes; describe the subsequent line of treatment and corresponding PFS; describe overall survival (OS); evaluate PFS and OS according to visceral vs. non-visceral metastatic disease, primary endocrine resistance vs. acquired endocrine resistance, de novo versus recurrent disease, public vs. private health system and pre vs postmenopausal status. Statistical Methods: No a priori sample size calculation was performed. The expected sample size of 150 patients in each group allows description of the proportion of patients using CDK 4/6 inhibitors with two-sided 90% confidence interval ranging from 53.4% to 66.6% when the expected proportion is 60% in the private health system. Present Accrual and Target Accrual: A total of 12 sites of 14 planned were activated. The first patient was enrolled on February 8, 2022. As of June 24, 2022, a total of 122 patients were enrolled, 86 from public and 36 from private health system. The target accrual of 300 patients is expected to be completed by November 2022. Results are expected to be presented by April 2023. Funding: Novartis. Acknowledgements: SAS. Citation Format: Gustavo Werutsky, Tomás Reinert, Daniela D. Rosa, Romualdo Barroso-Sousa, Heloísa Resende, Poliana A. Signorini, Juliana G. Martins Fagundes, Jose Marcio B. Figueiredo, Eduardo Cronemberger, Aline C. Vieira, Jorge Henrique Santos Leal, Luiza Nardin Weis, Ludmila Thommen, Rafaela G. Jesus, Gustavo Gössling, José Bines. Real-World Data on First-line Treatment of HR-positive, HER2-negative, Metastatic Breast Cancer in Brazil (BRAVE Study/LACOG 0221) [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr OT3-07-01.