Abstract PD2-2: Final efficacy results of the randomized phase III BEATRICE trial evaluating adjuvant bevacizumab-containing therapy in triple-negative early breast cancer

Abstract

Abstract Background: In the metastatic and neoadjuvant settings, bevacizumab (BEV) significantly improves progression-free survival and pathologic complete response rates, respectively, when combined with chemotherapy (CT) for breast cancer. In contrast, accumulating phase III data in the adjuvant setting in both colon and breast cancers have not shown a benefit from the addition of 1 year of BEV to standard therapy. Primary efficacy results from the BEATRICE trial in early triple-negative breast cancer (TNBC) showed no significant difference in invasive disease-free survival (IDFS; primary outcome measure) between adjuvant BEV and non-BEV regimens after events in 393 (15%) of the 2591 randomized patients (stratified hazard ratio 0.87 [95% CI 0.72–1.07]) [Cameron et al. Lancet Oncol 2013]. The low number of events at the prespecified primary analysis of BEATRICE, the largest prospective trial in patients with centrally confirmed early TNBC, suggested that the prognosis for patients with TNBC was better than previously thought. This observation, together with data from retrospective series suggesting that most recurrences occur within 3–5 years of TNBC diagnosis [Dent et al. 2007], makes longer follow-up important to fully understand outcomes in this patient population and the natural history of TNBC. We now report extended follow-up data from the prespecified overall survival (OS) analysis of BEATRICE. Methods: Eligible patients in the open-label randomized multinational phase III BEATRICE trial had centrally confirmed triple-negative and/or basal-like operable primary invasive breast cancer (pT1a-pT3). CT (anthracycline and/or taxane based) was selected by the investigator for each patient. After definitive surgery, patients were randomized 1:1 to receive ≥4 cycles of either CT alone or the same CT + 1 year of BEV (5 mg/kg/wk equivalent). Stratification factors were nodal status (0 vs 1-3 vs ≥4 involved nodes), selected CT backbone (anthracycline vs taxane vs both), hormone receptor status (negative vs low), and surgery (breast conserving vs mastectomy). Secondary outcome measures were OS, breast cancer-free interval, disease-free survival (DFS), distant DFS, and safety (NCI CTCAE v3.0). The prespecified final OS analysis will be performed approximately 52 months after randomization of the last patient into the study. Results: The planned clinical cut-off date is June 30, 2014, when the duration of follow-up will be 4.3–6.5 years in those who have not died or been lost to follow-up. OS (with at least 284 events; 11%), updated IDFS with longer follow-up, and long-term safety results will be analyzed and reported. Citation Format: Richard Bell, Julia Brown, Mahesh Parmar, Mark Toi, Thomas Suter, Guenther Steger, Xavier Pivot, John Mackey, Christian Jackisch, Rebecca Dent, Peter Hall, Almut Mecke, Leilani Morales, Louise Provencher, Elzbieta Staroslawska, Roberto Hegg, Laurence Vanlemmens, Andreas Kirsch, Andreas Schneeweiss, Norikazu Masuda, Friedrich Overkamp, David Cameron. Final efficacy results of the randomized phase III BEATRICE trial evaluating adjuvant bevacizumab-containing therapy in triple-negative early breast cancer [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr PD2-2.