Abstract OT1-04-03: Randomized phase II study of induction bevacizumab, etoposide and cisplatin followed by whole brain radiotherapy (WBRT) versus WBRT alone in breast cancer with untreated brain metastases (A-PLUS)

Background For breast cancer (BC) patients with brain metastases (BM) who are not suitable for surgery/radiosurgery, whole brain radiotherapy (WBRT) remained the only standard treatment. Recently, we have demonstrated that bevacizumab preconditioning followed by etoposide and cisplatin (BEEP) is a highly effective treatment for BM of BC progressing from WBRT (Clin Cancer Res. 2015;21(8):1851). The CNS objective response rate is 77.1% according to volumetric criteria, and 60% according to RECIST 1.1. It has been demonstrated that enlarged brain tumor size is a predictor of WBRT failure. We hypothesized that, for BC with BM, induction BEEP treatment could decrease the size of brain metastases and thereby enhance effectiveness of WBRT. Methods This is a Phase II, randomized, open-labelled study (NCT02185352). Key inclusion criteria: BC with measurable brain metastatic tumor who had not received WBRT and not suitable for surgery or radiosurgery; KPS ≥30%. Key exclusion criteria: patients who had leptomeningeal metastases; history of disease progression during prior cisplatin treatment. In the experimental arm, patients will be treated by induction BEEP for three cycles followed by WBRT. In the control arm, patients will receive upfront WBRT for brain metastases. The BEEP regimen consist of bevacizumab (15 mg/kg) on Day 1 and, with a 1 day window period, followed by etoposide (70 mg/m 2 /day, Day 2 to Day 4) and cisplatin (70 mg/m 2 , Day 2), in a 21-day cycle. Stratification is based on the Graded Prognostic Assessment (GPA) score. Primary endpoint: brain-specific progression free survival (PFS) according to RECIST 1.1; key secondary endpoint: the 2-month brain-specific objective response rate (BS-ORR) of BEEP alone and WBRT alone. Other secondary endpoints include overall survival, extra-CNS tumor PFS, safety, time-to-improvement of neurological function,brain-specific PFS according to volumetric criteria, and BS-ORR. Approximately 126 patients will be 2:1 randomized. Multi-center recruitment is ongoing. To our knowledge this is the first randomized trial investigating a targeted therapy plus chemotherapy as induction regimen followed by WBRT as first line treatment for BC with BM. Citation Format: Lu Y-S, Tseng L-M, Yu J-C, Rau K-M, Chao T-Y, Chen S-C, Chiu C-F, Chang Y-C, Chen TW-W, Lin C-H, Chang D-Y, Chao T-C, Huang S-M, Huang C-S, Cheng A-L. Randomized phase II study of induction bevacizumab, etoposide and cisplatin followed by whole brain radiotherapy (WBRT) versus WBRT alone in breast cancer with untreated brain metastases (A-PLUS) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr OT1-04-03.