181TiP Xentuzumab (Xe) in combination with everolimus (Ev) and exemestane (Ex) in patients with hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer (mBC) and non-visceral involvement (XENERA™-1)

Abstract

taxel) plus trastuzumab (cohort C2). ET options are either an aromatase inhibitor, fulvestrant or tamoxifen +/-ovarian suppression. Stratification factors include the number of previous regimens for advanced BC (1-2 vs 3-4) and the presence of visceral disease (yes vs no). Primary objective is to compare the PFS between two arms. The study has an 80% power with two-sided alpha¼0.05 to detect a HR of 0.62 in favor of the palbociclib arm. An interim analysis (IA) adjusted for multiplicity from O'Brien-Fleming method and an estimation of the conditional power (CP) will be performed at 70% of the events. Secondary objectives include response rate, overall survival, safety, and Quality of Life. Tumor tissue and blood samples will be collected for biomarker analyses. A total of 516 patients will be screened and 232 patients will be recruited. As of January 16 th , 2020, 7 patients were randomized in the trial. The study is sponsored by SOLTI and financially supported by Pfizer.Clinical trial identification: NCT02448420.