Study of LEE011 With Fulvestrant and BYL719 or BKM120 in Advanced Breast Cancer

The purpose of this trial is to explore the clinical utility of the three investigational agents in HR+, HER2- breast cancer. LEE011 (CDK4/6 inhibitor), BKM120 (PI3K-pan class I-inhibitor) and BYL719 (PI3K-alpha specific class I inhibitor) in combination with fulvestrant. This is a multi-center, open-label Phase Ib/II study. The Phase Ib portion of the study is a dose escalation to estimate the MTD and/or RP2D for three regimens: LEE011 with fulvestrant; LEE011 and BKM120 with fulvestrant; LEE011and BYL719 with fulvestrant. The Phase II portion of the study was planned to be a randomized study to assess the anti-tumor activity as well as safety and tolerability of LEE011 with fulvestrant to LEE011 and BKM120 with fulvestrant, and LEE011 and BYL719 with fulvestrant in patients with ER+/HER2- locally advanced or metastatic breast cancer. Approximately 216 adult women with ER+/HER2- locally advanced or metastatic breast cancer were planned to be enrolled.