Abstract P6-12-02: Phase Ib dose-escalation study of an Akt inhibitor ipatasertib (Ipat) in combination with docetaxel (Doc) or paclitaxel (Pac) in patients (pts) with metastatic breast cancer (MBC)

Abstract Background: The Akt pathway is frequently aberrantly activated in MBC (e.g. via PTEN loss, and/or alterations of PIK3CA, AKT1, or AKT3); additionally, Akt activation may occur in response to chemotherapy, leading to cell survival and chemoresistance. Ipat (GDC-0068) is a potent oral, ATP-competitive inhibitor of all Akt isoforms. In preclinical models, Ipat synergistically combined with taxanes. In the Phase I dose-escalation single agent study, Ipat was given to pts including MBC, and downregulated Akt signaling at doses ≥ 100 mg. Methods: Eligible pts with MBC, treated with up to 3 prior systemic chemotherapy regimens, received Doc 75 mg/m2 intravenously (IV) on Day 1 with escala…