A Study Assessing the Safety and Efficacy of Adding Ipatasertib to Paclitaxel Treatment in Participants With Breast Cancer That Has Spread Beyond the Initial Site, and the Cancer Does Not Have Certain Hormonal Receptors

Inclusion Criteria:

Histologically documented triple-negative adenocarcinoma of the breast that is inoperable locally advanced or metastatic and is not amenable to resection with curative intent
Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1
Availability of a representative formalin-fixed, paraffin-embedded (FFPE) tumor specimen, required prior to randomization
Measurable disease, according to the RECIST v1.1
Adequate hematologic and organ function within 14 days before the first study treatment
For female participants of childbearing potential, agreement (by both participant and partner) to use an effective form of contraception for the duration of the study and for 6 months after last dose of study treatment

Exclusion Criteria:

Any previous therapy, including chemotherapy or hormonal or targeted therapy, for inoperable locally advanced or metastatic triple-negative adenocarcinoma of the breast. Participants may have received prior neoadjuvant or adjuvant chemotherapy and/or radiation treatment for locally advanced triple negative adenocarcinoma, provided all treatments were completed greater than or equal to (>/=) 6 months prior to Cycle 1 Day 1. Locally recurrent disease must not be amenable to resection with curative intent
Any radiation treatment to metastatic site within 28 days of Cycle 1, Day 1
Known Human Epidermal Growth Factor Receptor 2 (HER2) positive, erythrocyte receptor (ER) positive, or progesterone receptor (PR) positive breast cancer
Previous therapy with Akt, PI3K, and/or mTOR inhibitors
Major surgical procedure, open biopsy, or significant traumatic injury within 30 days prior to Cycle 1, Day 1 or anticipation of need for a major surgical procedure during the course of the study
Known presence of the brain or spinal cord metastasis, as determined by computed tomography (CT) or magnetic resonance imaging (MRI) evaluation during screening or prior radiographic assessments