Response defined per Response Evaluation Criteria In Solid Tumors (RECIST) criteria: Complete Response (CR)=disappearance of all target lesions; Partial Response (PR)=30% decrease in sum of longest diameter of target lesions; Progressive Disease=20% increase in sum of longest diameter of target lesions; Stable Disease=small changes that do not meet above criteria. ORR was defined as the proportion of participants who achieved a best response of either CR or PR. ORR=number of participants with CR or PR/number of participants qualified for tumor response analysis (per-protocol population).

Per-protocol population included intent-to-treat participants who met the following criteria: histological or cytological breast cancer diagnosis; baseline presence of measurable disease per RECIST; at least 1 dose of study drug; no current systemic anti-tumor therapy except protocol-specified therapy. One PB+G participant did not qualify.

PFS was measured from date of randomization to first date of disease progression or death from any cause. For participants not known to have died or had disease progression as of data-inclusion cut-off date, PFS duration was censored at date of last study visit prior to data-inclusion cut-off date.

ITT population=all randomized participants, eligible & ineligible. Participants with events: PB=74; PB+G=72. Censored participants: PB=20 PB+G=21.

Overall survival was measured from date of randomization to date of death from any cause. For participants not known to have died as of data-inclusion cut-off date, overall survival duration was censored at date of last study visit prior to the data cut-off date.

Intent-To-Treat (ITT) population=all randomized participants, eligible & ineligible. Number of participants with events: PB=35; PB+G=34. Censored participants: PB=59;PB+G=59.

FACT-B measures the following domains of health-related quality of life (HR-QL): physical well-being (PWB), social/family well-being (SFWB), emotional well-being (EWB), functional well-being (FWB), & additional concerns of breast cancer (BCS). Total FACT-B scores range from 0-144, with higher scores representing better HR-QOL. Minimally important differences estimates obtained for FACT-B is 7-8 points. FACT-B was assessed at baseline (prior to start of Cycle 1 [Day 1]), prior to start of each subsequent cycle (approximately every 4 weeks) during therapy, through 30-day post therapy follow-up.

Last Observation Carried Forward (LOCF) for all ITT patients with valid baseline and at least one valid post-baseline assessment

The PWB subscale of FACT-B measures physical well-being. Total PWB scores range from 0 to 28, with higher scores representing better HR-QOL. FACT-B was assessed at baseline (prior to start of Cycle 1 [Day 1]), then prior to start of each subsequent cycle (approximately every 4 weeks) during therapy, through 30-day post therapy follow-up.

Last Observation Carried Forward (LOCF) for all ITT patients with valid baseline and at least one valid post-baseline assessment

The SFWB subscale of FACT-B measures social/family well-being. Total SFWB scores range from 0 to 28, with higher scores representing better HR-QOL. FACT-B was assessed at baseline (prior to start of Cycle 1 [Day 1]), then prior to start of each subsequent cycle (approximately every 4 weeks) during therapy, through 30-day post therapy follow-up.

Last Observation Carried Forward (LOCF) for all ITT patients with valid baseline and at least one valid post-baseline assessment

The EWB subscale of FACT-B measures emotional well-being. Total EWB scores range from 0 to 24, with higher scores representing better HR-QOL. FACT-B was assessed at baseline (prior to start of Cycle 1 [Day 1]), then prior to start of each subsequent cycle (approximately every 4 weeks) during therapy, through 30-day post therapy follow-up.

Last Observation Carried Forward (LOCF) for all ITT patients with valid baseline and at least one valid post-baseline assessment

The FWB subscale of FACT-B measures functional well-being. Total FWB scores range from 0 to 28, with higher scores representing better HR-QOL. FACT-B was assessed at baseline (prior to start of Cycle 1 [Day 1]), then prior to start of each subsequent cycle (approximately every 4 weeks) during therapy, through 30-day post therapy follow-up.

Last Observation Carried Forward (LOCF) for all ITT patients with valid baseline and at least one valid post-baseline assessment

The BCS subscale of FACT-B measures additional concerns of breast cancer . Total BCS scores range from 0 to 36, with higher scores representing better HR-QOL. Minimally important differences estimates obtained for BCS is 2-3 points. FACT-B was assessed at baseline (prior to start of Cycle 1 [Day 1]), then prior to start of each subsequent cycle (approximately every 4 weeks) during therapy, through 30-day post therapy follow-up.

Last Observation Carried Forward (LOCF) for all ITT patients with valid baseline and at least one valid post-baseline assessment

The TOI-B represents the total of the subscales PWB,FWB, and BCS. Total TOI-B scores range from 0 to 92, with higher scores representing better HR-QOL. Minimally important differences estimates obtained for TOI is 5-6 points. FACT-B was assessed at baseline (prior to start of Cycle 1 [Day 1]), then prior to start of each subsequent cycle (approximately every 4 weeks) during therapy, through 30-day post therapy follow-up.

Last Observation Carried Forward (LOCF) for all ITT patients with valid baseline and at least one valid post-baseline assessment