Participants received fulvestrant, 500 mg, as an IM injection on Days 1 and 15 of Cycle 1 and then on Day 1 of each cycle thereafter until unacceptable toxicity or PD (1 cycle = 28 days). After Stage 1, participants who did not enter Stage 2 entered the long-term survival follow-up.

Participants received fulvestrant, 500 mg, as an IM injection on Days 1 and 15 of Cycle 1 and then on Day 1 of each cycle thereafter along with atezolizumab 840 mg as an IV infusion on Days 1 and 15 of each cycle until unacceptable toxicity or loss of clinical benefit (1 cycle = 28 days). After Stage 1, participants who did not enter Stage 2 entered the long-term survival follow-up.

Participants received fulvestrant, 500 mg, as an IM injection on Days 1 and 15 of Cycle 1 and then on Day 1 of each cycle thereafter along with atezolizumab, 840 mg, as an IV infusion on Days 1 and 15 of each cycle and ipatasertib, 400 mg, PO, QD, on Days 1 to 21 of each 28-day cycle until unacceptable toxicity or loss of clinical benefit (1 cycle = 28 days). After Stage 1, participants who did not enter Stage 2 entered the long-term survival follow-up.

Participants received atezolizumab, 840 mg as an IV infusion on Days 1 and 15 of each cycle along with ipatasertib, 400 mg, PO, QD, on Days 1 to 21 of each 28-day cycle until unacceptable toxicity or loss of clinical benefit (1 cycle = 28 days). After Stage 1, participants who did not enter Stage 2 entered the long-term survival follow-up.

Participants received atezolizumab, 1200 mg, as an IV infusion on Day 1 of each cycle along with entinostat, 5 mg, PO, once a week on Days 1, 8, and 15 of each cycle until unacceptable toxicity or loss of clinical benefit (1 cycle = 21 days). After Stage 1, participants who did not enter Stage 2 entered the long-term survival follow-up.

Participants received fulvestrant, 500 mg, as IM injection on Days 1 and 15 of Cycle 1 and then on Day 1 of each cycle thereafter along with atezolizumab, 840 mg, as an IV infusion on Days 1 and 15 of each cycle and abemaciclib, 150 mg, PO, BID until unacceptable toxicity or loss of clinical benefit (1 cycle = 28 days). After Stage 1, participants who did not enter Stage 2 entered the long-term survival follow-up.

Participants received fulvestrant, 500 mg, as an IM injection on Days 1 and 15 of Cycle 1 and then on Day 1 of each cycle thereafter until unacceptable toxicity or PD (1 cycle = 28 days). After Stage 1, participants who did not enter Stage 2 entered the long-term survival follow-up.

Participants received fulvestrant, 500 mg, as an IM injection on Days 1 and 15 of Cycle 1 and then on Day 1 of each cycle thereafter along with atezolizumab 840 mg as an IV infusion on Days 1 and 15 of each cycle until unacceptable toxicity or loss of clinical benefit (1 cycle = 28 days). After Stage 1, participants who did not enter Stage 2 entered the long-term survival follow-up.

Participants received fulvestrant, 500 mg, as an IM injection on Days 1 and 15 of Cycle 1 and then on Day 1 of each cycle thereafter until unacceptable toxicity or PD (1 cycle = 28 days). After Stage 1, participants who did not enter Stage 2 entered the long-term survival follow-up.

Participants received fulvestrant, 500 mg, as an IM injection on Days 1 and 15 of Cycle 1 and then on Day 1 of each cycle thereafter until unacceptable toxicity or PD (1 cycle = 28 days). After Stage 1, participants who did not enter Stage 2 entered the long-term survival follow-up.

Participants received fulvestrant, 500 mg, as an IM injection on Days 1 and 15 of Cycle 1 and then on Day 1 of each cycle thereafter along with atezolizumab 840 mg as an IV infusion on Days 1 and 15 of each cycle until unacceptable toxicity or loss of clinical benefit (1 cycle = 28 days). After Stage 1, participants who did not enter Stage 2 entered the long-term survival follow-up.

Participants received fulvestrant, 500 mg, as an IM injection on Days 1 and 15 of Cycle 1 and then on Day 1 of each cycle thereafter until unacceptable toxicity or PD (1 cycle = 28 days). After Stage 1, participants who did not enter Stage 2 entered the long-term survival follow-up.

Participants received fulvestrant, 500 mg, as an IM injection on Days 1 and 15 of Cycle 1 and then on Day 1 of each cycle thereafter along with atezolizumab 840 mg as an IV infusion on Days 1 and 15 of each cycle until unacceptable toxicity or loss of clinical benefit (1 cycle = 28 days). After Stage 1, participants who did not enter Stage 2 entered the long-term survival follow-up.

Participants received fulvestrant, 500 mg, as an IM injection on Days 1 and 15 of Cycle 1 and then on Day 1 of each cycle thereafter until unacceptable toxicity or PD (1 cycle = 28 days). After Stage 1, participants who did not enter Stage 2 entered the long-term survival follow-up.

Participants received fulvestrant, 500 mg, as an IM injection on Days 1 and 15 of Cycle 1 and then on Day 1 of each cycle thereafter until unacceptable toxicity or PD (1 cycle = 28 days). After Stage 1, participants who did not enter Stage 2 entered the long-term survival follow-up.

Participants received fulvestrant, 500 mg, as an IM injection on Days 1 and 15 of Cycle 1 and then on Day 1 of each cycle thereafter along with atezolizumab 840 mg as an IV infusion on Days 1 and 15 of each cycle until unacceptable toxicity or loss of clinical benefit (1 cycle = 28 days). After Stage 1, participants who did not enter Stage 2 entered the long-term survival follow-up.

Participants received atezolizumab, 1200 mg, as an IV infusion on Day 1 of each cycle along with entinostat, 5 mg, PO, once a week on Days 1, 8, and 15 of each cycle until unacceptable toxicity or loss of clinical benefit (1 cycle = 21 days). After Stage 1, participants who did not enter Stage 2 entered the long-term survival follow-up.

Participants received fulvestrant, 500 mg, as IM injection on Days 1 and 15 of Cycle 1 and then on Day 1 of each cycle thereafter along with atezolizumab, 840 mg, as an IV infusion on Days 1 and 15 of each cycle and abemaciclib, 150 mg, PO, BID until unacceptable toxicity or loss of clinical benefit (1 cycle = 28 days). After Stage 1, participants who did not enter Stage 2 entered the long-term survival follow-up.

Participants received fulvestrant, 500 mg, as an IM injection on Days 1 and 15 of Cycle 1 and then on Day 1 of each cycle thereafter along with atezolizumab, 840 mg, as an IV infusion on Days 1 and 15 of each cycle and ipatasertib, 400 mg, PO, QD, on Days 1 to 21 of each 28-day cycle until unacceptable toxicity or loss of clinical benefit (1 cycle = 28 days). After Stage 1, participants who did not enter Stage 2 entered the long-term survival follow-up.

Participants received atezolizumab, 840 mg as an IV infusion on Days 1 and 15 of each cycle along with ipatasertib, 400 mg, PO, QD, on Days 1 to 21 of each 28-day cycle until unacceptable toxicity or loss of clinical benefit (1 cycle = 28 days). After Stage 1, participants who did not enter Stage 2 entered the long-term survival follow-up.

Participants received fulvestrant, 500 mg, as IM injection on Days 1 and 15 of Cycle 1 and then on Day 1 of each cycle thereafter along with atezolizumab, 840 mg, as an IV infusion on Days 1 and 15 of each cycle and abemaciclib, 150 mg, PO, BID until unacceptable toxicity or loss of clinical benefit (1 cycle = 28 days). After Stage 1, participants who did not enter Stage 2 entered the long-term survival follow-up.

Participants received fulvestrant, 500 mg, as an IM injection on Days 1 and 15 of Cycle 1 and then on Day 1 of each cycle thereafter along with atezolizumab 840 mg as an IV infusion on Days 1 and 15 of each cycle until unacceptable toxicity or loss of clinical benefit (1 cycle = 28 days). After Stage 1, participants who did not enter Stage 2 entered the long-term survival follow-up.

Participants in Stage 1 who received atezolizumab, 1200 mg, as an IV infusion on Day 1 of each cycle along with entinostat, 5 mg, PO, once a week on Days 1, 8, and 15 of each cycle (1 cycle = 21 days), and had PD, entered Stage 2 and received fulvestrant, 500 mg, as IM injection on Days 1 and 15 of Cycle 1 and on Day 1 of each cycle thereafter along with atezolizumab, 840 mg, and bevacizumab, 10 mg/kg, as an IV infusion on Days 1 and 15 of each cycle until unacceptable toxicity or loss of clinical benefit (1 cycle = 28 days).

Participants in Stage 1 who received fulvestrant, 500 mg, as an IM injection on Days 1 and 15 of Cycle 1 and then on Day 1 of each cycle (1 cycle = 28 days), and had PD, entered Stage 2 and received fulvestrant, 500 mg, as IM injection on Days 1 and 15 of Cycle 1 and on Day 1 of each cycle thereafter along with atezolizumab, 840 mg, and bevacizumab, 10 mg/kg, as an IV infusion on Days 1 and 15 of each cycle until unacceptable toxicity or loss of clinical benefit (1 cycle = 28 days).

Participants in Stage 1 who received fulvestrant, 500 mg, as IM injection on Days 1 and 15 of Cycle 1 and then on Day 1 of each cycle thereafter along with atezolizumab, 840 mg, as an IV infusion on Days 1 and 15 of each cycle and abemaciclib, 150 mg, PO, BID (1 cycle = 28 days), and had PD, entered Stage 2 and received fulvestrant, 500 mg, as IM injection on Days 1 and 15 of Cycle 1 and on Day 1 of each cycle thereafter along with atezolizumab, 840 mg, and bevacizumab, 10 mg /kg, as an IV infusion on Days 1 and 15 of each cycle until unacceptable toxicity or loss of clinical benefit (1 cycle = 28 days).

Participants received fulvestrant, 500 mg, as IM injection on Days 1 and 15 of Cycle 1 and on Day 1 of each cycle thereafter along with atezolizumab, 840 mg, as an IV infusion on Days 1 and 15 of each cycle and bevacizumab, 10 milligrams per kilogram (mg /kg), as an IV infusion on Days 1 and 15 of each cycle until unacceptable toxicity or loss of clinical benefit (1 cycle = 28 days). Participants who completed Stage 2 treatment entered the long-term survival follow-up.