A Study Evaluating the Efficacy and Safety of Multiple Treatment Combinations in Patients With Metastatic or Locally Advanced Breast Cancer

Capecitabine will be administered 1250 mg/m\^2 orally twice daily on Days 1-14, of each 21 day cycle.

"For Atezolizumab (Atezo) + SGN-LIV1A, Atezo + Sacituzumab Govitecan, or Atezo + Chemo arms: atezolizumab will be administered intravenously (IV), 1200 mg, on Day 1 of each 21-day cycle.~For Atezo + Nab-Paclitaxel, Atezo + Selicrelumab + Bevacizumab, Atezo + Ipatasertib, or Atezo + Nab-Paclitaxel + Tocilizumab: atezolizumab will be administered IV, 840 mg on Days 1 and 15, of each 28-day cycle."

Ipatasertib will be administered by mouth 400 mg once a day, on Day 1-21 of each 28 day cycle.

SGN-LIV1A will be administered IV, 2.5 mg/kg (maximum calculated dose 250 mg), on Day 1 of each 21 day cycle.

Bevacizumab will be administered IV, 10 mg/kg, on Days 1 and 15 of each 28 day cycle.

"Gemcitabine will be administered by IV, 1000 mg/m\^2, along with carboplatin, by IV, AUC 2, on Days 1 and 8 of each 21 day cycle.~Or~Eribulin will be administered by IV, 1.4 mg/m\^2 on days 1 and 8 of each 21 day cycle."

Selicrelumab will be administered by subcutaneous (SC) injection at a fixed dose of 16 mg on Day 1 of Cycles 1 to 4 and every third cycle thereafter (cycle = 28 days).

Tocilizumab will be administered IV, 8 mg/kg infusion on Day 1 of each 28 day cycle.

Nab-Paclitaxel will be administered by IV, 100 mg/m\^2, on Days 1, 8, and 15 of each 28-day cycle.

Sacituzumab govitecan will be administered by IV, 10 mg/kg, on Days 1 and 8 of each 21-day cycle.

Abemaciclib tablets will be administered at a dose of 150 mg twice daily by mouth on Days 1-28 of each cycle (cycle=28 days).

Fulvestrant IM injection at a dose of 500 mg will be administered on Days 1 and 15 of Cycle 1, and then on Day 1 of each cycle thereafter (cycle=28 days).

Ribociclib tablets will be administered by mouth once daily.

Inavolisib tablets will be administered by mouth once daily.

Trastuzumab Deruxtecan will be administered at a dose of 5.4 mg/kg by IV infusion on Day 1 of each 21-day cycle.

Ribociclib tablets will be administered by mouth once daily.

Letrozole tablets will be administered at a dose of 2.5 mg once a day by mouth on Days 1-28 of each cycle (cycle = 28 days).

Inavolisib tablets will be administered by mouth once daily.

Inavolisib tablets will be administered by mouth once daily.