Study: NCT02715531

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: 5-FU
Description: 5-FU (400 mg/m\^2) will be administered as an IV bolus, followed by 2400 mg/m\^2 by continuous IV infusion over 46 (± 1) hours, q2w.

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: 5-FU
Description: 5-FU (400 mg/m\^2) will be administered as an IV bolus, followed by 2400 mg/m\^2 by continuous IV infusion over 46 (± 1) hours, q2w.

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Atezolizumab
Description: Participants will receive atezolizumab in a flat dose of 1200 mg q3w (Arm A, Group E2, and Arm F) or 840 mg q2w (Arm B, Arm C, and Groups E1 and E3).

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Atezolizumab
Description: Participants will receive atezolizumab in a flat dose of 1200 mg q3w (Arm A, Group E2, and Arm F) or 840 mg q2w (Arm B, Arm C, and Groups E1 and E3).

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Atezolizumab
Description: Participants will receive atezolizumab in a flat dose of 1200 mg q3w (Arm A, Group E2, and Arm F) or 840 mg q2w (Arm B, Arm C, and Groups E1 and E3).

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Atezolizumab
Description: Participants will receive atezolizumab in a flat dose of 1200 mg q3w (Arm A, Group E2, and Arm F) or 840 mg q2w (Arm B, Arm C, and Groups E1 and E3).

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Atezolizumab
Description: Participants will receive atezolizumab in a flat dose of 1200 mg q3w (Arm A, Group E2, and Arm F) or 840 mg q2w (Arm B, Arm C, and Groups E1 and E3).

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Bevacizumab
Description: Participants will receive bevacizumab at 15 mg/kg q3w (Arm A and Group F1) or 10 mg/kg q2w (Arm B).

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Bevacizumab
Description: Participants will receive bevacizumab at 15 mg/kg q3w (Arm A and Group F1) or 10 mg/kg q2w (Arm B).

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Bevacizumab
Description: Participants will receive bevacizumab at 15 mg/kg q3w (Arm A and Group F1) or 10 mg/kg q2w (Arm B).

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Gemcitabine
Description: Gemcitabine will be administered according to the local prescribing information. The starting dose-level of gemcitabine (1000 mg/m\^2) will be administered intravenously over 35 (± 5) minutes on Days 1, 8, and 15 of each 28-day cycle (3-weeks-on/1-week-off schedule).

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Leucovorin
Description: Leucovorin 200 mg/m\^2 L-isomer form or 400 mg/m\^2 D,L-racemic form will be administered IV over 120 (± 15) minutes, q2w.

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Leucovorin
Description: Leucovorin 200 mg/m\^2 L-isomer form or 400 mg/m\^2 D,L-racemic form will be administered IV over 120 (± 15) minutes, q2w.

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Nab-Paclitaxel
Description: Nab-Paclitaxel will be administered according to the local prescribing information. The starting dose-level of nab-paclitaxel (125 mg/m\^2) will be administered intravenously over 35 (± 5) minutes on Days 1, 8, and 15 of each 28-day cycle (3-weeks-on/1-week-off schedule).

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Oxaliplatin
Description: Oxaliplatin 85 mg/m\^2 will be administered IV over 120 (± 5) minutes q2w.

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Oxaliplatin
Description: Oxaliplatin 85 mg/m\^2 will be administered IV over 120 (± 5) minutes q2w.

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Capecitabine
Description: Capecitabine may be administered after 6 months at the discretion of the investigator (range of 650-1000 mg/m\^2) twice daily on Days 1-4 of a 21-day cycle.

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Cisplatin
Description: Cisplatin will be administered as 80 mg/m\^2 IV over 120 minutes q3w (Group E2).