Trial Outcomes & Findings for A Study Comparing Atezolizumab (Anti PD-L1 Antibody) In Combination With Adjuvant Anthracycline/Taxane-Based Chemotherapy Versus Chemotherapy Alone In Patients With Operable Triple-Negative Breast Cancer (NCT NCT03498716)

Last Updated: 2024-08-21

Results Overview

iDFS was defined as the time from randomization until the date of the first occurrence of one of the following events: Ipsilateral invasive breast tumor recurrence (an invasive breast cancer involving the same breast parenchyma as the original primary lesion); Ipsilateral local-regional invasive breast cancer recurrence (an invasive breast cancer in the axilla, regional lymph nodes, chest wall, \&/or skin of the ipsilateral breast); Ipsilateral second primary invasive breast cancer; Contralateral invasive breast cancer; Distant recurrence (evidence of breast cancer in any anatomic site \[other than the sites mentioned\]) that has either been histologically confirmed \&/or clinically/radiographically diagnosed as recurrent invasive breast cancer; \& Death attributable to any cause, including breast cancer, non-breast cancer, or unknown cause. Analysis used Kaplan-Meier estimates where participants with no events at the time of analysis or no post-baseline information were censored.

Recruitment status

TERMINATED

Study phase

PHASE3

Target enrollment

2199 participants

Primary outcome timeframe

From randomization until the occurrence of an iDFS event or death from any cause, whichever occurred earlier (up to 5 years)

Results posted on

2024-08-21

Participant Flow

Participants with newly diagnosed Stage II-III primary invasive Breast cancer (BC) that is of triple negative phenotype and who were to be treated with adjuvant systemic chemotherapy following definitive surgery, were enrolled in 342 centers in 31 countries.

A total of 2199 participants were enrolled in the study. Participants were randomized in a 1:1 ratio to receive Atezolizumab and Chemotherapy or Chemotherapy alone.

Participant milestones

Participant milestones
Measure	Chemotherapy Participants were administered paclitaxel, 80 milligram per square meter (mg/m\^2), intravenous (IV) infusion weekly (QW) for maximum of 36 weeks followed by dose-dense doxorubicin, 60 mg/m\^2 or dose-dense epirubicin, 90 mg/m\^2 IV (investigator's choice) plus cyclophosphamide, 600 mg/m\^2, IV repeated every 2 weeks (Q2W) for a maximum of 20 weeks supported with granulocyte colony-stimulating factor (G-CSF) or granulocyte-macrophage colony-stimulating factor (GM-CSF) treatment.	Atezolizumab and Chemotherapy Participants were administered atezolizumab 840 mg, IV infusion, Q2W in combination with chemotherapy (paclitaxel 80 mg/m\^2, IV infusion QW for maximum of 22 weeks followed by dose-dense doxorubicin, 60 mg/m\^2 or dose-dense epirubicin, 90 mg/m\^2, IV (investigator's choice) plus cyclophosphamide, 600 mg/m\^2, IV repeated Q2W for maximum of 17 weeks supported with G-CSF or GM-CSF treatment followed by atezolizumab, 1200 mg IV infusion every 3 weeks (Q3W) as a maintenance therapy to complete 1 year of atezolizumab treatment from the first dose.
Overall Study STARTED	1098	1101
Overall Study Safety Evaluable Population	1084	1093
Overall Study COMPLETED	0	0
Overall Study NOT COMPLETED	1098	1101

Reasons for withdrawal

Reasons for withdrawal
Measure	Chemotherapy Participants were administered paclitaxel, 80 milligram per square meter (mg/m\^2), intravenous (IV) infusion weekly (QW) for maximum of 36 weeks followed by dose-dense doxorubicin, 60 mg/m\^2 or dose-dense epirubicin, 90 mg/m\^2 IV (investigator's choice) plus cyclophosphamide, 600 mg/m\^2, IV repeated every 2 weeks (Q2W) for a maximum of 20 weeks supported with granulocyte colony-stimulating factor (G-CSF) or granulocyte-macrophage colony-stimulating factor (GM-CSF) treatment.	Atezolizumab and Chemotherapy Participants were administered atezolizumab 840 mg, IV infusion, Q2W in combination with chemotherapy (paclitaxel 80 mg/m\^2, IV infusion QW for maximum of 22 weeks followed by dose-dense doxorubicin, 60 mg/m\^2 or dose-dense epirubicin, 90 mg/m\^2, IV (investigator's choice) plus cyclophosphamide, 600 mg/m\^2, IV repeated Q2W for maximum of 17 weeks supported with G-CSF or GM-CSF treatment followed by atezolizumab, 1200 mg IV infusion every 3 weeks (Q3W) as a maintenance therapy to complete 1 year of atezolizumab treatment from the first dose.
Overall Study Withdrawal by Subject	88	73
Overall Study Study Terminated By Sponsor	933	927
Overall Study Lost to Follow-up	15	26
Overall Study Disease Relapse	0	1
Overall Study Death	58	72
Overall Study Physician Decision	4	2

Baseline Characteristics

A Study Comparing Atezolizumab (Anti PD-L1 Antibody) In Combination With Adjuvant Anthracycline/Taxane-Based Chemotherapy Versus Chemotherapy Alone In Patients With Operable Triple-Negative Breast Cancer

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Chemotherapy n=1098 Participants Participants were administered paclitaxel, 80 mg/m\^2, IV infusion QW for maximum of 36 weeks followed by dose-dense doxorubicin, 60 mg/m\^2 or dose-dense epirubicin, 90 mg/m\^2 IV (investigator's choice) plus cyclophosphamide, 600 mg/m\^2, IV repeated every Q2W for a maximum of 20 weeks supported with G-CSF or GM-CSF treatment.	Atezolizumab and Chemotherapy n=1101 Participants Participants were administered atezolizumab 840 mg, IV infusion, Q2W in combination with chemotherapy (paclitaxel 80 mg/m\^2, IV infusion QW for maximum of 22 weeks followed by dose-dense doxorubicin, 60 mg/m\^2 or dose-dense epirubicin, 90 mg/m\^2, IV (investigator's choice) plus cyclophosphamide, 600 mg/m\^2, IV repeated Q2W for maximum of 17 weeks supported with G-CSF or GM-CSF treatment followed by atezolizumab, 1200 mg IV infusion every Q3W as a maintenance therapy to complete 1 year of atezolizumab treatment from the first dose.	Total n=2199 Participants Total of all reporting groups
Age, Continuous	52.8 years STANDARD_DEVIATION 11.4 • n=5 Participants	52.3 years STANDARD_DEVIATION 11.9 • n=7 Participants	52.5 years STANDARD_DEVIATION 11.6 • n=5 Participants
Sex: Female, Male Female	1094 Participants n=5 Participants	1101 Participants n=7 Participants	2195 Participants n=5 Participants
Sex: Female, Male Male	4 Participants n=5 Participants	0 Participants n=7 Participants	4 Participants n=5 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	100 Participants n=5 Participants	75 Participants n=7 Participants	175 Participants n=5 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	906 Participants n=5 Participants	950 Participants n=7 Participants	1856 Participants n=5 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	92 Participants n=5 Participants	76 Participants n=7 Participants	168 Participants n=5 Participants
Race (NIH/OMB) American Indian or Alaska Native	28 Participants n=5 Participants	29 Participants n=7 Participants	57 Participants n=5 Participants
Race (NIH/OMB) Asian	401 Participants n=5 Participants	423 Participants n=7 Participants	824 Participants n=5 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	1 Participants n=5 Participants	0 Participants n=7 Participants	1 Participants n=5 Participants
Race (NIH/OMB) Black or African American	2 Participants n=5 Participants	8 Participants n=7 Participants	10 Participants n=5 Participants
Race (NIH/OMB) White	567 Participants n=5 Participants	554 Participants n=7 Participants	1121 Participants n=5 Participants
Race (NIH/OMB) More than one race	0 Participants n=5 Participants	1 Participants n=7 Participants	1 Participants n=5 Participants
Race (NIH/OMB) Unknown or Not Reported	99 Participants n=5 Participants	86 Participants n=7 Participants	185 Participants n=5 Participants

PRIMARY outcome

Timeframe: From randomization until the occurrence of an iDFS event or death from any cause, whichever occurred earlier (up to 5 years)

Population: ITT population included all randomized participants, whether or not the assigned study treatment was received.

Outcome measures

Outcome measures
Measure	Chemotherapy n=1098 Participants Participants were administered paclitaxel, 80 mg/m\^2, IV infusion QW for maximum of 36 weeks followed by dose-dense doxorubicin, 60 mg/m\^2 or dose-dense epirubicin, 90 mg/m\^2 IV (investigator's choice) plus cyclophosphamide, 600 mg/m\^2, IV repeated every Q2W for a maximum of 20 weeks supported with G-CSF or GM-CSF treatment.	Atezolizumab and Chemotherapy n=1101 Participants Participants were administered atezolizumab 840 mg, IV infusion, Q2W in combination with chemotherapy (paclitaxel 80 mg/m\^2, IV infusion QW for maximum of 22 weeks followed by dose-dense doxorubicin, 60 mg/m\^2 or dose-dense epirubicin, 90 mg/m\^2, IV (investigator's choice) plus cyclophosphamide, 600 mg/m\^2, IV repeated Q2W for maximum of 17 weeks supported with G-CSF or GM-CSF treatment followed by atezolizumab, 1200 mg IV infusion every Q3W as a maintenance therapy to complete 1 year of atezolizumab treatment from the first dose.
Invasive Disease-Free Survival (iDFS)	NA months Median and 95% CI for iDFS were not estimable due to too few events having occurred.	NA months Median and 95% CI for iDFS were not estimable due to too few events having occurred.

SECONDARY outcome

Timeframe: From randomization until the occurrence of an iDFS event or death from any cause, whichever occurred earlier (up to 5 years)

Population: PD-L1-positive subpopulation included participants in the ITT population whose PD-L1 status was IC1/2/3 at the time of randomization. ITT population included all randomized participants, whether or not the assigned study treatment was received.

iDFS = the time from randomization until the date of the first occurrence of one of the following events: Ipsilateral invasive breast tumor recurrence (an invasive breast cancer involving the same breast parenchyma as the original primary lesion); Ipsilateral local-regional invasive breast cancer recurrence (an invasive breast cancer in the axilla, regional lymph nodes, chest wall, and/or skin of the ipsilateral breast); Ipsilateral second primary invasive breast cancer, Contralateral invasive breast cancer, Distant recurrence (i.e., evidence of breast cancer in any anatomic site \[other than the sites mentioned\]) that has either been histologically confirmed and/or clinically/radiographically diagnosed as recurrent invasive breast cancer and Death attributable to any cause, including breast cancer, non-breast cancer, or unknown cause. Analysis used Kaplan-Meier estimates where participants with no events at the time of analysis or no post-baseline information were censored.

Outcome measures

Outcome measures
Measure	Chemotherapy n=782 Participants Participants were administered paclitaxel, 80 mg/m\^2, IV infusion QW for maximum of 36 weeks followed by dose-dense doxorubicin, 60 mg/m\^2 or dose-dense epirubicin, 90 mg/m\^2 IV (investigator's choice) plus cyclophosphamide, 600 mg/m\^2, IV repeated every Q2W for a maximum of 20 weeks supported with G-CSF or GM-CSF treatment.	Atezolizumab and Chemotherapy n=785 Participants Participants were administered atezolizumab 840 mg, IV infusion, Q2W in combination with chemotherapy (paclitaxel 80 mg/m\^2, IV infusion QW for maximum of 22 weeks followed by dose-dense doxorubicin, 60 mg/m\^2 or dose-dense epirubicin, 90 mg/m\^2, IV (investigator's choice) plus cyclophosphamide, 600 mg/m\^2, IV repeated Q2W for maximum of 17 weeks supported with G-CSF or GM-CSF treatment followed by atezolizumab, 1200 mg IV infusion every Q3W as a maintenance therapy to complete 1 year of atezolizumab treatment from the first dose.
Invasive Disease-Free Survival (iDFS) in the Subpopulation With Programmed Death-ligand 1 (PD-L1) Selected Tumor Status (IC1/2/3)	NA months Median and 95% CI for iDFS were not estimable due to too few events having occurred.	NA months Median and 95% CI for iDFS were not estimable due to too few events having occurred.

SECONDARY outcome

Timeframe: From randomization until the occurrence of an iDFS event or death from any cause, whichever occurred earlier (up to 5 years)

Population: Node positive subpopulation included all participants in the ITT population whose lymph node (LN) status was positive at the time of randomization. ITT population included all randomized participants, whether or not the assigned study treatment was received.

iDFS = the time from randomization until the date of the first occurrence of one of the following events: Ipsilateral invasive breast tumor recurrence (an invasive breast cancer involving the same breast parenchyma as the original primary lesion); Ipsilateral local-regional invasive breast cancer recurrence (an invasive breast cancer in the axilla, regional lymph nodes, chest wall, and/or skin of the ipsilateral breast); Ipsilateral second primary invasive breast cancer; Contralateral invasive breast cancer; Distant recurrence (evidence of breast cancer in any anatomic site \[other than the sites mentioned\]) that has either been histologically confirmed and/or clinically/radiographically diagnosed as recurrent invasive breast cancer; and Death attributable to any cause, including breast cancer, non-breast cancer, or unknown cause. Analysis used Kaplan-Meier estimates where participants with no events at the time of analysis or no post-baseline information were censored.

Outcome measures

Outcome measures
Measure	Chemotherapy n=533 Participants Participants were administered paclitaxel, 80 mg/m\^2, IV infusion QW for maximum of 36 weeks followed by dose-dense doxorubicin, 60 mg/m\^2 or dose-dense epirubicin, 90 mg/m\^2 IV (investigator's choice) plus cyclophosphamide, 600 mg/m\^2, IV repeated every Q2W for a maximum of 20 weeks supported with G-CSF or GM-CSF treatment.	Atezolizumab and Chemotherapy n=534 Participants Participants were administered atezolizumab 840 mg, IV infusion, Q2W in combination with chemotherapy (paclitaxel 80 mg/m\^2, IV infusion QW for maximum of 22 weeks followed by dose-dense doxorubicin, 60 mg/m\^2 or dose-dense epirubicin, 90 mg/m\^2, IV (investigator's choice) plus cyclophosphamide, 600 mg/m\^2, IV repeated Q2W for maximum of 17 weeks supported with G-CSF or GM-CSF treatment followed by atezolizumab, 1200 mg IV infusion every Q3W as a maintenance therapy to complete 1 year of atezolizumab treatment from the first dose.
Invasive Disease-Free Survival (iDFS) in the Node Positive Subpopulation	NA months Median and 95% CI for iDFS were not estimable due to too few events having occurred.	NA months Median and 95% CI for iDFS were not estimable due to too few events having occurred.

SECONDARY outcome

Timeframe: From randomization up to death from any cause (up to 5 years)

Population: ITT population included all randomized participants, whether or not the assigned study treatment was received.

Overall Survival (OS) is defined as the time from randomization to the date of death due to any cause. Analysis used Kaplan-Meier estimates where participants with no events at the time of analysis or no post-baseline information were censored.

Outcome measures

Outcome measures
Measure	Chemotherapy n=1098 Participants Participants were administered paclitaxel, 80 mg/m\^2, IV infusion QW for maximum of 36 weeks followed by dose-dense doxorubicin, 60 mg/m\^2 or dose-dense epirubicin, 90 mg/m\^2 IV (investigator's choice) plus cyclophosphamide, 600 mg/m\^2, IV repeated every Q2W for a maximum of 20 weeks supported with G-CSF or GM-CSF treatment.	Atezolizumab and Chemotherapy n=1101 Participants Participants were administered atezolizumab 840 mg, IV infusion, Q2W in combination with chemotherapy (paclitaxel 80 mg/m\^2, IV infusion QW for maximum of 22 weeks followed by dose-dense doxorubicin, 60 mg/m\^2 or dose-dense epirubicin, 90 mg/m\^2, IV (investigator's choice) plus cyclophosphamide, 600 mg/m\^2, IV repeated Q2W for maximum of 17 weeks supported with G-CSF or GM-CSF treatment followed by atezolizumab, 1200 mg IV infusion every Q3W as a maintenance therapy to complete 1 year of atezolizumab treatment from the first dose.
Overall Survival (OS)	NA months Median and 95% CI for OS were not estimable due to too few events having occurred.	NA months Median and 95% CI for OS were not estimable due to too few events having occurred.

SECONDARY outcome

Timeframe: From randomization up to death from any cause (up to 5 years)

Population: ITT population included all randomized participants, whether or not the assigned study treatment was received.

iDFS = the time from randomization until the date of first occurrence of one of the events: Ipsilateral invasive breast tumor recurrence (an invasive breast cancer involving same breast parenchyma as the original primary lesion); Ipsilateral local-regional invasive breast cancer recurrence (an invasive breast cancer in axilla, regional lymph nodes, chest wall, \&/or skin of the ipsilateral breast); Ipsilateral second primary invasive breast cancer; Second primary non-breast invasive cancer; Contralateral invasive breast cancer; Distant recurrence (i.e., evidence of breast cancer in any anatomic site \[other than sites mentioned\]) that has either been histologically confirmed \&/or clinically/radiographically diagnosed as recurrent invasive breast cancer; Death attributable to any cause, including breast cancer, non-breast cancer, or unknown cause. Analysis used Kaplan-Meier estimates where participants with no events at the time of analysis or no post-baseline information were censored.

Outcome measures

Outcome measures
Measure	Chemotherapy n=1098 Participants Participants were administered paclitaxel, 80 mg/m\^2, IV infusion QW for maximum of 36 weeks followed by dose-dense doxorubicin, 60 mg/m\^2 or dose-dense epirubicin, 90 mg/m\^2 IV (investigator's choice) plus cyclophosphamide, 600 mg/m\^2, IV repeated every Q2W for a maximum of 20 weeks supported with G-CSF or GM-CSF treatment.	Atezolizumab and Chemotherapy n=1101 Participants Participants were administered atezolizumab 840 mg, IV infusion, Q2W in combination with chemotherapy (paclitaxel 80 mg/m\^2, IV infusion QW for maximum of 22 weeks followed by dose-dense doxorubicin, 60 mg/m\^2 or dose-dense epirubicin, 90 mg/m\^2, IV (investigator's choice) plus cyclophosphamide, 600 mg/m\^2, IV repeated Q2W for maximum of 17 weeks supported with G-CSF or GM-CSF treatment followed by atezolizumab, 1200 mg IV infusion every Q3W as a maintenance therapy to complete 1 year of atezolizumab treatment from the first dose.
Invasive Disease-Free Survival (iDFS) Including Second Primary Non-Breast Invasive Cancer	NA months Median and 95% CI for iDFS were not estimable due to too few events having occurred	NA months Median and 95% CI for iDFS were not estimable due to too few events having occurred

SECONDARY outcome

Timeframe: From randomization up to 5 years

Population: ITT population included all randomized participants, whether or not the assigned study treatment was received.

Recurrence-Free Interval (RFI) was defined as the time from randomization to the first occurrence of any recurrence (local, regional \[including invasive ipsilateral tumor and invasive locoregional tumor\], or distant), as determined by investigators. Analysis used Kaplan-Meier estimates where participants with no events at the time of analysis, participants with no events who died, or participants with no post-baseline information were censored.

Outcome measures

Outcome measures
Measure	Chemotherapy n=1098 Participants Participants were administered paclitaxel, 80 mg/m\^2, IV infusion QW for maximum of 36 weeks followed by dose-dense doxorubicin, 60 mg/m\^2 or dose-dense epirubicin, 90 mg/m\^2 IV (investigator's choice) plus cyclophosphamide, 600 mg/m\^2, IV repeated every Q2W for a maximum of 20 weeks supported with G-CSF or GM-CSF treatment.	Atezolizumab and Chemotherapy n=1101 Participants Participants were administered atezolizumab 840 mg, IV infusion, Q2W in combination with chemotherapy (paclitaxel 80 mg/m\^2, IV infusion QW for maximum of 22 weeks followed by dose-dense doxorubicin, 60 mg/m\^2 or dose-dense epirubicin, 90 mg/m\^2, IV (investigator's choice) plus cyclophosphamide, 600 mg/m\^2, IV repeated Q2W for maximum of 17 weeks supported with G-CSF or GM-CSF treatment followed by atezolizumab, 1200 mg IV infusion every Q3W as a maintenance therapy to complete 1 year of atezolizumab treatment from the first dose.
Recurrence-Free Interval (RFI)	NA months Median and 95% CI for RFI were not estimable due to too few events having occurred	NA months Median and 95% CI for RFI were not estimable due to too few events having occurred

SECONDARY outcome

Timeframe: From randomization up to 5 years

Population: ITT population included all randomized participants, whether or not the assigned study treatment was received.

Distant Recurrence-Free Interval (DRFI) was defined as the time from randomization to the distant breast cancer recurrence. Analysis used Kaplan-Meier estimates where participants with no events at the time of analysis, participants with no events who died, or participants with no post-baseline information were censored.

Outcome measures

Outcome measures
Measure	Chemotherapy n=1098 Participants Participants were administered paclitaxel, 80 mg/m\^2, IV infusion QW for maximum of 36 weeks followed by dose-dense doxorubicin, 60 mg/m\^2 or dose-dense epirubicin, 90 mg/m\^2 IV (investigator's choice) plus cyclophosphamide, 600 mg/m\^2, IV repeated every Q2W for a maximum of 20 weeks supported with G-CSF or GM-CSF treatment.	Atezolizumab and Chemotherapy n=1101 Participants Participants were administered atezolizumab 840 mg, IV infusion, Q2W in combination with chemotherapy (paclitaxel 80 mg/m\^2, IV infusion QW for maximum of 22 weeks followed by dose-dense doxorubicin, 60 mg/m\^2 or dose-dense epirubicin, 90 mg/m\^2, IV (investigator's choice) plus cyclophosphamide, 600 mg/m\^2, IV repeated Q2W for maximum of 17 weeks supported with G-CSF or GM-CSF treatment followed by atezolizumab, 1200 mg IV infusion every Q3W as a maintenance therapy to complete 1 year of atezolizumab treatment from the first dose.
Distant Recurrence-Free Interval (DRFI)	NA months Median and 95% CI for DRFI were not estimable due to too few events having occurred	NA months Median and 95% CI for DRFI were not estimable due to too few events having occurred

SECONDARY outcome

Timeframe: From randomization up to first disease recurrence or death from any cause (up to 5 years)

Population: ITT population included all randomized participants, whether or not the assigned study treatment was received.

Disease-Free Survival (DFS) was defined as the time from randomization to the first occurrence of disease recurrence or death from any cause. DFS events include: Ipsilateral invasive breast tumor recurrence; Ipsilateral local-regional invasive breast cancer recurrence; Distant recurrence that has either been histologically confirmed or clinically diagnosed as recurrent invasive breast cancer; Contralateral invasive breast cancer; Ipsilateral or contralateral DCIS; Second primary non-breast invasive cancer; Death attributable to any cause. Analysis used Kaplan-Meier estimates where participants with no events at the time of analysis or no post-baseline information were censored.

Outcome measures

Outcome measures
Measure	Chemotherapy n=1098 Participants Participants were administered paclitaxel, 80 mg/m\^2, IV infusion QW for maximum of 36 weeks followed by dose-dense doxorubicin, 60 mg/m\^2 or dose-dense epirubicin, 90 mg/m\^2 IV (investigator's choice) plus cyclophosphamide, 600 mg/m\^2, IV repeated every Q2W for a maximum of 20 weeks supported with G-CSF or GM-CSF treatment.	Atezolizumab and Chemotherapy n=1101 Participants Participants were administered atezolizumab 840 mg, IV infusion, Q2W in combination with chemotherapy (paclitaxel 80 mg/m\^2, IV infusion QW for maximum of 22 weeks followed by dose-dense doxorubicin, 60 mg/m\^2 or dose-dense epirubicin, 90 mg/m\^2, IV (investigator's choice) plus cyclophosphamide, 600 mg/m\^2, IV repeated Q2W for maximum of 17 weeks supported with G-CSF or GM-CSF treatment followed by atezolizumab, 1200 mg IV infusion every Q3W as a maintenance therapy to complete 1 year of atezolizumab treatment from the first dose.
Disease-Free Survival (DFS)	NA months Median and 95% CI for DFS were not estimable due to too few events having occurred	NA months Median and 95% CI for DFS were not estimable due to too few events having occurred

SECONDARY outcome

Timeframe: Baseline (Cycle 1 Day 1), Day 1 of Cycles 4, 6, 8, 10, 12, 14 & 16; end of treatment/discontinuation (approximately at Day 351); Follow up: Months 3 to 48 (Total duration is up to 5 years); Cycles 1-5= 28 day cycles; Cycles 6-16: 21 day cycles

Population: Patient-reported outcome (PRO)-evaluable populations included participants in the ITT population with baseline PRO assessment and at least one post-baseline PRO assessment in the EORTC QLQC30. ITT population included all randomized participants, whether or not the assigned study treatment was received. Overall number analyzed is the number of participants with data available for analyses. Number analyzed is the number of participants with data available for analysis at the specified time point.

The EORTC QLQ-C30 is a cancer specific health-related quality-of life (QoL) questionnaire. For the role functioning scale, participant responses to the 2 questions "Q6: Were you limited in doing either your work or daily activities" and "Q7: Were you limited in pursuing your hobbies or other leisure time activities" were scored on a 4-point scale (1=Not at All to 4=Very Much). The scores were linearly transformed on a scale of 0 to 100, with a low score indicating better functioning. Negative change from baseline indicated improvement.

Outcome measures

Outcome measures
Measure	Chemotherapy n=1083 Participants Participants were administered paclitaxel, 80 mg/m\^2, IV infusion QW for maximum of 36 weeks followed by dose-dense doxorubicin, 60 mg/m\^2 or dose-dense epirubicin, 90 mg/m\^2 IV (investigator's choice) plus cyclophosphamide, 600 mg/m\^2, IV repeated every Q2W for a maximum of 20 weeks supported with G-CSF or GM-CSF treatment.	Atezolizumab and Chemotherapy n=1088 Participants Participants were administered atezolizumab 840 mg, IV infusion, Q2W in combination with chemotherapy (paclitaxel 80 mg/m\^2, IV infusion QW for maximum of 22 weeks followed by dose-dense doxorubicin, 60 mg/m\^2 or dose-dense epirubicin, 90 mg/m\^2, IV (investigator's choice) plus cyclophosphamide, 600 mg/m\^2, IV repeated Q2W for maximum of 17 weeks supported with G-CSF or GM-CSF treatment followed by atezolizumab, 1200 mg IV infusion every Q3W as a maintenance therapy to complete 1 year of atezolizumab treatment from the first dose.
Change From Baseline (CFB) in European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30 (QLQ-C30) Patient-reported Function (Role Functioning [Q6, Q7]) Baseline	87.26 score on scale Standard Deviation 18.92	86.43 score on scale Standard Deviation 19.66
Change From Baseline (CFB) in European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30 (QLQ-C30) Patient-reported Function (Role Functioning [Q6, Q7]) CFB: Cycle 6 Day 1	-17.31 score on scale Standard Deviation 29.94	-16.56 score on scale Standard Deviation 29.18
Change From Baseline (CFB) in European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30 (QLQ-C30) Patient-reported Function (Role Functioning [Q6, Q7]) CFB: Cycle 8 Day 1	-4.58 score on scale Standard Deviation 23.58	-4.58 score on scale Standard Deviation 24.31
Change From Baseline (CFB) in European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30 (QLQ-C30) Patient-reported Function (Role Functioning [Q6, Q7]) CFB: Cycle 10 Day 1	-3.77 score on scale Standard Deviation 23.59	-3.43 score on scale Standard Deviation 22.77
Change From Baseline (CFB) in European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30 (QLQ-C30) Patient-reported Function (Role Functioning [Q6, Q7]) CFB: Cycle 12 Day 1	-1.53 score on scale Standard Deviation 22.39	-1.59 score on scale Standard Deviation 23.05
Change From Baseline (CFB) in European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30 (QLQ-C30) Patient-reported Function (Role Functioning [Q6, Q7]) CFB: Cycle 14 Day 1	-1.02 score on scale Standard Deviation 21.69	-0.70 score on scale Standard Deviation 20.61
Change From Baseline (CFB) in European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30 (QLQ-C30) Patient-reported Function (Role Functioning [Q6, Q7]) CFB: Cycle 16 Day 1	-1.09 score on scale Standard Deviation 23.16	-0.10 score on scale Standard Deviation 21.77
Change From Baseline (CFB) in European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30 (QLQ-C30) Patient-reported Function (Role Functioning [Q6, Q7]) CFB: Study Drug Completion/Early Discontinuation	-2.66 score on scale Standard Deviation 23.48	-4.37 score on scale Standard Deviation 26.12
Change From Baseline (CFB) in European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30 (QLQ-C30) Patient-reported Function (Role Functioning [Q6, Q7]) CFB: Follow-up Month 3	-0.26 score on scale Standard Deviation 22.62	-0.40 score on scale Standard Deviation 23.34
Change From Baseline (CFB) in European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30 (QLQ-C30) Patient-reported Function (Role Functioning [Q6, Q7]) CFB: Follow-up Month 6	0.20 score on scale Standard Deviation 24.08	0.02 score on scale Standard Deviation 24.03
Change From Baseline (CFB) in European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30 (QLQ-C30) Patient-reported Function (Role Functioning [Q6, Q7]) CFB: Follow-up Month 9	-0.18 score on scale Standard Deviation 23.52	0.47 score on scale Standard Deviation 23.35
Change From Baseline (CFB) in European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30 (QLQ-C30) Patient-reported Function (Role Functioning [Q6, Q7]) CFB: Follow-up Month 12	0.32 score on scale Standard Deviation 22.42	1.22 score on scale Standard Deviation 21.95
Change From Baseline (CFB) in European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30 (QLQ-C30) Patient-reported Function (Role Functioning [Q6, Q7]) CFB: Follow-up Month 18	-0.47 score on scale Standard Deviation 24.41	1.52 score on scale Standard Deviation 21.82
Change From Baseline (CFB) in European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30 (QLQ-C30) Patient-reported Function (Role Functioning [Q6, Q7]) CFB: Follow-up Month 24	0.67 score on scale Standard Deviation 23.54	1.74 score on scale Standard Deviation 22.28
Change From Baseline (CFB) in European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30 (QLQ-C30) Patient-reported Function (Role Functioning [Q6, Q7]) CFB: Follow-up Month 30	2.24 score on scale Standard Deviation 23.36	2.01 score on scale Standard Deviation 24.19
Change From Baseline (CFB) in European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30 (QLQ-C30) Patient-reported Function (Role Functioning [Q6, Q7]) CFB: Follow-up Month 36	3.08 score on scale Standard Deviation 23.57	4.74 score on scale Standard Deviation 20.36
Change From Baseline (CFB) in European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30 (QLQ-C30) Patient-reported Function (Role Functioning [Q6, Q7]) CFB: Follow-up Month 48	0.00 score on scale Standard Deviation NA The standard deviation was not estimable for one participant.	13.33 score on scale Standard Deviation 13.94
Change From Baseline (CFB) in European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30 (QLQ-C30) Patient-reported Function (Role Functioning [Q6, Q7]) CFB: Cycle 4 Day 1	-10.88 score on scale Standard Deviation 25.00	-10.26 score on scale Standard Deviation 24.87

SECONDARY outcome

Population: PRO-evaluable populations included participants in the ITT population with baseline PRO assessment and at least one post-baseline PRO assessment in the EORTC QLQC30. ITT population included all randomized participants, whether or not the assigned study treatment was received. Overall number analyzed is the number of participants with data available for analyses. Number analyzed is the number of participants with data available for analysis at the specified time point.

The EORTC QLQ-C30 is a cancer specific health-related quality-of life (QoL) questionnaire. For the physical functioning scale, participant responses to 5 questions about daily activities (strenuous activities, long walks, short walks, bed/chair rest \& needing help with eating, dressing, washing themselves, or using the toilet) were scored on a 4-point scale (1=Not at All to 4=Very Much). The scores were linearly transformed on a scale of 0 to 100, with a high score indicating worst functioning. Negative change from baseline indicated improvement in functioning.

Outcome measures

Outcome measures
Measure	Chemotherapy n=1083 Participants Participants were administered paclitaxel, 80 mg/m\^2, IV infusion QW for maximum of 36 weeks followed by dose-dense doxorubicin, 60 mg/m\^2 or dose-dense epirubicin, 90 mg/m\^2 IV (investigator's choice) plus cyclophosphamide, 600 mg/m\^2, IV repeated every Q2W for a maximum of 20 weeks supported with G-CSF or GM-CSF treatment.	Atezolizumab and Chemotherapy n=1089 Participants Participants were administered atezolizumab 840 mg, IV infusion, Q2W in combination with chemotherapy (paclitaxel 80 mg/m\^2, IV infusion QW for maximum of 22 weeks followed by dose-dense doxorubicin, 60 mg/m\^2 or dose-dense epirubicin, 90 mg/m\^2, IV (investigator's choice) plus cyclophosphamide, 600 mg/m\^2, IV repeated Q2W for maximum of 17 weeks supported with G-CSF or GM-CSF treatment followed by atezolizumab, 1200 mg IV infusion every Q3W as a maintenance therapy to complete 1 year of atezolizumab treatment from the first dose.
Change From Baseline in EORTC QLQ-C30 Patient-reported Function (Physical Functioning [Q1-Q5]) Baseline	89.86 score on scale Standard Deviation 12.14	89.92 score on scale Standard Deviation 11.57
Change From Baseline in EORTC QLQ-C30 Patient-reported Function (Physical Functioning [Q1-Q5]) CFB: Cycle 4 Day 1	-8.93 score on scale Standard Deviation 14.97	-8.69 score on scale Standard Deviation 14.91
Change From Baseline in EORTC QLQ-C30 Patient-reported Function (Physical Functioning [Q1-Q5]) CFB: Cycle 6 Day 1	-13.30 score on scale Standard Deviation 18.63	-13.55 score on scale Standard Deviation 18.47
Change From Baseline in EORTC QLQ-C30 Patient-reported Function (Physical Functioning [Q1-Q5]) CFB: Cycle 8 Day 1	-5.33 score on scale Standard Deviation 13.79	-6.42 score on scale Standard Deviation 14.41
Change From Baseline in EORTC QLQ-C30 Patient-reported Function (Physical Functioning [Q1-Q5]) CFB: Cycle 10 Day 1	-3.71 score on scale Standard Deviation 13.28	-4.42 score on scale Standard Deviation 13.15
Change From Baseline in EORTC QLQ-C30 Patient-reported Function (Physical Functioning [Q1-Q5]) CFB: Cycle 12 Day 1	-2.41 score on scale Standard Deviation 12.87	-3.42 score on scale Standard Deviation 12.95
Change From Baseline in EORTC QLQ-C30 Patient-reported Function (Physical Functioning [Q1-Q5]) CFB: Cycle 14 Day 1	-1.41 score on scale Standard Deviation 12.87	-1.92 score on scale Standard Deviation 12.11
Change From Baseline in EORTC QLQ-C30 Patient-reported Function (Physical Functioning [Q1-Q5]) CFB: Cycle 16 Day 1	-1.65 score on scale Standard Deviation 12.78	-1.82 score on scale Standard Deviation 12.12
Change From Baseline in EORTC QLQ-C30 Patient-reported Function (Physical Functioning [Q1-Q5]) CFB:Study Drug Completion/Early Discontinuation	-2.56 score on scale Standard Deviation 13.72	-4.68 score on scale Standard Deviation 16.69
Change From Baseline in EORTC QLQ-C30 Patient-reported Function (Physical Functioning [Q1-Q5]) CFB:Follow-up Month 3	-1.62 score on scale Standard Deviation 12.71	-2.29 score on scale Standard Deviation 13.47
Change From Baseline in EORTC QLQ-C30 Patient-reported Function (Physical Functioning [Q1-Q5]) CFB: Follow-up Month 6	-1.70 score on scale Standard Deviation 13.46	-1.96 score on scale Standard Deviation 13.78
Change From Baseline in EORTC QLQ-C30 Patient-reported Function (Physical Functioning [Q1-Q5]) CFB: Follow-up Month 9	-1.55 score on scale Standard Deviation 13.75	-1.33 score on scale Standard Deviation 13.91
Change From Baseline in EORTC QLQ-C30 Patient-reported Function (Physical Functioning [Q1-Q5]) CFB: Follow-up Month 12	-1.70 score on scale Standard Deviation 13.85	-1.37 score on scale Standard Deviation 13.39
Change From Baseline in EORTC QLQ-C30 Patient-reported Function (Physical Functioning [Q1-Q5]) CFB: Follow-up Month 18	-1.92 score on scale Standard Deviation 13.60	-0.91 score on scale Standard Deviation 13.79
Change From Baseline in EORTC QLQ-C30 Patient-reported Function (Physical Functioning [Q1-Q5]) CFB: Follow-up Month 24	-1.37 score on scale Standard Deviation 13.89	-0.72 score on scale Standard Deviation 12.91
Change From Baseline in EORTC QLQ-C30 Patient-reported Function (Physical Functioning [Q1-Q5]) CFB: Follow-up Month 30	-1.61 score on scale Standard Deviation 15.61	-0.74 score on scale Standard Deviation 12.72
Change From Baseline in EORTC QLQ-C30 Patient-reported Function (Physical Functioning [Q1-Q5]) CFB: Follow-up Month 36	-0.42 score on scale Standard Deviation 14.40	0.82 score on scale Standard Deviation 13.18
Change From Baseline in EORTC QLQ-C30 Patient-reported Function (Physical Functioning [Q1-Q5]) CFB: Follow-up Month 48	-13.33 score on scale Standard Deviation NA The standard deviation was not estimable for one participant.	-2.67 score on scale Standard Deviation 3.65

SECONDARY outcome

Timeframe: Baseline (Cycle 1 Day 1), Day 1 of Cycles 4, 6, 8, 10, 12, 14 & 16; end of treatment/discontinuation (approximately 351 days); Follow up: Months 3 to 48 (Total duration is up to 5 years); Cycles 1-5= 28 day cycles; Cycles 6-16: 21 day cycles

The EORTC QLQ-C30 is a cancer specific health-related quality-of life (QoL) questionnaire. Participant responses to the questions regarding Global Health Status (Q29:GHS; "How would you rate your overall health during the past week?") and Quality of Life (Q30: QoL; "How would you rate your overall quality of life during the past week?") are scored on a 7-point scale (1= Very poor to 7=Excellent). Using linear transformation, raw scores are standardized, so that scores range from 0 to 100. A higher score indicates a better outcome. Negative change from Baseline values indicated deterioration in QOL or functioning and positive values indicated improvement.

Outcome measures

Outcome measures
Measure	Chemotherapy n=1081 Participants Participants were administered paclitaxel, 80 mg/m\^2, IV infusion QW for maximum of 36 weeks followed by dose-dense doxorubicin, 60 mg/m\^2 or dose-dense epirubicin, 90 mg/m\^2 IV (investigator's choice) plus cyclophosphamide, 600 mg/m\^2, IV repeated every Q2W for a maximum of 20 weeks supported with G-CSF or GM-CSF treatment.	Atezolizumab and Chemotherapy n=1087 Participants Participants were administered atezolizumab 840 mg, IV infusion, Q2W in combination with chemotherapy (paclitaxel 80 mg/m\^2, IV infusion QW for maximum of 22 weeks followed by dose-dense doxorubicin, 60 mg/m\^2 or dose-dense epirubicin, 90 mg/m\^2, IV (investigator's choice) plus cyclophosphamide, 600 mg/m\^2, IV repeated Q2W for maximum of 17 weeks supported with G-CSF or GM-CSF treatment followed by atezolizumab, 1200 mg IV infusion every Q3W as a maintenance therapy to complete 1 year of atezolizumab treatment from the first dose.
Change From Baseline in EORTC QLQ-C30 Global Health Status (GHS) [Q29] and Health-Related Quality of Life (HRQoL) [Q30] Combined Score CFB: Cycle 14 Day 1	-0.37 score on scale Standard Deviation 19.04	-1.25 score on scale Standard Deviation 18.35
Change From Baseline in EORTC QLQ-C30 Global Health Status (GHS) [Q29] and Health-Related Quality of Life (HRQoL) [Q30] Combined Score CFB: Cycle 16 Day 1	0.08 score on scale Standard Deviation 18.56	-1.30 score on scale Standard Deviation 18.34
Change From Baseline in EORTC QLQ-C30 Global Health Status (GHS) [Q29] and Health-Related Quality of Life (HRQoL) [Q30] Combined Score Baseline	76.26 score on scale Standard Deviation 18.15	75.90 score on scale Standard Deviation 18.52
Change From Baseline in EORTC QLQ-C30 Global Health Status (GHS) [Q29] and Health-Related Quality of Life (HRQoL) [Q30] Combined Score CFB: Cycle 4 Day 1	-10.49 score on scale Standard Deviation 20.25	-10.02 score on scale Standard Deviation 19.48
Change From Baseline in EORTC QLQ-C30 Global Health Status (GHS) [Q29] and Health-Related Quality of Life (HRQoL) [Q30] Combined Score CFB: Cycle 6 Day 1	-15.87 score on scale Standard Deviation 23.83	-15.68 score on scale Standard Deviation 22.32
Change From Baseline in EORTC QLQ-C30 Global Health Status (GHS) [Q29] and Health-Related Quality of Life (HRQoL) [Q30] Combined Score CFB: Cycle 10 Day 1	-1.84 score on scale Standard Deviation 19.57	-2.82 score on scale Standard Deviation 18.38
Change From Baseline in EORTC QLQ-C30 Global Health Status (GHS) [Q29] and Health-Related Quality of Life (HRQoL) [Q30] Combined Score CFB: Cycle 12 Day 1	-0.71 score on scale Standard Deviation 19.41	-2.31 score on scale Standard Deviation 18.91
Change From Baseline in EORTC QLQ-C30 Global Health Status (GHS) [Q29] and Health-Related Quality of Life (HRQoL) [Q30] Combined Score CFB:Study Drug Completion/Early Discontinuation	-1.56 score on scale Standard Deviation 20.68	-4.39 score on scale Standard Deviation 22.01
Change From Baseline in EORTC QLQ-C30 Global Health Status (GHS) [Q29] and Health-Related Quality of Life (HRQoL) [Q30] Combined Score CFB: Follow-up Month 3	1.01 score on scale Standard Deviation 20.25	-0.74 score on scale Standard Deviation 20.50
Change From Baseline in EORTC QLQ-C30 Global Health Status (GHS) [Q29] and Health-Related Quality of Life (HRQoL) [Q30] Combined Score CFB: Follow-up Month 6	1.10 score on scale Standard Deviation 20.23	-0.90 score on scale Standard Deviation 20.72
Change From Baseline in EORTC QLQ-C30 Global Health Status (GHS) [Q29] and Health-Related Quality of Life (HRQoL) [Q30] Combined Score CFB: Follow-up Month 9	0.62 score on scale Standard Deviation 20.47	0.07 score on scale Standard Deviation 20.83
Change From Baseline in EORTC QLQ-C30 Global Health Status (GHS) [Q29] and Health-Related Quality of Life (HRQoL) [Q30] Combined Score CFB: Follow-up Month 12	1.21 score on scale Standard Deviation 20.42	0.19 score on scale Standard Deviation 19.84
Change From Baseline in EORTC QLQ-C30 Global Health Status (GHS) [Q29] and Health-Related Quality of Life (HRQoL) [Q30] Combined Score CFB: Follow-up Month 18	1.09 score on scale Standard Deviation 22.18	0.47 score on scale Standard Deviation 20.77
Change From Baseline in EORTC QLQ-C30 Global Health Status (GHS) [Q29] and Health-Related Quality of Life (HRQoL) [Q30] Combined Score CFB: Follow-up Month 24	2.32 score on scale Standard Deviation 22.30	0.43 score on scale Standard Deviation 21.33
Change From Baseline in EORTC QLQ-C30 Global Health Status (GHS) [Q29] and Health-Related Quality of Life (HRQoL) [Q30] Combined Score CFB: Follow-up Month 30	1.54 score on scale Standard Deviation 21.36	-0.57 score on scale Standard Deviation 22.43
Change From Baseline in EORTC QLQ-C30 Global Health Status (GHS) [Q29] and Health-Related Quality of Life (HRQoL) [Q30] Combined Score CFB: Follow-up Month 36	2.64 score on scale Standard Deviation 20.95	0.58 score on scale Standard Deviation 23.57
Change From Baseline in EORTC QLQ-C30 Global Health Status (GHS) [Q29] and Health-Related Quality of Life (HRQoL) [Q30] Combined Score CFB: Follow-up Month 48	0.00 score on scale Standard Deviation NA The standard deviation was not estimable for one participant.	6.25 score on scale Standard Deviation 31.46
Change From Baseline in EORTC QLQ-C30 Global Health Status (GHS) [Q29] and Health-Related Quality of Life (HRQoL) [Q30] Combined Score CFB: Cycle 8 Day 1	-3.54 score on scale Standard Deviation 19.72	-5.09 score on scale Standard Deviation 18.88

SECONDARY outcome

Timeframe: Up to 5 years

Population: Safety Evaluable Population included all participants who received any amount of any study drug.

An Adverse Event (AE) is any untoward medical occurrence in a participant administered a pharmaceutical product, regardless of causal attribution. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding, for example), symptom, or disease temporally associated with the use of a pharmaceutical product, whether or not considered related to the pharmaceutical product. Preexisting conditions which worsen during a study are also considered as adverse events. AEs are reported based on the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE), Version 5.0.

Outcome measures

Outcome measures
Measure	Chemotherapy n=1084 Participants Participants were administered paclitaxel, 80 mg/m\^2, IV infusion QW for maximum of 36 weeks followed by dose-dense doxorubicin, 60 mg/m\^2 or dose-dense epirubicin, 90 mg/m\^2 IV (investigator's choice) plus cyclophosphamide, 600 mg/m\^2, IV repeated every Q2W for a maximum of 20 weeks supported with G-CSF or GM-CSF treatment.	Atezolizumab and Chemotherapy n=1093 Participants Participants were administered atezolizumab 840 mg, IV infusion, Q2W in combination with chemotherapy (paclitaxel 80 mg/m\^2, IV infusion QW for maximum of 22 weeks followed by dose-dense doxorubicin, 60 mg/m\^2 or dose-dense epirubicin, 90 mg/m\^2, IV (investigator's choice) plus cyclophosphamide, 600 mg/m\^2, IV repeated Q2W for maximum of 17 weeks supported with G-CSF or GM-CSF treatment followed by atezolizumab, 1200 mg IV infusion every Q3W as a maintenance therapy to complete 1 year of atezolizumab treatment from the first dose.
Number of Participants With Adverse Events (AE)	1074 Participants	1090 Participants

SECONDARY outcome

Timeframe: Postdose Day 1 of Cycle 1; Predose Day 1 of Cycles 2, 3, and 4; Predose Cycles 6, 10, and 14; Predose Day 2 of Cycle 16; Cycles 1-5= 28-day cycles; Cycles 6-16: 21-day cycles

Population: Pharmacokinetic (PK)-evaluable population included all participants who received any dose of study medication and who have at least one evaluable postbaseline PK sample. Overall number analyzed is the number of participants with data available for analyses. Number analyzed is the number of participants with data available for analysis at the specified time point.

Outcome measures

Outcome measures
Measure	Chemotherapy n=952 Participants Participants were administered paclitaxel, 80 mg/m\^2, IV infusion QW for maximum of 36 weeks followed by dose-dense doxorubicin, 60 mg/m\^2 or dose-dense epirubicin, 90 mg/m\^2 IV (investigator's choice) plus cyclophosphamide, 600 mg/m\^2, IV repeated every Q2W for a maximum of 20 weeks supported with G-CSF or GM-CSF treatment.	Atezolizumab and Chemotherapy Participants were administered atezolizumab 840 mg, IV infusion, Q2W in combination with chemotherapy (paclitaxel 80 mg/m\^2, IV infusion QW for maximum of 22 weeks followed by dose-dense doxorubicin, 60 mg/m\^2 or dose-dense epirubicin, 90 mg/m\^2, IV (investigator's choice) plus cyclophosphamide, 600 mg/m\^2, IV repeated Q2W for maximum of 17 weeks supported with G-CSF or GM-CSF treatment followed by atezolizumab, 1200 mg IV infusion every Q3W as a maintenance therapy to complete 1 year of atezolizumab treatment from the first dose.
Serum Concentration of Atezolizumab Post-dose: Cycle 1 Day 1	319 microgram per milliliter (µg/mL) Geometric Coefficient of Variation 43.3	—
Serum Concentration of Atezolizumab Pre-dose: Cycle 2 Day 1	153 microgram per milliliter (µg/mL) Geometric Coefficient of Variation 85.2	—
Serum Concentration of Atezolizumab Pre-dose: Cycle 3 Day 1	220 microgram per milliliter (µg/mL) Geometric Coefficient of Variation 62.0	—
Serum Concentration of Atezolizumab Pre-dose: Cycle 4 Day 1	221 microgram per milliliter (µg/mL) Geometric Coefficient of Variation 120.4	—
Serum Concentration of Atezolizumab Pre-dose: Cycle 6	239 microgram per milliliter (µg/mL) Geometric Coefficient of Variation 146.9	—
Serum Concentration of Atezolizumab Pre-dose: Cycle 10	250 microgram per milliliter (µg/mL) Geometric Coefficient of Variation 92.2	—
Serum Concentration of Atezolizumab Pre-dose: Cycle 14	258 microgram per milliliter (µg/mL) Geometric Coefficient of Variation 118.7	—
Serum Concentration of Atezolizumab Pre-dose: Cycle 16 Day 2	355 microgram per milliliter (µg/mL) Geometric Coefficient of Variation 29.5	—

SECONDARY outcome

Timeframe: Up to 5 years

Population: Safety Evaluable Population included all participants who received any amount of any study drug. Number analyzed at baseline and postbaseline are unique number of participants out of all the assessed participants who may have been ADA positive at that timepoint. Different participants may have contributed data for baseline and postbaseline.

Baseline evaluable participant= participant with an ADA assay result from a baseline sample(s). Post-baseline evaluable participant= participant with an ADA assay result from at least one postbaseline sample.

Outcome measures

Outcome measures
Measure	Chemotherapy n=1093 Participants Participants were administered paclitaxel, 80 mg/m\^2, IV infusion QW for maximum of 36 weeks followed by dose-dense doxorubicin, 60 mg/m\^2 or dose-dense epirubicin, 90 mg/m\^2 IV (investigator's choice) plus cyclophosphamide, 600 mg/m\^2, IV repeated every Q2W for a maximum of 20 weeks supported with G-CSF or GM-CSF treatment.	Atezolizumab and Chemotherapy Participants were administered atezolizumab 840 mg, IV infusion, Q2W in combination with chemotherapy (paclitaxel 80 mg/m\^2, IV infusion QW for maximum of 22 weeks followed by dose-dense doxorubicin, 60 mg/m\^2 or dose-dense epirubicin, 90 mg/m\^2, IV (investigator's choice) plus cyclophosphamide, 600 mg/m\^2, IV repeated Q2W for maximum of 17 weeks supported with G-CSF or GM-CSF treatment followed by atezolizumab, 1200 mg IV infusion every Q3W as a maintenance therapy to complete 1 year of atezolizumab treatment from the first dose.
Percentage of Participants With Anti-Drug Antibodies (ADAs) to Atezolizumab Baseline	2.1 percentage of participants	—
Percentage of Participants With Anti-Drug Antibodies (ADAs) to Atezolizumab Post-baseline	11.5 percentage of participants	—

Adverse Events

Chemotherapy

Serious events: 173 serious events

Other events: 1068 other events

Deaths: 58 deaths

Atezolizumab and Chemotherapy

Serious events: 280 serious events

Other events: 1082 other events

Deaths: 72 deaths

Serious adverse events

Other adverse events

Additional Information

Medical Communications

Hoffmann-La Roche

Phone: 800 821-8590

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee The Study being conducted under this Agreement is part of the Overall Study. Investigator is free to publish in reputable journals or to present at professional conferences the results of the Study, but only after the first publication or presentation that involves the Overall Study. The Sponsor may request that Confidential Information be deleted and/or the publication be postponed in order to protect the Sponsor's intellectual property rights.
Publication restrictions are in place

Restriction type: OTHER