A Study To Evaluate the Efficacy and Safety Of Atezolizumab or Placebo in Combination With Neoadjuvant Doxorubicin + Cyclophosphamide Followed By Paclitaxel + Trastuzumab + Pertuzumab In Early Her2-Positive Breast Cancer

pCR (ypT0/is ypN0) based upon hormone receptor status (estrogen receptor [ER]/progesterone receptor [PgR] positive or ER/PgR negative).

pCR (ypT0/is ypN0) in the IC 0 Population

EFS defined as the time from randomization to the first documented disease recurrence, unequivocal tumor progression determined by the treating investigator, or death from any cause, whichever occurs first, in all patients and based upon hormone receptor status (ER/PgR positive or ER/PgR negative) and PD-L1 status (IC 0; IC 1/2/3).

DFS defined as the time from surgery to the first documented disease recurrence or death from any cause, whichever occurs first, in all patients who undergo surgery and based upon PD-L1 status (IC 0; IC 1/2/3).

OS defined as the time from randomization to death from any cause in all participants and based upon PD-L1 status (IC 0; IC 1/2/3).

EORTC QLQ-C30 is a self-reported questionnaire that included functional scales (physical, role, cognitive, emotional, social), symptom scales (fatigue, pain, nausea/vomiting), global health scale/quality of life (GHS/QOL) and single items (dyspnea, appetite loss, insomnia, constipation, diarrhea, financial difficulties). Questions 1-28 on the QLQ-C30 were on a 4-point scale (1=Not at All to 4=Very Much). Questions 29-30 (GHS scale) were on a 7-point scale (1=Very Poor to 7=Excellent). For this instrument, GHS/QOL and functional scales were linearly transformed so each score ranged 0-100, where lower scores indicate poorer functioning (e.g., worsening) and higher scores indicate better functioning (e.g., improvement).

EORTC QLQ-C30 is a self-reported questionnaire that included functional scales (physical, role, cognitive, emotional, social), symptom scales (fatigue, pain, nausea/vomiting), GHS/QOL and single items (dyspnea, appetite loss, insomnia, constipation, diarrhea, financial difficulties). Questions 1-28 on the QLQ-C30 were on a 4-point scale (1=Not at All to 4=Very Much). Questions 29-30 (GHS scale) were on a 7-point scale (1=Very Poor to 7=Excellent). For this instrument, GHS/QOL and functional scales were linearly transformed so each score ranged 0-100, where lower scores indicate poorer functioning (e.g., worsening) and higher scores indicate better functioning (e.g., improvement).

Cmax is the maximum (or peak) concentration that a study drug achieves in the body.

Cmin is the minimum (or trough) concentration that a study drug achieves in the body.

Cmax is the maximum (or peak) concentration that a study drug achieves in the body.

Cmin is the minimum (or trough) concentration that a study drug achieves in the body.

Participants were considered to be treatment-emergent ADA-positive if they were ADA-negative or had missing data at baseline but developed an ADA response following study drug exposure (treatment-induced ADA response), or if they were ADA-positive at baseline and the titer of one or more post-baseline samples was at least 0.60 titer units greater than the titer of the baseline sample (treatment-enhanced ADA response). Participants were considered to be treatment-emergent ADA-negative if they were ADA-negative or were missing data at baseline and all post-baseline samples were negative, or if they were ADA-positive at baseline but did not have any post-baseline samples with a titer that was at least 0.60 titer units greater than the titer of the baseline sample (treatment unaffected).

Participants were considered to be treatment-emergent ADA-positive if they were ADA-negative or had missing data at baseline but developed an ADA response following study drug exposure (treatment-induced ADA response), or if they were ADA-positive at baseline and the titer of one or more post-baseline samples was at least 0.60 titer units greater than the titer of the baseline sample (treatment-enhanced ADA response). Participants were considered to be treatment-emergent ADA-negative if they were ADA-negative or were missing data at baseline and all post-baseline samples were negative, or if they were ADA-positive at baseline but did not have any post-baseline samples with a titer that was at least 0.60 titer units greater than the titer of the baseline sample (treatment unaffected).

Participants were considered to be treatment-emergent ADA-positive if they were ADA-negative or had missing data at baseline but developed an ADA response following study drug exposure (treatment-induced ADA response), or if they were ADA-positive at baseline and the titer of one or more post-baseline samples was at least 0.60 titer units greater than the titer of the baseline sample (treatment-enhanced ADA response). Participants were considered to be treatment-emergent ADA-negative if they were ADA-negative or were missing data at baseline and all post-baseline samples were negative, or if they were ADA-positive at baseline but did not have any post-baseline samples with a titer that was at least 0.60 titer units greater than the titer of the baseline sample (treatment unaffected).

Participants were considered to be treatment-emergent ADA-positive if they were ADA-negative or had missing data at baseline but developed an ADA response following study drug exposure (treatment-induced ADA response), or if they were ADA-positive at baseline and the titer of one or more post-baseline samples was at least 0.60 titer units greater than the titer of the baseline sample (treatment-enhanced ADA response). Participants were considered to be treatment-emergent ADA-negative if they were ADA-negative or were missing data at baseline and all post-baseline samples were negative, or if they were ADA-positive at baseline but did not have any post-baseline samples with a titer that was at least 0.60 titer units greater than the titer of the baseline sample (treatment unaffected).

pCR is defined as the absence of residual invasive cancer on hematoxylin and eosin evaluation of the complete resected breast specimen and all sampled regional lymph nodes following completion of neoadjuvant systemic therapy (NAST) (i.e., ypT0/is ypN0 in the current American Joint Committee on Cancer [AJCC] staging system, 8th edition).