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Study in Participants With Early-Stage or Locally Advanced Human Epidermal Growth Factor Receptor (HER) 2-Positive Breast Cancer to Evaluate Treatment With Trastuzumab Plus (+) Pertuzumab + Docetaxel Compared With Trastuzumab + Placebo + Docetaxel

A Randomized, Multicenter, Double-Blind, Placebo-Controlled, Phase III Study to Evaluate Pertuzumab in Combination With Docetaxel and Trastuzumab as Neoadjuvant Therapy, and Pertuzumab in Combination With Trastuzumab as Adjuvant Therapy After Surgery and Chemotherapy in Patients With Early-Stage or Locally Advanced HER2-Positive Breast Cancer

Status
Completed
Phases
Phase 3
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT02586025
Acronym
PEONY
Enrollment
329
Registered
2015-10-26
Start date
2016-03-14
Completion date
2022-03-14
Last updated
2023-05-22

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Breast Cancer

Brief summary

This is an Asia-Pacific regional, randomized, double-blind, multicenter trial designed to evaluate treatment with trastuzumab + pertuzumab + docetaxel compared with trastuzumab + placebo + docetaxel in chemotherapy-naïve participants with early-stage or locally advanced HER2-positive breast cancer. The anticipated treatment duration is approximately 17 months.

Interventions

DRUGFEC Chemotherapy

Fluorouracil 500-600 milligrams per square meter (mg/m2), epirubicin 90-120 mg/m2, and cyclophosphamide 500-600 mg/m2 by intravenous (IV) infusion every 3 weeks for three cycles (Cycles 5-7). FEC chemotherapeutic agents will be administered following surgery on Day 1 of each specified cycle.

PROCEDURESurgery

All participants who are eligible for surgery will undergo surgery and have their pathologic response evaluated.

DRUGDocetaxel

Docetaxel IV infusion in 3-week cycles. Neoadjuvant treatment: 75 mg/m2 for Cycles 1-4.

DRUGPertuzumab

Pertuzumab IV infusion in 3-week cycles. Prior to surgery (neoadjuvant treatment): 840 milligrams (mg) loading dose for Cycle 1, followed by 420 mg for Cycles 2-4. After surgery and 3 cycles of FEC chemotherapy (adjuvant treatment): 840 mg loading dose for Cycle 8, followed by 420 mg for Cycles 9-20)

DRUGPlacebo

Placebo by IV infusion in 3-week cycles as neoadjuvant treatment (Cycles 1-4)and as adjuvant treatment (Cycles 8-20)

DRUGTrastuzumab

Trastuzumab IV infusion in 3-week cycles. Neoadjuvant treatment: 8 milligrams per kilogram (mg/kg) loading dose for Cycle 1, followed by 6 mg/kg for Cycles 2-4. Adjuvant treatment: 8 mg/kg loading dose for Cycle 8, followed by 6 mg/kg for Cycles 9-20.

Sponsors

Hoffmann-La Roche
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* Histologically confirmed invasive breast carcinoma with a primary tumor size of more than (\>) 2 centimeters (cm) by standard local assessment technique * Breast cancer stage at presentation: early-stage (T2-3, N0-1, M0) or locally advanced (T2-3, N2 or N3, M0; T4, any N, M0) * HER2-positive breast cancer confirmed by a Sponsor-designated central laboratory and defined as 3+ score by immunohistochemistry in \> 10 percent (%) of immunoreactive cells or HER2 gene amplification (ratio of HER2 gene signals to centromere 17 signals equal to or more than \[\>=\] 2.0) by in situ hybridization * Known hormone receptor status (estrogen receptor and/or progesterone receptor) * Eastern Cooperative Oncology Group Performance Status equal to or less than (\<=) 1 * Baseline left ventricular ejection fracture \>= 55% measured by echocardiography (preferred) or multiple gated acquisition scan * Negative serum pregnancy test

Exclusion criteria

* Stage IV metastatic breast cancer * Inflammatory breast cancer * Previous anti-cancer therapy or radiotherapy for any malignancy * History of other malignancy within 5 years prior to screening, except for appropriately-treated carcinoma in situ of the cervix, non-melanoma skin carcinoma, or Stage I uterine cancer * Concurrent anti-cancer treatment in another investigational trial, including hormone therapy, bisphosphonate therapy, or immunotherapy * Major surgical procedure unrelated to breast cancer within 4 weeks prior to randomization or from which the participant has not fully recovered * Serious cardiac illness or medical condition * Other concurrent serious diseases that may interfere with planned treatment, including severe pulmonary conditions/illness * Any abnormalities in liver, kidney or hematologic function laboratory tests immediately prior to randomization * Sensitivity to any of the study medications, any of the ingredients or excipients of these medications, or benzyl alcohol * Pregnant or lactating

Design outcomes

Primary

MeasureTime frameDescription
Percentage of Participants With Total Pathologic Complete Response (tpCR) as Assessed by the Independent Review Committee (IRC)At surgery (Cycle 4 Days 22-35)This tpCR was assessed by the IRC. tpCR was defined as the absence of any residual invasive cancer on hematoxylin and eosin evaluation of the resected breast specimen and all sampled ipsilateral lymph nodes after completion of neoadjuvant therapy and surgery (that is, ypT0/is, ypN0, in accordance with the current American Joint Committee on Cancer \[AJCC\] staging system). The analysis was based on the ITT population with participants grouped by the treatment assigned at the time of randomization. Participants whose tpCR assessment was missing or invalid were counted as not achieving tpCR. The duration of one treatment cycle was 21 days; the administration of therapy in Cycle 5 did not occur until 2 weeks after surgery. The percentages have been rounded off to first decimal point.

Secondary

MeasureTime frameDescription
Percentage of Participants With tpCR as Assessed by the Local PathologistAt surgery (Cycle 4 Days 22-35)This tpCR was assessed by the local pathologist. tpCR was defined as the absence of any residual invasive cancer on hematoxylin and eosin evaluation of the resected breast specimen and all sampled ipsilateral lymph nodes after completion of neoadjuvant therapy and surgery (that is, ypT0/is, ypN0, in accordance with the current AJCC staging system). The analysis was based on the ITT population with participants grouped by the treatment assigned at the time of randomization. Participants whose tpCR assessment was missing or invalid were counted as not achieving tpCR. The duration of one treatment cycle was 21 days; the administration of therapy in Cycle 5 did not occur until 2 weeks after surgery. The percentages have been rounded off to first decimal point.
Percentage of Participants With Breast Pathologic Complete Response (bpCR), Defined as ypT0/is According to the AJCC Staging System as Assessed by the IRCAt surgery (Cycle 4 Days 22-35)This bpCR was assessed by the IRC. bpCR was defined as the absence of any residual invasive cancer on the hematoxylin and eosin evaluation of the resected breast specimen after completion of neoadjuvant therapy and surgery (that is, ypT0/is, in accordance with current AJCC staging system). The analysis was based on the ITT population with participants grouped by the treatment assigned at the time of randomization. Participants whose bpCR assessment was missing or invalid were counted as not achieving bpCR. The duration of one treatment cycle was 21 days; the administration of therapy in Cycle 5 did not occur until 2 weeks after surgery. The percentages have been rounded off to first decimal point.
Percentage of Participants With bpCR as Assessed by the Local PathologistAt surgery (Cycle 4 Days 22-35)This bpCR was assessed by the local pathologist. bpCR was defined as the absence of any residual invasive cancer on the hematoxylin and eosin evaluation of the resected breast specimen after completion of neoadjuvant therapy and surgery (that is, ypT0/is in accordance with current AJCC staging system). The analysis was based on the ITT population with participants grouped by the treatment assigned at the time of randomization. Participants whose bpCR assessment was missing or invalid were counted as not achieving bpCR. The duration of one treatment cycle was 21 days; the administration of therapy in Cycle 5 did not occur until 2 weeks after surgery. The percentages have been rounded off to first decimal point.
Percentage of Participants With Complete Response (CR), Partial Response (PR), Stable Disease (SD), or Progressive Disease (PD) During Cycles 1-4, According to Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1At surgery (Cycle 4 Days 22-35)Clinical responses that include percentage of participants with a CR, PR, SD, or PD were determined by investigator during Cycles 1-4 (prior to surgery) on basis of RECIST version 1.1. CR=disappearance of all target lesions i.e., any pathological lymph nodes (whether target or non-target) must have reduction in short axis to \<10 millimeters (mm). PR=at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum of diameters. SD=neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for PD, taking as reference the smallest sum during the study. PD=at least a 20% increase in the sum of diameters of target lesions, taking as reference the smallest sum during the study (nadir) with inclusion of baseline. Only participants with measurable disease at baseline were included in the analysis. 1 Cycle=21 days. The percentages have been rounded off to first decimal point.
Percentage of Participants With an Objective Response (CR or PR) During Cycles 1-4, According to RECIST Version 1.1At surgery (Cycle 4 Days 22-35)An objective response was defined as the percentage of participants who achieved a CR or PR as the best tumor response during the neoadjuvant period (that is, during Cycles 1-4 prior to surgery), as determined by the investigator on the basis of RECIST version 1.1. CR=disappearance of all target lesions i.e., any pathological lymph nodes (whether target or non-target) must have reduction in short axis to \<10 mm. PR=at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum of diameters. No confirmation was required for objective response. Only participants with measurable disease at baseline were included in the analysis. The duration of one treatment cycle was 21 days; the administration of therapy in Cycle 5 did not occur until 2 weeks after surgery. The percentages have been rounded off to first decimal point.
Kaplan-Meier Estimate of the Percentage of Participants Event-Free for Event-Free Survival (EFS) at 1, 3, and 5 YearsFrom Baseline to EFS event or date last known to be alive and event-free at 1, 3, and 5 yearsKaplan-Meier approach was used to estimate percentage of participants who were event-free for EFS at 1, 3 & 5 years. EFS=time from randomization to first documentation of one of the following events: PD (before surgery) as determined by investigator with RECIST v1.1. PD=at least a 20% increase in sum of diameters of target lesions, taking as reference smallest sum during the study (nadir) with inclusion of baseline. Any evidence of contralateral disease in situ was not identified as PD; Disease recurrence (local, regional, distant, or contralateral) after surgery; Death from any cause. After treatment completion/discontinuation, follow-up data was collected every 3 months for 1 year & then every 6 months thereafter, until disease progression/recurrence or until 5 years after randomization of last participant, whichever occurred first. Participants without an EFS event at time of analysis were censored as of the date they were last known to be alive & event-free.
Kaplan-Meier Estimate of the Percentage of Participants Event-Free for Disease-Free Survival (DFS) at 1, 3, and 5 YearsFrom surgery (Cycle 4: Days 22-35) to DFS event or date last known to be alive and event-free at 1, 3, and 5 yearsKaplan-Meier approach was used to estimate the percentage of participants who were event-free for DFS at 1, 3 and 5 years. DFS = time from first date of no disease (i.e., date of surgery) to first documentation of one of the following events: Disease recurrence (local, regional, distant, or contralateral) after surgery or death from any cause. After treatment completion/discontinuation, follow-up data was collected every 3 months for 1 year and then every 6 months thereafter, until disease progression or recurrence or until 5 years after randomization of the last participant, whichever occurred first. Participants were considered to be disease-free if they underwent surgery and no recurrence of disease was reported thereafter. Data from participants who did not have an event at analysis were censored as of the date they were last known to be alive and event-free.
Kaplan-Meier Estimate of the Percentage of Participants Event-Free for Overall Survival (OS) at 1, 3, and 5 YearsFrom Baseline to OS event or date last known to be alive at 1, 3, and 5 yearsKaplan-Meier approach was used to estimate the percentage of participants who were event-free for OS at 1, 3 and 5 years. OS was defined as the time from randomization to death from any cause. After treatment completion/discontinuation, follow-up data was collected every 3 months for 1 year and then every 6 months thereafter, until disease progression or recurrence or until 5 years after randomization of the last participant, whichever occurred first. Data from participants who were alive at the time of the analysis was censored as of the last date they were known to be alive.
Percentage of Participants With at Least One Adverse Event (AE) During the Neoadjuvant Treatment PeriodBaseline up to end of Cycle 4 (1 cycle = 21 days)The percentage of participants who experienced at least one AE during the neoadjuvant period is reported here. An AE is any untoward medical occurrence in a clinical investigation participant who is administered a pharmaceutical product regardless of the causal attribution. An adverse event was therefore any unfavourable 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. Pre-existing conditions which worsened during the study were also considered as adverse events. The neoadjuvant treatment period began after randomization upon receiving the first dose of any of the neoadjuvant study medications and ended before receiving the first dose of adjuvant study treatment. The duration of one treatment cycle is 21 days. The percentages have been rounded off to first decimal point.
Percentage of Participants With at Least One AE During the Adjuvant Treatment PeriodFrom Cycle 5 (1 cycle = 21 days) up to 42 days after the last dose in Cycle 20 Day 1 (approximately 1 year)Percentage of participants who experienced at least one adverse event during the adjuvant period is reported here. An AE is any untoward medical occurrence in a clinical investigation participant who is administered a pharmaceutical product regardless of the causal attribution. An adverse event was therefore 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. Pre-existing conditions which worsened during the study were also considered as adverse events. Adjuvant treatment period began after primary surgery, upon receiving the first dose of any of the adjuvant study medications. It ended 42 days after last dose of adjuvant study treatment upon treatment completion or discontinuation. 1 Cycle=21 days. The percentages have been rounded off to first decimal point.
Percentage of Participants With at Least One Adverse Event During the Treatment-Free Follow-Up PeriodFrom end of overall study treatment until disease progression or until 5 years after randomization of the last patient, whichever occurred first (up to 6 years)The percentage of participants who experienced at least one adverse event during the treatment-free follow-up period is reported here. An AE is any untoward medical occurrence in a clinical investigation participant who is administered a pharmaceutical product regardless of the causal attribution. An adverse event was therefore any unfavourable 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. The percentages have been rounded off to first decimal point.
Percentage of Participants Who Experienced a Primary Cardiac EventFrom Baseline until end of study (up to 6 years)A primary cardiac event is defined as heart failure (New York Heart Association \[NYHA\] Class III or NYHA Class IV) and a drop in left ventricular ejection fraction (LVEF) of at least 10 ejection fraction points from baseline and to below 50%.
Percentage of Participants Who Experienced a Secondary Cardiac EventFrom Baseline until end of study (up to 6 years)A secondary cardiac event is defined as an asymptomatic or mildly symptomatic (NYHA Class II) drop in LVEF by multiple-gated acquisition (MUGA) scan or echocardiogram confirmed by a second LVEF assessment within approximately 3 weeks showing also a documented drop. A significant LVEF drop is defined as an absolute decrease of at least 10 points below the baseline measurement and to below 50%.
Maximum Change From Baseline in LVEFBaseline; Day 1 of Cycles 2, 4, 5, 8, 11, and 20 (1 cycle = 21 days)LVEF is the measurement of how much blood is being pumped out of the left ventricle of the heart (the main pumping chamber) with each contraction. A normal LVEF ranges from 55% to 70%, as measured by echocardiogram (preferred) or MUGA scan. The same method was used throughout the study for each participant and preferably performed and evaluated by the same assessor. Here, we report the maximum change from baseline in LVEF at any point during the study.
Change From Baseline in LVEF Over TimeBaseline; Day 1 of Cycles 2, 4, 5, 8, 11, and 20 (1 cycle = 21 days)LVEF is the measurement of how much blood is being pumped out of the left ventricle of the heart (the main pumping chamber) with each contraction. A normal LVEF ranges from 55% to 70%, as measured by echocardiogram (preferred) or MUGA scan. The same method was used throughout the study for each participant and preferably performed and evaluated by the same assessor. Here, we report the change from baseline in LVEF over time.

Countries

China, South Korea, Taiwan, Thailand

Participant flow

Recruitment details

A total of 329 participants with early-stage or locally advanced human epidermal growth factor receptor (HER) 2-positive breast cancer were enrolled in this study at 23 investigative sites in China, Republic of Korea, Taiwan, and Thailand from 14 March 2016 to 14 March 2022.

Participants by arm

ArmCount
Pertuzumab, Trastuzumab, and Chemotherapy
Prior to surgery: Participants received trastuzumab, 8 mg/kg loading dose in Cycle 1, followed by 6 mg/kg from Cycles 2-4, pertuzumab, 840 mg loading dose in Cycle 1, followed by 420 mg from Cycles 2-4, and docetaxel, 75 mg/m\^2 from Cycles 1-4 (1 cycle = 21 days) by IV infusion. Post surgery: Participants received chemotherapy with fluorouracil 500-600 mg/m\^2, epirubicin 90-120 mg/m\^2, and cyclophosphamide 500-600 mg/m\^2 by IV infusion every 3 weeks from Cycles 5-7 (1 cycle = 21 days) followed by trastuzumab, 8 mg/kg loading dose in Cycle 8, followed by 6 mg/kg from Cycles 9-20 and pertuzumab, 840 mg loading dose in Cycle 8, followed by 420 mg from Cycles 9-20 (1 cycle = 21 days).
219
Placebo, Trastuzumab, and Chemotherapy
Prior to surgery: Participants received trastuzumab, 8 mg/kg loading dose in Cycle 1, followed by 6 mg/kg from Cycles 2-4, docetaxel, 75 mg/m\^2 and placebo from Cycles 1-4 (1 cycle = 21 days) by IV infusion. Post surgery: Participants received chemotherapy with fluorouracil 500-600 mg/m\^2, epirubicin 90-120 mg/m\^2, and cyclophosphamide 500-600 mg/m\^2 by IV infusion every 3 weeks from Cycles 5-7 (1 cycle = 21 days) followed by trastuzumab, 8 mg/kg loading dose in Cycle 8, followed by 6 mg/kg from Cycles 9-20 and placebo from Cycles 8-20 (1 cycle =21 days).
110
Total329

Withdrawals & dropouts

PeriodReasonFG000FG001
Adjuvant TreatmentPhysician Decision01
Adjuvant TreatmentPregnancy10
Adjuvant TreatmentRecurrent Disease45
Adjuvant TreatmentWithdrawal by Subject53
Neoadjuvant TreatmentAdverse Event10
Neoadjuvant TreatmentDeath10
Neoadjuvant TreatmentDid Not Receive Study Drug10
Neoadjuvant TreatmentPhysician Decision21
Neoadjuvant TreatmentProgression of Disease23
Neoadjuvant TreatmentWithdrawal by Subject43
Treatment-Free Follow-UpDeath1111
Treatment-Free Follow-UpLost to Follow-up94
Treatment-Free Follow-UpNon-compliance01
Treatment-Free Follow-UpReason Not Specified03
Treatment-Free Follow-UpWithdrawal by Subject133

Baseline characteristics

CharacteristicTotalPlacebo, Trastuzumab, and ChemotherapyPertuzumab, Trastuzumab, and Chemotherapy
Age, Continuous48.8 years
STANDARD_DEVIATION 9.5
49.5 years
STANDARD_DEVIATION 9.1
48.4 years
STANDARD_DEVIATION 9.7
Age, Customized
40-49 years old
115 Participants40 Participants75 Participants
Age, Customized
<40 years old
58 Participants18 Participants40 Participants
Age, Customized
50-64 years old
140 Participants44 Participants96 Participants
Age, Customized
≥65 years old
16 Participants8 Participants8 Participants
Baseline LVEF value66.28 percentage points of LVEF
STANDARD_DEVIATION 5.01
66.03 percentage points of LVEF
STANDARD_DEVIATION 5.19
66.41 percentage points of LVEF
STANDARD_DEVIATION 4.93
Disease Category
Early Stage
229 Participants77 Participants152 Participants
Disease Category
Locally Advanced
100 Participants33 Participants67 Participants
Ethnicity (NIH/OMB)
Hispanic or Latino
0 Participants0 Participants0 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
329 Participants110 Participants219 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
0 Participants0 Participants0 Participants
Hormone Receptor Status
Estrogen Receptor (ER) and/or Progesterone Receptor (PgR) Positive
170 Participants56 Participants114 Participants
Hormone Receptor Status
Estrogen Receptor (ER) and Progesterone Receptor (PgR) Negative
159 Participants54 Participants105 Participants
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Asian
329 Participants110 Participants219 Participants
Race (NIH/OMB)
Black or African American
0 Participants0 Participants0 Participants
Race (NIH/OMB)
More than one race
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Unknown or Not Reported
0 Participants0 Participants0 Participants
Race (NIH/OMB)
White
0 Participants0 Participants0 Participants
Sex: Female, Male
Female
329 Participants110 Participants219 Participants
Sex: Female, Male
Male
0 Participants0 Participants0 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
12 / 21811 / 110
other
Total, other adverse events
218 / 218108 / 110
serious
Total, serious adverse events
37 / 21815 / 110

Outcome results

Primary

Percentage of Participants With Total Pathologic Complete Response (tpCR) as Assessed by the Independent Review Committee (IRC)

This tpCR was assessed by the IRC. tpCR was defined as the absence of any residual invasive cancer on hematoxylin and eosin evaluation of the resected breast specimen and all sampled ipsilateral lymph nodes after completion of neoadjuvant therapy and surgery (that is, ypT0/is, ypN0, in accordance with the current American Joint Committee on Cancer \[AJCC\] staging system). The analysis was based on the ITT population with participants grouped by the treatment assigned at the time of randomization. Participants whose tpCR assessment was missing or invalid were counted as not achieving tpCR. The duration of one treatment cycle was 21 days; the administration of therapy in Cycle 5 did not occur until 2 weeks after surgery. The percentages have been rounded off to first decimal point.

Time frame: At surgery (Cycle 4 Days 22-35)

Population: ITT population included all participants who were enrolled regardless of whether they received any study treatment.

ArmMeasureValue (NUMBER)
Pertuzumab, Trastuzumab, and ChemotherapyPercentage of Participants With Total Pathologic Complete Response (tpCR) as Assessed by the Independent Review Committee (IRC)39.3 percentage of participants
Placebo, Trastuzumab, and ChemotherapyPercentage of Participants With Total Pathologic Complete Response (tpCR) as Assessed by the Independent Review Committee (IRC)21.8 percentage of participants
p-value: 0.001495% CI: [6.89, 28.01]Cochran-Mantel-Haenszel
Secondary

Change From Baseline in LVEF Over Time

LVEF is the measurement of how much blood is being pumped out of the left ventricle of the heart (the main pumping chamber) with each contraction. A normal LVEF ranges from 55% to 70%, as measured by echocardiogram (preferred) or MUGA scan. The same method was used throughout the study for each participant and preferably performed and evaluated by the same assessor. Here, we report the change from baseline in LVEF over time.

Time frame: Baseline; Day 1 of Cycles 2, 4, 5, 8, 11, and 20 (1 cycle = 21 days)

Population: Safety evaluable population included all participants who received at least one dose of study drugs. Overall number analyzed is the number of participants with data available for analysis. Number analyzed is the number of participants with data available for analysis at specified timepoints.

ArmMeasureGroupValue (MEAN)
Pertuzumab, Trastuzumab, and ChemotherapyChange From Baseline in LVEF Over TimeCycle 2 Day 1-0.62 percentage points of LVEF
Pertuzumab, Trastuzumab, and ChemotherapyChange From Baseline in LVEF Over TimeCycle 4 Day 1-1.02 percentage points of LVEF
Pertuzumab, Trastuzumab, and ChemotherapyChange From Baseline in LVEF Over TimeCycle 5 Day 1-0.96 percentage points of LVEF
Pertuzumab, Trastuzumab, and ChemotherapyChange From Baseline in LVEF Over TimeCycle 8 Day 1-1.63 percentage points of LVEF
Pertuzumab, Trastuzumab, and ChemotherapyChange From Baseline in LVEF Over TimeCycle 11 Day 1-1.38 percentage points of LVEF
Pertuzumab, Trastuzumab, and ChemotherapyChange From Baseline in LVEF Over TimeCycle 20 Day 1-1.22 percentage points of LVEF
Placebo, Trastuzumab, and ChemotherapyChange From Baseline in LVEF Over TimeCycle 11 Day 1-0.65 percentage points of LVEF
Placebo, Trastuzumab, and ChemotherapyChange From Baseline in LVEF Over TimeCycle 2 Day 10.29 percentage points of LVEF
Placebo, Trastuzumab, and ChemotherapyChange From Baseline in LVEF Over TimeCycle 8 Day 1-1.18 percentage points of LVEF
Placebo, Trastuzumab, and ChemotherapyChange From Baseline in LVEF Over TimeCycle 4 Day 10.09 percentage points of LVEF
Placebo, Trastuzumab, and ChemotherapyChange From Baseline in LVEF Over TimeCycle 20 Day 1-1.18 percentage points of LVEF
Placebo, Trastuzumab, and ChemotherapyChange From Baseline in LVEF Over TimeCycle 5 Day 10.07 percentage points of LVEF
Secondary

Kaplan-Meier Estimate of the Percentage of Participants Event-Free for Disease-Free Survival (DFS) at 1, 3, and 5 Years

Kaplan-Meier approach was used to estimate the percentage of participants who were event-free for DFS at 1, 3 and 5 years. DFS = time from first date of no disease (i.e., date of surgery) to first documentation of one of the following events: Disease recurrence (local, regional, distant, or contralateral) after surgery or death from any cause. After treatment completion/discontinuation, follow-up data was collected every 3 months for 1 year and then every 6 months thereafter, until disease progression or recurrence or until 5 years after randomization of the last participant, whichever occurred first. Participants were considered to be disease-free if they underwent surgery and no recurrence of disease was reported thereafter. Data from participants who did not have an event at analysis were censored as of the date they were last known to be alive and event-free.

Time frame: From surgery (Cycle 4: Days 22-35) to DFS event or date last known to be alive and event-free at 1, 3, and 5 years

Population: ITT population included all participants who were enrolled regardless of whether they received any study treatment. Overall number of participants analyzed are unique number of participants who underwent surgery. Number analyzed per timepoint are unique number of participants out of all the assessed participants who remain at risk for a DFS event at that timepoint. Different participants may have contributed data for each timepoint.

ArmMeasureGroupValue (NUMBER)
Pertuzumab, Trastuzumab, and ChemotherapyKaplan-Meier Estimate of the Percentage of Participants Event-Free for Disease-Free Survival (DFS) at 1, 3, and 5 Years1 Year97.55 estimate of percentage of participants
Pertuzumab, Trastuzumab, and ChemotherapyKaplan-Meier Estimate of the Percentage of Participants Event-Free for Disease-Free Survival (DFS) at 1, 3, and 5 Years3 Years90.09 estimate of percentage of participants
Pertuzumab, Trastuzumab, and ChemotherapyKaplan-Meier Estimate of the Percentage of Participants Event-Free for Disease-Free Survival (DFS) at 1, 3, and 5 Years5 Years85.99 estimate of percentage of participants
Placebo, Trastuzumab, and ChemotherapyKaplan-Meier Estimate of the Percentage of Participants Event-Free for Disease-Free Survival (DFS) at 1, 3, and 5 Years1 Year92.08 estimate of percentage of participants
Placebo, Trastuzumab, and ChemotherapyKaplan-Meier Estimate of the Percentage of Participants Event-Free for Disease-Free Survival (DFS) at 1, 3, and 5 Years3 Years81.10 estimate of percentage of participants
Placebo, Trastuzumab, and ChemotherapyKaplan-Meier Estimate of the Percentage of Participants Event-Free for Disease-Free Survival (DFS) at 1, 3, and 5 Years5 Years75.02 estimate of percentage of participants
Comparison: Hazard Ratio for DFS Event in the Pertuzumab arm vs. Placebo armp-value: 0.01495% CI: [0.3, 0.88]Stratified log-rank
Comparison: Difference in DFS Event-Free Rates at 1 yearp-value: 0.059295% CI: [-11.15, 0.21]Z-test
Comparison: Difference in DFS Event-Free Rates at 3 yearsp-value: 0.042695% CI: [-17.69, -0.3]Z-test
Comparison: Difference in DFS Event-Free Rates at 5 yearsp-value: 0.027695% CI: [-20.73, -1.21]Z-test
Secondary

Kaplan-Meier Estimate of the Percentage of Participants Event-Free for Event-Free Survival (EFS) at 1, 3, and 5 Years

Kaplan-Meier approach was used to estimate percentage of participants who were event-free for EFS at 1, 3 & 5 years. EFS=time from randomization to first documentation of one of the following events: PD (before surgery) as determined by investigator with RECIST v1.1. PD=at least a 20% increase in sum of diameters of target lesions, taking as reference smallest sum during the study (nadir) with inclusion of baseline. Any evidence of contralateral disease in situ was not identified as PD; Disease recurrence (local, regional, distant, or contralateral) after surgery; Death from any cause. After treatment completion/discontinuation, follow-up data was collected every 3 months for 1 year & then every 6 months thereafter, until disease progression/recurrence or until 5 years after randomization of last participant, whichever occurred first. Participants without an EFS event at time of analysis were censored as of the date they were last known to be alive & event-free.

Time frame: From Baseline to EFS event or date last known to be alive and event-free at 1, 3, and 5 years

Population: ITT population included all participants who were enrolled regardless of whether they received any study treatment. Number analyzed per timepoint are unique number of participants out of all the assessed participants who remain at risk for an EFS event at that timepoint. Different participants may have contributed data for each timepoint.

ArmMeasureGroupValue (NUMBER)
Pertuzumab, Trastuzumab, and ChemotherapyKaplan-Meier Estimate of the Percentage of Participants Event-Free for Event-Free Survival (EFS) at 1, 3, and 5 Years1 Year98.62 estimate of percentage of participants
Pertuzumab, Trastuzumab, and ChemotherapyKaplan-Meier Estimate of the Percentage of Participants Event-Free for Event-Free Survival (EFS) at 1, 3, and 5 Years3 Years88.85 estimate of percentage of participants
Pertuzumab, Trastuzumab, and ChemotherapyKaplan-Meier Estimate of the Percentage of Participants Event-Free for Event-Free Survival (EFS) at 1, 3, and 5 Years5 Years84.80 estimate of percentage of participants
Placebo, Trastuzumab, and ChemotherapyKaplan-Meier Estimate of the Percentage of Participants Event-Free for Event-Free Survival (EFS) at 1, 3, and 5 Years1 Year90.46 estimate of percentage of participants
Placebo, Trastuzumab, and ChemotherapyKaplan-Meier Estimate of the Percentage of Participants Event-Free for Event-Free Survival (EFS) at 1, 3, and 5 Years3 Years79.68 estimate of percentage of participants
Placebo, Trastuzumab, and ChemotherapyKaplan-Meier Estimate of the Percentage of Participants Event-Free for Event-Free Survival (EFS) at 1, 3, and 5 Years5 Years73.70 estimate of percentage of participants
Comparison: Hazard Ratio for EFS Event in the Pertuzumab arm vs. Placebo armp-value: 0.01495% CI: [0.32, 0.89]Stratified log-rank
Comparison: Difference in EFS Event-Free Rates at 1 yearp-value: 0.006295% CI: [-14, -2.32]Z-test
Comparison: Difference in EFS Event-Free Rates at 3 yearsp-value: 0.042995% CI: [-18.05, -0.29]Z-test
Comparison: Difference in EFS Event-Free Rates at 5 Yearsp-value: 0.027495% CI: [-20.95, -1.24]Z-test
Secondary

Kaplan-Meier Estimate of the Percentage of Participants Event-Free for Overall Survival (OS) at 1, 3, and 5 Years

Kaplan-Meier approach was used to estimate the percentage of participants who were event-free for OS at 1, 3 and 5 years. OS was defined as the time from randomization to death from any cause. After treatment completion/discontinuation, follow-up data was collected every 3 months for 1 year and then every 6 months thereafter, until disease progression or recurrence or until 5 years after randomization of the last participant, whichever occurred first. Data from participants who were alive at the time of the analysis was censored as of the last date they were known to be alive.

Time frame: From Baseline to OS event or date last known to be alive at 1, 3, and 5 years

Population: ITT population included all participants who were enrolled regardless of whether they received any study treatment. Number analyzed per timepoint are unique number of participants out of all the assessed participants who remain at risk for an OS event at that timepoint. Different participants may have contributed data for each timepoint.

ArmMeasureGroupValue (NUMBER)
Pertuzumab, Trastuzumab, and ChemotherapyKaplan-Meier Estimate of the Percentage of Participants Event-Free for Overall Survival (OS) at 1, 3, and 5 Years1 Year99.54 estimate of percentage of participants
Pertuzumab, Trastuzumab, and ChemotherapyKaplan-Meier Estimate of the Percentage of Participants Event-Free for Overall Survival (OS) at 1, 3, and 5 Years3 Years97.01 estimate of percentage of participants
Pertuzumab, Trastuzumab, and ChemotherapyKaplan-Meier Estimate of the Percentage of Participants Event-Free for Overall Survival (OS) at 1, 3, and 5 Years5 Years93.86 estimate of percentage of participants
Placebo, Trastuzumab, and ChemotherapyKaplan-Meier Estimate of the Percentage of Participants Event-Free for Overall Survival (OS) at 1, 3, and 5 Years1 Year100.00 estimate of percentage of participants
Placebo, Trastuzumab, and ChemotherapyKaplan-Meier Estimate of the Percentage of Participants Event-Free for Overall Survival (OS) at 1, 3, and 5 Years3 Years90.99 estimate of percentage of participants
Placebo, Trastuzumab, and ChemotherapyKaplan-Meier Estimate of the Percentage of Participants Event-Free for Overall Survival (OS) at 1, 3, and 5 Years5 Years89.97 estimate of percentage of participants
Comparison: Hazard Ratio for OS Event in the Pertuzumab arm vs. Placebo armp-value: 0.118195% CI: [0.23, 1.19]Stratified log-rank
Comparison: Difference in OS Event-Free Rates at 1 yearp-value: 0.316295% CI: [-0.44, 1.36]Z-test
Comparison: Difference in OS Event-Free Rates at 3 yearsp-value: 0.052995% CI: [-12.11, 0.08]Z-test
Comparison: Difference in OS Event-Free Rates at 5 yearsp-value: 0.261695% CI: [-10.69, 2.9]Z-test
Secondary

Maximum Change From Baseline in LVEF

LVEF is the measurement of how much blood is being pumped out of the left ventricle of the heart (the main pumping chamber) with each contraction. A normal LVEF ranges from 55% to 70%, as measured by echocardiogram (preferred) or MUGA scan. The same method was used throughout the study for each participant and preferably performed and evaluated by the same assessor. Here, we report the maximum change from baseline in LVEF at any point during the study.

Time frame: Baseline; Day 1 of Cycles 2, 4, 5, 8, 11, and 20 (1 cycle = 21 days)

Population: Safety evaluable population included all participants who received at least one dose of study drugs and participants were grouped by the treatment they actually received. Overall number analyzed is the number of participants with data available for analysis.

ArmMeasureValue (MEAN)Dispersion
Pertuzumab, Trastuzumab, and ChemotherapyMaximum Change From Baseline in LVEF-6.55 percentage points of LVEFStandard Deviation 5.22
Placebo, Trastuzumab, and ChemotherapyMaximum Change From Baseline in LVEF-6.20 percentage points of LVEFStandard Deviation 6.08
95% CI: [-1.62, 0.93]
Secondary

Percentage of Participants Who Experienced a Primary Cardiac Event

A primary cardiac event is defined as heart failure (New York Heart Association \[NYHA\] Class III or NYHA Class IV) and a drop in left ventricular ejection fraction (LVEF) of at least 10 ejection fraction points from baseline and to below 50%.

Time frame: From Baseline until end of study (up to 6 years)

Population: Safety evaluable population included all participants who received at least one dose of study drugs and participants were grouped by the treatment they actually received.

ArmMeasureValue (NUMBER)
Pertuzumab, Trastuzumab, and ChemotherapyPercentage of Participants Who Experienced a Primary Cardiac Event0 percentage of participants
Placebo, Trastuzumab, and ChemotherapyPercentage of Participants Who Experienced a Primary Cardiac Event0 percentage of participants
Secondary

Percentage of Participants Who Experienced a Secondary Cardiac Event

A secondary cardiac event is defined as an asymptomatic or mildly symptomatic (NYHA Class II) drop in LVEF by multiple-gated acquisition (MUGA) scan or echocardiogram confirmed by a second LVEF assessment within approximately 3 weeks showing also a documented drop. A significant LVEF drop is defined as an absolute decrease of at least 10 points below the baseline measurement and to below 50%.

Time frame: From Baseline until end of study (up to 6 years)

Population: Safety evaluable population included all participants who received at least one dose of study drugs and participants were grouped by the treatment they actually received.

ArmMeasureValue (NUMBER)
Pertuzumab, Trastuzumab, and ChemotherapyPercentage of Participants Who Experienced a Secondary Cardiac Event0 percentage of participants
Placebo, Trastuzumab, and ChemotherapyPercentage of Participants Who Experienced a Secondary Cardiac Event0 percentage of participants
Secondary

Percentage of Participants With an Objective Response (CR or PR) During Cycles 1-4, According to RECIST Version 1.1

An objective response was defined as the percentage of participants who achieved a CR or PR as the best tumor response during the neoadjuvant period (that is, during Cycles 1-4 prior to surgery), as determined by the investigator on the basis of RECIST version 1.1. CR=disappearance of all target lesions i.e., any pathological lymph nodes (whether target or non-target) must have reduction in short axis to \<10 mm. PR=at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum of diameters. No confirmation was required for objective response. Only participants with measurable disease at baseline were included in the analysis. The duration of one treatment cycle was 21 days; the administration of therapy in Cycle 5 did not occur until 2 weeks after surgery. The percentages have been rounded off to first decimal point.

Time frame: At surgery (Cycle 4 Days 22-35)

Population: ITT population included all participants who were enrolled regardless of whether they received any study treatment.

ArmMeasureValue (NUMBER)
Pertuzumab, Trastuzumab, and ChemotherapyPercentage of Participants With an Objective Response (CR or PR) During Cycles 1-4, According to RECIST Version 1.188.6 percentage of participants
Placebo, Trastuzumab, and ChemotherapyPercentage of Participants With an Objective Response (CR or PR) During Cycles 1-4, According to RECIST Version 1.178.2 percentage of participants
p-value: 0.012595% CI: [1.12, 19.69]Cochran-Mantel-Haenszel
Secondary

Percentage of Participants With at Least One Adverse Event (AE) During the Neoadjuvant Treatment Period

The percentage of participants who experienced at least one AE during the neoadjuvant period is reported here. An AE is any untoward medical occurrence in a clinical investigation participant who is administered a pharmaceutical product regardless of the causal attribution. An adverse event was therefore any unfavourable 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. Pre-existing conditions which worsened during the study were also considered as adverse events. The neoadjuvant treatment period began after randomization upon receiving the first dose of any of the neoadjuvant study medications and ended before receiving the first dose of adjuvant study treatment. The duration of one treatment cycle is 21 days. The percentages have been rounded off to first decimal point.

Time frame: Baseline up to end of Cycle 4 (1 cycle = 21 days)

Population: Safety evaluable population included all participants who received at least one dose of neoadjuvant study treatment and participants were grouped by the treatment they actually received.

ArmMeasureValue (NUMBER)
Pertuzumab, Trastuzumab, and ChemotherapyPercentage of Participants With at Least One Adverse Event (AE) During the Neoadjuvant Treatment Period97.7 percentage of participants
Placebo, Trastuzumab, and ChemotherapyPercentage of Participants With at Least One Adverse Event (AE) During the Neoadjuvant Treatment Period96.4 percentage of participants
Secondary

Percentage of Participants With at Least One Adverse Event During the Treatment-Free Follow-Up Period

The percentage of participants who experienced at least one adverse event during the treatment-free follow-up period is reported here. An AE is any untoward medical occurrence in a clinical investigation participant who is administered a pharmaceutical product regardless of the causal attribution. An adverse event was therefore any unfavourable 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. The percentages have been rounded off to first decimal point.

Time frame: From end of overall study treatment until disease progression or until 5 years after randomization of the last patient, whichever occurred first (up to 6 years)

Population: Safety evaluable population included all participants who received at least one dose of study drugs and participants were grouped by the treatment they actually received.

ArmMeasureValue (NUMBER)
Pertuzumab, Trastuzumab, and ChemotherapyPercentage of Participants With at Least One Adverse Event During the Treatment-Free Follow-Up Period6.0 percentage of participants
Placebo, Trastuzumab, and ChemotherapyPercentage of Participants With at Least One Adverse Event During the Treatment-Free Follow-Up Period7.3 percentage of participants
Secondary

Percentage of Participants With at Least One AE During the Adjuvant Treatment Period

Percentage of participants who experienced at least one adverse event during the adjuvant period is reported here. An AE is any untoward medical occurrence in a clinical investigation participant who is administered a pharmaceutical product regardless of the causal attribution. An adverse event was therefore 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. Pre-existing conditions which worsened during the study were also considered as adverse events. Adjuvant treatment period began after primary surgery, upon receiving the first dose of any of the adjuvant study medications. It ended 42 days after last dose of adjuvant study treatment upon treatment completion or discontinuation. 1 Cycle=21 days. The percentages have been rounded off to first decimal point.

Time frame: From Cycle 5 (1 cycle = 21 days) up to 42 days after the last dose in Cycle 20 Day 1 (approximately 1 year)

Population: Safety evaluable population included all participants who received at least one dose of adjuvant study treatment and participants were grouped by the treatment they actually received. Overall number analyzed is the number of participants with data available for analysis.

ArmMeasureValue (NUMBER)
Pertuzumab, Trastuzumab, and ChemotherapyPercentage of Participants With at Least One AE During the Adjuvant Treatment Period98.1 percentage of participants
Placebo, Trastuzumab, and ChemotherapyPercentage of Participants With at Least One AE During the Adjuvant Treatment Period98.1 percentage of participants
Secondary

Percentage of Participants With bpCR as Assessed by the Local Pathologist

This bpCR was assessed by the local pathologist. bpCR was defined as the absence of any residual invasive cancer on the hematoxylin and eosin evaluation of the resected breast specimen after completion of neoadjuvant therapy and surgery (that is, ypT0/is in accordance with current AJCC staging system). The analysis was based on the ITT population with participants grouped by the treatment assigned at the time of randomization. Participants whose bpCR assessment was missing or invalid were counted as not achieving bpCR. The duration of one treatment cycle was 21 days; the administration of therapy in Cycle 5 did not occur until 2 weeks after surgery. The percentages have been rounded off to first decimal point.

Time frame: At surgery (Cycle 4 Days 22-35)

Population: ITT population included all participants who were enrolled regardless of whether they received any study treatment.

ArmMeasureValue (NUMBER)
Pertuzumab, Trastuzumab, and ChemotherapyPercentage of Participants With bpCR as Assessed by the Local Pathologist41.6 percentage of participants
Placebo, Trastuzumab, and ChemotherapyPercentage of Participants With bpCR as Assessed by the Local Pathologist22.7 percentage of participants
p-value: 0.000695% CI: [8.14, 29.51]Cochran-Mantel-Haenszel
Secondary

Percentage of Participants With Breast Pathologic Complete Response (bpCR), Defined as ypT0/is According to the AJCC Staging System as Assessed by the IRC

This bpCR was assessed by the IRC. bpCR was defined as the absence of any residual invasive cancer on the hematoxylin and eosin evaluation of the resected breast specimen after completion of neoadjuvant therapy and surgery (that is, ypT0/is, in accordance with current AJCC staging system). The analysis was based on the ITT population with participants grouped by the treatment assigned at the time of randomization. Participants whose bpCR assessment was missing or invalid were counted as not achieving bpCR. The duration of one treatment cycle was 21 days; the administration of therapy in Cycle 5 did not occur until 2 weeks after surgery. The percentages have been rounded off to first decimal point.

Time frame: At surgery (Cycle 4 Days 22-35)

Population: ITT population included all participants who were enrolled regardless of whether they received any study treatment.

ArmMeasureValue (NUMBER)
Pertuzumab, Trastuzumab, and ChemotherapyPercentage of Participants With Breast Pathologic Complete Response (bpCR), Defined as ypT0/is According to the AJCC Staging System as Assessed by the IRC42.0 percentage of participants
Placebo, Trastuzumab, and ChemotherapyPercentage of Participants With Breast Pathologic Complete Response (bpCR), Defined as ypT0/is According to the AJCC Staging System as Assessed by the IRC23.6 percentage of participants
p-value: 0.00195% CI: [7.6, 29.15]Cochran-Mantel-Haenszel
Secondary

Percentage of Participants With Complete Response (CR), Partial Response (PR), Stable Disease (SD), or Progressive Disease (PD) During Cycles 1-4, According to Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1

Clinical responses that include percentage of participants with a CR, PR, SD, or PD were determined by investigator during Cycles 1-4 (prior to surgery) on basis of RECIST version 1.1. CR=disappearance of all target lesions i.e., any pathological lymph nodes (whether target or non-target) must have reduction in short axis to \<10 millimeters (mm). PR=at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum of diameters. SD=neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for PD, taking as reference the smallest sum during the study. PD=at least a 20% increase in the sum of diameters of target lesions, taking as reference the smallest sum during the study (nadir) with inclusion of baseline. Only participants with measurable disease at baseline were included in the analysis. 1 Cycle=21 days. The percentages have been rounded off to first decimal point.

Time frame: At surgery (Cycle 4 Days 22-35)

Population: ITT population included all participants who were enrolled regardless of whether they received any study treatment.

ArmMeasureGroupValue (NUMBER)
Pertuzumab, Trastuzumab, and ChemotherapyPercentage of Participants With Complete Response (CR), Partial Response (PR), Stable Disease (SD), or Progressive Disease (PD) During Cycles 1-4, According to Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1Partial Response77.6 percentage of participants
Pertuzumab, Trastuzumab, and ChemotherapyPercentage of Participants With Complete Response (CR), Partial Response (PR), Stable Disease (SD), or Progressive Disease (PD) During Cycles 1-4, According to Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1Progressive Disease0.5 percentage of participants
Pertuzumab, Trastuzumab, and ChemotherapyPercentage of Participants With Complete Response (CR), Partial Response (PR), Stable Disease (SD), or Progressive Disease (PD) During Cycles 1-4, According to Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1Stable Disease8.2 percentage of participants
Pertuzumab, Trastuzumab, and ChemotherapyPercentage of Participants With Complete Response (CR), Partial Response (PR), Stable Disease (SD), or Progressive Disease (PD) During Cycles 1-4, According to Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1Missing or Unevaluable2.7 percentage of participants
Pertuzumab, Trastuzumab, and ChemotherapyPercentage of Participants With Complete Response (CR), Partial Response (PR), Stable Disease (SD), or Progressive Disease (PD) During Cycles 1-4, According to Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1Complete Response11.0 percentage of participants
Placebo, Trastuzumab, and ChemotherapyPercentage of Participants With Complete Response (CR), Partial Response (PR), Stable Disease (SD), or Progressive Disease (PD) During Cycles 1-4, According to Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1Missing or Unevaluable0.9 percentage of participants
Placebo, Trastuzumab, and ChemotherapyPercentage of Participants With Complete Response (CR), Partial Response (PR), Stable Disease (SD), or Progressive Disease (PD) During Cycles 1-4, According to Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1Complete Response10.0 percentage of participants
Placebo, Trastuzumab, and ChemotherapyPercentage of Participants With Complete Response (CR), Partial Response (PR), Stable Disease (SD), or Progressive Disease (PD) During Cycles 1-4, According to Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1Partial Response68.2 percentage of participants
Placebo, Trastuzumab, and ChemotherapyPercentage of Participants With Complete Response (CR), Partial Response (PR), Stable Disease (SD), or Progressive Disease (PD) During Cycles 1-4, According to Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1Stable Disease19.1 percentage of participants
Placebo, Trastuzumab, and ChemotherapyPercentage of Participants With Complete Response (CR), Partial Response (PR), Stable Disease (SD), or Progressive Disease (PD) During Cycles 1-4, According to Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1Progressive Disease1.8 percentage of participants
Secondary

Percentage of Participants With tpCR as Assessed by the Local Pathologist

This tpCR was assessed by the local pathologist. tpCR was defined as the absence of any residual invasive cancer on hematoxylin and eosin evaluation of the resected breast specimen and all sampled ipsilateral lymph nodes after completion of neoadjuvant therapy and surgery (that is, ypT0/is, ypN0, in accordance with the current AJCC staging system). The analysis was based on the ITT population with participants grouped by the treatment assigned at the time of randomization. Participants whose tpCR assessment was missing or invalid were counted as not achieving tpCR. The duration of one treatment cycle was 21 days; the administration of therapy in Cycle 5 did not occur until 2 weeks after surgery. The percentages have been rounded off to first decimal point.

Time frame: At surgery (Cycle 4 Days 22-35)

Population: ITT population included all participants who were enrolled regardless of whether they received any study treatment.

ArmMeasureValue (NUMBER)
Pertuzumab, Trastuzumab, and ChemotherapyPercentage of Participants With tpCR as Assessed by the Local Pathologist39.3 percentage of participants
Placebo, Trastuzumab, and ChemotherapyPercentage of Participants With tpCR as Assessed by the Local Pathologist20.9 percentage of participants
p-value: 0.000895% CI: [7.89, 28.83]Cochran-Mantel-Haenszel

Source: ClinicalTrials.gov · Data processed: Mar 7, 2026