A Study to Evaluate Pertuzumab + Trastuzumab + Docetaxel vs. Placebo + Trastuzumab + Docetaxel in Previously Untreated HER2-Positive Metastatic Breast Cancer

Study Overview
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Brief Summary
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This study was a Phase III, randomized, double-blind, placebo-controlled, multicenter international clinical trial conducted to investigate the use of pertuzumab in combination with trastuzumab and docetaxel as first-line treatment for participants with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (MBC). Participants could have received one prior hormonal treatment for MBC. Participants may have received systemic breast cancer treatment in the neo-adjuvant or adjuvant setting, provided that the participant had experienced a disease-free interval (DFI) of greater than or equal to (≥)12 months from completion of adjuvant systemic treatment (excluding hormonal therapy) to metastatic diagnosis. Participants may have received trastuzumab and/or a taxane during the neo-adjuvant or adjuvant treatment. Participants were randomized in 1:1 ratio to receive either pertuzumab or placebo, along with trastuzumab and docetaxel once every 3 weeks (q3w), during the treatment phase of the study until investigator-assessed radiographic or clinical progressive disease, unmanageable toxicity, or study termination. Participants in the Placebo arm were not allowed to receive open-label pertuzumab after discontinuation from study treatment. However, if any analysis of overall survival had met the predefined criteria for statistical significance, participants in the Placebo arm still on treatment were offered the option to receive open-label pertuzumab in addition to other study medications.

Official Title
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A Phase III, Randomized, Double-Blind, Placebo-Controlled Clinical Trial to Evaluate the Efficacy and Safety of Pertuzumab + Trastuzumab + Docetaxel vs. Placebo + Trastuzumab + Docetaxel in Previously Untreated HER2-Positive Metastatic Breast Cancer

Conditions
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Metastatic Breast Cancer

Intervention / Treatment
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* Drug: Pertuzumab
* Drug: Placebo
* Drug: Trastuzumab
* Drug: Docetaxel


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Histologically or cytologically confirmed adenocarcinoma of the breast with locally recurrent or metastatic disease, and candidate for chemotherapy. Participants with measurable and non-measurable disease are eligible (locally recurrent disease must not be amenable to resection with curative intent; participants with de novo Stage IV disease are eligible) Human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (MBC) Left ventricular ejection fraction (LVEF) ≥50 percent (%) at baseline (within 42 days of randomization) Eastern Cooperative Oncology Group (ECOG) performance status (PS) 0 or 1 For women of childbearing potential and men with partners of childbearing potential, agreement to use a highly effective form of contraception and to continue its use for the duration of study treatment and for at least 7 months after the last dose of study treatment Exclusion Criteria: History of anti-cancer therapy for MBC (with the exception of one prior hormonal regimen for MBC, which must be stopped prior to randomization) History of approved or investigative tyrosine kinase/HER inhibitors for breast cancer in any treatment setting, except trastuzumab used in the neoadjuvant or adjuvant setting History of systemic breast cancer treatment in the neo-adjuvant or adjuvant setting with a disease-free interval from completion of the systemic treatment (excluding hormonal therapy) to metastatic diagnosis of less than (<)12 months History of persistent Grade ≥2 hematologic toxicity resulting from previous adjuvant therapy Current peripheral neuropathy of National Cancer Institute-Common Terminology Criteria for Adverse Events (NCI-CTCAE) Version 3.0, Grade ≥3 at randomization History of other malignancy within the last 5 years, except for carcinoma in situ of the cervix, basal cell carcinoma or squamous cell carcinoma of the skin that has been previously treated with curative intent Current clinical or radiographic evidence of central nervous system (CNS) metastases Computed tomography (CT) or magnetic resonance imaging (MRI) scan of the brain is mandatory in cases of clinical suspicion of brain metastases History of exposure to cumulative doses of anthracyclines Current uncontrolled hypertension or unstable angina History of congestive heart failure (CHF) of any New York Heart Association (NYHA) criteria, or serious cardiac arrhythmia requiring treatment (exception: atrial fibrillation or paroxysmal supraventricular tachycardia) History of myocardial infarction within 6 months of randomization History of LVEF decline to below 50% during or after prior trastuzumab neo-adjuvant or adjuvant therapy Current dyspnea at rest due to complications of advanced malignancy, or other diseases that require continuous oxygen therapy Inadequate organ function, as defined in the protocol, within 28 days prior to randomization Current severe, uncontrolled systemic disease Major surgical procedure or significant traumatic injury within 28 days prior to study treatment start or anticipation of the need for major surgery during the course of study treatment Pregnant or lactating women History of receiving any investigational treatment within 28 days of randomization Current known infection with human immunodeficiency virus (HIV), hepatitis B virus (HBV), or hepatitis C virus (HCV) Receipt of IV antibiotics for infection within 14 days of randomization Current chronic daily treatment with corticosteroids (excluding inhaled steroids) Known hypersensitivity to any of the study drugs Assessed by the investigator to be unable or unwilling to comply with the requirements of the protocol

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Pertuzumab + Trastuzumab + Docetaxel<br>Participants randomized to this arm received pertuzumab 420 milligrams (mg) intravenously (IV) once every 3 weeks (q3w) and trastuzumab 6 milligrams per kilogram (mg/kg) IV q3w, plus docetaxel 75 milligrams per square metre of body surface (mg/m^2) IV q3w (for at least 6 cycles; 1 cycle was 21 days). After Cycle 6, continuation of docetaxel treatment was at the discretion of the participant and treating physician. Participants remained in the treatment phase of the study until investigator-assessed radiographic or clinical evidence of disease progression, unmanageable toxicity, or study termination and were followed for survival until death, loss to follow-up, withdrawal of consent, or study termination. | Drug: Pertuzumab<br>* Pertuzumab was administered as an intravenous (IV) loading dose of 840 milligrams (mg) q3w on Day 1 of Cycle 1 (1 Cycle length = 21 days), and 420 mg q3w on Day 1 of subsequent cycles until investigator-assessed radiographic or clinical progressive disease, unmanageable toxicity, or study termination.<br>* Other names: RG1273;Drug: Trastuzumab<br>* Trastuzumab was administered as an IV loading dose of 8 milligrams per kilogram (mg/kg) q3w on Day 2 of Cycle 1 (1 Cycle length = 21 days), and 6 mg/kg q3w on Day 1 of subsequent cycles until investigator-assessed radiographic or clinical progressive disease, unmanageable toxicity, or study termination.<br>* Other names: Herceptin;Drug: Docetaxel<br>* Docetaxel was administered as an IV dose of 75 milligrams per square meter of body surface area (mg/m^2) q3w on Day 2 of Cycle 1 (1 Cycle length = 21 days), and 75 mg/m^2 (up to 100 mg/m^2 as per treating physician discretion) q3w on Day 1 of subsequent cycles until investigator-assessed radiographic or clinical progressive disease, unmanageable toxicity, or study termination. On or prior to Cycle 6, docetaxel was only to be discontinued for progressive disease or unmanageable toxicity. After Cycle 6, continuation of docetaxel treatment was at the discretion of the participant and treating physician.<br>* Other names: Taxotere;|
| Placebo Comparator: Placebo + Trastuzumab + Docetaxel<br>Participants randomized to this arm received placebo IV q3w and trastuzumab 6 mg/kg IV q3w, plus docetaxel 75 mg/m^2 IV q3w (for at least 6 cycles; 1 cycle was 21 days). After Cycle 6, continuation of docetaxel treatment was at the discretion of the participant and treating physician. Participants remained in the treatment phase of the study until investigator-assessed radiographic or clinical evidence of disease progression, unmanageable toxicity, or study termination and were followed for survival until death, loss to follow-up, withdrawal of consent, or study termination. | Drug: Placebo<br>* Placebo (matching pertuzumab) was administered intravenously.<br>Drug: Trastuzumab<br>* Trastuzumab was administered as an IV loading dose of 8 milligrams per kilogram (mg/kg) q3w on Day 2 of Cycle 1 (1 Cycle length = 21 days), and 6 mg/kg q3w on Day 1 of subsequent cycles until investigator-assessed radiographic or clinical progressive disease, unmanageable toxicity, or study termination.<br>* Other names: Herceptin;Drug: Docetaxel<br>* Docetaxel was administered as an IV dose of 75 milligrams per square meter of body surface area (mg/m^2) q3w on Day 2 of Cycle 1 (1 Cycle length = 21 days), and 75 mg/m^2 (up to 100 mg/m^2 as per treating physician discretion) q3w on Day 1 of subsequent cycles until investigator-assessed radiographic or clinical progressive disease, unmanageable toxicity, or study termination. On or prior to Cycle 6, docetaxel was only to be discontinued for progressive disease or unmanageable toxicity. After Cycle 6, continuation of docetaxel treatment was at the discretion of the participant and treating physician.<br>* Other names: Taxotere;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Progression-Free Survival (PFS) Determined by an Independent Review Facility | PFS was defined as the time from randomization to first documented radiographical progressive disease (PD), as determined by an independent review facility (IRF) using RECIST version 1.0, or death from any cause (within 18 weeks of last tumor assessment), whichever occurred first (Kaplan-Meier method). For target lesions, PD was defined as at least a 20% increase in the sum of the longest diameter (LD) of target lesions, taking as reference the smallest sum of the LD recorded since treatment started or the appearance of ≥1 new lesion. For non-target lesions, PD was defined as the appearance of ≥1 new lesion or unequivocal progression of existing lesions. Participants without IRF-determined PD or who had not died within 18 weeks of their last IRF-determined, progression-free tumor assessment were censored at the date of the last IRF-reviewed, evaluable tumor assessment; those with no post-baseline tumor assessment and who had not died within 18 weeks of baseline were censored at 1 day. | Tumor assessments every 9 weeks from randomization to IRF-determined PD or death from any cause, whichever occurred first, up to the primary completion date (up to 3 years, 3 months) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Overall Survival | Overall survival (OS) was the time from randomization to death from any cause, using Kaplan-Meier methodology. Survival data was collected every 18 weeks during the post-treatment follow-up period until death, loss to follow-up, or withdrawal of consent. Those who were alive, lost to follow up, or withdrew consent were censored at the latest date they participated in the study; those without post-baseline data were censored at 1 day. OS analyses were planned to take place at the primary completion date (First Interim), after 385 deaths (Event-Driven Final), and at the end of study (End-of-Study). A second interim OS analysis was planned due to a formal request from the European Medicines Agency. Median [range] time in weeks on study at each OS analysis (Pertuzumab vs. Placebo): First: 77.1 [0.7-165.3] vs. 73.1 [0.4-165.3]; Second: 117.1 [0.7-207.9] vs. 105.9 [0.4-207.9]; Event-Driven Final: 189.9 [0.7-304.1] vs. 140.5 [0.4-301.6]; End-of-Study: 201.8 [0.7-520.0] vs. 138.0 [0.4-514.7]. | From randomization to death from any cause, up to each respective analysis data cut-off date (see the Description field for the median time on study per treatment arm) | 
| Progression-Free Survival (PFS) Determined by the Investigator | PFS was defined as the time from randomization to first documented radiographical progressive disease (PD), as determined by the investigator using RECIST version 1.0, or death from any cause (within 18 weeks of last tumor assessment), whichever occurred first (Kaplan-Meier method). For target lesions, PD was defined as at least a 20% increase in the sum of the longest diameter (LD) of target lesions, taking as reference the smallest sum of the LD recorded since treatment started or the appearance of ≥1 new lesion. For non-target lesions, PD was defined as the appearance of ≥1 new lesion or unequivocal progression of existing lesions. Participants without PD or who had not died within 18 weeks of their last investigator-determined, progression-free tumor assessment were censored at the date of the last investigator tumor assessment; those with no post-baseline tumor assessment and who had not died within 18 weeks of baseline were censored at 1 day. | Tumor assessments every 9 weeks from randomization to investigator-determined PD or death from any cause, whichever occurred first (median [range] time on study in pertuzumab vs. placebo arms: 201.8 [0.7-520.0] weeks vs. 138.0 [0.4-514.7] weeks) | 
| Objective Response Determined by an Independent Review Facility | An objective response was defined as the percentage of participants with confirmed best overall response of complete response (CR) or partial response (PR) determined by an independent review facility (IRF) using RECIST v1.0 on two consecutive occasions ≥4 weeks apart. For target lesions, CR: disappearance of all target lesions; PR: ≥30% decrease in the sum of the longest diameter (LD) of target lesions (baseline sum LD as reference); PD: ≥20% increase in the sum of the LD of target lesions (smallest sum of the LD recorded as reference) or appearance of ≥1 new lesion; SD: neither sufficient shrinkage to qualify for PR nor sufficient increase for PD. For non-target lesions, CR: disappearance of all non-target lesions; Incomplete/SD: persistence of ≥1 non-target lesions; PD: unequivocal progression of existing non-target lesions. 95% confidence intervals (CI) were calculated only for clinical responses using the Pearson-Clopper method. | Tumor assessments every 9 weeks from Baseline until IRF-determined progressive disease (PD), death, or first administration of next line of anti-cancer therapy (whichever occurred first), up to the primary completion date (up to 3 years, 3 months) | 
| Duration of Objective Response Determined by an Independent Review Facility | Duration of objective response (estimated using the Kaplan-Meier method) was defined as the time from the initial confirmed complete response (CR) or partial response (PR), the date of tumor assessment at which the CR/PR was first detected by the independent review facility (IRF) using RECIST version 1.0, until the date of IRF-determined progressive disease (PD), death from any cause within 18 weeks of the last tumor assessment, or first administration of next line of anti-cancer therapy (whichever occurred first). If the visit when the initial CR or PR was observed spanned multiple dates, the latest date was used. Only participants in the ITT analysis population with an IRF-determined objective response (CR or PR), observed prior to IRF-assessed PD, death or next line of anti-cancer therapy, were included in the analysis. Participants who did not progress or die after they had a confirmed response were censored at the date of their last IRF-evaluable tumor measurement. | From initial IRF-confirmed objective response until IRF-determined progressive disease (PD), death, or first administration of next line of anti-cancer therapy (whichever occurred first), up to the primary completion date (up to 3 years, 3 months) | 
| Time to Symptom Progression | Time to symptom progression was defined as the time from randomization to the first symptom progression as measured by the Functional Assessment of Cancer Therapy-for patients with Breast Cancer (FACT-B) questionnaire with the Trial Outcomes Index-Physical/Functional/Breast (TOI-PFB) subscale. The FACT-B TOI-PFB subscale contains 24 items from 3 subsections of the FACT-B questionnaire: Physical well-being, functional well-being, and additional concerns for breast cancer patients (breast cancer subscale [BCS]). All items in the questionnaire were rated by the patient on a 5-point scale ranging from 0 (not at all) to 4 (very much). The total score ranged from 0 to 96. A higher score indicates better perceived quality of life. A positive change score from baseline indicates improvement. Symptom progression was defined as a decrease from baseline of 5 points or more. | Every 9 weeks from Baseline until investigator-determined progressive disease, up to the primary completion date (up to 3 years, 3 months) | 
| Overall Number of Participants Who Experienced at Least One Adverse Event, Including Serious and Non-Serious Adverse Events, by Most Severe Intensity (According to NCI-CTCAE v3.0) During the Treatment Period | Adverse event (AE) severity was assessed according to the National Cancer Institute Common Terminology Criteria for Adverse Events, Version 3.0 (NCI-CTCAE v3.0); if the AE was not specifically listed, the following grades of severity were used: Grade 1 = mild; Grade 2 = moderate; Grade 3 = severe; Grade 4 = life-threatening or disabling; and Grade 5 = death. Severe and serious are not synonymous. Severity refers to the intensity of an AE, whereas a serious AE must meet criteria set out in the protocol; both were independently assessed for each AE. Only the most severe intensity was counted for multiple occurrences of the same AE in one participant. AEs reported prior to first crossover treatment were included in the Placebo arm, and in the Crossover arm after that date, for participants who crossed over from placebo to pertuzumab. Median [range] time on study treatment per arm: Placebo: 49.3 [0.3-514.7] weeks; Pertuzumab: 75.7 [0.6-519.6] weeks; Crossover: 129.9 [0.3-322.3] weeks. | Placebo arm: Baseline to last dose of study treatment +42 days (or crossover date); Pertuzumab arm: Baseline to last dose of study treatment +42 days; Crossover arm: Crossover date to last dose of study treatment +42 days (see Description - time per arm) | 
| Overall Number of Adverse Events by Severity (NCI-CTCAE v3.0 All Grades and Grades 3 to 5) Per 100 Patient-Years of Exposure During the Treatment Period | Adverse event (AE) severity, including serious and non-serious AEs, was assessed according to the NCI-CTCAE version 3.0; if the AE was not specifically listed, the following grades of severity were used: Grade 1 is mild; Grade 2 is moderate; Grade 3 is severe; Grade 4 is life-threatening or disabling; and Grade 5 is death. Multiple occurrences of the same AE in 1 participant were counted multiple times. Only AEs that started during the overall study treatment period were included. The cutoff date for inclusion of events and for calculation of patient-years was the date of the most recent follow-up of the participant, defined as the last available date during the treatment period, excluding pre-treatment and safety follow-up data. Confidence intervals were calculated assuming the number of events followed a Poisson distribution. Data reported prior to the date of first crossover treatment were included under the Placebo arm for participants who crossed over from placebo to pertuzumab. | From Baseline to 42 days after the last dose of study treatment (total patient-years of exposure on study treatment in Placebo vs. Pertuzumab arms: 526.81 vs. 989.88 patient-years) | 
| Cardiac-Related AEs to Monitor: Number of Participants Who Experienced at Least One Symptomatic Left Ventricular Dysfunction (LVD), Any LVD, or Serious AE Suggestive of Congestive Heart Failure by Severity During the Treatment Period | Cardiac-related adverse events (AEs) to monitor during the study included investigator-assessed symptomatic left ventricular dysfunction (LVD), any LVD, or a serious adverse event (SAE) suggestive of congestive heart failure (CHF). All cardiac-related AEs were graded for severity according to NCI-CTCAE v3.0. Asymptomatic (Grades 1-2) and symptomatic (Grades 3-5) left ventricular systolic dysfunction (LVSD) both coded to the MedDRA preferred term LVD. Investigator-assessed events of symptomatic LVD were also graded for severity of symptoms according to Classes I (least severe) to IV (most severe) of the New York Heart Association (NYHA) Classification. SAEs suggestive of CHF were identified as serious events from the Standardized MedDRA Query (SMQ) (Wide) 'Cardiac Failure'. Median [range] time on study treatment per arm: Placebo: 49.3 [0.3-514.7] weeks; Pertuzumab: 75.7 [0.6-519.6] weeks; Crossover: 129.9 [0.3-322.3] weeks. | Placebo arm: Baseline to last dose of study treatment +42 days (or crossover date); Pertuzumab arm: Baseline to last dose of study treatment +42 days; Crossover arm: Crossover date to last dose of study treatment +42 days (see Description - time per arm) | 
| Number of Participants Who Experienced at Least One Adverse Event to Monitor (Excluding Cardiac-Related AEs) by Severity During the Treatment Period | The clinical diagnoses listed in this table, excluding cardiac safety (summarized separately), were also selected as adverse events (AEs) to monitor based on clinical and nonclinical data for pertuzumab and the safety profile established for trastuzumab, monoclonal antibodies in general, and potential effects associated with HER receptor inhibition. Search strategies were defined by single or aggregate MedDRA Preferred Terms (PT) through Standardized MedDRA Queries (SMQ), where possible, or based on Roche AE Group Terms (AEGT). Diarrhoea AEs: High-Level Term (HLT) 'Diarrhoea (excl. infective)' and PT 'Diarrhoea infectious'. Leukopenic and Febrile Neutropenic Infections: AEs from 'Infections & Infestations' with start ≤14 days after start date of Grade ≥3 AEs in SMQ(narrow) 'Leukopenia' or PT 'Febrile neutropenia', respectively. Median [range] time on study treatment per arm: Placebo: 49.3 [0.3-514.7] weeks; Pertuzumab: 75.7 [0.6-519.6] weeks; Crossover: 129.9 [0.3-322.3] weeks. | Placebo arm: Baseline to last dose of study treatment +42 days (or crossover date); Pertuzumab arm: Baseline to last dose of study treatment +42 days; Crossover arm: Crossover date to last dose of study treatment +42 days (see Description - time per arm) | 
| Overall Number of Participants Who Experienced at Least One Adverse Event Leading to Discontinuation of Any or All Study Medication | Participants could continue study treatment with pertuzumab/placebo plus trastuzumab when docetaxel was discontinued due to an adverse event (AE). Discontinuation of pertuzumab/placebo or trastuzumab due to an AE led to discontinuation of all study medication. The number of participants who discontinued any study medication due to an AE includes those who discontinued all study medication and those who discontinued docetaxel only and then continued on targeted therapy (note: some of these participants may have subsequently discontinued all treatment due to a separate AE). Multiple occurrences of the same adverse event in 1 participant was counted only once. AEs reported prior to first crossover treatment were included in the Placebo arm, and after that date in the Crossover arm, for those who crossed over from placebo to pertuzumab. Median [range] time on study treatment per arm: Placebo: 49.3 [0.3-514.7] weeks; Pertuzumab: 75.7 [0.6-519.6] weeks; Crossover: 129.9 [0.3-322.3] weeks. | Placebo arm: Baseline to last dose of study treatment +42 days (or crossover date); Pertuzumab arm: Baseline to last dose of study treatment +42 days; Crossover arm: Crossover date to last dose of study treatment +42 days (see Description - time per arm) | 
| Overall Number of Participants Who Experienced at Least One Adverse Event That Resulted in Interruption or Modification of Any Study Medication | Pertuzumab, trastuzumab, and docetaxel administration could have been delayed to assess or treat adverse events (AEs). Docetaxel dose reduction was allowed for myelosuppression, hepatic dysfunction, and other toxicities. No dose reduction was allowed for pertuzumab or trastuzumab. Multiple occurrences of the same adverse event in one participant was counted only once. AEs reported prior to first crossover treatment were included in the Placebo arm, and after that date in the Crossover arm, for participants who crossed over from placebo to pertuzumab. Median [range] time on study treatment per arm: Placebo: 49.3 [0.3-514.7] weeks; Pertuzumab: 75.7 [0.6-519.6] weeks; Crossover: 129.9 [0.3-322.3] weeks | Placebo arm: Baseline to last dose of study treatment +42 days (or crossover date); Pertuzumab arm: Baseline to last dose of study treatment +42 days; Crossover arm: Crossover date to last dose of study treatment +42 days (see Description - time per arm) | 
| Number of Participants Who Experienced at Least One Adverse Event During the Post-Treatment Follow-Up Period | The post-treatment period was defined as the period following the treatment discontinuation visit. Only the following new adverse events (AEs) should have been reported during the post-treatment follow-up period: 1. Cardiac events (regardless of causality or seriousness) that started up to 1 year after the last dose, except for symptomatic left ventricular systolic dysfunction (regardless of causality) that started up to 3 years after the last dose; and 2. Treatment-related serious AEs, regardless of start date. AEs are listed by Medical Dictionary for Regulatory Activities, Version 21.1 (MedDRA v21.1) System Organ Class (SOC) and Preferred Term (PT); PTs fall under the SOC that is listed immediately above it in the table. Multiple occurrences of the same AE in one participant was counted only once. AEs reported prior to first crossover treatment were included in the Placebo arm, and after that date in the Crossover arm, for participants who crossed over from placebo to pertuzumab. | From Day 43 after discontinuation of all study medication to end of post-treatment follow-up period (up to 3 years) | 
| Number of Participants by Categories for the Maximum Absolute Decrease From Baseline in LVEF Value During the Treatment Period | All participants were required to have an left ventricular ejection fraction (LVEF) ≥50% at baseline, as measured by echocardiogram (preferred) or multiple-gated acquisition (MUGA) scan. The same method of LVEF assessment and the same institution/facility used at baseline was used throughout the study, to the extent possible. The baseline value was defined as the last valid value recorded during the pre-treatment period before or on study Day 1. The maximum absolute decrease in LVEF value was defined as the lowest post-baseline value up to the end of the overall study treatment period. Data reported prior to first crossover treatment were included in the Placebo arm, and after that date in the Crossover arm, for participants who crossed over from placebo to pertuzumab. Median [range] time on study treatment per arm: Placebo: 49.3 [0.3-514.7] weeks; Pertuzumab: 75.7 [0.6-519.6] weeks; Crossover: 129.9 [0.3-322.3] weeks. | Every 9 weeks from the date of randomization until Treatment Discontinuation Visit (see Description for time on study treatment per arm) | 
| Baseline LVEF Value and Change in LVEF From Baseline at Maximum Absolute Decrease Value During the Treatment Period | All participants were required to have a left ventricular ejection fraction (LVEF) ≥50% at baseline, as measured by echocardiogram (preferred) or multiple-gated acquisition (MUGA) scan. The same method of LVEF assessment and the same institution/facility used at baseline was used throughout the study, to the extent possible. The baseline value was defined as the last valid value recorded during the pre-treatment period before or on study Day 1. The maximum absolute decrease in LVEF value was defined as the lowest post-baseline value up to the end of the overall study treatment period. Only data reported prior to the date of first crossover treatment were included for participants who crossed over from placebo to pertuzumab. | Every 9 weeks from the date of randomization until Treatment Discontinuation Visit (median [range] time on study treatment per arm: Placebo: 49.3 [0.3-514.7] weeks; Pertuzumab: 75.7 [0.6-519.6] weeks) | 
| Number of Participants With Laboratory Abnormalities in Blood Biochemistry Tests by Highest Grade According to NCI-CTCAE v3.0 During the Treatment Period | Clinical laboratory tests for blood biochemistry parameters were performed at local laboratories; any abnormal values (High or Low) were based on local laboratory normal ranges. Laboratory abnormalities are presented by the highest grade according to NCI-CTCAE v3.0. Not every abnormal laboratory value qualified as an adverse event, only if it met any of the following criteria: clinically significant (per investigator); accompanied by clinical symptoms; resulted in a change in study treatment; or required a change in concomitant therapy. Median [range] time on study treatment per arm: Placebo: 49.3 [0.3-514.7] weeks; Pertuzumab: 75.7 [0.6-519.6] weeks; Crossover: 129.9 [0.3-322.3] weeks. ALP = alkaline phosphatase; GGT = gamma-glutamyl transferase; SGOT = serum glutamic-oxaloacetic transaminase; SGPT = serum glutamic-pyruvic transaminase | On Day 1 of every treatment cycle (1 cycle is 21 days) until Treatment Discontinuation Visit (see Description for time on study treatment per arm) | 
| Number of Participants With Laboratory Abnormalities in Hematology Tests by Highest Grade According to NCI-CTCAE v3.0 During the Treatment Period | Clinical laboratory tests for hematology parameters were performed at local laboratories; any abnormal values (High or Low) were based on local laboratory normal ranges. Laboratory abnormalities are presented by the highest grade according to NCI-CTCAE v3.0. Not every abnormal laboratory value qualified as an adverse event, only if it met any of the following criteria: clinically significant (per investigator); accompanied by clinical symptoms; resulted in a change in study treatment; or required a change in concomitant therapy. Median [range] time on study treatment per arm: Placebo: 49.3 [0.3-514.7] weeks; Pertuzumab: 75.7 [0.6-519.6] weeks; Crossover: 129.9 [0.3-322.3] weeks. INR = International Normalized Ratio; PTT = partial thromboplastin time; WBC = white blood cell | On Day 1 (and Day 8 for some measures) of every treatment cycle (1 cycle is 21 days) until Treatment Discontinuation Visit (see Description for time on study treatment per arm) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Herceptin, Breast cancer, MBC, Taxotere, HER2, HER2 positive breast cancer, HER2 + breast cancer, HER2-positive, HER2-positive metastatic breast cancer