Conditions: Metastatic Breast Cancer
Keywords: Herceptin Breast cancer MBC Taxotere HER2 HER2 positive breast cancer HER2 + breast cancer HER2-positive HER2-positive metastatic breast cancer
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 808
Healthy volunteers: no

Brief summary:
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.

Detailed description:

Arms:
arm 1: 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. arm 2: 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.

Interventions: intervention 1: Pertuzumab intervention 2: Placebo intervention 3: Trastuzumab intervention 4: Docetaxel
Intervention descriptions: intervention 1: 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. intervention 2: Placebo (matching pertuzumab) was administered intravenously. intervention 3: 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. intervention 4: 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.

Protocol document: