A Study to Evaluate the Efficacy and Safety of Herceptin® (Trastuzumab) in Combination With Arimidex® (Anastrozole) an Aromatase Inhibitor Compared to Arimidex® Alone in Patients With Metastatic Breast Cancer

PFS was assessed by the investigator based on World Health Organization (WHO) criteria using radiographic tumor evaluations. Disease progression was defined as the appearance of any new lesion not previously identified or an estimated increase of 25% or more in existent bidimensionally or unidimensionally measurable lesions or progression of an existing non-measurable lesion. For bidimensionally measurable malignant lesions with an area of at least 2.0 centimeters squared (cm^2) an increase of 1.0 cm^2 was required and for unidimensionally measurable lesions of 1.0 cm or less an increase of 0.5 cm was required. PFS was defined as the number of days between date of randomization and date of documented disease progression or date of death. Kaplan Meier estimates of PFS are presented.

Clinical Benefit was defined as stable disease for ≥ six months or complete response or partial response.

Duration of response was defined as the number of days from the day complete response or partial response was first noted to the day of progression of disease, death or last follow-up.

Time to response was defined as the number of days from the day of randomization to the day complete response or partial response was first noted.

Overall Survival is defined as the number of days from randomization to death.

Tumor Response levels were determined by the investigator and an Independent Response Evaluation Committee and Reconciled. Overall Response was defined as either complete response or partial response.

Tumor Response levels were determined by the investigator and an Independent Response Evaluation Committee and Reconciled. Best Response was defined as the best response a patient achieves in the study.

Participants rated their performance status using the ECOG Questionnaire on the following scale: 0=Fully active, perform all pre-disease activities without restriction; 1=Restricted in physically strenuous activity but ambulatory, carry out work of a light or sedentary nature; 2=Ambulatory, capable of self-care, unable to carry out any work activities, up and about more than >50% of waking hours; 3=Capable of limited self-care, confined to bed or chair >50% of waking hours; 4=Completely disabled, not capable of any self-care, totally confined to bed or chair; 5=Dead.

The percentage of participants in the following categories:

Improved: Score decrease from baseline. Unchanged: Score the same as baseline. Worse: Score increase from baseline.

Duration of response was defined as the number of days from the day complete response or partial response was first noted to the day of progression of disease, death or last follow-up.

Time to response was defined as the number of days from the day of randomization to the day complete response or partial response was first noted.

Tumor Response levels were determined by the investigator and an Independent Response Evaluation Committee and Reconciled. Overall Response was defined as either complete response or partial response.

Tumor Response levels were determined by the investigator and an Independent Response Evaluation Committee and Reconciled. Best Response was defined as the best response a patient achieves in the study.

Number of participants with adverse events as a measure for safety as assessed by the collection of adverse events, laboratory tests for Hematology and Serum Chemistry, clinical assessments and cardiac monitoring.