Statement: The median time from randomization until the first documented sign of disease progression or death due to any cause for all participants in the primary trial, was lower than the median time for patients in the secondary trial.
Primary_evidence: Outcome Measurement:    Progression-Free Survival (PFS)   PFS was defined as the time from randomization until the first documented sign of disease progression or death due to any cause.   Time frame: Baseline to disease progression or death due to any cause or 30 days after last dose (up to 216 weeks) Results 1:    Arm/Group Title: Trastuzumab + Lapatinib   Arm/Group Description: Participants received Lapatinib 1000 milligram (mg) tablets orally daily 1 hour before or after breakfast along with Trastuzumab infusion at a loading dose of 4 milligrams/kilogram (mg/kg) body weight intravenously (IV) over 90 minutes on Day 1, followed by 2 mg/kg IV over 30 minutes weekly, in a 4 week cycle.   Overall Number of Participants Analyzed: 146   Median (95% Confidence Interval)   Unit of Measure: weeks  12.0        (8.1 to 16.0) Results 2:    Arm/Group Title: Lapatinib   Arm/Group Description: Participants received Lapatinib 1500 mg tablets orally daily 1 hour before or after breakfast.   Overall Number of Participants Analyzed: 145   Median (95% Confidence Interval)   Unit of Measure: weeks  8.1        (7.6 to 9.0)
Secondary_evidence: Outcome Measurement:    Time to Progression as Evaluated by the Investigator   Time to progression (TTP) is defined as the interval between the date of randomization and the earliest date of progression of disease (PD) or death due to breast cancer. The investigator assessed PD based on radiological PD (imaging data) and clinical symptomatic progress (Response Evaluation Criteria in Solid Tumors [RECIST] Criteria: target lesion (TL), at least a 20% increase in the sum of largest diameter (LD) of TLs or the appearance of one or more new lesions; non-TL (NTL), the appearance of one or more new lesions and/or unequivocal progression of existing NTLs). TTP was assessed in participants who died due to breast cancer or progressed, as assessed by the investigator, as well as in those who were censored and completed follow-up and those who were censored but are still being followed. For censored participants (those without a documented date of disease progression/death due to breast cancer), the date of the last radiographic assessment was used.   Time frame: Randomization until the date of disease progression or death (average of 26 weeks) Results 1:    Arm/Group Title: Lapatinib With Paclitaxel   Arm/Group Description: Participants received lapatinib 1500 milligrams (mg) orally once daily (OD) with paclitaxel 175 mg/meters squared (m^2) intravenously (IV) over the course of 3 hours, every 3 weeks. The treatment group was stratified by sites of metastatic disease and stage of disease. Participants were treated until disease progression, unacceptable toxicity, or consent withdrawal.   Overall Number of Participants Analyzed: 291   Median (Inter-Quartile Range)   Unit of Measure: weeks  29.0        (13.9 to 46.9) Results 2:    Arm/Group Title: Placebo With Paclitaxel   Arm/Group Description: Participants received matching placebo orally OD with paclitaxel (175 mg/m^2 IV) over the course of 3 hours, every 3 weeks. The treatment group was stratified by sites of metastatic disease and stage of disease. Participants were treated until disease progression, unacceptable toxicity, or consent withdrawal.   Overall Number of Participants Analyzed: 288   Median (Inter-Quartile Range)   Unit of Measure: weeks  22.9        (12.0 to 38.3)