The PFS was defined as the median time between the day of enrollment and the first documentation of progressive disease (PD) or date of death, whichever occurred first. PD was defined as at least 20 percent (%) increase (including an absolute increase of at least 5 millimeters [mm]) in the sum of diameters of target lesions, taking as reference the smallest sum on study and/or unequivocal progression of existing non-target lesions and/or appearance of 1 or more new lesions. The censoring date was the last date of "last tumor measurement," "last date of study drug treatment," or "last follow-up." The median PFS time with 95% confidence interval (CI) was estimated using Kaplan Meier method.

ITT population.

OS was defined as the time from the date of enrollment to the date of the death (from any cause). If no death was observed, censored observations were taken into account in the analysis. The censoring date was the last date of "last tumor measurement," "last date in drug log," or "last follow-up." The median overall survival time with 95% CI was estimated using Kaplan Meier method.

ITT population.

Overall tumor response was defined as the occurrence of either a confirmed complete response (CR) or a partial response (PR) as best overall response as determined by the Response Evaluation Criteria In Solid Tumors (RECIST) criteria version (v) 1.1 from confirmed radio-graphic evaluations of target and non-target lesions. CR was defined as complete disappearance of all target lesions and non-target disease, with the exception of nodal disease; all nodes, both target and non-target, must decrease to normal (short axis less than [<]10 mm); no new lesions. PR was defined as greater than or equal to (>=) 30% decrease under baseline of the sum of diameters of all target lesions (the short axis was used in the sum for target nodes, while the longest diameter was used in the sum for all other target lesions); no unequivocal progression of non-target disease; no new lesions.

ITT population.

CBR was defined as any response among stable disease (SD) for 6 weeks or longer, CR, or PR as determined by the RECIST v 1.1. CR was defined as complete disappearance of all target lesions and non-target disease, with the exception of nodal disease; all nodes, both target and non-target, must decrease to normal (short axis <10 mm); no new lesions. PR was defined as >=30% decrease under baseline of the sum of diameters of all target lesions (the short axis was used in the sum for target nodes, while the longest diameter was used in the sum for all other target lesions); no unequivocal progression of non-target disease; no new lesions. PD was defined as at least 20% increase (including an absolute increase of at least 5 mm) in the sum of diameters of target lesions, taking as reference the smallest sum on study and/or unequivocal progression of existing non-target lesions and/or appearance of 1 or more new lesions. SD was defined as not qualifying for CR, PR, or PD.

ITT population.

DR was based on RECIST criteria v1.1 and was defined as time from date the CR or PR was first recorded to the date on which PD was first noted. CR: complete disappearance of all target lesions and non-target disease, with the exception of nodal disease; all nodes, both target and non-target, must decrease to normal (short axis <10 mm); no new lesions. PR: >=30% decrease under baseline of the sum of diameters of all target lesions; no unequivocal progression of non-target disease; no new lesions. PD: at least 20% increase (including an absolute increase of at least 5 mm) in the sum of diameters of target lesions and/or appearance of 1 or more new lesions. For the participants with no documented progression after CR or PR, the censored date (the date of "death," the "last tumor measurement," "last date in drug log," or "last follow-up") was taken into consideration. The median duration of response with 95% CI was estimated using Kaplan Meier method.

ITT population. The number of participants analyzed signifies the number of participants analyzed for this outcome measure.

An AE was any untoward medical occurrence attributed to study drug in a participant who received study drug. An SAE was an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged in participant hospitalization; life-threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly. AEs included both serious and non-serious AEs.

Safety population included all participants who had received at least 1 dose of study drug.

Lab parameters assessed during the study were serum chemistry, biochemistry - serum electrolytes, hematology, 12 lead electrocardiogram, and urinalysis - protein, glucose, blood and other lab tests. Laboratory tests were graded according to the National Cancer Institute-Common Toxicity Criteria (NCI-CTC) version 3.

Safety population.

The LVEF was measured using Multi Gated Acquisition (MUGA) or echocardiography (echocardiography was preferred), using the same technique throughout for consistency in an individual participant. Baseline LVEF assessments were done within 21 days prior to the start of treatment. Participants with clinically significant change from baseline (that is, absolute drop in LVEF of >=15%, and drop to a value <50%) have been reported.

Safety population.

The HER2 status was determination by using immunohistochemistry (IHC) and confirmatory Fluorescent In Situ Hybridization (FISH) techniques. Only participants with HER2 positivity were allowed to receive study medication.

Safety population.