A Study to Determine Best Tumor Response With Trastuzumab Emtansine in Human Epidermal Growth Factor Receptor 2 (HER2) Overexpressing Solid Tumors

Exclusion Criteria

• •Participants with previous exposure to HER2-targeted therapies in any setting
• •Participants showing histologically confirmed focal HER2-expression, that is, less than (\<) 30% of positively stained tumor cells
• •Participants with brain metastasis as the sole site of metastatic disease and/or are symptomatic or require therapy to control symptoms
• •Current uncontrolled hypertension (systolic greater than \[\>\] 150 millimeters of mercury \[mmHg\] and/or diastolic \>100 mmHg)
• •Current unstable angina pectoris
• •History of symptomatic congestive heart failure (CHF) of any New York Heart Association (NYHA) criteria or ventricular arrhythmia that requires treatment
• •History of myocardial infarction within the last 6 months
• •Peripheral neuropathy, Grade \>/=3
• •Current dyspnea at rest due to complications of advanced malignancy, or other diseases that require continuous oxygen therapy
• •Current severe, uncontrolled systemic disease
• •History of other malignancy within the last 5 years
• •Concurrent, serious, uncontrolled infections or current known infection with human immunodeficiency virus (HIV), active hepatitis B and/or hepatitis C
• •Known prior severe hypersensitivity to trastuzumab and trastuzumab emtansine or the excipients of the investigational medicinal product (IMP)
• •Clinically significant bleeding within 30 days before enrollment
• •Major surgical procedure or significant traumatic injury within 28 days prior to randomization or anticipation of the need for major surgery during the course of study treatment
• •Concurrent participation in any other therapeutic clinical trial