Inclusion Criteria:

          -  Men or women the age of majority in their country

          -  Has pathologically documented breast cancer that:

               1. is unresectable or metastatic

               2. has HER2 positive expression confirmed per protocol

          -  Has an adequate tumor sample

          -  Has at least one measurable lesion per Response Evaluation Criteria in Solid Tumors
             (RECIST) version 1.1

          -  Has protocol-defined adequate cardiac, renal and hepatic function

          -  Agrees to follow protocol-defined method(s) of contraception

        Exclusion Criteria:

          -  Has a medical history of myocardial infarction, symptomatic congestive heart failure
             (CHF) (NYHA classes II-IV), unstable angina or serious cardiac arrhythmia

          -  Has a QTc prolongation to > 450 millisecond (ms) in males and > 470 ms in females

          -  Has a medical history of clinically significant lung disease

          -  Is suspected to have certain other protocol-defined diseases based on imaging at
             screening period

          -  Has history of any disease, metastatic condition, drug/medication use or other
             condition that might, per protocol or in the opinion of the investigator, compromise:

               1. safety or well-being of the participant or offspring

               2. safety of study staff

               3. analysis of results