Inclusion Criteria:

          -  Histologically documented locally advanced/metastatic non-squamous NSCLC

          -  Patients must have tumors that lack activating EGFR mutations, EML4-ALK fusion, and
             ROS-1 mutation

          -  Patients must be treatment- naïve for locally advanced or mNSCLC and medically fit to
             receive first-line treatment. Prior adjuvant, neo adjuvant therapies are permitted if
             progression has occurred > 12 months from the end of last therapy

          -  HER2+ (IHC 3+ or IHC 2+) status as determined by central review of tumor tissue

          -  WHO / ECOG performance status of 0 or 1

          -  Has a measurable target disease assessed by the investigator using RECIST 1.1

          -  Has a protocol defined adequate organ and bone marrow functions

        Exclusion criteria:

          -  Has a history of (non-infectious) ILD/pneumonitis that required steroids, has current
             ILD/pneumonitis, or where suspected ILD/pneumonitis cannot be ruled out by imaging at
             screening

          -  Lung-specific intercurrent clinically significant illnesses including, but not limited
             to, any underlying pulmonary disorder and prior pneumonectomy

          -  Active primary immunodeficiency known HIV infection, or active hepatitis B or C
             infection

          -  Active infection including tuberculosis and uncontrolled infection requiring IV
             antibiotics, antivirals, or antifungals

          -  Spinal cord compression or clinically active central nervous system metastases,
             defined as untreated and symptomatic, or requiring therapy with corticosteroids or
             anticonvulsants to control associated symptoms

          -  Medical history of myocardial infarction within 6 months before treatment assignment,
             symptomatic CHF (New York Heart Association Class II to IV), clinically important
             cardiac arrhythmias, or a recent (< 6 months) cardiovascular event including stroke

          -  A pleural effusion, ascites or pericardial effusion that requires drainage, peritoneal
             shunt, or CART