Inclusion Criteria:

          -  Age ≥18 years (≥ 20 years in Japan; ≥ 19 years in South Korea)

          -  Easter Cooperative Oncology Group (ECOG) performance status 0 or 1

          -  Adequate bone marrow function, renal and liver functions Phase 1b

          -  Histological or Cytological diagnosis of advanced solid tumor with clinical evidence
             of response to anti-PD-1 or PD-L1 agent

          -  Participant must have received at least 1 prior line of therapy for recurrent or
             metastatic disease, and must have progressed/relapsed, be refractory, or intolerant to
             standard therapy approved for the specific tumor type Phase 2

          -  Participants must have a documented diagnosis of stage III where participants are not
             candidates for surgical resection or definitive chemoradiation, or stage IV NSCLC

          -  EGFR mutation, BRAF mutation, and ALK or ROS1 translocation/rearrangement are not
             permitted

          -  Participants whose tumor is known to be PD-L1 positive (Tumor Proportion Score [TPS]
             ≥1%) or unknown are eligible

          -  Up to 1 line of prior therapy in advanced or metastatic disease settings allowed

          -  Participant should not have received prior treatment with anti PD-1/PD-L1 drugs

          -  At least one measurable lesion as defined by RECIST version 1.1

        Exclusion Criteria:

          -  Participants with known symptomatic brain metastases requiring steroids

          -  Participants with Interstitial Lung Disease history or complication

          -  Q-T interval corrected for heart rate QTc > 450 msec for male participants or QTc >
             470 msec for female participants or QTc > 480 msec in participants with right bundle
             branch block.

          -  Hypertension that cannot be controlled by medications (eg, systolic > 150 mmHg and
             diastolic > 90 mmHg) despite optimal medical therapy.

          -  Known or suspected hypersensitivity to active ingredient or excipients of the study
             drug.

          -  History of Grade ≥3 immune mediated AE (including AST/ ALT elevations that where
             considered drug related and cytokine release syndrome [CRS]) that was considered
             related to prior immune modulatory therapy (eg, immune checkpoint inhibitors,
             co-stimulatory agents, etc.) and required immunosuppressive therapy (For Phase 1b
             only).

          -  Vaccination with live attenuated vaccines within 4 weeks prior to randomization is
             prohibited; however inactivated vaccines are permitted.