Inclusion Criteria:

          -  Histological/cytological diagnosis of selected advanced or metastatic tumor

          -  Prior treatment with PD-1 (Programmed cell death 1) or PD-L1 (programmed death-ligand
             1) in NSCLC and SCCHN or platinum-based therapy in Ovarian cancer

          -  Confirmed radiographic progression of disease

          -  PD-L1 IHC positivity ≥1%

          -  Have ≥1 measurable lesion as defined by RECIST 1.1 that has not been previously
             irradiated

          -  Eastern Cooperative Oncology Group performance status 0-1

          -  Adequate hematologic, renal and liver functions

          -  Resolved acute effects of any prior therapy

          -  Participants in Part 1 must be able to provide archival tumor tissue collected within
             the prior 6 months or consent to undergo a fresh biopsy during screening. Participants
             enrolled to the MTD (Maximum Tolerated Dose) cohort in Part 1 must consent to
             mandatory paired pre-treatment and on-treatment biopsies. Participants in Part 2 must
             consent to a pre-treatment biopsy and a subset of patients must consent to a paired
             on-study biopsy as well until the Sponsor deems an adequate number have been received.

        Exclusion Criteria:

          -  Participants with known brain metastasis larger than 4 cm or that is symptomatic. New
             brain metastases detected at screening. Participants with previously diagnosed brain
             metastases are eligible if they have completed treatment and recovered from acute
             effects prior to study entry.

          -  Abnormal neurological assessment by investigator

          -  Other active malignancy within 3 years prior to enrollment, except for adequately
             treated basal cell or squamous cell skin cancer, or carcinoma in situ

          -  Major surgery or radiation therapy within 4 weeks prior to planned first dose

          -  Last systemic anti-cancer therapy within 28 days or 5 half-lives (whichever is
             shorter) prior to planned first dose (6 weeks for mitomycin C or nitrosoureas)

          -  Active bleeding disorder in the past 6 months prior to first dose

          -  History of clinically significant severe immune mediated adverse event that was
             considered related to prior immune modulatory therapy and required immunosuppressive
             therapy (other than hormone replacement therapy)

          -  History of idiopathic pulmonary fibrosis (including pneumonitis), drug-induced
             pneumonitis, organizing pneumonia (ie, bronchiolitis obliterans, cryptogenic
             organizing pneumonia), evidence of active pneumonitis on screening chest CT(computer
             tomography) scan

          -  Anticoagulation with vitamin K antagonists or factor Xa inhibitors is not allowed

          -  Treatment with chronic systemic corticosteroids or other immunosuppressive medications

          -  Participation in other studies involving investigational drug(s) within 4 weeks prior
             to planned first dose

          -  Active, uncontrolled bacterial, fungal, or viral infection, Hepatitis B, Hepatitis C,
             or Human immunodeficiency virus (HIV) infection

          -  Active COVID-19/SARS-CoV2

          -  Pregnant or breastfeeding female participant

          -  Organ transplant requiring immunosuppressive treatment or prior allogeneic bone marrow
             or hematopoietic stem cell transplant

          -  Significant cardiac or pulmonary conditions or events within previous 6 months