Inclusion Criteria:

          -  For Dose Escalation only: Participants with an advanced solid tumor who are considered
             refractory to or intolerant of all existing therapy(ies) known to provide a clinical
             benefit for their condition. Additionally, participants who have been offered standard
             therapies and refused, or who are considered ineligible for standard therapies, may be
             eligible for this study on a case-by-case basis, after discussion with and agreement
             from the sponsor. Participants with triple-negative breast cancer (TNBC), pancreatic
             adenocarcinoma, urothelial cancer, Hepatocellular carcinoma (HCC), or Head and neck
             squamous cell carcinoma (HNSCC) who are being considered for the dose escalation
             cohorts must also meet the histology specific eligibility criteria described below for
             dose expansion

          -  For Dose Expansion only participants must meet criteria specific to the type of
             cancer:

          -  TNBC - Female or male participants with confirmed breast adenocarcinoma that is
             ER-negative, PR-negative, and HER2-negative, (as defined per American Society of
             Clinical Oncology [ASCO]/College of American Pathology [CAP] guidelines), who must
             have disease progression during or after at least 1 systemic therapy that included a
             taxane in the metastatic or recurrent setting.

          -  Pancreatic adenocarcinoma and have disease progression during or after 1 systemic
             therapy (gemcitabine monotherapy or in combination with other agents, FOLFIRINOX [or
             another regimen including both 5-fluorouracil and oxaliplatin], capecitabine
             monotherapy or in combination with other agents) administered in the adjuvant, locally
             advanced, or metastatic setting. If the therapy was used in an adjuvant setting,
             disease progression must have occurred within 6 months of completing adjuvant therapy.

          -  Urothelial cancer of the bladder and urinary tract and must have progressed following
             treatment with a platinum-based regimen (administered in any line of therapy) and a
             programmed death 1/programmed death ligand 1 (PD1/PDL1) antagonist administered in the
             recurrent or metastatic setting (progression following a PD1/PDL1 antagonist is
             defined as unequivocal progression on or within 3 months of the last dose of anti-PD1
             or anti-PDL1 therapy).

          -  HCC and must have disease progression during or after 1 prior line of systemic
             therapy.

          -  HNSCC (arising from the oral cavity, oropharynx, hypopharynx, or larynx) and must have
             progressed following treatment with platinum-based regimen (administered in any line
             of therapy) and a PD1/PDL1 antagonist administered in the recurrent or metastatic
             setting (progression following a PD1/PDL1 antagonist is defined as unequivocal
             progression on or within 3 months of the last dose of anti-PD1 or anti-PDL1 therapy).

          -  Participant has an Eastern Cooperative Oncology Group (ECOG) Performance Status of 0
             to 1.

          -  Participant has adequate bone marrow, renal, hepatic, and coagulation function. Must
             have a viral status consistent with the requirements described in the protocol
             specific to type of cancer and stage of study (Dose Escalation or Dose Expansion).

        Exclusion Criteria:

          -  For Dose Expansion only: Participants (except for participants with urothelial cancer
             or HNSCC) who have had prior exposure to immunotherapies as listed in the protocol.

          -  Has received anticancer therapy including chemotherapy, immunotherapy, radiation
             therapy, biologic, herbal therapy, or any investigational therapy within a period of 5
             half-lives or 28 days (whichever is shorter), prior to the first dose of the study
             drug.

          -  Participant has unresolved AEs > Grade 1 from prior anticancer therapy except for
             alopecia.

          -  Has a history of primary immunodeficiency, bone marrow transplantation, solid organ
             transplantation, or previous clinical diagnosis of tuberculosis.

          -  Has a known uncontrolled metastases to the central nervous system (with certain
             exceptions).

          -  Current or prior use of immunosuppressive medication within 14 days prior to the first
             dose of the study drug.