Inclusion Criteria:

          -  Must have histological or cytological evidence of a diagnosis of cancer that is not
             amenable/resistant to approved standard-of-care therapy for the following solid
             tumors: Melanoma, non-small cell lung cancer (NSCLC), squamous cell carcinoma of the
             head and neck (SCCHN), urothelial cancer, gastric cancer, colorectal cancer, biliary
             tract cancer, anal cancer, nasopharyngeal cancer, esophageal cancer, SCLC, ovarian
             cancer, mesothelioma, pan-tumor MSIhi solid tumors, hepatocellular carcinoma, merkel
             cell cancer, cutaneous squamous cell carcinoma, endometrial cancer, breast cancer,
             cervical cancer, thyroid cancer, salivary cancer, and prostate cancer who have
             received at least one line of standard systemic therapy for their respective tumor
             type in the metastatic setting with progressive locally advanced or metastatic
             disease. Prior anti-programmed death 1 (PD-1) and anti-programmed death ligand 1
             (PD-L1) allowed if they received another therapy immediately prior to this study or
             there has been a lapse of approximately ≥90 days from prior therapy.

          -  Must be willing to undergo pretreatment and on-treatment core needle or excisional
             tumor biopsies.

          -  Have at least one measurable lesion assessable as defined by the Response Evaluation
             Criteria in Solid Tumors (RECIST) 1.1.

          -  Have adequate organ function.

          -  Have a performance status of 0 or 1 on the Eastern Cooperative Oncology Group (ECOG)
             scale.

          -  Have an estimated life expectancy of 12 weeks, in the judgment of the investigator.

        Exclusion Criteria:

          -  Have symptomatic central nervous system (CNS) malignancy or metastasis not requiring
             concurrent treatment, including but not limited to surgery, radiation, corticosteroids
             and/or anticonvulsants to treat CNS metastases, and their disease is asymptomatic and
             radiographically stable for at least 30 days.

          -  Have moderate or severe cardiovascular disease.

          -  Have active or suspected autoimmune disease (eg. autoimmune vasculitis, autoimmune
             myocarditis, among others).

          -  Have serious concomitant systemic disorder that would compromise the participant's
             ability to adhere to the protocol, including known infection with human
             immunodeficiency virus (HIV) unless they are well controlled on highly active
             antiretroviral therapy (HAART) therapy with no evidence of acquired immune deficiency
             syndrome (AIDS)-defining opportunistic infections within the last 2 years, and CD4
             T-cells count > 350 cells/µl , active hepatitis B virus (HBV), active hepatitis C
             virus (HCV), active autoimmune disorders, or prior documented severe autoimmune or
             inflammatory disorders requiring immunosuppressive treatment.

               -  Use of escalating or chronic supraphysiologic doses of corticosteroids or
                  immunosuppressive agents (such as, exceeding 10 milligrams/day of prednisone or
                  equivalent). Use of topical, ophthalmic, inhaled, and intranasal corticosteroids
                  permitted.

          -  Bowel obstruction, history or presence of inflammatory enteropathy or extensive
             intestinal resection, Crohn's disease, ulcerative colitis, or chronic diarrhea.

          -  Evidence of interstitial lung disease or noninfectious pneumonitis (active or treated
             by corticosteroid therapy).