Key Inclusion Criteria:

          1. Phase 1a (dose escalation): Participants with histologically or cytologically
             confirmed advanced, metastatic, and unresectable solid tumors who have previously
             received standard systemic therapy or for whom treatment is not available, not
             tolerated or refused, and who have not received prior therapy targeting HPK1

          2. At least 1 measurable lesion as defined per RECIST 1.1. The target lesion(s) selected
             have not been previously treated with local therapy or the target lesion(s) selected
             that are within the field of prior local therapy have subsequently progressed as
             defined by RECIST 1.1

          3. Participants must be able to provide an archived formalin-fixed paraffin embedded
             (FFPE) tumor tissue sample (block or approximately 15 to 17 freshly unstained FFPE
             slides after the most recent line of therapy. If archival tissue is not available,
             fresh tumor biopsy is mandatory

          4. Eastern Cooperative Oncology Group (ECOG) Performance Status ≤ 1

          5. Adequate organ function as indicated by the following laboratory values up to first
             dose of study drug: Hemoglobin≥ 90 g/L, Absolute neutrophil count ≥ 1.5 x 109/L ,
             Serum total bilirubin ≤ 1.5 x ULN (< 3 x ULN for participants with Gilbert syndrome ),
             AST and ALT≤ 2.5 x ULN (≤5 x ULNs for participants with hepatocellular carcinoma or
             liver metastases )

        Key Exclusion Criteria:

          1. Active leptomeningeal disease or uncontrolled and untreated brain metastasis.
             Participants with equivocal findings or with confirmed brain metastases are eligible
             for enrollment provided that they are asymptomatic and radiologically stable without
             the need for corticosteroid treatment for at least 4 weeks prior to the first dose of
             study drug(s)

          2. Active autoimmune diseases or history of autoimmune diseases that may relapse, with
             the following exceptions:

               1. Controlled Type 1 diabetes

               2. Hypothyroidism (provided that it is managed with hormone-replacement therapy
                  only)

               3. Controlled celiac disease

               4. Skin diseases not requiring systemic treatment (eg, vitiligo, psoriasis, or
                  alopecia)

               5. Any other disease that is not expected to recur in the absence of external
                  triggering factors

          3. Any active malignancy ≤ 2 years before the first dose of study drug(s) except for the
             specific cancer under investigation in this study and any locally recurring cancer
             that has been treated with curative intent (eg, resected basal or squamous cell skin
             cancer, superficial bladder cancer, or carcinoma in situ of the cervix or breast)

          4. Any condition that required systemic treatment with either corticosteroids (> 10 mg
             daily of prednisone or equivalent) or other immunosuppressive medication ≤ 14 days
             before the first dose of study drug(s), with the following exceptions:

               1. Adrenal replacement steroid (dose ≤ 10 mg daily of prednisone or equivalent)

               2. Topical, ocular, intra-articular, intranasal, or inhalational corticosteroid with
                  minimal systemic absorption

               3. Short course (≤ 7 days) of corticosteroid prescribed prophylactically (eg, for
                  contrast dye allergy) or for the treatment of a nonautoimmune condition (eg,
                  delayed-type hypersensitivity reaction caused by contact allergen)

          5. History of interstitial lung disease, noninfectious pneumonitis, or uncontrolled lung
             diseases including but not limited to pulmonary fibrosis, acute lung diseases, etc.

        NOTE: Other protocol defined Inclusion/Exclusion criteria may apply.