A Study to Evaluate the Safety, Pharmacokinetics, and Activity of Enzelkitug as a Single Agent and in Combination With Checkpoint Inhibitor in Participants With Locally Advanced or Metastatic Solid Tumors

Inclusion Criteria: * Life expectancy of at least 12 weeks * Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 * Measurable disease according to Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST v1.1) * Histologically confirmed locally advanced, recurrent, or metastatic incurable solid tumor malignancy * Tumor specimen availability Exclusion Criteria: * Pregnant or breastfeeding or intention of becoming pregnant during the study or within 4 months after the final dose of enzelkitug, or 4 months after the final dose of pembrolizumab, or 5 months after the final dose of atezolizumab * Any anti-cancer therapy, whether investigational or approved, including chemotherapy, hormonal therapy, and/or radiotherapy, within 3 weeks prior to initiation of study treatment * Active hepatitis B (HBV) or hepatitis C (HCV) or tuberculosis * Positive test for human immunodeficiency virus (HIV) infection * Acute or chronic active Epstein-Barr virus (EBV) infection at screening * Administration of a live, attenuated vaccine (e.g., FluMist) within 4 weeks before first enzelkitug infusion * Symptomatic, untreated, or actively progressing central nervous system (CNS) metastases * Active or history of autoimmune disease * Prior allogeneic stem cell or organ transplantation