A Study of SIM0689 in Adult Participants With Locally Advanced or Metastatic Solid Tumors

Inclusion Criteria: * In dose-escalation cohorts (Part 1), histologically or cytologically documented advanced or metastatic solid tumor that is refractory/relapsed to standard therapies, or for which no effective standard therapy is available, or the subject refuses standard therapy. * In the dose-expansion cohorts (Part 2), histologically or cytologically confirmed selected advanced solid tumors. * Subjects must have at least one measurable lesion according to RECIST Version1.1. * Eastern Cooperative Oncology Group (ECOG) Performance Score of 0 or 1. * Adequate organ function. * Available archived tumor tissue sample to allow for correlative biomarker studies. If unavailable or unsuitable, the subject must consent and undergo fresh tumor biopsy. * Life expectancy ≥12 weeks. * Patients of childbearing potential (male and female) must agree to use reliable methods of contraception until at least 180 days after the last dose. Exclusion Criteria: * Symptomatic brain metastases. * Serious non-healing wounds, ulcers or fractures. * Toxicity from previous treatment has to restore to ≤ grade 1. * Major surgery (excluding biopsy) or significant trauma within 4 weeks prior to enrollment. * Use of aspirin (\> 325 mg/day) within 6 months prior to the first dose. * Active hepatitis B or hepatitis C. * Known human immunodeficiency virus (HIV) infection or acquired immunodeficiency syndrome (AIDS). * Known hereditary or acquired predisposition to bleeding and thrombosis. * History of gastrointestinal perforation, gastrointestinal bleeding, fistula, or any life-threatening bleeding event within 6 months prior to enrollment. * Prior permanent discontinuation of PD-(L)1 and/or VEGF monoclonal antibody because of immune/anti-angiogenesis toxicities, or history of Grade ≥3 immune/anti-angiogenesis-related AEs * Known or suspected active autoimmune disease. * Patients with proteinuria at screening (Urine protein \>2+ at screening, or 2+ urine protein accompanied by 24-h urine protein ≥1 g/24 h). * History of myocardial infarction or stroke within 6 months prior to enrollment. * Subjects with clinically significant cardiovascular disease within 6 months prior to the first dose. * Pregnant and lactating women. * Known allergies to any excipient in the study drug.