A Study of JSKN027 in Patients With Advanced Solid Tumors

Inclusion Criteria: * Age ≥ 18 years at the time of signing the ICF. * ECOG performance status 0-1. * Estimated life expectancy ≥ 3 months. * Histologically or cytologically confirmed advanced or metastatic malignant solid tumor. * For dose escalation (Part Ia): disease has progressed on standard therapy. * For dose expansion (Part Ib): participants with prespecified tumor types (e.g., colorectal cancer, non-small cell lung cancer, hepatocellular carcinoma, and other selected solid tumors) who have progressed on standard therapy. * At least one measurable extracranial lesion per RECIST v1.1. * Adequate bone marrow function within 7 days prior to enrollment (e.g., ANC ≥ 1.5×10\^9/L, hemoglobin ≥ 90 g/L, platelets ≥ 100×10\^9/L). * Adequate hepatic function within 7 days prior to enrollment (e.g., total bilirubin, AST/ALT, ALP within protocol-defined limits; albumin ≥ 30 g/L). * Adequate renal function within 7 days prior to enrollment (e.g., serum creatinine ≤ 1.5×ULN or creatinine clearance ≥ 60 mL/min; urine protein within acceptable limits). * Adequate coagulation function within 7 days prior to enrollment (e.g., PT/INR and aPTT within protocol-defined limits). * Adequate cardiac function (e.g., LVEF ≥ 50%). * Women of childbearing potential must have a negative pregnancy test within 7 days prior to enrollment. * Participants of reproductive potential agree to use highly effective contraception from ICF signing until 7 months after the last dose. Exclusion Criteria: * Active central nervous system (CNS) disease (e.g., active brain metastases or leptomeningeal disease). * Received an investigational agent within 28 days or 5 half-lives (whichever is shorter) prior to first dose. * Major surgery within 28 days prior to first dose or planned major surgery during the study. * History of severe immune-related adverse events or prior toxicity that would preclude safe participation, as judged by the investigator. * Significant gastrointestinal disorders that increase risk of perforation, bleeding, obstruction, or interfere with study participation. * Active or uncontrolled interstitial lung disease (ILD) or non-infectious pneumonitis, or suspected ILD/pneumonitis at screening. * Active autoimmune disease requiring systemic immunosuppression (exceptions may apply for limited, stable conditions). * Active hepatitis B or C, HIV infection, or other clinically significant immunodeficiency/infection not adequately controlled per local standards. * Prior allogeneic organ or bone marrow transplant. * Known hypersensitivity to the study drug or its excipients, or history of severe hypersensitivity to similar biologic agents. * Pregnant or breastfeeding. * Any condition that, in the investigator's judgment, would compromise participant safety or compliance.