This trial is a first-in-human, multicenter, open-label Phase I/II clinical study to evaluate the safety, tolerability, pharmacokinetics, and preliminary efficacy of KY-0301 as monotherapy in patients with advanced solid tumors. This trial will be conducted at approximately multi-sites nationwide, and approximately110\~212 participants with unresectable locally advanced or metastatic solid tumors will be invited to participate. The study consists of three parts: Phase I dose escalation \& dose expansion phases of KY-0301 as monotherapy, Phase II cohort expansion phase of KY-0301 as monotherapy.