AD1208 in Subjects With Any Progressive, Locally Advanced or Metastatic Solid Tumors

Inclusion Criteria: * Male or female subjects ≥19 years of age * Willing to consent to participate in study and ability to comply with scheduled visits, treatment plan, laboratory tests and other study procedures * Histologically and/or cytologically confirmed any progressive, locally advanced (unresectable), or metastatic solid tumors that have relapsed or are refractory following the last line of treatment and for which prior standard therapy has been ineffective, standard therapy does not exist or is not considered appropriate. * Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1 * Life expectancy of at least 12 weeks * Subjects with adequate hematologic, hepatic, and renal functions confirmed based on the screening laboratory test within 2 weeks prior to the first administration of IP. * Female subject who is surgically sterile, is postmenopausal, or agrees to use a highly effective method of birth control (2 methods strongly recommended) during the study and for 6 months following the last dose of IP. * Male subject with a pregnant or breastfeeding partner(s) must agree to remain abstinent or use a condom for the duration of the pregnancy or for the time the partner is breastfeeding throughout the study period and for 6 months after the final administration of IP. Exclusion Criteria: * Untreated active brain metastases. * has leptomeningeal disease. * unrecovered \> Grade 1 from the adverse event of prior therapy except for alopecia. * has an active autoimmune disease requiring systemic treatment within the past 2 years. * Active interstitial lung disease (ILD) or pneumonitis or a history of ILD. * Subject has received the following treatment; * prior anticancer monoclonal antibody treatment or investigational therapy * prior any chemotherapy * prior radiotherapy * Major surgery * Clinically significant (i.e., active) cardiovascular disease * known positive of human immunodeficiency virus (HIV) infection. * Active hepatitis B or C subjects. * known allergic reaction for active ingredients or inactive ingredients such as excipients of Investigational product. * Live vaccine administered against infectious disease. * Gastrointestinal (GI) track disease causing the inability to take oral medication, malabsorption syndrome or uncontrolled inflammatory GI disease. * having psychiatric illness/social situations that would limit compliance with study requirements. * women with a positive pregnancy test at screening test. * women who are breast feeding. * subject has any condition because of which, in the opinion of the investigator, the participation would not be in the best interest of the subject.