CPO301 for Advanced Solid Tumors

Major Inclusion Criteria: * Age ≥18 years * Patients with histologically confirmed locally advanced or metastatic solid tumors who have disease progression, intolerance to prior therapy, are ineligible for available therapies, or refuse standard of care therapy in the metastatic setting. * In Part A, patients with solid tumors including but not limited to NSCLC (adenocarcinoma and squamous cell carcinoma), breast cancer, KRAS-wild type colorectal cancer, and head \& neck cancer based on previous biopsy result. * In Part B, Cohort 1 will exclusively include NSCLC patients with documented EGFR mutations based on previous biopsy result and Cohort 2 will be patients with other cancer(s) suggested to have sensitivity to CPO301 in Part A. * At least 1 measurable target lesion present and documented by CT or MRI according to RECIST v1.1 * ECOG performance status 0 or 1 at screening * Life expectancy \>12 weeks Major Exclusion Criteria: * Known, active, or uncontrolled central nervous system (CNS) metastasis or carcinomatous meningitis. * Has AEs due to previous anti-tumor treatments not recovered to ≤Grade 1 (except for alopecia; some tolerable chronic toxicities of Grade 2 may be excluded after consultation with the sponsor, as judged by the investigator) according to NCI-CTCAE v5.0. * Any serious and/or uncontrolled concurrent illness that may interfere with study participation Prior therapy * Received other investigational drugs or treatments within 4 weeks before the first dose of the investigational drug in the study * The time interval between the latest anti-tumor treatment and the first dose of the investigational drug meets the following requirements: Have received anti-tumor treatments such as chemotherapy, radiotherapy, targeted therapy, immunotherapy and other clinical investigational drugs within 4 weeks before the first dose of the investigational drug; have received oral fluoropyrimidines, small molecule targeted drugs within 2 weeks before the first dose of the investigational drug; have received palliative radiotherapy or local therapy within 2 weeks before the first dose of investigational drug. * Had major surgery within 4 weeks before the first dose of the investigational drug in the study.