A First-in-Human Study of YL217 in Patients With Advanced Solid Tumors

Inclusion Criteria

• Informed of the study before the start of the study and voluntarily sign their name and date in the ICF
• Able and willing to comply with protocol visits and procedures
• Age≥ 18 years
• ECOG PS of 0 or 1
• Pathologically confirmed diagnosis of an advanced solid tumor. For CRC cohorts: : Histologically or cytologically documented locally advanced unresectable or metastatic colorectal carcinoma that is not eligible for curative surgery and/or definitive chemoradiotherapy
• Adequate organ and bone marrow function.
• Have at least 1 extracranial measurable tumor lesion.
• Adequate archival formalin-fixed paraffin embedded （FFPE） tissue from prior biopsy.

Exclusion Criteria

• Prior treatment with an agent targeting CDH17
• Prior discontinuation of a topoisomerase I inhibitor due to treatment-related toxicities.
• Have received an ADC consisting of a topoisomerase I inhibitor.
• Concurrent enrollment in another clinical study, unless it is an observational clinical study.
• Inadequate washout period for prior anticancer treatment before the first dose of study drug
• Undergone major surgery within 4 weeks before the first dose of study drug or expect major surgery during the study, minor procedures (e.g., core needle biopsy, superficial biopsy) within 7 days before the first dose of study drug.
• Received long term systemic steroids or other immunosuppressive therapy within 2 weeks before the first dose of study drug.
• Received any live vaccine within 4 weeks before the first dose of study drug or intend to receive a live vaccine during the study.
• Diagnosis or evidence of spinal cord compression or leptomeningeal carcinomatosis.
• Uncontrolled or clinically significant cardiovascular and cerebrovascular diseases.
• A history of non-infectious interstitial lung disease (ILD)/pneumonitis that requires steroids, current active ILD/pneumonitis.
• Have clinically severe pulmonary compromise resulting from intercurrent pulmonary illnesses.
• Uncontrolled third-space fluid that requires repeated drainage.
• Digestive system disease that may cause bleeding, perforation, jaundice, fistula, GI obstruction within 6 months prior to the first dose of study drug administration or have active inflammatory bowel disease.
• An active tuberculosis based on medical history.
• Known human immunodeficiency virus (HIV) infection.
• Active hepatitis C infection.