A Phase I/II Clinical Study to Evaluate the Safety and Efficacy of RCZY690 in Advanced Solid Tumors

Inclusion Criteria: 1. Voluntarily participate in this study, sign the informed consent form, and be able to comply with the study protocol. 2. Age between 18 and 75 years inclusive. 3. ECOG performance status of 0 or 1. 4. Expected survival ≥ 12 weeks. 5. At least one measurable target lesion based on imaging assessment per RECIST version 1.1 criteria. 6. Adequate bone marrow, hepatic, renal and coagulation function. Exclusion Criteria: 1. Female participants who are pregnant, lactating, or planning to become pregnant. 2. Participants with brain metastases. 3. History of severe bleeding tendency or coagulation dysfunction. 4. Toxicities from prior anti-tumor therapy have not recovered to Grade 1 per NCI-CTCAE version 6.0. 5. Known hypersensitivity or delayed-type allergic reaction to any components of the investigational drug or similar agents. 6. Any condition that impairs the participant's ability to swallow study medication, or conditions judged by the investigator to significantly affect study drug absorption. 7. Participants with acute, chronic or symptomatic infection. 8. Uncontrolled cardiovascular disease. 9. Participants with confirmed or suspected interstitial lung disease (ILD), drug-related pneumonitis or other pulmonary diseases. 10. History of liver cirrhosis (Child-Pugh Class B or C). 11. Active inflammatory bowel disease. 12. Participants with uncontrolled diabetes (HbA1c ≥10%). 13. Arterial or venous thromboembolic events within 6 months prior to the first study drug administration. 14. Pericardial effusion, cardiac tamponade, or third-space effusions (including massive pleural effusion or ascites) that cannot be stably controlled by drainage or other measures as judged by the investigator. 15. Active autoimmune disease requiring systemic therapy within the past 2 years. 16. History of other invasive malignancies within 5 years prior to first dose, or any evidence of residual disease from previously diagnosed malignancy. 17. History of acquired or congenital immunodeficiency disorders, or history of organ transplantation. 18. Past or current poorly controlled psychiatric disorders. 19. Poor compliance, and participants who are expected to be unable to comply with study procedures.