A Phase Ib/II Study of SYS6090 Combination Therapy in Advanced Colorectal Cancer

This study constitutes an open-label, multi-cohort, multi-center Phase Ib/II clinical study, developed to assess the safety, tolerability, and therapeutic efficacy of SYS6090 injection when administered in combination with bevacizumab, or in triple combination with bevacizumab and chemotherapy, among patients diagnosed with advanced colorectal cancer.

\*Eligibility Criteria: Inclusion Criteria: 1. Subjects must be ≥18 years of age. 2. Histologically or cytologically confirmed unresectable advanced or metastatic colorectal cancer with pMMR/MSS status, assigned to corresponding cohorts as follows: Cohort 1 (2L/3L) of Phase Ib \& Phase II: Subjects must have disease progression after no more than 2 lines of standard systemic therapy (prior regimens must contain fluoropyrimidine-, oxaliplatin-, and irinotecan-based chemotherapy); tumor tissue confirmed as pMMR by IHC or MSS by NGS/PCR; Cohort 2 (1L) of Phase Ib \& Phase II: Subjects have received no prior systemic anti-tumor therapy for advanced disease; tumor tissue confirmed as pMMR by IHC or MSS by NGS/PCR. 3. At least one extracranial measurable lesion at baseline according to RECIST 1.1 criteria. 4. Eastern Cooperative Oncology Group performance status of 0 or 1. 5. Expected survival ≥ 3 months. 6. Has protocol-defined adequate organ and bone marrow function. Exclusion Criteria: 1. Subjects with clinically active central nervous system metastases; 2. with a history of other primary malignant tumors within 5 years before administration; 3. Subjects assigned to Cohort 1 who have received prior regorafenib treatment.; 4. Prior documented interstitial lung disease (ILD)/ pneumonitis that required steroids, current ILD/ pneumonitis, or suspected ILD/ pneumonitis that cannot be ruled out by imaging at screening; 5. Uncontrolled or significant cardiovascular disease; 6. Clinically uncontrolled pleural effusion, ascites or pericardial effusion; 7. Has unresolved toxicities from previous anticancer therapy, defined as toxicities not yet resolved to Grade ≤ 1 or baseline .