This is a multicenter, open-label, parallel-group, randomised, A phase IIb clinical trial of efficacy and safety of Ametumumab in combination with anti-PD-1 monoclonal antibody and FOLFIRI versus Ametumumab or Cetuximab in combination with FOLFIRI in patients with RAS wild-type advanced colorectal cancer.

This is a multicenter, open-label, parallel-group, randomised, phase IIb trial. This study is to evaluate and compare the efficacy and safety of Ametumumab (anti-EGFR monoclonal antibody) combined with anti-PD-1 monoclonal antibody in first-line treatment of RAS wild-type colorectal cancer patients, as well as to assess the immunogenicity and pharmacokinetic profile and recommend dosing regimen for phase III clinical trials.Conditions and keywords.

Inclusion Criteria:

Voluntarily sign written informed consent; Age 18 ~ 85 years (inclusive), male or female;

•Patients requiring first-line treatment for locally advanced colorectal cancer with distant metastasis or unresectable disease; Histologically or cytologically confirmed adenocarcinoma of the colon or rectum; RAS (KRAS, NRAS) gene is wild-type and no BRAF V600E mutation has been identified; Presence of at least one measurable lesion (non-radiation field) confirmed by CT or MRI that meets RECIST 1.1 criteria; Performance status (ECOG) score 0 or 1.

Exclusion Criteria:

Previous chemotherapy for colorectal cancerPrevious treatment with anti-EGFR monoclonal antibodies Received systemic anti-tumor treatment approved or of other clinical studies within 4 weeks prior to the first dose.

Radiotherapy or surgery within 4 weeks prior to enrollment, except for diagnostic biopsy Participation in other clinical trials within 4 weeks prior to enrollment; Severe skin disease requiring systemic treatment. Presence of serious clinical infection.\ Uncontrolled pleural effusion, pericardial effusion or peritoneal effusion after treatment.