A Clinical Study to Evaluate the Efficacy and Safety of Envafolimab Combined With Cetuxima-βand mFOLFOX6 in Patients With MSS, RAS/BRAF Wild-Type Metastatic Colorectal Cancer (mCRC)

500 mg/m², initial intravenous infusion (IV)\>120 min, subsequent IV \>60 min , D1，every 2 weeks

a single fixed dose of 200 mg, subcutaneous injection(SC), every 2 weeks (Day 1 of each cycle \[D1\])

Oxaliplatin 85 mg/m² , IV, over 120 min, Day 1; Leucovorin 400 mg/m² (or Calcium Folinate 200 mg/m²), IV, over 120 min, D1; 5-FU 400 mg/m² , bolus injection, followed by 1200 mg/(m²·d) continuous IV for 2 days (total dose 2400 mg/m² over 46 - 48 hours)