Cetuximab plus irinotecan, fluorouracil, and leucovorin (FOLFIRI) represents a first-line therapeutic standard for RAS/BRAF wild-type metastatic colorectal cancer (mCRC) patients. Despite this established approach, cetuximab β (CMAB009), as a modified antibody of cetuximab, prospectively selected for dual RAS/BRAF wild-type patients, has not yet been validated in the Chinese mCRC patients through phase 3 trial...This study demonstrated that cetuximab β plus FOLFIRI provided significant clinical benefits as a first-line treatment for patients with RAS/BRAF wild-type mCRC. Compared to FOLFIRI alone, cetuximab β plus FOLFIRI therapy led to prolonged median PFS and OS while maintaining a manageable safety profile, offering a new treatment option for this patient population.