TQB2922 Injection Given Under the Skin With Chemotherapy as Initial Treatment for Colorectal Cancer That Has Spread

This study will assess the safety and anticancer activity of TQB2922 injection given under the skin together with chemotherapy in adults with colorectal cancer that has spread, cannot be removed by surgery, and has no RAS or BRAF mutations. Participants have not received systemic treatment for advanced colorectal cancer, apart from the prior adjuvant treatment allowed by the protocol. TQB2922 is designed to block two proteins involved in cancer growth. The study tests whether adding TQB2922 to chemotherapy can improve tumor response with tolerable side effects. An initial safety stage will help select doses for further study. In the next stage, participants will be randomly assigned in a 2:1 ratio to two TQB2922 dose groups, each receiving mFOLFOX6 chemotherapy (oxaliplatin, calcium folinate, and fluorouracil). The planned TQB2922 doses are 2000 mg and 1600 mg, subject to the initial safety findings. Participants and doctors will know the treatment given. After 6 to 8 treatment cycles, maintenance treatment consists of TQB2922 and fluorouracil, with protocol-specified exceptions. Each participant may remain in the study for up to 24 months.