This prospective, single-arm study aims to investigate the efficacy and safety of pembrolizumab plus bevacizumab and chemotherapy as neoadjuvant treatment in pMMR/MSS locally advanced rectal cancer patients
Histologically confirmed rectal adenocarcinoma with cT3+N+M0
Immunohistochemistry and/or genetic testing confirmed pMMR/MSS
Initial diagnosed or recurrent patients will be accepted, patients with recurrence should not have received any treatment include chemotherapy, targeted therapy or immunotherapy within 1 month or radiotherapy within 1 year
Measurable disease according to the Response Evaluation Criteria In Solid Tumors (RECIST) 1.1 criteria and haven't received any local treatment.
Previously received anti-PD1 or anti-PDL1 or anti-PDL2 or anti-CTLA4.
Uncontrolled active bleeding from the primary tumor or intestinal obstruction.
Contraindications of bevacizumab
Hypersensitivity to other monoclonal antibodies.