This study is a single-arm, prospective, phase II clinical study to evaluate the efficacy and safety of preoperative short-course radiotherapy combined with ivonescimab and chemotherapy + total mesorectal excision(TME) surgery in patients with advanced rectal cancer.
ECOG score of 0-1;
histologically or cytologically confirmed colorectal adenocarcinoma with non-distant metastasis
Tumor distance from anal verge ≦10cm
at least one high-risk criterion defined by pelvic MRI: cT stage >T2 (tumor invades intrinsic muscularis propria by more than 5 mm); Extramural vascular invasion; cN2; Involvement of the rectal mesorectal fascia (tumor or lymph node ≤1mm from the rectal mesorectal fascia); Lateral lymph node short diameter ≥5mm
with known MSI-H or dMMR
Multiple primary adenocarcinomas
History of pelvic radiotherapy
Previous immunotherapy, including immune checkpoint inhibitors (e.g., anti-PD-1 antibody, anti-PD-L1 antibody, anti-CTLA-4 antibody, etc.), immune checkpoint agonists (e.g., ICOS, CD40, CD137, GITR, OX40 antibody, etc.), immunocellular therapy, and other treatments targeting the immune mechanism of the tumor.