XELOX Plus DoSTARlimab Versus XELOX Alone as Consolidation Treatment After Standard Chemoradiation in pMMR/MSS or MSI-Low Locally Advanced Rectal Cancer (LARC) Patients

Study Summary

This is a phase II, multicenter, randomized (2:1) controlled, clinical trial to evaluate the preliminary efficacy and safety of consolidation chemotherapy (XELOX) plus dostarlimab after standard long-course CRT (ARM A) compared to XELOX alone (ARM B) in patients with pMMR/MSS or MSI-Low LARC (cT3-4 cN0, any cT cN+) candidate to receive standard long course CRT followed by TME. After the surgery, the patients in ARM A will be randomized (1:1) to receive adjuvant dostarlimab (ARM A1) versus follow-up (ARM A2), and in ARM B only follow-up. If clinical complete responses (cCR) are documented after consolidation treatment, the patient may choose not to proceed with surgery and pursue nonoperative management (NOM).