A Phase III study of perioperative dostarlimab in patients with dMMR/MSI-H resectable colon cancer: AZUR-2 study design.

The role of perioperative immunotherapy as a chemotherapy-free option for patients with resectable mismatch repair-deficient/microsatellite instability-high (dMMR/MSI-H) colon cancer is evolving, with early-phase neoadjuvant studies reporting favorable long-term outcomes. AZUR-2 is an ongoing global, Phase III, open-label, randomized study evaluating the efficacy of perioperative dostarlimab monotherapy compared with standard of care (SoC) (adjuvant chemotherapy or surveillance) in adult patients with previously untreated, pathologically confirmed, radiologically evaluable T4N0 or Stage III resectable dMMR/MSIH colon adenocarcinoma. Patients will be randomized 2:1 to receive neoadjuvant dostarlimab 500 mg every 3 weeks (4 cycles), followed by surgery, then adjuvant dostarlimab 1000 mg every 6 weeks (6 cycles), or to receive immediate surgery followed by SoC. The primary endpoint is event-free survival assessed by blinded independent central review. The key secondary endpoint is overall survival; additional secondary endpoints include pathological response assessed by residual viable tumor determined by local assessment, safety, and tolerability. NCT05855200 (www.clinicaltrials.gov).