Neoadjuvant chemoradiotherapy plus sintilimab in proficient mismatch repair locally advanced rectal cancer with intermediate/high-immunoscore (SILAR): a single-arm phase II trial.

ABSTRACT: There is an urgent need to identify those who may benefit from immunotherapy-based chemoradiotherapy (CRT) for patients with locally advanced rectal cancer (LARC) with proficient mismatch repair (pMMR). This single-arm, phase-II trial (NCT05450029), enrolled 46 treatment-naïve patients with histologically confirmed T_3-4N₀M₀ or T_1-4N₊M₀ LARC with intermediate or high Immunoscore. Patients received 6 cycles of mFOLFOX6 and long-course radiotherapy (50 Gy in 25 fractions) followed by surgery. Sintilimab was added during CRT (2nd-6th cycle). The primary endpoint, pathologic complete response (pCR) rate, was 65.2% [30/46, 95%CI: 49.7-78.6], with 85.7% (6/7) in high and 61.5% (24/39) in intermediate Immunoscore, meeting the pre-sp

SUBMITTER: Zheng X 

PROVIDER: S-EPMC12824280 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature