Phase II study of preoperative (PREOP) chemoradiotherapy (CTRT) plus avelumab (AVE) in patients (PTS) with locally advanced rectal cancer (LARC): The AVANA study.

3511 Background: Preop CTRT is considered the standard of care in the management of LARC. RT can induce antigen release from a low neoantigen-burden tumor (such as a mismatch repair proficient colorectal cancer) and activate dendritic cells leading to a CD8+ T lymphocyte-mediated anticancer immune response. In LARC patients, neoadjuvant CTRT increases PD-L1 expression in tumor cells, strongly suggesting a neoadjuvant combinatory strategy with RT...