RECTIFY-1: Neoadjuvant Botensilimab + Balstilimab in MSS/pMMR Early Rectal Cancer

Inclusion Criteria: * Histologically confirmed diagnosis of early-rectal cancer clinically staged T1-T2 N0 M0 by MRI (American Joint Committee on Cancer (AJCC) staging 8th edition, 2017). * The tumor must confirmed to be MSS/MMRp by local testing. * The tumor must be evaluable by endoscopy. * Voluntarily agree to participate by giving signed, dated, and written informed consent prior to any study-specific procedures. * Age ≥ 18 years of age. Because no dosing or adverse event data are currently available on the use of botensilimab with balstilimab in participants \< 18 years of age, children are excluded from this study. * Measurable rectal primary on baseline imaging by MRI. The tumor must be definitively at least T1. * Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1. * Adequate organ function defined as the following laboratory values within 7 days of Cycle 1 Day 1 (C1D1): * Neutrophils ≥ 1500/μL (Must be stable and off any growth factor within 4 weeks of first study treatment administration). * Platelets ≥ 50× 103/μL. * Hemoglobin ≥ 8.0 g/dL (transfusion to achieve this level is not permitted within 2 weeks of first study treatment administration). * Creatinine clearance ≥ 30 mL/min as measured or calculated per local institutional standards. * Aspartate aminotransferase/alanine aminotransferase ≤ 1.5 × upper limit of normal (ULN). * Total bilirubin ≤ 1.5 × ULN (except patients with Gilbert syndrome who must have a total bilirubin level…