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

This is a multi-site, prospective, non-randomized phase 2 study evaluating neoadjuvant botensilimab in combination with balstilimab for patients with microsatellite stable (MSS) / mismatch repair proficient (MMRp) early rectal cancer staged T1-T2 N0 by MRI and considered candidates for surgical resection without standard neoadjuvant therapies. Participants will receive a single IV dose of botensilimab on Day 1 followed by balstilimab IV every 2 weeks for up to 6 months, with tumor response assessments during treatment and follow-up afterward.

NCT Number	NCT07735624
Lead Sponsor	Dana-Farber Cancer Institute Collaborators: Agenus Inc., Gateway for Cancer Research
Conditions	Early Rectal Cancer, Stage I Rectal Cancer, Microsatellite Stable Rectal Carcinoma
Enrollment	16 participants
Start Date	2026-09
Primary Completion	2027-01-01 (estimated)
Study Completion	2032-12-31 (estimated)
Updated on ClinicalTrials.gov	2026-07-30