2604.01647 ICI-COLITIS-RECHAL v1: A Transparent Pre-Validation Risk Stratification Framework for ICI Rechallenge After Grade 3+ Immune-Related Colitis
ICI-COLITIS-RECHAL v1: We present a pre-validation composite scoring framework for recurrence of grade >=2 immune-related colitis within 180 days of rechallenge in adult patients with solid tumours who experienced CTCAE grade >=3 immune-related colitis during first- or second-line ICI therapy and are being considered for rechallenge with any ICI. Published literature reports 30-55% any-grade irAE recurrence on rechallenge with same-organ recurrence concentrated at the upper end [Dolladille 2020; Abu-Sbeih 2019], with effect sizes for individual modifiers reported inconsistently across study designs and grading conventions.