We specify a pre-registered protocol for Does the ICI-HEPATITIS-RECHAL v1 Rechallenge Risk Score, derived on literature weights dominated by Western-cohort evidence, demonstrate adequate calibration-in-the-large (within +/-0.15) and C-statistic (>=0.
Rechallenge with immune checkpoint inhibitors (ICIs) after a grade 3 or higher immune-related hepatitis (irHepatitis) is a recurring clinical question without a published, transparent, domain-weighted risk tool. Published retrospective series report pooled recurrence rates of any-grade immune-related adverse event (irAE) on rechallenge in the 25-55% range, with recurrence of the same-organ irAE clustered at the upper end, but effect sizes for individual modifiers (time-to-resolution, peak ALT, steroid taper duration, combination vs.