GRWD5769, a first-in-class oral ERAP1 inhibitor, paired with cemiplimab generated durable responses across six completed phase 1b expansion cohorts in patients with secondary resistance to anti–PD-1 therapy and in MSS-CRC, according to interim results from the EMITT-1 program. In the fully recruited study (n=81) with median follow-up of 6.0 months, reported ORR ranged from 10% to 33% and durable clinical benefit (DCB) from 26% to 57%. Median PFS varied by cohort from 1.9 to 7.5 months, and the combination was described as well tolerated with no observed safety signals. Translational analyses suggested immune remodeling via alternating antigen repertoires, including increased TCR repertoire diversity among responders and gene-expression signals consistent with antigen-driven T-cell remodelling. Stage 2 expansions are ongoing to support a planned randomized phase 2 study.