REM-422 MYB mRNA Degrader Hits 42% ORR at RP2D in MYB+ ACC

REM-422 is a first-in-class oral small-molecule MYB mRNA degrader tested in recurrent/metastatic adenoid cystic carcinoma in the Phase 1/2 ARIA trial (NCT06118086). Among efficacy-evaluable patients (n=59), activity concentrated in the retrospectively defined MYB-transcript-positive group; at the 24 mg RP2D, 3/7 biomarker-positive patients had PRs (ORR 42%), with responses emerging at 4–8 months and lasting up to 12 months and ongoing. RP2D safety was mostly low-grade, with epistaxis 60%, fatigue 60%, anemia 40%, all grade 1–2, and no DLTs, comparing favorably with VEGFR TKI toxicity in ACC.