KRRO-121 - (ANCHOR)

October 5, 2026: Korro Bio (NASDAQ: KRRO) announced first dosing in the ANCHOR global Phase 1/2 trial of KRRO-121, a GalNAc-conjugated RNA-editing oligonucleotide being developed for hyperammonemia in urea cycle disorders (UCDs) and hepatic encephalopathy. The first healthy-volunteer cohort received a single 2 mg/kg dose.

ANCHOR Part 1 is a placebo-controlled Phase 1 program in healthy volunteers in Australia, including single ascending dose and multiple ascending dose cohorts, evaluating safety, tolerability, and pharmacokinetics in up to 50 participants total (up to 30 in SAD across five cohorts; up to 20 in MAD across two cohorts). Part 2 is a Phase 2 multiple-dose study in up to 15 UCD patients across all genotypes, subject to regulatory approval, to assess safety, tolerability, PK, and clinical activity.

The SAD portion started in September 2026. Korro said dosing in UCD patients is expected to begin in the first half of 2027, with an interim clinical readout expected in the second half of 2027. ClinicalTrials.gov identifier: NCT07773246.