Korro Bio is a preclinical-stage biopharmaceutical company developing RNA editing therapies. Rather than permanently altering DNA like gene therapy or CRISPR, Korro Bio's platform makes precise, reversible edits at the RNA level using the body's own ADAR enzyme. Because RNA edits naturally decay over time, the approach is transient — allowing physicians to adjust or stop dosing — which Korro Bio argues makes it safer and more broadly applicable than DNA editing. Korro Bio's proprietary OPERA platform delivers short synthetic oligonucleotides to target tissues, recruiting endogenous ADAR to make single-letter RNA changes that alter the resulting protein. The company uses GalNAc conjugation for subcutaneous delivery to the liver, a clinically validated approach already used in approved drugs. Korro Bio has four programs: its lead, KRRO-121, targets hyperammonemia in urea cycle disorders and hepatic encephalopathy; a second program targets alpha-1 antitrypsin deficiency; and two early-stage programs target liver metabolic health and ALS, respectively. Korro Bio has no approved products and no product revenue. The company funds operations through equity financing and a collaboration with Novo Nordisk, which covers up to two cardiometabolic programs and provides research cost reimbursement plus potential milestones and royalties. Long-term, Korro Bio aims to either commercialize drugs independently or partner with larger pharmaceutical companies. Manufacturing is fully outsourced to CMOs.