Recent Updates — KRRO
Korro Bio announced best-in-class preclinical results for KRRO-111, a development candidate targeting Alpha-1 Antitrypsin Deficiency (AATD). In mouse models, the therapy achieved greater than 95% SERPINA1 mRNA editing and restored circulating functional M-AAT levels by approximately six-fold. It also reduced pathogenic hepatic Z-AAT accumulation by up to 95%, demonstrating potential to address both liver and lung manifestations of the disease. The company expects to submit regulatory filings for KRRO-111 in the first half of 2027. Korro Bio is a clinical-stage biopharmaceutical company developing genetic medicines using its OPERA RNA editing platform.
Korro Bio announced the dosing of the first cohort of healthy volunteers in its ANCHOR Phase 1/2 clinical trial for KRRO-121, a GalNAc-conjugated RNA-editing oligonucleotide. The single ascending dose study is enrolling up to 30 participants across five cohorts to evaluate safety and pharmacokinetics. Dosing of patients with urea cycle disorders is expected to begin in the first half of 2027, with interim results anticipated in the second half of that year. Korro Bio operates as a clinical-stage biopharmaceutical company developing genetic medicines using its proprietary RNA editing platform.
On August 19, 2026, Korro Bio announced the submission of an application to the Australian Alfred Health Human Ethics Committee to initiate a first-in-human Phase 1/2 clinical trial for KRRO-121. This GalNAc-conjugated RNA editing oligonucleotide is in development for the potential treatment of hyperammonemia in patients with Urea Cycle Disorders (UCDs). The trial aims to determine safety, tolerability, pharmacokinetics, and efficacy in healthy volunteers and participants with UCDs under ClinicalTrials.gov identifier NCT 07773246. Korro Bio operates as a biopharmaceutical company focused on developing genetic medicines.
Korro Bio reported a net loss of $18.9 million for the quarter ended June 30, 2026, compared to $25.8 million in the prior year period. The company ended the quarter with $137.9 million in cash and marketable securities, providing a runway into the second half of 2028. Korro received Orphan Drug Designation from the European Medicines Agency for KRRO-121 to treat urea cycle disorders and nominated KRRO-111 as a development candidate for Alpha-1 Antitrypsin Deficiency, with preclinical data showing over 90% editing of pathogenic transcripts. Additionally, Korro entered into an exchange agreement with VenRock Healthcare Capital Partners on August 5, 2026, whereby VenRock surrendered 1,000,000 shares for no consideration in exchange for pre-funded warrants to purchase 1,000,000 shares at $0.001 per share exercise price with no expiration date. Following the transaction, Korro had 13,725,646 common shares outstanding and unexercised pre-funded warrants for an additional 4,148,836 shares. Korro Bio is a biopharmaceutical company developing genetic medicines using its proprietary RNA editing platform.