Korro Bio Reports Preclinical KRRO-111 Data Showing Up to 95% Liver Z-AAT Reduction in AATD
KRRO sits 80% above its 52-week low of $5.204.
Summary
Korro Bio released preclinical data for KRRO-111 in alpha-1 antitrypsin deficiency, including >95% SERPINA1 editing and up to 95% reduction of toxic Z-AAT in mouse models, with a regulatory submission targeted for the first half of 2027.
Key Events · Product Development and Regulatory · KRRO
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KRRO-111 Preclinical Data Released
Repeat-dose mouse studies achieved >95% SERPINA1 mRNA editing with sustained restoration of functional M-AAT and total AAT up ~6-fold versus vehicle.
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Liver Z-AAT Cut Up to 95%
In immunocompetent C57BL/6-PiZ mice, KRRO-111 reduced whole liver Z-AAT by 95% relative to vehicle at Day 57, targeting the liver manifestation of AATD.
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Submission Targeted for 1H 2027
Korro expects a regulatory submission for KRRO-111 in the first half of 2027, with the program positioned to enter the clinic alongside lead candidate KRRO-121.
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Mouse Data, Human Risk Unproven
The filing states preclinical results in animal models may not be predictive of results in humans, and no head-to-head comparisons support the best-in-class claim.
Analysis · KRRO · Life Sciences
Korro's second pipeline program, KRRO-111 for alpha-1 antitrypsin deficiency, produced preclinical results the company calls best-in-class: >95% SERPINA1 mRNA editing, ~6-fold higher total AAT, and up to 95% reduction of the toxic Z-AAT protein that drives liver injury. That dual lung-and-liver profile is the commercial pitch, since the only approved AATD therapy is a weekly plasma infusion that addresses the lung side only. The company now points to a regulatory submission in the first half of 2027, which would put KRRO-111 in the clinic alongside lead candidate KRRO-121. The caveat is that this is mouse data, and the filing itself flags that animal results may not predict human results. With $137.9M in cash and runway into 2H 2028 as of the last 10-Q, this readout broadens the pipeline story rather than changing the funding picture.
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At the time of this filing, KRRO was trading at $9.35 on NASDAQ in the Life Sciences sector, with a market capitalization of approximately $136.8M. The 52-week trading range was $5.20 to $46.28. This filing was assessed with positive market sentiment and an importance score of 7 out of 10.