Korro Presents Additional Preclinical Data for KRRO-110 at the American Thoracic Society 2024 International Conference

• KRRO-110 showed sustained editing efficiency of approximately 60% and increased total alpha-1 antitrypsin (AAT) protein levels to greater than 60uM at week 13 in an in vivo genetic Alpha-1 Antitrypsin Deficiency (AATD) mouse model
  
• KRRO-110 showed 35µM of M-AAT one week post the first dose, with 0µM of M-AAT at baseline, increasing to 45µM of M-AAT at week 13

CAMBRIDGE, Mass., May 20, 2024 (GLOBE NEWSWIRE) --  Korro Bio, Inc. (Korro) (Nasdaq: KRRO), a biopharmaceutical company focused on developing a new class of genetic medicines for both rare and highly prevalent diseases, is presenting new preclinical data demonstrating the specificity and the completion of a genetic mouse study and sustained editing activity for KRRO-110, its development candidate for the treatment of AATD.

New data for KRRO-110 shows approximately 60% editing efficiency and greater than 60µM total AAT (45µM M-AAT) protein at week 13, while previous data showed efficacy up to week 9. In addition, data included in the poster shows the utility of a non-human primate surrogate test article that further supports species translation toward human dose projections. The data are being presented today from 11:30 AM to 1:15 PM PT in a poster at the American Thoracic Society (ATS) 2024 International Conference, taking place May 17-22, 2024, in San Diego.

“The latest data from our preclinical study demonstrates KRRO-110 has the potential to restore AAT protein levels well beyond the minimum threshold considered to have an impact for patients,” said Steve Colletti, Ph.D., Chief Scientific Officer of Korro. “The new data at week 13 provides further support for the potential of KRRO-110 to be a best-in-class therapeutic for the treatment of AATD.”

Korro remains on track to submit a regulatory filing for a first-in-human study of KRRO-110 in AATD patients anticipated in the second half of 2024.

ATS Preclinical Data Presentation:
“KRRO-110, an RNA Editing Oligonucleotide Encapsulated in a Lipid Nanoparticle (LNP) Delivered to Liver Cells for the Treatment of Alpha-1 Antitrypsin Deficiency (AATD)”
Abstract number: P1299
Presentation location and time: San Diego Convention Center, Area K (Hall H, Ground Level); Monday, May 20 from 11:30 AM - 1:15 PM PT

About AATD
AATD is an inherited, autosomal recessive genetic disorder that is most frequently caused by a single nucleotide variant (SNV) mutation in the SERPINA1 gene, the most common of which is the “PiZ” mutation. Greater than 95% of severe clinical cases are homozygous for the PiZ mutation (known as the PiZZ genotype). AATD can lead to severe progressive lung disease, including emphysema and chronic obstructive pulmonary disease (COPD), and liver disease. There are an estimated 3.4 million individuals with deficiency allele combinations worldwide. The only current FDA-approved treatment for AATD in lung disease is augmentation therapy, a once-weekly infusion of pooled human plasma-derived AAT protein, which does not adequately address the manifestations of AATD.