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.

About Korro
Korro is a biopharmaceutical company focused on developing a new class of genetic medicines for both rare and highly prevalent diseases using its proprietary RNA editing platform. Korro is generating a portfolio of differentiated programs that are designed to harness the body’s natural RNA editing process to effect a precise yet transient single base edit. By editing RNA instead of DNA, Korro is expanding the reach of genetic medicines by delivering additional precision and tunability, which has the potential for increased specificity and improved long-term tolerability. Using an oligonucleotide-based approach, Korro expects to bring its medicines to patients by leveraging its proprietary platform with precedented delivery modalities, manufacturing know-how, and established regulatory pathways of approved oligonucleotide drugs. Korro is based in Cambridge, Massachusetts. For more information, visit korrobio.com. 

Forward-Looking Statements

Certain statements in this press release may constitute “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, as amended. Forward-looking statements include, but are not limited to, express or implied statements regarding expectations, hopes, beliefs, intentions or strategies of Korro regarding the future including, without limitation, express or implied statements regarding: species translation; KRRO-110’s ability to restore protein levels, KRRO-110’s potential as an AATD treatment, and timing of Korro’s planned regulatory filing; among others. In addition, any statements that refer to projections, forecasts, or other characterizations of future events or circumstances, including any underlying assumptions, are forward-looking statements. The words “anticipate,” “believe,” “continue,” “could,” “estimate,” “expect,” “intend,” “may,” “might,” “plan,” “possible,” “potential,” “predict,” “project,” “should,” “strive,” “would,” “aim,” “target,” “commit,” and similar expressions may identify forward-looking statements, but the absence of these words does not mean that statement is not forward looking. Forward-looking statements are based on current expectations and assumptions that, while considered reasonable are inherently uncertain. New risks and uncertainties may emerge from time to time, and it is not possible to predict all risks and uncertainties. Factors that may cause actual results to differ materially from current expectations include, but are not limited to, various factors beyond management’s control including risks inherent in biopharmaceutical development; risks associated with pre-clinical studies and clinical trials; and other risks associated with obtaining regulatory approvals and protecting intellectual property; as well as risks associated with general economic conditions; and other risks and uncertainties indicated from time to time in Korro’s filings with the SEC, including Part II Item 1A. “Risk Factors” in Korro’s Quarterly Report on Form 10-Q filed with the SEC on May 14, 2024, as such may be amended or supplemented by its other filings with the SEC. Nothing in this press release should be regarded as a representation by any person that the forward-looking statements set forth herein will be achieved or that any of the contemplated results of such forward-looking statements will be achieved. You should not place undue reliance on forward-looking statements in this press release, which speak only as of the date they are made and are qualified in their entirety by reference to the cautionary statements herein. Except as required by law, Korro does not undertake or accept any duty to release publicly any updates or revisions to any forward-looking statements to reflect any change in its expectations or in the events, conditions or circumstances on which any such statement is based. This press release does not purport to summarize all of the conditions, risks and other attributes of an investment in Korro.

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