LXEO

EX-99.1

2 lxeo-ex99_1.htm

EX-99.1

EX-99.1

Exhibit 99.1

Lexeo Therapeutics Reports First Quarter 2026 Financial Results and Operational Highlights

SUNRISE-FA2 open-label, pivotal trial protocol and SAP for LX2006 submitted to FDA in Q1 2026; Awaiting final FDA feedback

Multiple presentations highlighting progress across cardiac genetic medicine pipeline and optimized, Sf9-baculovirus AAV manufacturing platform to be presented at ASGCT 2026

Appointed Laura Sepp-Lorenzino, Ph.D. to Board of Directors

Cash, cash equivalents and investments of $227.6 million expected to provide operational runway into 2028

NEW YORK – May 11, 2026 (GLOBE NEWSWIRE) – Lexeo Therapeutics, Inc. (Nasdaq: LXEO), a clinical stage genetic medicine company dedicated to pioneering novel treatments for cardiovascular diseases, today provided business updates across its portfolio and reported financial results for the first quarter 2026.

“We continued to make steady progress across our key priorities in the first quarter of 2026. As we work with the FDA to finalize the SUNRISE‑FA 2 pivotal study protocol, we are advancing site readiness and patient identification activities to ensure we are prepared to initiate the study promptly once the protocol is complete,” said R. Nolan Townsend, Chief Executive Officer of Lexeo Therapeutics. “We will also have a meaningful scientific presence at ASGCT this week, where we will share updates from our LX2006 program as well as new preclinical data for LX2022. We remain committed to advancing our pipeline toward meaningful therapies for patients and look forward to providing further updates as our programs continue to progress.”

Program Updates and Recent Progress

LX2006 in Friedreich Ataxia (FA)

• In May 2026, Lexeo will share multiple presentations on LX2006 at the 29th American Society of Gene and Cell Therapies (ASGCT) Annual Meeting:

o Phase I/II interim clinical data of LX2006 continue to show sustained or deepening improvements across both cardiac and neurologic measures of FA, including statistically significant improvement in mean mFARS scores for LX2006-treated participants compared to a propensity-matched control cohort from the UNIFAI natural history study (n=17; p=0.003). LX2006 remains generally well tolerated with no Grade 3+ SAEs to date.

o Nonhuman primate research with LX2006 conducted by researchers at Weill Cornell Medicine demonstrates the potential of sequential dosing strategies to treat FA. Eight weeks following systemic intravenous administration of LX2006, nonhuman primates were administered LX2006 directly to the cerebellum or cerebral spinal fluid (CSF), and potentially therapeutic levels of cerebellar vector genome copies were detected via both routes of administration despite pre-existing immunity to the therapeutic vector.

o CMC comparability data for LX2006 between adherent HEK293 and Sf9 baculovirus suspension processes was shared, highlighting Lexeo’s optimized manufacturing platform that can maintain purity and potency while significantly improving scalability of production and reducing cost.

• In February 2026, Lexeo submitted the final registrational trial design and statistical analysis plan (SAP) for the SUNRISE‑FA 2 pivotal study to the FDA following a Type B meeting. The company is in contact with the FDA and is awaiting final feedback on the study protocol. Lexeo plans to provide an update when the protocol and SAP are finalized.

• Anticipated milestones for the remainder of 2026 include:

o FDA feedback on protocol submission expected in Q2 2026

o Initiation of SUNRISE-FA 2 pivotal trial in Q2 2026

LX2020 in PKP2 Arrhythmogenic Cardiomyopathy (PKP2-ACM)

• In January 2026, Lexeo reported positive interim clinical data from the HEROIC PKP2 Phase I/II clinical trial evaluating LX2020. LX2020 remains generally well tolerated across ten participants dosed with no clinically significant complement activation to date.

• Anticipated milestones for the remainder of 2026 include:

o 12-month data update for all high dose participants in Q4 2026

o Regulatory engagement with the FDA expected in 2026

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Pre-Clinical Assets

• In May 2026, Lexeo will present preclinical data for LX2022 at the ASGCT Annual Meeting, demonstrating proof‑of‑concept efficacy for TNNI3 replacement in a newly developed porcine model of hypertrophic cardiomyopathy. This novel model closely recapitulates severe disease physiology and mortality and was specifically developed by Lexeo to evaluate TNNI3‑targeted therapies. TNNI3‑related disease is estimated to account for approximately 1-3% of genetic cardiomyopathies.

Corporate Updates

• Appointed Laura Sepp Lorenzino, Ph.D., as an independent, non-executive director to the Board of Directors. Laura was the former Chief Scientific Officer at Intellia Therapeutics and previously held senior research leadership roles at Alnylam Pharmaceuticals and Vertex Pharmaceuticals. She currently serves on the boards of AskBio, Taysha Gene Ther

EX-99.1

2 lxeo-ex99_1.htm

EX-99.1

EX-99.1

Exhibit 99.1

Lexeo Therapeutics Reports Fourth Quarter and Full Year 2025 Financial Results and Operational Highlights

SUNRISE-FA 2 open-label, pivotal trial protocol and SAP for LX2006 submitted to FDA in Q1 2026 following

Type B meeting; study initiation on track for 1H 2026

First CMC Development and Readiness Program (CDRP) meeting for LX2006 in Q1 2026; aligned with FDA on flexible approach to process validation such as reduced PPQ manufacturing batches

Late-breaking oral presentations at the American College of Cardiology (ACC) Annual Meeting demonstrate continued, encouraging efficacy and safety data across LX2006 and LX2020 programs

Established research collaboration with Johnson & Johnson to explore targeted cardiac delivery of AAV gene therapy using novel, localized routes of administration

Strengthened leadership team with addition of new Chief Medical Officer and senior appointments bolstering cardiac expertise

Cash, cash equivalents and investments of $246.6 million expected to provide operational runway into 2028

NEW YORK – March 30, 2026 (GLOBE NEWSWIRE) – Lexeo Therapeutics, Inc. (Nasdaq: LXEO), a clinical stage genetic medicine company dedicated to pioneering novel treatments for cardiovascular diseases, today provided business updates across its portfolio and reported financial results for the fourth quarter and full year 2025.

“Over the past year we have made meaningful progress across our cardiac pipeline, including significant advancements for both LX2006 and LX2020,” said R. Nolan Townsend, Chief Executive Officer of Lexeo Therapeutics. “Most recently, we were pleased to be selected for two Late-Breaker presentations at the American College of Cardiology and appreciate the opportunity to engage the cardiology community around the future of precision medicine in cardiovascular care. Looking ahead, we remain focused on disciplined execution as we continue to advance our pipeline toward key milestones. With additional resources from our October financing, the expansion of our cardiac leadership team, and multiple announced preclinical research collaborations, we believe Lexeo is well positioned to drive significant long-term value for patients and shareholders.”

Program Updates and Recent Progress

LX2006 in Friedreich Ataxia (FA)

• In October 2025, Lexeo announced progress in FDA discussions and reported positive interim clinical data from both ongoing Phase I/II studies of LX2006 demonstrating an encouraging safety profile and evidence of meaningful cardiac and functional benefit. LX2006 was generally well tolerated and associated with improvements in cardiac structure, biomarkers, and functional outcomes, including reduced left ventricular mass index (LVMI) and improved modified Friedreich Ataxia Rating Scale (mFARS) scores across participants with more than six months of follow‑up.

• In November 2025, FDA approved the analytical comparability report establishing comparability between LX2006 HEK293 and Sf9 manufacturing processes, endorsing use of the optimized, Sf9 final commercial manufacturing process for LX2006 in the planned pivotal study and clearing comparability requirements to begin dosing patients.

• In February 2026, Lexeo submitted the final registrational trial design and statistical analysis plan (SAP) for the SUNRISE‑FA 2 pivotal study to the FDA following a Type B meeting. The proposed open-label study is generally consistent with previously communicated guidance on key design elements, such as study size, duration, patient population, and the LVMI primary endpoint, and incorporates FDA feedback on minimizing bias, including physician selection bias of study participants. Lexeo expects to receive final feedback from the FDA in the second quarter of 2026 and plans to provide a more detailed update at that time.

• In March 2026, Lexeo conducted an initial Chemistry, Manufacturing and Controls (CMC) Development and Readiness Program (CDRP) meeting with the FDA for LX2006, during which the agency reiterated its support for a flexible validation approach including potential for reduced process performance qualification (PPQ) runs and concurrent process validation. Lexeo is proceeding with validation and commercial manufacturing readiness activities to support the Biologic License Application (BLA) submission for LX2006.

• In March 2026, Lexeo shared updated interim clinical data for LX2006 at the ACC Annual Meeting.

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o Phase I/II interim clinical data continue to show sustained or deepening improvements across both cardiac and neurologic measures of FA, including statistically significant improvement in mean mFARS scores for LX2006-treated participants compared to a propensity-matched control cohort from the UNIFAI natural history study.

o LX2006 remains generally well tolerated with no Grade 3+ SAEs to date.

• Anticipated milestones for the remainder of 2026 include:

o FDA feedback on protocol submission expec

8-K

0001907108false00019071082025-11-052025-11-05

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): November 05, 2025

Lexeo Therapeutics, Inc. (Exact name of Registrant as Specified in Its Charter)

Delaware

001-41855

85-4012572

(State or Other Jurisdiction of Incorporation)

(Commission File Number)

(IRS Employer Identification No.)

345 Park Avenue South, Floor 6

New York, New York

10010

(Address of Principal Executive Offices)

(Zip Code)

Registrant’s Telephone Number, Including Area Code: 212 547-9879

N/A

(Former Name or Former Address, if Changed Since Last Report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Securities registered pursuant to Section 12(b) of the Act:

Title of each class

Trading Symbol(s)

Name of each exchange on which registered

Common Stock, $0.0001 par value per share

LXEO

Nasdaq Global Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter). Emerging growth company ☒ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02 Results of Operations and Financial Condition.

On November 5, 2025, Lexeo Therapeutics, Inc. (the “Company”) issued a press release announcing business highlights and its financial results for the three and nine months ended September 30, 2025. A copy of this press release is furnished herewith as Exhibit 99.1 to this Current Report and is incorporated herein by reference.

The information in this Item 2.02 and Exhibit 99.1 hereto shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any of the Company’s filings under the Securities Act of 1933, as amended, or the Exchange Act, whether made before or after the date hereof, except as expressly set forth by specific reference in such a filing.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits

Exhibit Number

Description

99.1

Press Release

104

Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

Lexeo Therapeutics, Inc.

Date:

November 5, 2025

By:

/s/ R. Nolan Townsend

R. Nolan Townsend, Chief Executive Officer