Breakthrough Therapy designation granted for LX2006 based on interim data from Phase I/II trials demonstrating clinically meaningful improvements in cardiac and neurologic measures of Friedreich ataxia LX2006 selected for FDA Chemistry, Manufacturing, and Controls Development and Readiness Pilot (CDRP) program, created to facilitate CMC registrational readiness and support faster patient access Eight participants dosed in Phase I/II clinical trial (HEROIC-PKP2) of LX2020 for PKP2-ACM; interim clinical data update on track for second half of 2025 Strategic partnership announced with Perceptive Xontogeny Venture Funds and venBio Partners to advance non-viral, RNA-based therapeutics for genetic cardiac diseases $80 million equity financing to support development of clinical stage pipeline; cash, cash equivalents and investments in marketable securities of $152.5 million expected to provide operational runway into 2028 Louis Tamayo appointed Chief Financial Officer NEW YORK, Aug. 14, 2025 (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 second quarter 2025 financial results. “Over the last several months, Lexeo has made significant progress advancing our clinical stage programs, diversifying our pipeline through a strategic partnership that we believe enables us to stay on the cusp of leading-edge cardiovascular science, and further strengthening our balance sheet,” said R. Nolan Townsend, Chief Executive Officer of Lexeo Therapeutics. “FDA Breakthrough Therapy designation for LX2006 underscores the potential of this gene therapy candidate, and we are moving as quickly as possible in close partnership with patient advocates, clinicians, and the FA community to initiate a registrational study early next year. We are also continuing to advance our LX2020 program for arrhythmogenic cardiomyopathy with eight participants dosed to date and data updates expected in the second half of this year.” Business and Program Updates LX2006 in Friedreich Ataxia (FA): Regulatory Updates: In July 2025, Lexeo received Breakthrough Therapy designation from the U.S. Food and Drug Administration (FDA) for LX2006 based on interim clinical data demonstrating clinically meaningful improvements in cardiac and neurologic measures of FA. LX2006 has also been selected to participate in the FDA Chemistry, Manufacturing, and Controls (CMC) Development Readiness Pilot (CDRP) program, created to accelerate CMC registrational readiness for therapies with expedited clinical development timelines. Lexeo expects final alignment with FDA on the LX2006 registrational study in late Q3 to early Q4 2025.Natural History: The CLARITY-FA natural history study is currently enrolling and is expected to serve as a concurrent external control arm for the planned registrational study.Safety: LX2006 continues to be generally well tolerated with no clinically significant complement activation, and no new treatment-related serious adverse events to report.Next Steps: Lexeo expects to initiate a registrational study in early 2026 with a potential efficacy readout in 2027. LX2020 in PKP2-ACM: Dosing Update: Eight participants have been dosed to date in the HEROIC-PKP2 Phase I/II clinical trial, including three participants in Cohort 1 at the low dose (2×1013 vg/kg), three participants in Cohort 2 at the high dose (6×1013 vg/kg), and two participants in dose-expansion Cohort 3 at the high dose (6×1013 vg/kg). Cohort 3 is still enrolling and up to two additional participants may be dosed in this cohort.Safety: LX2020 has been generally well tolerated with no clinically significant complement activation, and no treatment-related serious adverse events to date across all dose cohorts.Next Steps: Lexeo expects to share an interim clinical data update in the second half of 2025. Closed $80 Million Equity Financing: In May 2025, Lexeo announced the closing of an $80 million equity financing to further advance development of its clinical stage genetic medicine candidates. Lexeo anticipates that current cash, cash equivalents and marketable securities will be sufficient to fund operating and capital expenditures into 2028, through a potential efficacy readout for the registrational study of LX2006 in 2027. Research Collaboration with Perceptive Xontogeny Venture Funds and venBio Partners: In June 2025, Lexeo announced a strategic partnership to develop therapies for genetic cardiac diseases utilizing a novel non-viral RNA platform. PXV Funds and venBio will contribute up to $40 million in private equity financing to a new entity addressing cardiac genetic diseases that existing AAV platforms are unable to treat. Lexeo is contributing expertise and know-how in cardiac genetic medicines, preclinical intellectual property and technology to the partnership, with a double-digit percentage equity position in the new entity at transaction close alongside entitlement to future milestone payments, royalties, and opt-in rights to certain program(s). New Leadership Appointment: Lexeo announced today that Louis Tamayo has been appointed Chief Financial Officer. Mr. Tamayo succeeds Kyle Rasbach who remains an advisor to Lexeo. Mr. Tamayo will support Lexeo’s late-stage clinical and commercialization plans as LX2006 development accelerates and LX2020 development continues, alongside strategic planning, portfolio management, capital allocation, and other financial operations. Mr. Tamayo brings extensive commercial finance experience, having previously served as Senior Vice President at Siemens Healthineers AG, responsible for driving revenue growth and market expansion for the company’s $5 billion global diagnostics division. In this role, he built and led high-performing finance organizations that supported multiple global product launches and strategic partnerships, directed R&D capital allocation, and oversaw large-scale transformation initiatives. Prior to Siemens Healthineers, Mr. Tamayo was the Business Unit CFO for Becton, Dickinson and Company’s $1.2 billion global diabetes care business. Mr. Tamayo began his career at Pfizer where he held a series of financial, strategic, and analytical leadership roles across U.S. and international markets. Mr. Tamayo holds a BBA in Finance and Marketing from Northeastern University. Recent Data Presentations: Lexeo presented new data at the 28th American Society of Gene & Cell Therapy (ASGCT) Annual Meeting on AAV manufacturing optimization via the Company’s Sf9-baculovirus process. Data presentations reviewed the high purity and potency of Lexeo yields with improved scalability of production and reduced cost. Lexeo also presented data at the Global Cell and Gene Therapy Summit reviewing the favorable complement profile of AAVrh10 based on clinical monitoring experience across the three gene therapy studies in FA and PKP2 in which no clinically significant events related to complement activation have been observed to date. Second Quarter Financial Results Cash Position: As of June 30, 2025, cash, cash equivalents, and investments in marketable securities were $152.5 million, which Lexeo believes will be sufficient to fund operations into 2028. Research and Development Expenses: Research and Development expenses were $14.7 million for the three months ended June 30, 2025, compared to $16.6 million for the three months ended June 30, 2024. General and Administrative Expenses: General and Administrative expenses were $16.0 million for the three months ended June 30, 2025, compared to $7.0 million for the three months ended June 30, 2024. Net Loss: Net loss was $26.1 million or $0.60 per share (basic and diluted) for the three months ended June 30, 2025, compared to $21.2 million or $0.64 per share (basic and diluted) for the three months ended June 30, 2024. About Lexeo TherapeuticsLexeo Therapeutics is a New York City-based, clinical stage genetic medicine company dedicated to reshaping heart health by applying pioneering science to fundamentally change how cardiovascular diseases are treated. The Company is advancing a portfolio of therapeutic candidates that take aim at the underlying genetic causes of conditions, including LX2006 in Friedreich ataxia (FA) cardiomyopathy, LX2020 in plakophilin-2 (PKP2) arrhythmogenic cardiomyopathy, and others in devastating diseases with high unmet need. Cautionary Note Regarding Forward-Looking StatementsCertain statements in this press release may constitute “forward-looking statements” within the meaning of the federal securities laws, including, but not limited to, Lexeo’s expectations and plans regarding its current product candidates and programs and the timing for receipt and announcement of data from its clinical trials, the timing and likelihood of potential regulatory developments and approval, expectations regarding the time period over which Lexeo’s capital resources will be sufficient to fund its anticipated operations and estimates regarding Lexeo’s financial condition. Words such as “may,” “might,” “will,” “objective,” “intend,” “should,” “could,” “can,” “would,” “expect,” “believe,” “design,” “estimate,” “predict,” “potential,” “develop,” “plan” or the negative of these terms, and similar expressions, or statements regarding intent, belief, or current expectations, are forward-looking statements. While Lexeo believes these forward-looking statements are reasonable, undue reliance should not be placed on any such forward-looking statements. These forward-looking statements are based upon current information available to the company as well as certain estimates and assumptions and are subject to various risks and uncertainties (including, without limitation, those set forth in Lexeo’s filings with the U.S. Securities and Exchange Commission (SEC)), many of which are beyond the company’s control and subject to change. Actual results could be materially different from those indicated by such forward-looking statements as a result of many factors, including but not limited to: risks and uncertainties related to global macroeconomic conditions and related volatility; expectations regarding the initiation, progress, and expected results of Lexeo’s preclinical studies, clinical trials and research and development programs; the unpredictable relationship between preclinical study results and clinical study results; delays in submission of regulatory filings or failure to receive regulatory approval; liquidity and capital resources; and other risks and uncertainties identified in Lexeo’s Quarterly Report on Form 10-Q for the quarterly period ended March 31, 2025, filed with the SEC on May 12, 2025, and subsequent future filings Lexeo may make with the SEC. New risks and uncertainties may emerge from time to time, and it is not possible to predict all risks and uncertainties. Lexeo claims the protection of the Safe Harbor contained in the Private Securities Litigation Reform Act of 1995 for forward-looking statements. Lexeo expressly disclaims any obligation to update or alter any statements whether as a result of new information, future events or otherwise, except as required by law. Media Response:Media@lexeotx.com Investor Response:Carlo Tanzi, Ph.D.ctanzi@kendallir.com Lexeo Therapeutics, Inc.Selected Financial Information(Unaudited, in thousands, except share and per share amounts)  Condensed Statements of Operations  Three Months Ended June 30, Six Months Ended June 30,  2025 2024 2025 2024 Operating expenses                 Research and development$14,721  $16,560  $31,892  $32,302   General and administrative 15,967   6,990   32,601   14,539          Total operating expenses 30,688   23,550   64,493   46,841  Operating loss (30,688)  (23,550)  (64,493)  (46,841) Other income and expense                 Gain on long-term investment 3,390   –   3,390   –   Other income (expense), net (14)  (1)  (18)  (6)  Interest expense (25)  (35)  (53)  (72)  Interest income 1,268   2,348   2,461   3,999   Amortization of premium on investments (34)  –   (46)  –          Total other income and expense 4,585   2,312   5,734   3,921  Loss from operations before income taxes (26,103)  (21,238)  (58,759)  (42,920)  Income taxes –   –   –   –  Net loss$(26,103) $(21,238) $(58,759) $(42,920) Net loss per common share, basic and diluted$(0.60) $(0.64) $(1.53) $(1.41) Weighted average number of shares outstanding used incomputation of net loss per common share, basic and diluted 43,573,628   33,001,946   38,372,704   30,490,892    Condensed Balance Sheet Data  June 30,2025 December 31,2024 Cash, cash equivalents, and investments in marketable securities$152,506 $128,530 Total assets 176,068  146,942 Total liabilities 37,850  30,100 Total stockholders’ equity 138,218  116,842 

Cash runway extended into 2028; capital proceeds to fund operations through potential 2027 efficacy readout for LX2006 in Friedreich ataxia cardiomyopathy Financing led by Frazier Life Sciences and Janus Henderson Investors with participation from new and existing investors NEW YORK, May 27, 2025 (GLOBE NEWSWIRE) — Lexeo Therapeutics, Inc. (Nasdaq: LXEO), a clinical stage genetic medicine company dedicated to pioneering novel treatments for cardiovascular diseases, today announced it has entered into a securities purchase agreement with a select group of institutional and healthcare accredited investors to issue and sell an aggregate of 20,790,120 shares (“Shares”) of its common stock (“Common Stock”) or, in lieu thereof, to certain investors, pre-funded warrants (“Pre-Funded Warrants”) to purchase 6,963,556 shares of Common Stock, in a private placement. Each full Share (or Pre-Funded Warrant in lieu thereof) will be accompanied by a warrant (a “Common Warrant”) to purchase one-half of a share of Common Stock. The purchase price for each Share and accompanying Common Warrant will be $2.8825 (or $2.8824 for each Pre-Funded Warrant and accompanying Common Warrant). Lexeo anticipates the gross proceeds from the private placement to be approximately $80 million, before deducting any offering related expenses. The private placement is expected to close on May 28, 2025, subject to customary closing conditions. The Pre-Funded Warrants will have an exercise price of $0.0001 per share until exercised in full, and the Common Warrants will have an exercise price of $2.82 per share and expire on May 28, 2029. The private placement was co-led by Frazier Life Sciences and Janus Henderson Investors with participation from new and existing investors, including Adar1 Capital Management, Affinity Healthcare Fund, LP, Ally Bridge Group, Coastlands Capital, Surveyor Capital (a Citadel company), Vestal Point Capital, and Woodline Partners LP. “This financing will enable Lexeo to build on its leadership in cardiac genetic medicines as we continue to advance our clinical stage pipeline,” said R. Nolan Townsend, Chief Executive Officer of Lexeo Therapeutics. “With the support of an exceptional group of new and existing long-term investors, we believe we remain well-positioned to accelerate development of our programs and drive innovation with next-generation therapies that could redefine the treatment paradigm for devastating cardiovascular conditions.” J.P. Morgan and Oppenheimer & Co. acted as co-lead placement agents for the transaction. Baird also acted as placement agent. Lexeo intends to use net proceeds from the private placement to fund advancement of ongoing clinical stage programs, and for working capital and general corporate purposes. The proceeds from this private placement, combined with current cash, cash equivalents and marketable securities are expected to fund Lexeo’s operating and capital expenditures into 2028. The securities to be sold in this private placement have not been registered under the Securities Act of 1933, as amended (the “Securities Act”), or any state or other applicable jurisdiction’s securities laws and may not be offered or sold in the United States absent registration or an applicable exemption from the registration requirements of the Securities Act and applicable state or other jurisdictions’ securities laws. Concurrently with the execution of the securities purchase agreement, Lexeo and the investors entered into a registration rights agreement pursuant to which the company has agreed to file a registration statement with the U.S. Securities and Exchange Commission (the “SEC”) registering the resale of the Shares and Common Stock underlying the Pre-Funded Warrants and Common Warrants(together, the “Warrant Shares”) sold in the private placement. Any offering of the Shares and Warrant Shares under the resale registration statement will only be made by means of a prospectus. This press release shall not constitute an offer to sell or a solicitation of an offer to buy the Company’s securities, nor shall there be any offer, solicitation, or sale of the Company’s securities in any jurisdiction in which such offer, solicitation or sale would be unlawful. The private placement is being conducted in accordance with applicable Nasdaq rules and was priced to satisfy the “Minimum Price” requirement (as defined in the Nasdaq rules). About Lexeo TherapeuticsLexeo Therapeutics is a New York City-based, clinical stage genetic medicine company dedicated to reshaping heart health by applying pioneering science to fundamentally change how cardiovascular diseases are treated. The Company is advancing a portfolio of therapeutic candidates that take aim at the underlying genetic causes of conditions, including LX2006 for the treatment of Friedreich ataxia (FA) cardiomyopathy, LX2020 for the treatment of plakophilin-2 (PKP2) arrhythmogenic cardiomyopathy, and others for devastating diseases with high unmet need. Cautionary Note Regarding Forward-Looking StatementsCertain statements in this press release may constitute “forward-looking statements” within the meaning of the federal securities laws, including, but not limited to, statements regarding the expected closing of the private placement, anticipated receipt, impact and use of proceeds from the private placement, whether the conditions for the closing of the private placement will be satisfied, the filing of a registration statement or final prospectus, as applicable, to register the resale of the Shares and Warrant Shares to be issued and sold in the private placement, the anticipated cash runway following closing of the private placement , and other information that is not historical information. Words such as “may,” “might,” “will,” “objective,” “intend,” “should,” “could,” “can,” “would,” “expect,” “believe,” “design,” “estimate,” “predict,” “potential,” “develop,” “plan” or the negative of these terms, and similar expressions, or statements regarding intent, belief, or current expectations, are forward-looking statements. While Lexeo believes these forward-looking statements are reasonable, undue reliance should not be placed on any such forward-looking statements. These forward-looking statements are based upon current information available to the company as well as certain estimates and assumptions and are subject to various risks and uncertainties (including, without limitation, those set forth in Lexeo’s filings with the SEC), many of which are beyond the company’s control and subject to change. Actual results could be materially different from those indicated by such forward-looking statements as a result of many factors, including but not limited to: risks and uncertainties related to global macroeconomic conditions and related volatility; expectations regarding the initiation, progress, and expected results of Lexeo’s preclinical studies, clinical trials and research and development programs; the unpredictable relationship between preclinical study results and clinical study results; delays in submission of regulatory filings or failure to receive regulatory approval; liquidity and capital resources; and other risks and uncertainties identified in Lexeo’s Annual Report on Form 10-K for the annual period ended December 31, 2024, filed with the SEC on March 24, 2025, Quarterly Report on Form 10-Q for the quarterly period ended March 31, 2025, filed with the SEC on May 12, 2025, as amended, and subsequent future filings Lexeo may make with the SEC. New risks and uncertainties may emerge from time to time, and it is not possible to predict all risks and uncertainties. Lexeo claims the protection of the safe harbor contained in the Private Securities Litigation Reform Act of 1995 for forward-looking statements. Lexeo expressly disclaims any obligation to update or alter any statements whether as a result of new information, future events or otherwise, except as required by law. Media Response:Media@lexeotx.com Investor Response:Carlo Tanzi, Ph.D.ctanzi@kendallir.com

Additional alignment with FDA on LX2006 planned pivotal study including protein expression co-primary endpoint: based on improvements in LVMI across participants with abnormal LVMI at baseline, frataxin expression to be evaluated for any increase from baseline rather than numerical threshold Interim update from cohort 1 of LX2020 HEROIC-PKP2 Phase 1/2 trial: observed 71% and 115% increases in PKP2 protein expression in first two post-treatment biopsies; first participant evaluated 6-months after dosing experienced 67% reduction in premature ventricular contractions (PVCs) Completed enrollment of cohort 2 of LX2020 HEROIC-PKP2 Phase 1/2 trial; interim clinical data update expected in second half of 2025 LX2020 has been generally well tolerated with no treatment-related serious adverse events to date Cash, cash equivalents and investments of $128.5 million expected to provide operational runway into 2027 NEW YORK, March 24, 2025 (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 fourth quarter and full year 2024 financial results. “We are pleased to share further regulatory clarity for LX2006 for the treatment of Friedreich ataxia (FA) cardiomyopathy, and we appreciate the continued partnership from the FDA on an accelerated approval pathway to support adults and children living with this devastating condition,” said R. Nolan Townsend, Chief Executive Officer of Lexeo Therapeutics. “We are also encouraged by the favorable safety profile and early data observed in participants dosed with LX2020 to date. We look forward to sharing additional clinical updates later in 2025 now that the second cohort of the LX2020 HEROIC-PKP2 Phase 1/2 trial in arrhythmogenic cardiomyopathy is fully enrolled.” Business and Program UpdatesLX2006 for the Treatment of FA Cardiomyopathy: Regulatory Update: Further alignment on elements of the accelerated development pathway following a Type B RMAT meeting with the U.S. Food and Drug Administration (FDA): Frataxin expression to be evaluated for any increase from baseline rather than numerical threshold, based on improvements to date in LVMI across participants with abnormal LVMI at baselineInclusion of pediatric cohorts, both adolescents and children, in planned pivotal studyUse of prospective natural history data as external control in planned pivotal studyFinal dose selection and remaining elements of registrational trial alignment expected in 2025 In light of these regulatory updates and anticipated timelines for assay validation, the Company expects to measure frataxin protein expression using liquid chromatography mass spectrometry (LCMS) in the planned registrational trial. Mid-Year Clinical Update Expected to Include: Safety and tolerability data for all participants dosed across both the SUNRISE-FA and Weill Cornell clinical trials (at least 16 participants, including 6 participants with abnormal LVMI at baseline)Pre- and post-treatment cardiac frataxin protein expression measured via LCMS for all four participants at the highest dose (1.2×1012 vg/kg, Cohort 3)Clinical biomarker data, including left ventricular mass index (LVMI), left ventricular wall thickness and high-sensitivity troponin I, for participants with >6-months of follow upFunctional and patient-reported outcome data for participants with >6-months of follow up Safety: LX2006 continues to be generally well tolerated with no new treatment-related serious adverse events to report LX2020 for the Treatment of PKP2-ACM: Cohort 1 Interim Update: Post-treatment cardiac biopsies from two participants in cohort 1 showed increases in PKP2 protein expression from baseline; the third cohort 1 participant elected not to undergo a post-treatment biopsy Observed increases in exogenous mRNA and 71% and 115% increases in PKP2 protein levels from baselineFirst participant evaluated 6-months post treatment experienced 67% reduction in PVCs from baseline (from 861 to 284) and resolution of non-specific intraventricular block (normalization of QRS duration) Enrollment Update: Completed enrollment of cohort 2 of LX2020 HEROIC-PKP2 (n=3), interim clinical data update expected in second half of 2025Safety: LX2020 has been generally well tolerated with no treatment-related serious adverse events to date across both dose cohortsRegulatory Update: In March 2025 the European Commission granted orphan medicinal product designation for LX2020 for the treatment of PKP2-ACM Fourth Quarter and Full Year Financial Results Cash Position: As of December 31, 2024, cash, cash equivalents, and investments were $128.5 million, which Lexeo believes will be sufficient to fund operations into 2027.R&D Expenses: R&D expenses were $18.4 million for the three months ended December 31, 2024, compared to $8.2 million for the three months ended December 31, 2023. R&D expenses were $74.1 million for the year ended December 31, 2024, compared to $53.1 million for the year ended December 31, 2023.G&A Expenses: G&A expenses were $9.0 million for the three months ended December 31, 2024, compared to $6.8 million for the three months ended December 31, 2023. G&A expenses were $31.7 million for the year ended December 31, 2024, compared to $15.4 million for the year ended December 31, 2023.Net Loss: Net loss was $25.9 million or $0.78 per share (basic and diluted) for the three months ended December 31, 2024, compared to $14.2 million or $0.86 per share (basic and diluted) for the three months ended December 31, 2023. Net loss was $98.3 million or $3.09 per share (basic and diluted) for the year ended December 31, 2024, compared to $66.4 million or $12.40 per share (basic and diluted) for the year ended December 31, 2023. About Lexeo TherapeuticsLexeo Therapeutics is a New York City-based, clinical stage genetic medicine company dedicated to reshaping heart health by applying pioneering science to fundamentally change how cardiovascular diseases are treated. The Company is advancing a portfolio of therapeutic candidates that take aim at the underlying genetic causes of conditions, including LX2006 for the treatment of Friedreich ataxia (FA) cardiomyopathy, LX2020 for the treatment of plakophilin-2 (PKP2) arrhythmogenic cardiomyopathy, and other devastating diseases with high unmet need. Cautionary Note Regarding Forward-Looking StatementsCertain statements in this press release may constitute “forward-looking statements” within the meaning of the federal securities laws, including, but not limited to, Lexeo’s expectations and plans regarding its current product candidates and programs and the timing for receipt and announcement of data from its clinical trials, the timing and likelihood of potential regulatory approval, and expectations regarding the time period over which Lexeo’s capital resources will be sufficient to fund its anticipated operations and estimates regarding Lexeo’s financial condition. Words such as “may,” “might,” “will,” “objective,” “intend,” “should,” “could,” “can,” “would,” “expect,” “believe,” “design,” “estimate,” “predict,” “potential,” “develop,” “plan” or the negative of these terms, and similar expressions, or statements regarding intent, belief, or current expectations, are forward-looking statements. While Lexeo believes these forward-looking statements are reasonable, undue reliance should not be placed on any such forward-looking statements. These forward-looking statements are based upon current information available to the company as well as certain estimates and assumptions and are subject to various risks and uncertainties (including, without limitation, those set forth in Lexeo’s filings with the U.S. Securities and Exchange Commission (SEC)), many of which are beyond the company’s control and subject to change. Actual results could be materially different from those indicated by such forward-looking statements as a result of many factors, including but not limited to: risks and uncertainties related to global macroeconomic conditions and related volatility; expectations regarding the initiation, progress, and expected results of Lexeo’s preclinical studies, clinical trials and research and development programs; the unpredictable relationship between preclinical study results and clinical study results; delays in submission of regulatory filings or failure to receive regulatory approval; liquidity and capital resources; and other risks and uncertainties identified in Lexeo’s Annual Report on Form 10-K for the annual period ended December 31, 2023, filed with the SEC on March 11, 2024, Quarterly Report on Form 10-Q for the quarterly period ended September 30, 2024, filed with the SEC on November 13, 2024, and subsequent future filings Lexeo may make with the SEC. Additional information will also be set forth in Lexeo’s Annual Report on Form 10-K for the year ended December 31, 2024. New risks and uncertainties may emerge from time to time, and it is not possible to predict all risks and uncertainties. Lexeo claims the protection of the Safe Harbor contained in the Private Securities Litigation Reform Act of 1995 for forward-looking statements. Lexeo expressly disclaims any obligation to update or alter any statements whether as a result of new information, future events or otherwise, except as required by law. Media Response:Media@lexeotx.com Investor Response:Carlo Tanzi, Ph.D.ctanzi@kendallir.com Lexeo Therapeutics, Inc.Selected Financial Information(in thousands, except share and per share amounts) Statements of Operations  Three Months Ended December 31,  Year Ended December 31,  2024  2023  2024  2023  (unaudited)  (unaudited)       Operating expenses           Research and development$18,366  $8,210  $74,091  $53,130 General and administrative 9,016   6,764   31,675   15,383 Total operating expenses 27,382   14,974   105,766   68,513 Operating loss (27,382)  (14,974)  (105,766)  (68,513)Other income and expense           Loss on fair value adjustment to convertible SAFE Note –   (258)  –   (530)Other income (expense), net –   (8)  (9)  (13)Interest expense (30)  (51)  (137)  (205)Interest income 1,465   1,103   7,556   2,867 Accretion of discount on investments 23   –   23   – Total other income and expense 1,458   786   7,433   2,119 Loss from operations before income taxes (25,924)  (14,188)  (98,333)  (66,394)Income taxes –   –   –   – Net loss$(25,924) $(14,188) $(98,333) $(66,394)Net loss per common share, basic and diluted$(0.78) $(0.86) $(3.09) $(12.40)Weighted average number of shares outstanding used in computation of net loss per common share, basic and diluted 33,076,094   16,438,237   31,787,491   5,354,368  Balance Sheet Data   December 31,  December 31,   2024  2023 Cash, cash equivalents, and investments $128,530  $121,466 Total assets  146,942   139,807 Total liabilities  30,100   26,272 Total stockholders’ equity  116,842   113,535 

Announced positive interim data from Phase 1/2 studies in Friedreich ataxia (FA) cardiomyopathy, which showed LX2006 was well tolerated with no treatment-related serious adverse events and demonstrated evidence of sustained and consistent treatment effect across multiple cardiac measures

NEW YORK, Aug. 28, 2023 (GLOBE NEWSWIRE) — LEXEO Therapeutics (LEXEO), a clinical-stage gene therapy company advancing gene therapy candidates for genetically defined cardiovascular diseases and a genetically defined sub-group of Alzheimer’s disease, today announced a strategic investment from Sarepta Therapeutics, Inc. (Sarepta) to support the advancement of LEXEO’s adeno-associated virus (AAV) […]

Eric Adler, M.D., joins LEXEO as Chief Scientific Officer New Scientific Advisory Board comprised of molecular cardiology, cardiovascular imaging, cardiac gene-editing, and RNA biology experts NEW YORK, Nov. 02, 2022 (GLOBE NEWSWIRE) — LEXEO Therapeutics, Inc. (LEXEO), a clinical-stage biotech company advancing a pipeline of adeno-associated virus (AAV)-based gene therapy candidates […]