NEW YORK, Dec. 19, 2024 (GLOBE NEWSWIRE) — Lexeo Therapeutics, Inc. (Nasdaq: LXEO), a clinical stage genetic medicine company dedicated to pioneering treatments for genetically defined cardiovascular diseases and APOE4-associated Alzheimer’s disease, today announced that Dr. Kyle Rasbach has been appointed Chief Financial Officer, effective immediately. Dr. Rasbach brings a wealth of life sciences experience to the company and joins ahead of multiple anticipated catalysts across its gene therapy programs. “Kyle has an exceptional track record as an operator and life sciences portfolio manager, and we are excited to welcome him to Lexeo at a time when we are advancing our pipeline and transitioning towards pivotal studies,” said R. Nolan Townsend, Chief Executive Officer of Lexeo Therapeutics. “His experience in strategic planning, financial management and business development, combined with his scientific background, will complement our management team and support Lexeo’s continued growth into 2025.” Most recently, Dr. Rasbach served as the Chief Business Officer at Zentalis Pharmaceuticals. Before Zentalis, he was a Portfolio Manager for Eventide Asset Management’s $1.8 billion healthcare & life sciences fund, a Managing Director for Eventide Ventures, and a Senior Research Analyst for other Eventide investments. Prior to joining Eventide, Dr. Rasbach was a Managing Partner at Pappas Capital, a life science venture capital firm. Earlier in his career, he was an equity research analyst and Vice President at T. Rowe Price, where he managed pharmaceutical, specialty pharmaceutical, and biotechnology investments representing over $40 billion in assets under management, and an equity research associate and Vice President at Cowen and Company, where he covered global pharmaceutical equities. “With several meaningful catalysts ahead, I am thrilled to join Lexeo at this pivotal point in the company’s growth trajectory,” said Dr. Rasbach. “Lexeo has a robust and compelling pipeline alongside outstanding talent, and I look forward to delivering on our mission of bringing life-changing therapies to patients with devastating genetic conditions.” Dr. Rasbach holds a PhD in Pharmaceutical and Biomedical Sciences as well as a PharmD from the Medical University of South Carolina, and he completed his postdoctoral training in the laboratory of Dr. Bruce Spiegelman at the Harvard Medical School. He also holds an MBA from The Citadel. About Lexeo Therapeutics  Lexeo Therapeutics is a New York City-based, clinical stage genetic medicine company dedicated to transforming healthcare by applying pioneering science to fundamentally change how genetically defined cardiovascular diseases and APOE4-associated Alzheimer’s disease are treated. Using a stepwise development approach, Lexeo is leveraging early proof-of-concept functional and biomarker data to advance a pipeline of cardiovascular and APOE4-associated Alzheimer’s disease programs. 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 regarding its current product candidates and programs, and the receipt and announcement of data from its clinical trials. 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. 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:Media@lexeotx.com Investors:Carlo Tanzi, Ph.D.ctanzi@kendallir.com

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

Lexeo extends runway into 2027 with private placement co-led by Braidwell LP and Adage Capital Partners LP with participation from new and existing investors including RA Capital Management, Surveyor Capital (a Citadel company), Eventide Asset Management, Novo Holdings A/S, Invus, Laurion Capital Management, Longitude Capital, Omega Funds and Woodline Partners LPNEW YORK, March 13, 2024 (GLOBE NEWSWIRE) — Lexeo Therapeutics, Inc. (Nasdaq: LXEO), a clinical stage genetic medicine company dedicated to pioneering treatments for genetically defined cardiovascular diseases and APOE4-associated Alzheimer’s disease, today announced the closing of its previously announced private placement. The financing was co-led by Braidwell LP and Adage Capital Partners LP with participation from new and existing investors including RA Capital Management, Surveyor Capital (a Citadel company), Eventide Asset Management, Novo Holdings A/S, Invus, Laurion Capital Management, Longitude Capital, Omega Funds and Woodline Partners LP for total gross proceeds of approximately $95.0 million. Lexeo sold 6,278,905 shares of its common stock (“Common Stock”) in a private placement exempt from the registration requirements of the Securities Act of 1933, as amended (the “Securities Act”), at a sale price equal to $15.13 per share. J.P. Morgan and Leerink Partners acted as co-lead placement agents for the transaction. Stifel also acted as co-placement agent. Lexeo intends to use net proceeds from the financing to fund advancement of ongoing clinical stage programs, and for working capital and general corporate purposes. The proceeds from this financing, combined with current cash, cash equivalents and marketable securities, are expected to fund operating and capital expenditures into 2027. The common stock sold in the private placement has not been registered under 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. In connection with the private placement, Lexeo and the investors entered into a registration rights agreement pursuant to which Lexeo will file a registration statement (the “Resale Registration Statement”) with the U.S. Securities and Exchange Commission (the “SEC”) registering the resale of the shares sold in the private placement. Any offering of the shares sold in the private placement 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 Common Stock, nor shall there be any offer, solicitation, or sale of the Company’s Common Stock in any jurisdiction in which such offer, solicitation or sale would be unlawful. The private placement was conducted in accordance with applicable Nasdaq rules and was priced to satisfy the “Minimum Price” requirement (as defined in the Nasdaq rules). About Lexeo Therapeutics  Lexeo Therapeutics is a New York City-based, clinical stage genetic medicine company dedicated to transforming healthcare by applying pioneering science to fundamentally change how genetically defined cardiovascular diseases and APOE4-associated Alzheimer’s disease are treated. Using a stepwise development approach, Lexeo is leveraging early proof-of-concept functional and biomarker data to advance a pipeline of cardiovascular and APOE4-associated Alzheimer’s disease programs. 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, our expectations and plans regarding our current product candidates and programs, including statements regarding the anticipated use of proceeds from the private placement, the filing of a registration statement or final prospectus, as applicable, to register the resale of the shares of Common Stock issued and sold in the private placement, the Company’s anticipated cash runway, 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, including the anticipated closing of the private placement and anticipated runway extension; 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, 2023, 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:Janine Bogris (201) 245-6838 janine.bogris@inizioevoke.com Investor Response:Laurence Watts(619) 916-7620laurence@gilmartinir.com

Lexeo announces $95.0M equity financing, which in addition to 2023 year-end cash and cash equivalents of $121.5M, extends runway to fund operations into 2027 Reports frataxin protein expression data from a subset of the second dose cohort of SUNRISE-FA, a Phase 1/2 clinical trial of LX2006 for the treatment of Friedreich’s ataxia (FA) cardiomyopathy, showing positive change in post-treatment frataxin levels Additional interim data readout from SUNRISE-FA expected in mid-2024, with follow-up out to one year from the low-dose and multiple time points of follow-up expected from at least three patients treated at the mid-dose Initiated SNAPSHOT-PKP2, a natural history study designed to evaluate PKP2-ACM disease progression up to two years retrospectively and over twelve months prospectively, in up to 20 patients in the U.S. All milestones for LX2020 remain on track NEW YORK, March 11, 2024 (GLOBE NEWSWIRE) — Lexeo Therapeutics, Inc. (Nasdaq: LXEO), a clinical stage genetic medicine company dedicated to pioneering treatments for genetically defined cardiovascular diseases and APOE4-associated Alzheimer’s disease, today reported fourth quarter and full year 2023 financial results and provided operational highlights. “The past year has been transformative for Lexeo as we successfully completed our initial public offering and continued to advance our pipeline of genetic medicines,” stated R. Nolan Townsend, Chief Executive Officer of Lexeo Therapeutics. “Building on our success in 2023, we are pleased to report that we have observed a positive change in frataxin levels now in Cohort 2 of the SUNRISE-FA trial. The low baseline protein levels observed in these patients provide unique insights into the biology of FA and we believe the increases in post treatment protein expression mediated by LX2006 may be sufficient to restore mitochondrial function with physiological improvement. These data, combined with our recent financing and progress across our pipeline, reflect exciting developments and add to our track record of clinical execution.” SUNRISE-FA Liquid Chromatography Mass Spectrometry (LCMS) Assay Protein Expression Data SubjectPre-Treatment FXN Levels (ng/mg protein)Post-Treatment FXNLevels (ng/mg protein)Change fromBaseline (ng/mg protein)Cohort 1 Subject 1 (1.8×1011 vg/kg)0.750.970.22Cohort 2 Subject 1 (5.6×1011 vg/kg)0.972.771.81Cohort 2 Subject 2 (5.6×1011 vg/kg)1.832.230.40 Note: Only one patient in Cohort 1 underwent pre and post treatment cardiac biopsy. Average pre-treatment FXN level across three subjects was 1.18ng/mg. Compared to FXN levels observed in 29 cadaver tissue samples from 16 individuals without heart disease, we believe the average pre-treatment FXN level represents approximately two percent of healthy individual frataxin levels in the heart.To our knowledge, SUNRISE-FA is the first clinical trial to evaluate frataxin levels in the target organ of FA cardiomyopathy patients via cardiac biopsy. Data to date suggest that FA patients may have lower FXN levels in the heart versus peripheral tissues.Across all three cardiac biopsies, we observed an increase in FXN levels as measured by liquid chromatography mass spectrometry relative to pre-treatment baseline levels.We observed an approximately five-fold increase in protein on average in the second cohort (5.6×1011 vg/kg) to date, relative to the first cohort (1.8×1011 vg/kg). A dose-dependent response was also seen in our IND-enabling preclinical studies, where a non-linear relationship was observed between dose delivered and frataxin protein expression. Lexeo expects to present additional interim data from SUNRISE-FA Cohorts 1 and 2 in mid-2024, including measures of hypertrophy and other cardiac biomarkers at multiple timepoints(1). Ahead of this interim readout, Lexeo expects to provide an analysis of baseline characteristics from LX2006-treated patients to characterize the cardiovascular disease phenotype seen in FA as well as baseline levels of hypertrophy and other cardiac biomarkers that will be reported at mid-year. ____________(1)  Trial participants receive immune suppression with prednisone beginning on the day prior to treatment/infusion through 14 weeks following LX2006 administration. Given the potential impact of corticosteroids on systemic status and cardiac biomarkers, efficacy data in the mid-2024 data readout will be presented for timepoints following cessation of corticosteroid administration. Business and Program Updates LX2006 for the Treatment of FA Cardiomyopathy: Announced preliminary frataxin protein expression data from the second dose cohort of SUNRISE-FA showing positive change in post-treatment frataxin levels three months following administration of LX2006. Lexeo expects to report additional interim data from the SUNRISE-FA Phase 1/2 clinical trial in mid-2024 with follow-up out to one year from the low-dose and multiple timepoints of follow-up expected from at least three patients treated at the mid-dose.LX2020 for the Treatment of PKP2-ACM: In December 2023, the FDA granted Fast Track designation (FTD) and Orphan Drug designation (ODD) to LX2020, which allows more frequent interactions with FDA to facilitate development and expedite review processes. The ODD also provides additional benefits to Lexeo, such as market exclusivity upon regulatory approval. Clinical trial start-up activities are underway and Lexeo expects to dose the first patient in the HEROIC-PKP2 Phase 1/2 clinical trial of LX2020 in 1H 2024, with an interim data readout from Cohort 1 expected in 2H 2024. Lexeo has also initiated SNAPSHOT-PKP2, a natural history study designed to evaluate PKP2-ACM disease progression up to two years retrospectively and over twelve months prospectively in up to 20 patients in the United States.APOE4-associated Alzheimer’s Disease Programs: Lexeo completed enrollment of all four cohorts in the LEAD Phase 1/2 clinical trial of LX1001 for the treatment of APOE4-associated Alzheimer’s disease in Q4 2023. The Company expects to provide an interim data readout of all cohorts in 2H 2024.Pricing of $95 Million Equity Financing: Lexeo today announced that it has entered into a common stock purchase agreement with certain new and existing investors to issue and sell an aggregate of 6,278,905 shares of its common stock at a price of $15.13 per share, through a private placement. Lexeo anticipates the gross proceeds from the private placement to be approximately $95.0 million, before deducting any offering related expenses. The financing is expected to close on or about March 13, 2024, subject to customary closing conditions. The proceeds from this financing, combined with current cash, cash equivalents and marketable securities, are expected to fund operating and capital expenditures into 2027.Completed Initial Public Offering: In November 2023, Lexeo completed its underwritten initial public offering of 10,139,656 shares of its common stock, including the exercise of the underwriter’s option to purchase 1,048,746 additional shares of its common stock. The aggregate gross proceeds from the offering were $111.5 million, before deducting underwriting discounts and commissions and offering expenses payable by Lexeo. Expected Upcoming Milestones LX2006 for the treatment of Friedreich’s ataxia cardiomyopathy Interim data readout in mid-2024 LX2020 for the treatment of PKP2-ACM First patient dosed in 1H 2024Interim data readout (Cohort 1) in 2H 2024 LX1001 for the treatment of APOE4-associated Alzheimer’s disease Interim Phase 1/2 data readout (all cohorts) in 2H 2024 LX2021 for the treatment of DSP cardiomyopathy Initiate IND-enabling studies in 2024 Fourth Quarter and Full Year Financial Results Cash Position: As of December 31, 2023, cash and cash equivalents were $121.5 million, excluding the $95.0 million gross proceeds expected to be raised in the private placement announced today. Lexeo expects the additional funds raised in the financing to extend its runway into 2027.R&D Expenses: R&D expenses were $8.2 million for the three months ended December 31, 2023, compared to $11.4 million for the three months ended December 31, 2022. Research and Development expenses were $53.1 million for the year ended December 31, 2023, compared to $49.2 million for the same period in 2022.G&A Expenses: G&A expenses were $6.8 million for the three months ended December 31, 2023, compared to $3.8 million for the three months ended December 31, 2022. G&A expenses were $15.4 million for the year ended December 31, 2023, compared to $12.0 million for the same period in 2022.Net Loss: Net loss was $14.2 million or $0.86 per share (basic and diluted) for the three months ended December 31, 2023, compared to $14.6 million or $8.86 per share (basic and diluted) for the three months ended December 31, 2022. Net loss was $66.4 million or $12.40 per share (basic and diluted) for the year ended December 31, 2023, compared to $59.3 million or $36.36 per share (basic and diluted) for the year ended December 31, 2022. About Lexeo Therapeutics Lexeo Therapeutics is a New York City-based, clinical stage genetic medicine company dedicated to transforming healthcare by applying pioneering science to fundamentally change how genetically defined cardiovascular diseases and APOE4-associated Alzheimer’s disease are treated. Using a stepwise development approach, Lexeo is leveraging early proof-of-concept functional and biomarker data to advance a pipeline of cardiovascular and APOE4-associated Alzheimer’s disease programs. Forward looking Statements Certain statements in this press release may constitute “forward-looking statements” within the meaning of the federal securities laws, including, but not limited to, our expectations and plans regarding our current product candidates and programs, including the anticipated timing of the initiation of and results from our clinical trials, expectations regarding the time period over which our capital resources will be sufficient to fund our 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 (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 our 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, including the anticipated closing of the private placement and anticipated runway extension; and other risks and uncertainties identified in our Quarterly Report of 10-Q for the quarterly period ended September 30, 2023, filed with the SEC on December 11, 2023, and subsequent future filings we 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: Carolyn Hawley (619) 849-5382 Carolyn.hawley@inizioevoke.com Investor Response: Laurence Watts (619) 916-7620 laurence@gilmartinir.com   Lexeo Therapeutics, Inc. Selected Condensed Financial Information (unaudited, in thousands, except share and per share amounts)   Condensed Consolidated Statements of Operations     Three Months Ended December 31,  Year Ended December 31,   2023  2022  2023  2022 Revenue            Grant revenue $-  $-  $-  $654 Total revenue  –   –   –   654 Operating expenses            Research and development  8,210   11,437   53,130   49,162 General and administrative  6,764   3,760   15,383   12,001 Total operating expenses  14,974   15,197   68,513   61,163 Operating loss  (14,974)  (15,197)  (68,513)  (60,509)Other income and expense            Loss on fair value adjustment to convertible SAFE Note  (258)  –   (530)  – Other income (expense), net  (8)  (1)  (13)  (2)Interest expense  (51)  (54)  (205)  (91)Interest income  1,103   675   2,867   1,325 Total other income and expense  786   620   2,119   1,232 Loss from operations before income taxes  (14,188)  (14,577)  (66,394)  (59,277)Income taxes  –   –   –   – Net loss and comprehensive loss $(14,188) $(14,577) $(66,394) $(59,277)             Net loss per common share, basic and diluted $(0.86) $(8.86) $(12.40) $(36.36)             Weighted average number of shares outstanding used in computation of net loss per common share, basic and diluted  16,438,237   1,644,403   5,354,368   1,630,348  Condensed Consolidated Balance Sheet Data   December 31,  December 31,   2023  2022 Cash, cash equivalents, and investments $121,466  $77,335 Total assets  139,807   97,076 Total liabilities  26,272   24,997 Total convertible preferred stock  –   185,033 Total stockholders’ equity (deficit)  113,535   (112,954)

NEW YORK, Nov. 02, 2023 (GLOBE NEWSWIRE) — Lexeo Therapeutics, Inc. (Nasdaq: LXEO), a clinical stage genetic medicine company dedicated to transforming healthcare by applying pioneering science to fundamentally change how genetically defined cardiovascular diseases and APOE4-associated Alzheimer’s disease are […]

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. […]

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 […]