Careers

Role Summary

Lexeo is seeking an experienced and motivated clinical development leader to advance late-stage development programs as a key member of our development team. This individual will report to the Vice President, Clinical Development, Cardiology and will provide strategic and hands-on leadership across clinical strategy, study execution, and cross-functional integration to deliver high-quality evidence to support regulatory interactions and submissions (e.g., BLA). This role requires strong scientific and operational judgment and the ability to build effective partnerships with internal stakeholders and external collaborators. 

Primary Responsibilities

 
Provide clinical development leadership for assigned programs, including late-stage (Phase 2/3 and/or registrational) studies in rare disease and gene therapy.
Partner with Regulatory, CMC, Quality, Biometrics, Medical Writing, and Clinical Operations to shape an integrated development plan aligned with program objectives and BLA strategy.
Lead clinical strategy and oversight of protocol development, endpoint selection, eligibility criteria, safety monitoring approach, and clinical rationale to support health authority interactions.
Serve as a clinical leader for investigator and external expert engagement, including KOL interactions, advisory boards (as applicable), and site relationships to support enrollment and high-quality study conduct.
Drive cross-functional issue resolution and risk management for study execution; ensure decisions are documented and aligned with quality standards and inspection readiness.
Contribute to BLA readiness by ensuring clinical deliverables and timelines are aligned across functions (e.g., CSR strategy, data review readiness, and clinical modules inputs).
Lead and/or mentor team members through matrix leadership; support a culture of accountability, collaboration, and scientific rigor. 

Required Skills and Qualifications

PhD, PharmD, or MD with a minimum of 6 years experience in industry (8 years for Senior Director), including 5 - 6 years of progressive experience within clinical development and late-stage trial delivery.
Proven experience leading late-stage (Phase 2/3 and/or registrational) development for rare disease programs.
Demonstrated experience supporting regulatory submission readiness, including BLA filing activities (e.g., clinical deliverables coordination, inspection readiness support, and cross-functional alignment).
Thorough knowledge of development program management from IND through NDA/BLA, including audit/inspection readiness.
Experience partnering with Clinical Operations and CROs/vendors to deliver high-quality data and documentation, including milestone management, budget awareness, and reporting/CSR support.
Advanced working knowledge of relevant guidelines and regulations (including ICH, GCP, and FDA requirements).
Ability to operate effectively in a fast-paced environment with shifting priorities and timelines.
Excellent communication skills and demonstrated ability to influence across multiple functions and levels, internally and externally. 

$247,500 - $382,000 a year.

About Lexeo

Lexeo Therapeutics is a New York City-based, clinical stage company dedicated to reshaping the path of genetic disease. By advancing pioneering science, Lexeo seeks to set a new standard in the treatment of cardiovascular and neurological genetic diseases, charting the path to patient outcomes once thought out of reach. The Company is advancing a portfolio of therapeutic candidates designed to address the underlying genetic causes of disease, including LX2006 for Friedreich ataxia (FA), LX2020 for plakophilin-2 (PKP2) arrhythmogenic cardiomyopathy, and others in devastating diseases with high unmet need. 

Our work culture is a hybrid model with 2 days/week in the New York City office and 3 days working from home.

Lexeo Therapeutics is an EEO employer committed to an exciting, diverse,  and enriching work environment. 

Role Summary

We are looking for a talented and highly motivated contract Lab Operations Associate Scientist/Scientist I to join the Lexeo Team in NYC to support the operations within our gene therapy laboratory. 

You will be expected to support the daily operations of the laboratory, ensuring that workflows run smoothly, safely, and efficiently. This role reports to the Lab Manager to oversee equipment, procure supplies, manage shipments, and ensure compliance with safety standards. The ideal candidate is organized, detail-oriented, and comfortable balancing administrative responsibilities with hands‑on lab support.  The nature of the role will require in-person work 5 days per week. 

Primary Responsibilities

Assist in managing day‑to‑day lab operations, including inventory management, consumables ordering, managing a stock room, and equipment maintenance
Maintain digital inventory of supplies, reagents, and equipment. Place orders and track deliveries
Oversee equipment maintenance, calibration, and service records to ensure operational readiness
Support onboarding and continuous training of laboratory staff on lab procedures and safety protocols
Monitor the environmental elements of the laboratory with safety regulations, institutional policies, and quality standards
Help develop and update standard operating procedures (SOPs) and documentation
Coordinate shipping samples, supplies, and reagents to/from a biorepository, CDMOs, and the Lexeo lab
Coordinate waste disposal, chemical storage, and safety inspections
Serve as a point of contact for vendors, facilities, and service technicians
Actively collaborate and communicate cross-functionally within Lexeo. 
The successful candidate will embrace this challenging role with enthusiasm, demonstrate the ability to work within a team, and maintain professionalism while getting things done quickly and efficiently. Attention to detail is expected. The ability to juggle many task at the same time meticulous and detail-oriented approach is crucial for maintaining accuracy.

Required Skills and Qualifications

Bachelor’s or Master's degree in a scientific discipline (e.g Biology, Chemistry,  Biotechnology)
5 years of relevant experience in lab operations (in industry or in combination with academia) with a deep understanding of lab safety
Hands-on experience in a pharmaceutical/biotech environment; knowledge of gene therapy basis a plus
Strong organizational skills with attention to detail and accuracy
Ability to manage multiple priorities and meet deadlines in a fast-paced environment
Excellent communication and coordination skills
Familiarity with Benchling or Quartzy is beneficial
Ability to regularly work onsite 5 days per week plus occasional adhoc hours outside of standard business hours when emergencies arise

About Lexeo

Lexeo Therapeutics is a clinical-stage genetic medicine company headquartered in New York City, pioneering cardiac genetic medicine candidates to treat the root causes of inherited cardiovascular diseases. Our lead program, LX2006, targets cardiomyopathy associated with Friedreich’s Ataxia and anchors a broader pipeline addressing genetically defined conditions such as hypertrophic and arrhythmogenic cardiomyopathies. Backed by a strong financial foundation, Lexeo is positioned to translate groundbreaking science into durable clinical impact. 

Lexeo Therapeutics is an EEO employer committed to an exciting, diverse, and enriching work environment. 

Role Summary

The Manager/Senior Manager, CMC Quality Control (QC) is responsible for providing strategic and operational oversight of QC activities supporting Lexeo's gene therapy programs. This role serves as a QC lead for external contract testing laboratories (CTLs), analytical lifecycle management (i.e., late-phase method validation), stability programs, release testing support, and analytical investigation activities. 

The individual will work closely with Analytical Development, Technical Operations, Regulatory Affairs, Quality Assurance, and external partners to ensure analytical methods, specifications, and testing programs support clinical development, process validation readiness, and future commercial requirements. 

This position requires technical expertise in analytical testing, preferably of AAV-based products, as well as demonstrated experience overseeing external laboratories and driving cross-functional CMC initiatives. 

Primary Responsibilities

Lead QC oversight of external contract testing laboratories supporting release, characterization, validation, comparability, and stability testing activities
Support product specification lifecycle management, including establishment, justification, trending, revision, and regulatory impact assessment
Partner with Analytical Development and Technical Operations to support method qualification, validation, transfer, verification, and continued performance monitoring across testing laboratories
Serve as QC subject matter expert for laboratory investigations, including OOS, OOT, atypical results, assay failures, and method performance events
Support reference standard qualification, lifecycle management, and analytical comparability initiatives
Provide technical oversight for method transfers, comparability assessments, and laboratory readiness
Collaborate with Regulatory Affairs and CMC teams to author and review regulatory submissions, responses to health authority inquiries, technical reports, and analytical sections of INDs, BLAs, and other global filings
Prepare and manage sample submission paperwork for external contract testing labs (CTLs), including quotes, purchase orders, shipping documents
Coordinate shipment of samples, reference standards, and reagents to and from manufacturing sites, external vendors, and CTLs in compliance with storage and shipping requirements
Collaborate with cross-functional CMC teams to align on sample submission and testing needs

Required Skills and Qualifications

Bachelor’s degree in a scientific discipline (e.g., Chemistry, Biology, Biotechnology); advanced degree (MS) a plus
6+ years of experience  or 4+ with Master’s (Sr. Manager level: BS with 8+ years or MS with 6+ years experience) in Quality Control, Analytical Development, Manufacturing Sciences, Quality Assurance, or related CMC functions within biotechnology or pharmaceutical organizations
Experience supporting late-stage development, process validation, and/or commercial readiness activities preferred
Experience supporting biologics, cell therapy, gene therapy, or other advanced therapeutics preferred
Strong understanding of cGMP regulations and global regulatory expectations applicable to analytical testing and Quality Control
Experience with analytical method lifecycle management, including qualification, validation, transfer, verification, and continued performance monitoring
Knowledge of analytical techniques commonly used for AAV and biologic products (i.e., ddPCR, cell-based potency, ELISA/immunoassays, residual impurities, compendial safety testing)
Strong understanding of analytical control strategy development and specification management

$93,000 - $154,000 a year.

About LEXEO

Lexeo Therapeutics is a New York City-based, clinical stage company dedicated to reshaping the path of genetic disease. By advancing pioneering science, Lexeo seeks to set a new standard in the treatment of cardiovascular and neurological genetic diseases, charting the path to patient outcomes once thought out of reach. The Company is advancing a portfolio of therapeutic candidates designed to address the underlying genetic causes of disease, including LX2006 for Friedreich ataxia (FA), LX2020 for plakophilin-2 (PKP2) arrhythmogenic cardiomyopathy, and others in devastating diseases with high unmet need. 

Our work culture is a hybrid model with 2 days/week in the New York City office and 3 days working from home.

LEXEO Therapeutics is an EEO employer committed to an exciting, diverse, and enriching work environment. 

Role Summary

This Scientist II will independently design, execute, and analyze research studies and will drive one or more analytical development projects for AAV-based gene therapy programs. The role provides technical leadership in the development, optimization, qualification, validation, and transfer of analytical assays, including cell-based potency and molecular methods such as qPCR and ddPCR. The Scientist II will apply broad scientific knowledge and novel approaches to establish AAV mechanisms of action in cellular systems, resolve moderately complex technical issues, and support GMP manufacturing, material release, and regulatory submissions in collaboration with groups across CMC, Quality, QC, and external partners.  

The ideal candidate is highly collaborative, detail-oriented, able to manage multiple priorities, and effective in a fast-paced environment. The Scientist II is expected to exercise sound scientific judgment, communicate complex technical issues clearly, build alignment across functions, and serve as a technical resource to colleagues. This is a highly visible and impactful role in our CMC organization. 

Primary Responsibilities

Independently design and optimize analytical methods involving in-vitro cell culture and AAV transduction to demonstrate potency of the gene therapy vectors
Assist in the timely development and internal testing of CQAs, including potency assays, in a target-specific manner
Generate high-quality, reproducible data to support assay qualification, validation, method transfer, and QC-related activities for GMP material release
Analyze, interpret, summarize, and communicate findings through technical reports and presentations that clearly describe the scientific problem, relevant literature, experimental procedures, observations, and conclusions 
Assist in driving analytical strategy and support regulatory submissions in collaboration with internal groups across CMC, Quality, and CROs
Identify technical risks related to assay performance, evaluate relevant factors, and develop mitigation strategies, novel processes, or alternative approaches to solve problems and support continuous improvement
Collaborate on and review technical documentation and protocols to support late-phase assay validation projects at respective CDMO/CROs
Maintain accurate laboratory records and ensure compliance with company policies and regulatory standards
Apply industry best practices, regulatory expectations, and quality standards related to analytical development for gene therapy products, exercising judgment within generally defined practices and policies when selecting methods and techniques
Apply results and learnings from previous studies, and assimilate knowledge or techniques from adjacent scientific fields, to address new or different problems and achieve project goals
Collaborate and build constructive relationships across departments; serve as a technical resource and provide scientific coaching and technical guidance within project teams

Required Skills and Qualifications

BS in Biology, Chemistry, Biochemistry, Biotechnology, Pharmaceutical Sciences, Chemical Engineering, or a related scientific discipline with 6-8 years of relevant experience (MS with 4-6 years or PhD with 1-3 years of relevant industry experience)
Experience in cell and gene therapy products
Strong hands-on experience with tissue culture, analytical assay development and execution, data analysis, and troubleshooting
Experience with pharmaceutical drug-process validation and manufacture a plus
Knowledge of FDA, cGMP, and ICH guidelines and QBD principles a plus
Strong organizational skills, attention to detail, and data accuracy
Excellent communication, collaboration, and problem-solving skills with the ability to work effectively across functional teams
Cross functional acumen and highly skilled in working with complex issues and creating direction in shifting priorities and ambiguity. Results oriented with breadth and depth in pharmaceutical development and commercial products to resolve complex problems
Results-oriented, with strong initiative, accountability, and willingness to take ownership of projects, deliver milestones, and drive work to completion
Familiarity with electronic laboratory notebook and inventory systems such as Benchling or Quartzy preferred 

$99,680 - $138,500 a year.

About LEXEO

Lexeo Therapeutics is a New York City-based, clinical stage company dedicated to reshaping the path of genetic disease. By advancing pioneering science, Lexeo seeks to set a new standard in the treatment of cardiovascular and neurological genetic diseases, charting the path to patient outcomes once thought out of reach. The Company is advancing a portfolio of therapeutic candidates designed to address the underlying genetic causes of disease, including LX2006 for Friedreich ataxia (FA), LX2020 for plakophilin-2 (PKP2) arrhythmogenic cardiomyopathy, and others in devastating diseases with high unmet need. 

LEXEO Therapeutics is an EEO employer committed to an exciting, diverse, and enriching work environment. 

Role Summary

Lexeo is seeking a hands-on in vivo pharmacologist to build rodent models of cardiac disease and use them to de-risk targets, screen therapeutic candidates and advance our discovery pipeline. The scientist will design, perform or manage rodent studies from target validation through hit identification, working cross-functionally with In Vitro Pharmacology, Modality Engineering, and Translational Sciences to select-advance molecules. Reporting to the Head of Cardiac Research, this role joins cardiac, neuroscience, and non-clinical scientists developing therapies for genetic heart disease and offers broad experience in multidisciplinary biopharma research. 

Primary Responsibilities

Design and execute in vivo studies that de-risk novel targets, using genetic knockdown/overexpression and tool molecules to test target–phenotype links
Outsource or internally establish rodent cardiac disease models, including transgenic lines and surgical models such as TAC and MI
Run therapeutic screening studies that rank candidates on efficacy, dose-response, durability, and identify hit molecules for advancement
Dose by multiple routes (IV, IP, SC, IM, PO, retro-orbital) and by osmotic minipump across longitudinal studies
Lead study takedowns: necropsy, blood and tissue collection, and processing for histology, molecular, and ex vivo endpoints, including Langendorff cardiac dissociation
Partner with Translational Sciences to establish bioanalytical methods for biodistribution and target engagement in rodent tissues, and align on models with clinical endpoints/biomarkers
Analyze, interpret, and present data to project teams; keep study records in the ELN in line with IACUC and animal welfare standards
Manage study logistics, manage budgets, flag capacity or timeline risks early, and ideate novel methods for pharmacology and physiology 

Required Skills and Qualifications

PhD in physiology, pharmacology, cardiovascular biology, or a related field with 0–3 years of postdoctoral or industry experience; or MS with 5+ years of industry experience
Hands-on rodent experience: handling, multi-route dosing, blood collection, survival surgery, and necropsy
Track record using rodent disease models for target validation or efficacy testing of molecules
Proven understanding of power analyses, methods of randomizing animal models and appropriate uses of statistical methods
Strong data analysis skills (e.g., GraphPad) and clear written and verbal communication
Organized and independent; able to run several longitudinal studies at once within a collaborative team
Ability to regularly work onsite at HQ in New York City 

Preferred Skills and Qualifications

Industry experience in a small, fast-paced biotech is highly preferred
Working knowledge of qPCR/ddPCR for vector/mRNA, ELISA/LC-MS for ASO, RNAscope/IHC for tissue localization, WB/ ELISA/MSD for protein detection
Hands-on echocardiography in mice and rats (e.g., Vevo)
ECG and blood pressure telemetry implantation and analysis in mice and rats (e.g., Ponemah)
Cardiac surgical models (TAC, MI) and invasive hemodynamics (PV-loop)
Demonstrated experience with models of neurodegenerative disease, particularly ataxia or cerebellar disorders, including execution and interpretation of rotarod, gait analysis, balance beam, grip strength, and longitudinal behavioral studies
In vivo experience working with and advancing AAV or oligonucleotide therapeutics
Experience selecting and evaluating CROs to perform animal studies
AALAS certification or equivalent 

$111,400 - $150,000 a year.

About LEXEO

Lexeo Therapeutics is a New York City-based, clinical stage company dedicated to reshaping the path of genetic disease. By advancing pioneering science, Lexeo seeks to set a new standard in the treatment of cardiovascular and neurological genetic diseases, charting the path to patient outcomes once thought out of reach. The Company is advancing a portfolio of therapeutic candidates designed to address the underlying genetic causes of disease, including LX2006 for Friedreich ataxia (FA), LX2020 for plakophilin-2 (PKP2) arrhythmogenic cardiomyopathy, and others in devastating diseases with high unmet need. 

LEXEO Therapeutics is an EEO employer committed to an exciting, diverse, and enriching work environment. 

Role Summary

Lexeo is hiring a hands-on Modality Engineering Scientist to design, synthesize, and characterize oligonucleotides, bioconjugates, and AAV therapeutics for our discovery pipeline. The scientist will advance molecules from design through analytical characterization and handoff to in vitro and in vivo teams, working across chemistry, molecular biology, and pharmacology. Reporting to the Head of Cardiac Research, this role joins cardiac, neuroscience, and non-clinical scientists developing therapies for genetic heart disease and offers broad experience in multidisciplinary biopharma research. 

Primary Responsibilities

Select and manage CROs for oligonucleotide synthesis and bioconjugation, including scope, vendor guidance, data review, quality, and delivery timelines
Design and oversee oligonucleotide conjugates using peptides, antibodies, or ligands; optimize conjugation chemistry, linkers, purification, and analytical characterization
Build or outsource methods to confirm identity and assess purity using HPLC, LC-MS, SDS-PAGE, spectroscopy, and other fit-for-purpose assays
Engineer AAV capsids, regulatory elements, and transgene cassettes; conduct cloning, plasmid preparation, sequencing, and research-grade vector production
Design and screen sequence or vector/capsid with NGS readouts, applying state-of-the-art analytical methods to improve potency, selectivity, and production yield
Partner with In Vitro Pharmacology, In Vivo Physiology, Analytical DMPK, and CMC to define screening cascades, interpret data, assess developability and manufacturability, select leads, and support go/no-go decisions
Support molecule advancement through process development and formulation while identifying technical risks and recommending practical experiments or external capabilities
Write SOPs, maintain and troubleshoot instruments, document work in the ELN for intellectual property and regulatory filings, present results, and monitor platform advances 

Required Skills and Qualifications

PhD in chemistry, chemical biology, biochemistry, molecular biology, or a related field with 0–3 years of postdoctoral or industry experience; or MS with 5+ years of industry experience
Hands-on experience synthesizing, purifying, and characterizing research-scale ASOs, siRNAs, or bioconjugates using automated solid-phase synthesis, chromatography, and mass spectrometry
Working knowledge of ASO/siRNA therapeutic chemistry, backbone and sugar modifications, class-related toxicity, various delivery approaches
Strong research productivity demonstrated through publications, patent filings, or comparable technical contributions
Clear written and verbal communication skills, sound scientific judgment, and the ability to manage multiple projects in a collaborative, fast-paced team
Ability to regularly work onsite at our HQ in New York City 

Preferred Skills and Qualifications

Industry experience in a small, fast-paced biotech is highly preferred
Working knowledge of AAV biology and vector design
Hands-on experience in AAV capsid engineering, pooled library design, and NGS data analysis
Antibody- or peptide-oligonucleotide conjugate (AOC/POC) design or linker discovery 

$111,400 - $150,000 a year.

About LEXEO

Lexeo Therapeutics is a New York City-based, clinical stage company dedicated to reshaping the path of genetic disease. By advancing pioneering science, Lexeo seeks to set a new standard in the treatment of cardiovascular and neurological genetic diseases, charting the path to patient outcomes once thought out of reach. The Company is advancing a portfolio of therapeutic candidates designed to address the underlying genetic causes of disease, including LX2006 for Friedreich ataxia (FA), LX2020 for plakophilin-2 (PKP2) arrhythmogenic cardiomyopathy, and others in devastating diseases with high unmet need. 

LEXEO Therapeutics is an EEO employer committed to an exciting, diverse, and enriching work environment. 

Role Summary

We are seeking a highly collaborative, hands-on Scientist II to help establish a preclinical neuroscience laboratory supporting small-molecule and protein therapeutics. The immediate priorities are rapid cellular profiling and lead selection for an advanced small-molecule enzyme program, and leadership of cellular development for a transferrin-based protein replacement project. The role will also build fit-for-purpose human neuronal models, laboratory workflows, and external partnerships. 

Location 

We welcome applications from candidates located across the Northeast and Mid-Atlantic. 

Primary Responsibilities

Lead a rapid, tiered cellular assay strategy for small-molecule lead optimization, including target engagement, pharmacodynamics, concentration-response, duration, selectivity, neuronal phenotype, stress, and tolerability
Lead cellular development of a transferrin-based protein replacement project by establishing quantitative assays for construct uptake, internalization, intracellular trafficking, protein abundance and integrity, mitochondrial response, and disease-relevant phenotypic rescue
Use orthogonal methods to distinguish surface-bound, internalized, degraded, and functionally delivered protein; compare constructs and define advancement criteria
Establish fit-for-purpose neuronal culture models, including iPSC-derived neurons or glia where they add decision value, with appropriate banking and quality control
Define assay controls, acceptance criteria, reproducibility standards, analysis plans, SOPs, sample tracking, and electronic documentation
Translate data into concise recommendations to advance, modify, or discontinue assets
Partner across protein engineering, chemistry, bioanalysis, DMPK, pathology, computational biology, and in vivo pharmacology; scientifically manage CROs and assay transfers
Mentor junior scientists and build workflows that are reproducible across operators. Future scope may include ASO screening in partnership with external experts 

Required Skills and Qualifications

PhD in pharmacology, neuroscience, molecular biology, chemical biology, cell biology, or a related discipline, plus 1 to 3 years of biotechnology or pharmaceutical industry experience
Demonstrated experience in cellular pharmacology, assay development, and iterative drug discovery or lead optimization
Hands-on experience with neuronal cell culture models, preferably human iPSC-derived neurons or glia
Expertise in concentration-response, time-course, target-engagement, pharmacodynamic, quantitative data-analysis, and troubleshooting studies
Concrete examples of scientific ownership in which an assay, platform, or data package influenced a program decision
Excellent communication skills and willingness to maintain a substantial hands-on laboratory presence 

Preferred Skills and Qualifications

Enzyme biology, epigenetics, or transcriptional pharmacology; therapeutic proteins or targeted-delivery constructs; cellular uptake, trafficking, or protein quantification; mitochondrial functional assays; high-content imaging or neuronal functional assays; transferrin receptor biology, BBB transport, or biodistribution; laboratory start-up, assay transfer, or CRO management
Exposure to ASO screening or RNA pharmacology is beneficial 

$127,000 - $150,000 a year.

About LEXEO

Lexeo Therapeutics is a New York City-based, clinical stage company dedicated to reshaping the path of genetic disease. By advancing pioneering science, Lexeo seeks to set a new standard in the treatment of cardiovascular and neurological genetic diseases, charting the path to patient outcomes once thought out of reach. The Company is advancing a portfolio of therapeutic candidates designed to address the underlying genetic causes of disease, including LX2006 for Friedreich ataxia (FA), LX2020 for plakophilin-2 (PKP2) arrhythmogenic cardiomyopathy, and others in devastating diseases with high unmet need. 

LEXEO Therapeutics is an EEO employer committed to an exciting, diverse, and enriching work environment.