Careers

  • Imagine working for a company that is working to go beyond treating the symptoms of genetic disease by trying to stop its progress at its underlying cause.
  • That’s what we do every day at Lexeo Therapeutics.
  • We’re not content to simply make better therapies – we want to change the arc of medicine. That passion drives us, and we look for it in every person we bring to our team.
  • Ready to be a part of it? See our openings below.

COMPANY BENEFITS:

  • Health, dental and vision benefits
  • Flexible Spending Account (FSA)
  • Health Savings Account (HSA)
  • Disability insurance
  • Life insurance
  • Mental health benefits
  • Commuter benefits
  • Tech stipend
  • Stocked kitchen
  • In office lunch stipend
  • 401(K) with company match
  • Performance bonus
  • Company equity
  • Unlimited PTO
  • Paid holidays
  • Paid parental leave

Clinical Development

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.

Compensation is dependent on qualifications and experience
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. 

Apply

CMC

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. 

Apply
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.

Compensation is dependent on qualifications and experience
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. 

Apply
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.

Compensation is dependent on qualifications and experrience
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. 

Apply

Commercial

Role Summary

Lexeo’s Commercial team is building the strategy, insights, brand and infrastructure required to bring LX2006 to patients – marking Lexeo’s transition from a clinical-stage to a commercial company. 

We are seeking an Associate Director, Marketing to play a central role in preparing for the launch of LX2006, Lexeo’s first commercial product, anticipated in the US in 2028 and globally thereafter. Reporting to the Senior Director, Marketing, this individual will serve as the LX2006 brand lead, owning critical launch workstreams end to end – from customer insights and competitive intelligence to market development, campaigns, customer targeting and launch readiness – and working closely with cross-functional partners in Market Access/HEOR, Medical Affairs, Patient Affairs, Clinical Development, Regulatory, Legal, CMC, and Business Development (ad hoc) as part of Lexeo’s Launch Readiness Team. 

The role will also support early commercial planning for LX2020, Lexeo’s gene therapy candidate for PKP2-associated arrhythmogenic cardiomyopathy.  

This is a highly visible, hands-on opportunity to build a launch from the ground up and help shape the commercial foundation of a growing clinical stage company. 

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

Primary Responsibilities
  • LX2006 launch strategy and brand planning: Partner with the Senior Director, Marketing to enhance and execute the LX2006 US launch strategy and brand plan, including strategic imperatives, positioning, target patient definition and the pre-launch market development plan. Translate strategy into an integrated launch roadmap and prepare materials for Launch Readiness Reviews, senior leadership and Board discussions as well as investor calls. Define launch KPIs and the analytics and CRM capabilities needed to track launch performance
  • Launch readiness leadership: Serve as a core member of the cross-functional US and ex-US Launch Readiness Teams. Drive launch timelines, deliverables, interdependencies, risks and decisions across Commercial, Medical Affairs, Patient Affairs, Market Access/HEOR, Regulatory, Clinical, Legal and CMC
  • Customer insights and market research: Lead the HCP, patient/caregiver, and payer research program for LX2006 (e.g., awareness, trial and usage tracking, demand studies, message and concept testing, advisory boards). Distill findings into clear recommendations that shape positioning, patient segmentation, evidence generation and lifecycle decisions
  • Competitive intelligence: Own the Friedreich ataxia (FA) competitive intelligence program, including key intelligence questions, monitoring of competitor clinical, regulatory and commercial activity, scenario planning and war gaming, and regular updates to leadership and cross-functional partners
  • Brand development and campaigns: Lead global brand development for LX2006, including brand naming and trademark activities, brand identity and brand book. Develop and deploy unbranded disease-awareness and branded HCP and patient campaigns across channels, managing creative and media agencies and the medical/legal/regulatory (MLR) review process
  • Customer targeting and treatment center readiness: Build and refine the prescriber, account and treatment center universe across neurology and cardiology using claims and other third-party data. Define targeting and segmentation, and partner with Medical and Market Access on treatment center mapping, readiness assessments and referral pathways
  • HCP and KOL engagement: Develop and execute the commercial HCP and KOL engagement plan (e.g., KOL steering committee, peer-to-peer programs, advisory boards, medical congress presence) in compliant partnership with Medical Affairs
  • Global launch planning: Support ex-US launch sequencing and go-to-market planning, ensuring global brand strategy, insights and materials can be adapted for priority markets as LX2006 expands beyond the US
  • Field launch readiness: Develop core launch materials (e.g., sales aids, leave-behinds, websites, congress assets) and contribute to field training, launch meeting and plan-of-action planning ahead of field deployment
  • LX2020 early commercial planning: Support early commercial planning for LX2020 in PKP2-associated arrhythmogenic cardiomyopathy, including target product profile development, HCP and payer research, patient segmentation, market sizing and commercial input to pivotal trial design, leveraging synergies with LX2006
  • Budget and vendor management: Manage marketing budgets, statements of work and vendor relationships across market research, data, creative and strategy partners; track spend against plan and contribute to annual budget planning
  • Team building: Help scale the team as we get closer to launch and contribute to a collaborative cross-functional commercial mindset culture 
Required Skills and Qualifications
  • MBA or other advanced degree required
  • Minimum of 7 years of experience in the biopharmaceutical industry, including direct marketing experience on a launch brand and/or in rare disease. Gene therapy marketing experience is a plus
  • Demonstrated experience developing brand strategy, positioning and HCP and/or patient campaigns, including agency management and MLR review
  • Hands-on experience designing and managing primary market research and translating insights into strategy
  • Strong analytical skills, with comfort working with claims and other secondary data, forecasts and market sizing
  • Exceptional project management skills and a proven ability to lead cross-functional teams without direct authority while managing multiple workstreams
  • Excellent written and verbal communication skills, including the ability to synthesize complex information into concise, executive-ready narratives for senior leadership and the Board
  • Working knowledge of US compliance requirements governing pre-approval and promotional activities
  • Self-starter with a builder mindset who thrives in a lean, fast-paced, pre-commercial environment
  • Ability to travel as needed (e.g., medical congresses, advisory boards, vendor and treatment center meetings) 
Preferred Skills and Qualifications
  • Gene therapy or cell and gene therapy launch experience (significant plus)
  • Prior management or strategy consulting experience in life sciences
  • Experience in cardiology and/or neurology marketing
  • Exposure to market access, pricing and reimbursement for high-cost, one-time therapies
  • Global or ex-US launch experience, including familiarity with HTA requirements 

$170,000 - $230,000 a year.

Compensation is dependent on qualifications and experience
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 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. 

Apply

Pre-clinical

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.

Compensation is dependent on qualifications and experience
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. 

Apply
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.

Compensation is dependent on qualifications and experience
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. 

Apply
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.

Compensation is dependent on qualifications and experience
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. 

Apply
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