Sr. Scientist I, Antibody Engineering

ModeX is seeking an experienced, hands-on antibody discovery scientist to lead and execute integrated antibody discovery and engineering campaigns. The successful candidate will combine deep expertise in primary B-cell workflows with strong antibody engineering judgment, including humanization, affinity and specificity optimization, sequence-liability mitigation, and structure-based design. This Sr. Scientist I will work closely with Protein Sciences, Digital Biology, Translational Science, and project teams to generate differentiated, developable binders for multispecific therapeutics in oncology and infectious disease.

Key Responsibilities

• Lead and execute end-to-end antibody discovery campaigns, including antigen and immunization strategy, B-cell isolation, antigen-specific single-cell sorting, variable-region recovery, cloning, recombinant expression, screening, and lead selection.
• Design and perform primary B-cell discovery workflows using immunized rodents, including humanized transgenic animals; apply single-cell technologies and high-throughput cloning approaches to recover rare, diverse binders.
• Engineer therapeutic antibodies through rational humanization, affinity maturation, specificity optimization, germline and "humanness" assessment, and removal of sequence or chemical liabilities while preserving function.
• Apply structure-guided design using experimental structures and/or high-confidence models to interpret paratope–epitope interactions, guide mutagenesis, and improve affinity, specificity, stability, expression, or format compatibility.
• Design and analyze screening cascades spanning binding, competition, epitope diversity, affinity/kinetics, cell-surface binding, functional activity, and early developability.
• Use flow cytometry/FACS, ELISA, BLI or SPR, and sequence analysis to characterize and rank antibody candidates; partner with protein sciences on expression, purification, and biophysical assessment.
• Convert and evaluate antibodies across relevant formats, including IgG, Fab, scFv, bispecific, and higher-order multispecific molecules; identify format-dependent risks early.
• Integrate repertoire sequencing, NGS, bioinformatics, and computational/AI-enabled tools where they improve campaign design, sequence triage, clustering, or engineering decisions.
• Document campaign strategy, clone lineage, sequence, assay, and selection data in Benchling or equivalent systems, and communicate clear recommendations at project decision points.
• Mentor colleagues, troubleshoot complex workflows, manage external partners when needed, and contribute to platform-building and continuous improvement.

Required Qualifications

• PhD in immunology, molecular biology, biochemistry, protein engineering, or a related field with 5+ years of relevant industry experience, or MS with 8+ years of relevant industry experience.
• Demonstrated hands-on experience leading multiple therapeutic antibody discovery campaigns from source material through validated lead antibodies.
• Deep practical expertise in primary B-cell isolation, antigen-specific B-cell sorting, single-cell antibody cloning, variable-gene recovery, and recombinant expression.
• Demonstrated antibody engineering experience, including humanization and at least two of the following: affinity maturation, structure-based design, specificity engineering, sequence-liability remediation, or developability optimization.
• Strong experience with multiparameter flow cytometry and sorting-based methods, including panel design, controls, gating strategy, operation, and troubleshooting.
• Experience designing and interpreting antibody screening and characterization assays such as ELISA, BLI and/or SPR, cell-binding assays, competition or epitope-binning assays, and functional assays.
• Fluency in antibody sequence analysis, clonotype/lineage assessment, CDR and framework evaluation, and data-driven candidate selection.
• Proven ability to independently design experiments, resolve technical failures, integrate large datasets, and make sound lead-selection recommendations.
• Clear scientific communication, strong documentation practices, and success working across discovery, computational, protein sciences, and translational teams.

Preferred Qualifications

• Experience with humanized transgenic rodent platforms and/or human immune-repertoire mining.
• Experience with yeast, phage, mammalian, or ribosome display for antibody discovery or optimization.
• Hands-on use of single-cell discovery platforms or microfluidic workflows, such as Beacon or equivalent technologies.
• Experience with NGS-enabled discovery, repertoire analytics, sequence clustering, and campaign data management.
• Working knowledge of early developability assessments, including aggregation, hydrophobicity, self-interaction, thermal stability, expression, and polyspecificity risks.
• Experience using structural biology, molecular modeling, or AI/ML-supported tools to guide antibody design, with evidence of experimental validation.
• Experience engineering antibodies for bispecific, trispecific, T-cell engager, or other multispecific formats.

What Success Looks Like

• Delivers diverse, sequence-confirmed antibody panels and converts campaign output into decision-ready leads.
• Improves antibody quality through engineering without trading away binding, function, expression, or developability.
• Builds reproducible discovery workflows and raises technical capability across the team.
• Makes clear, evidence-based recommendations and identifies failure risks early.