About this role
ModeX builds higher-order multispecific antibodies using the mSTAR platform and complementary discovery technologies. This Sr. Scientist I position will help expand our ability to source, engineer, and select high-quality antibody building blocks with the binding, functional, biophysical, and developability properties needed for complex multispecific formats.
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.
ModeX Therapeutics is an Equal Opportunity Employer
ModeX Therapeutics, an OPKO Health company, is the leading clinical-stage biopharmaceutical company developing unique and proprietary-multispecific therapeutics. Its MSTAR platform unites the power of multiple biologics in a single molecule to create multispecific antibodies that bind four or more targets with unprecedented versatility and potency for complex diseases. Its promising first-in-class immunology pipeline includes candidates against immune diseases, including cancer (both solid and hematologic tumors), immune impairment, as well as several of the world's most pressing viral threats.
Its founding team includes globally recognized medical innovators with proven track records of delivering breakthroughs for patients. ModeX is based in Weston, Massachusetts. For more information, please visit www.modextx.com.