Principal Scientist / Director - Director Antibody

Job Description Principal Scientist / Director, Biotherapeutics Discovery & Development Company Summary: Our client is an AI-driven biotech startup integrating high-throughput biology with generative AI to discover and develop antibody therapeutics with exceptional speed and quality. Through multiple pharma partnerships, the platform has been validated to deliver best-in-class, differentiated antibodies that are difficult to identify using traditional approaches. Position Summary: Our client is seeking a highly motivated, passionate, and detail-oriented Principal Scientist to join their Antibody Therapeutics team. This is an exciting opportunity to contribute to a fast-growing, AI-driven biotherapeutics company dedicated to rapidly generating next-generation biologics for Immunology & Inflammation (I&I) and metabolic diseases. The successful candidate must have hands-on experience in protein engineering and immunoscreening techniques, with a strong track record in biotherapeutic discovery and development. This role will provide the opportunity to lead multiple discovery campaigns, advancing programs from concept through preclinical development in close collaboration with cross-functional teams, including bioassay, translational biology, and CMC. This is a bench-facing, on-site position based in Irvine, CA, offering high visibility and impact within a dynamic and collaborative environment. The final title and level will be determined based on experience. Key Responsibilities: Lead the design, discovery, and optimization of monoclonal, bispecific, and multi-specific antibodies using display and screening platforms (B-cell cloning, phage, and yeast display). Perform high-throughput antibody screening assays, including binding kinetics, ligand blocking, and epitope binning, to rapidly identify and prioritize lead candidates. Design and develop recombinant protein-based immunoassays to characterize therapeutic antibodies using biochemical and biophysical methods. Execute small- and large-scale antibody expression and purification using chromatography techniques and evaluate purity via SDS-PAGE, analytical SEC, and Western blot. Co-lead biotherapeutic discovery campaigns and partner closely with in vitro and in vivo pharmacology teams to evaluate PK/PD, efficacy, and safety profiles. Provide strategic and technical input on antibody design, developability, and candidate selection during early-stage development. Interface with CROs and external collaborators to ensure high-quality data generation and timely project execution. Present experimental results and program updates to project teams, senior management, and collaborators. Maintain accurate experimental documentation in ELN and ensure compliance with best data practices. Stay current with emerging literature and technologies relevant to antibody engineering and biologics discovery. Professional Experience and Qualifications: PhD in Biochemistry, Biomedical Engineering, Molecular Biology, Immunology or related discipline with at least 7 years (Principal Scientist) or 10 years (Director) of research experience working in a biotech or large pharma setting is a must. Experience with antibody pipeline discovery, screening, antibody engineering and optimization in the field of I&I or metabolic diseases is a must. Expertise in designing and conducting in vitro protein-based assays using diverse biophysical and bioanalytical methods (e.g., SPR/BLI, ELISA, DLS, thermal stability, immunoassays) is a must. Strong understanding of protein engineering, Fc modifications, and developability assessments is essential. Ability to work independently and as part of a team in a fast-paced environment with strong analytical and problem-solving skills, with attention to detail is essential. Experience with antibody screening databases and proficiency in data analysis/visualization software, such as Spotfire, Dotmatics, D360, etc. is a plus. Demonstrated scientific innovation and productivity, as evidenced by patents and/or peer-reviewed publications. Strong communication and interpersonal skills, with the ability to present complex data clearly to cross-functional teams, leadership and collaborators. Self-motivated, collaborative, and enthusiastic about contributing to a multidisciplinary, early-stage biotech focused on breakthrough antibody therapeutics. Compensation: Competitive and commensurate with experience, including salary, equity, and benefits - aligned with the company's long-term success. Why Join: Competitive compensation, comprehensive healthcare coverage, equity participation, family leave, paid time off, and 401k retirement plan. A dynamic early-stage work environment and highly interdisciplinary, talented team with a collaborative and innovation-driven culture. Participation in an unprecedented opportunity to significantly impact the quality of life of patients by developing a targeted approach to delivering therapeutic molecules. Professional growth opportunities through mentoring, training, immersion in cross-functional projects, and opportunities to learn and try new things. Walker Cole International