Principal Scientist, Upstream Process, Process Development

Principal Scientist, Upstream Process, Process Development Somerset, New Jersey, United States Legend Biotech is a global biotechnology company dedicated to treating, and one day curing, life-threatening diseases. Headquartered in Somerset, New Jersey, we are developing advanced cell therapies across a diverse array of technology platforms, including autologous and allogenic chimeric antigen receptor T-cell, T-cell receptor (TCR-T), and natural killer (NK) cell-based immunotherapy. From our three R&D sites around the world, we apply these innovative technologies to pursue the discovery of safe, efficacious and cutting-edge therapeutics for patients worldwide. Legend Biotech entered into a global collaboration agreement with Janssen, one of the pharmaceutical companies of Johnson & Johnson, to jointly develop and commercialize ciltacabtagene autolecuel (cilta-cel). Our strategic partnership is designed to combine the strengths and expertise of both companies to advance the promise of an immunotherapy in the treatment of multiple myeloma. Legend Biotech is seeking a Principal Scientist, Lentivirus Upstream Process Development as part of the Technical Development team based in Somerset, NJ. Role Overview The Principal Scientist, Lentivirus Upstream Process Development, will be a key technical leader responsible for designing, optimizing, and scaling upstream production processes for lentiviral vectors (LVV) within our innovative pipeline. This role focuses on delivering high-quality, high-titer vector products to support LVV generation and other advanced cell therapy programs. The successful candidate will drive scientific excellence in upstream processing (USP)—including seed train optimization, mammalian cell culture (HEK293 and HEK293T), large-scale transient transfection, and bioreactor scale-up and scale-down model—ensuring processes are robust, scalable, and phase-appropriate for GMP manufacturing. This position demands a blend of hands-on technical mastery and strategic thinking to accelerate timelines while maintaining a patient-focused approach. Key Responsibilities Design and execute highly efficient upstream production strategies for lentiviral vectors. Direct the development and optimization of upstream processes including but not limited to: seed train expansion, suspension mammalian cell culture (HEK293/HEK293T), plasmid transient transfection optimization, and feed batch/perfusion bioprocessing in stir-tank and rocker bioreactors. Establish and validate robust bioreactor scale-up and scale-down models to ensure process comparability and predictability across different manufacturing scales. Direct the translation of bench-scale processes to GMP manufacturing, ensuring seamless technology transfer and providing troubleshooting support during clinical production runs. Provide hands-on training as needed. Lead the execution of study protocols to define operating parameters, feeding strategies, and performance limits; implement state-of-the-art knowledge management for USP data. Communicate the potential for issues and delays along with solutions and mitigation approaches. In collaboration with the Senior Leaders, CMC Project Manager, Project Leader, and other technical leads, identify project acceleration opportunities. Leverage advanced science and technology to maximize vector titer, specific productivity, and quality, identifying creative solutions to define unknowns in the viral vector production field. Guide a team of scientists in the execution of project-specific activities, fostering a culture of transparency, scientific rigor, and continuous improvement. Author and serve as a primary reviewer for technical documents, including development reports, SOPs, and CMC sections for regulatory submissions (IND). Work closely with Downstream Process Development and Analytical Development teams to ensure integrated and holistic process outcomes. Tech transfer process to/from other Legend sites or CDMOs. Resolve conflict and proactively identify/address performance issues. Ensure compliance with regulatory requirements. Requirements Advanced degree (PhD preferred, or MS) in Chemical Engineering, Biomedical Engineering, Virology, Molecular Biology, or a related field. 8+ years (PhD) or 10+ years (MS) of experience in process development or manufacturing within a biotech or pharmaceutical setting Deep technical hands-on experience in mammalian cell culture (HEK293, HEK293T), seed train expansion, feeding strategy and transient transfection optimization specifically for viral vectors (Lentivirus preferred). Proven expertise in developing and implementing bioreactor scale-up and scale-down models. Strong understanding of GMP manufacturing requirements and CMC strategies for early-phase clinical trials. Deep knowledge and hands-on experiences in cell and lentiviral vector technologies within the current emerging field Strong knowledge in engineering modeling, mass transfer, and bioprocess optimization. Excellent leadership, emotional intelligence, and communication skills; ability to maintain composure and strategic focus during challenging development timelines. Creative, strategic thinking. Strong troubleshooting skills Preferred experience in handling large-scale (>50L, e.g., 200L/500L) upstream bioreactor processes. Language(s): English. Mandarin is a plus.