Principal Scientist

About the role

The Genomic Medicine Unit (GMU) CMC group at Sanofi is dedicated to establishing best-in-class manufacturing platforms for advanced cell and gene therapy products, including recombinant AAV vectors, lentiviral vectors, and cell therapy products. Sanofi is seeking an experienced cell culture development professional to join the Genomic Medicine Cell Therapy Process Development Group in Waltham, MA, as a Senior Scientist.

The Genomic Medicine Cell Therapy Development group operates with the mission to develop robust, scalable, and innovative cell culture processes for Sanofi’s genomic medicine pipeline. This senior individual contributor role is embedded within the Upstream Scale-Up Laboratory, responsible for executing cell culture bioprocesses at pilot and manufacturing scales (200L–2000L). The position serves as a technical cornerstone of the scale-up team, driving process understanding, operational excellence, and cross-functional alignment with downstream scale-up and manufacturing organizations.

While this position carries no direct people management responsibilities, the incumbent is expected to demonstrate strong technical leadership, guiding peers, influencing process strategy, and serving as a subject matter expert in upstream bioprocessing. The role operates at the intersection of process science, engineering rigor, and operational execution, requiring both hands-on laboratory proficiency and a strategic mindset to translate bench-scale learnings into robust, scalable processes.

Responsibilities

• Lead scale-up activities from bench scale to pilot scale (200L–2000L), applying engineering principles (mixing, mass transfer, shear stress, dissolved oxygen control) to ensure process comparability at large scale.
• Collaborate with process development scientists to translate laboratory findings into scalable, robust manufacturing processes.
• Review and approve JSAs written by equipment owners and provide feedback.
• Train employees to adopt best practices for safety, efficiency, and operational success.
• Build robust internal interfaces with the CMC community and promote the adoption of best practices.
• Demonstrate expertise in upstream process operations at all scales.
• Lead root cause analysis (RCA) investigations for process deviations and equipment failures at pilot scale.
• Present findings and/or results to senior management, external stakeholders, and industry leaders at national/international conferences.

Requirements

• Master’s degree in Chemical Engineering or a related discipline with a minimum of 6 years of relevant experience in large-scale bioreactors, or a Ph.D. degree with a minimum of 4 years of industry experience related to large-scale bioreactors.
• Strong background in cell culture bioreactor operations and scale-up technologies.
• Experience in the biotech/pharmaceutical industry within a cell culture role and an excellent understanding of operational excellence.
• Experience with perfusion process operations at various scales.
• Understanding of engineering principles related to cell culture processes.
• Ability to lead matrix teams for operations and lab management.

Preferred Qualifications

• Experience managing cross-functional teams and initiatives.
• Experience in cell culture process development for AAV manufacturing.
• Expertise in mammalian cell culture and related aspects such as cell metabolism/media optimization, engineering fundamentals on cell culture scale-up/down, cell biology/physiology.
• Process automation experience.