Senior Scientist, Process Development

Gilead Sciences • Foster City, CA

1d • $169,320 - $219,120

About The Position

The Senior Scientist, Purification Process Development & Technology Transfer provides scientific and technical leadership for developing, scaling up, characterizing, transferring, and implementing biologics drug substance purification processes. The role covers the purification process from harvest through bulk drug substance, including harvest clarification, chromatography, virus inactivation, virus filtration, ultrafiltration/diafiltration, formulation, and final drug substance filtration. The successful candidate brings hands-on purification expertise, experience transferring drug substance processes to internal manufacturing sites and external partners or contract development and manufacturing organizations, and experience supporting GMP manufacturing execution.

The role serves as the purification technical lead for pivotal and commercial programs, leads technology-transfer workstreams and process development activities, supports manufacturing campaigns and investigations, and prepares technical and regulatory documentation. It collaborates across CMC functions, mentors junior scientists, and contributes to purification technologies, platform processes, and organizational best practices. Travel may be required to support transfers and provide technical oversight at manufacturing facilities.

Requirements

• PhD in Chemical Engineering, Biochemical Engineering, Bioengineering, Biochemistry, or a related scientific discipline with 2 or more years of relevant experience; or an MS in a relevant scientific or engineering discipline with 6 or more years of relevant experience; or a BS in a relevant scientific or engineering discipline with 8 or more years of relevant experience.

Nice To Haves

• Experience in biologics purification process development, characterization, scale-up, and GMP manufacturing implementation.
• Demonstrated experience leading drug substance technology transfers to internal manufacturing sites, external partners, or contract development and manufacturing organizations.
• Broad technical expertise in harvest clarification, chromatography, virus inactivation, virus filtration, ultrafiltration/diafiltration, formulation, and final filtration.
• Experience supporting engineering, clinical, process performance qualification, and commercial manufacturing campaigns, including batch-record review and on-site or person-in-plant support.
• Experience establishing and qualifying scale-down models and applying Design of Experiments and statistical analysis to define operating ranges and characterize process performance.
• Experience developing process control strategies and supporting process validation readiness.
• Experience authoring or contributing to CMC regulatory filings and responses to health authority questions.
• Demonstrated ability to identify and resolve complex technical risks using sound scientific judgment.
• Strong technical writing, communication, cross-functional collaboration, and project leadership skills.

Responsibilities

• Serve as purification technical lead for assigned pivotal and commercial programs, providing scientific direction and communicating technical risks, recommendations, trade-offs, and mitigation strategies.
• Lead drug substance technology-transfer workstreams to internal manufacturing sites and external partners or contract development and manufacturing organizations, including scale-up, facility fit, manufacturing readiness, and transfer execution.
• Lead development, optimization, scale-up, and characterization of robust, scalable, and manufacturable biologics purification processes.
• Provide hands-on technical leadership across harvest clarification, chromatography, virus inactivation, virus filtration, other filtration operations, ultrafiltration/diafiltration, formulation, and final filtration.
• Design, execute, and interpret process characterization and scale-down studies using scientific and statistical approaches, including Design of Experiments.
• Establish scientifically justified operating ranges and contribute to integrated process control strategies.
• Develop project plans, coordinate technical activities, manage risks, and deliver purification work products in alignment with program objectives and timelines.
• Provide technical support during engineering, clinical, process performance qualification, and other GMP manufacturing campaigns, including on-site and person-in-plant support as needed.
• Lead or support troubleshooting, deviation investigations, root-cause assessments, and technical investigations related to process performance and GMP manufacturing.
• Author and review development reports, study protocols, process descriptions, technology-transfer documentation, standard operating procedures, manufacturing batch records, and CMC regulatory content.
• Collaborate across Process Development, Manufacturing and MSAT, Analytical Development, Formulation Development, Quality, Regulatory Affairs, Supply Chain, and other CMC functions.
• Mentor junior scientists and contribute to purification technologies, platform processes, and organizational best practices.
• Travel as needed to support technology transfers and provide technical oversight at internal and external manufacturing facilities.

Benefits

• Discretionary annual bonus may be available.
• Discretionary stock-based long-term incentives may be available, with eligibility varying by role.
• Paid time off.
• Company-sponsored medical insurance.
• Company-sponsored dental insurance.
• Company-sponsored vision insurance.
• Company-sponsored life insurance.
• Other benefits may be available; eligibility and participation are subject to applicable plan terms and conditions.

What This Job Offers

• Job Type: Full-time
• Career Level: Senior