
R&D
Where your curiosity drives the
miracles of
science
Senior Scientist
At a glance
Bring your curiosity to a team where deep immunoscience meets cutting-edge innovation. Across oncology, rare diseases, neurology, and vaccines, you’ll work at the intersection of lab science and AI-powered discovery — all while collaborating across boundaries to turn breakthrough ideas into real-world impact. Whether you want to deepen your scientific expertise or grow as a leader, you’ll find the opportunity here.
Job Title: Senior Scientist
Location: Waltham, MA
About the Job
Are you ready to shape the future of medicine? The race is on to speed up drug discovery and development to find answers for patients and their families. Your skills could be critical in helping our teams accelerate progress.
Sanofi is seeking a highly motivated Senior Scientist to join the Analytical Development team in our growing Genomic Medicines Unit (GMU) in Waltham, MA. The candidate will play a critical role in the design and development of cell and molecular assays to support product characterization studies, process development, and preclinical and clinical lot release and stability testing of viral (AAV) and non-viral gene therapeutics, including LNP/mRNA/DNA modalities. A successful candidate will have a strong scientific background in developing analytical methods, excellent oral and written communication skills, and a team player approach to problem-solving.
We are an innovative global healthcare company with one purpose: to chase the miracles of science to improve people’s lives. We’re also a company where you can flourish and grow your career, with countless opportunities to explore, make connections with people, and stretch the limits of what you thought was possible. Ready to get started?
Main Responsibilities:
Define scientific approaches and analysis methods for quantitative bioassays, immunoassays, and molecular assays including qPCR and digital PCR
Evaluate and implement new technologies within the GMU Analytical Development Team, with an emphasis on state-of-the-art analytical assays for gene therapy products
Participate in the development, qualification, and validation of analytical methods
Ensure timely completion and delivery of analytical results with GMP documentation to support product development during clinical phases
Write analytical sections of IND/IMPD filings
Write and review method protocols, assay qualification and validation plans/reports and ensure that the documents adhere to regulatory requirements
About You
Basic Qualifications:
PhD in Biological Sciences (Cell Biology, Biochemistry, Molecular Biology or related field), or Master’s Degree in a relevant discipline and at least 4 years of relevant experience,
or Bachelor’s Degree in relevant discipline and at least 6 years of relevant experience
Experience in developing and analyzing quantitative analytical methods
Preferred Qualifications:
Understanding of MOA for gene therapy-based therapeutics
Experience with quantitative PCR including primer design, digital PCR, ELISA, cell-based relative potency assays
Familiarity with software packages to analyze dose-responses and statistical analysis (SoftMax, JMP, GraphPad Prism etc)
Familiarity with QbD principles and DOE approaches for method development and optimization.
Working experience in GMP environment will be considered an advantage
Experience with validation and transfer of analytical methods according to ICH guidelines
Why Choose Us?
Bring the miracles of science to life alongside a supportive, future-focused team.
Discover endless opportunities to grow your talent and drive your career, whether it’s through a promotion or lateral move, at home or internationally.
Enjoy a thoughtful, well-crafted rewards package that recognizes your contribution and amplifies your impact.
Take good care of yourself and your family, with a wide range of health and wellbeing benefits including high-quality healthcare, prevention and wellness programs and at least 14 weeks’ gender-neutral parental leave.
Sanofi Inc. and its U.S. affiliates are Equal Opportunity and Affirmative Action employers committed to a culturally diverse workforce. All qualified applicants will receive consideration for employment without regard to race; color; creed; religion; national origin; age; ancestry; nationality; marital, domestic partnership or civil union status; sex, gender, gender identity or expression; affectional or sexual orientation; disability; veteran or military status or liability for military status; domestic violence victim status; atypical cellular or blood trait; genetic information (including the refusal to submit to genetic testing) or any other characteristic protected by law.
All compensation will be determined commensurate with demonstrated experience. Employees may be eligible to participate in Company employee benefit programs, and additional benefits information can be found here.
Sanofi US endeavors to make our career center accessible to any and all users. If you are experiencing difficulty and need assistance applying online, please click here.
Pursue Progress. Discover Extraordinary.
Join Sanofi and step into a new era of science - where your growth can be just as transformative as the work we do. We invest in you to reach further, think faster, and do what’s never-been-done-before. You’ll help push boundaries, challenge convention, and build smarter solutions that reach the communities we serve. Ready to chase the miracles of science and improve people’s lives? Let’s Pursue Progress and Discover Extraordinary – together.
At Sanofi, we provide equal opportunities to all regardless of race, color, ancestry, religion, sex, national origin, sexual orientation, age, citizenship, marital status, disability, gender identity, protected veteran status or other characteristics protected by law.
Watch 'One day at Sanofi' and check out our Diversity Equity and Inclusion initiatives at sanofi.com

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Why work with us
- Expand your horizons. Grow through curiosity, with support to move, learn, and lead in a culture that champions mentorship, mobility, and bold development.
- Accelerate results with technology. Harness the power of AI and automation to push scientific boundaries and reimagine what's possible in drug discovery.
- Impact through inclusive innovation. Help deliver better science and fairer outcomes by driving inclusive research that reaches more people, in more meaningful ways.
- Turn patient needs into breakthrough science. Drive scientific breakthroughs that start with patient needs—and end in treatments that change lives.
Meet Nils Libert, Associate Scientist
Meet Nils Libert, an Associate Scientist in Belgium, where he plays a key role in advancing groundbreaking research. Learn how his work helps drive innovation, uncover new scientific possibilities, and contribute to life-changing treatments that impact patients around the world.

"At Sanofi, we are building an R&D engine powered by the best science, digital innovation, and a commitment to transforming the lives of patients around the world."

Houman Ashrafian
EVP & Head of R&D
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