R&D
Where your curiosity drives the
miracles of
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Principal Scientist - Rare Diseases
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: Principal Scientist - Rare Diseases
Location: Cambridge, MA
About the job
As Principal Scientist - Rare Diseases within our R&D team, you will join Sanofi's Rare Diseases Research team and lead transformative drug discovery efforts for patients with rare Mendelian disorders. In this role, you will serve as a strategic scientific leader, driving innovation from target identification through clinical candidate selection. This position offers the unique opportunity to shape our rare disease pipeline by leveraging your deep expertise in metabolic disease biology and proven track record of drug discovery.
At Sanofi, we are committed to pursuing the miracles of science to improve people's lives. You will translate cutting-edge mechanistic insights into breakthrough therapeutic strategies, working at the intersection of academic innovation and pharmaceutical development. Your leadership will be instrumental in advancing novel treatments for patients with limited or no therapeutic options, including those suffering from inborn errors of metabolism, mitochondrial diseases, and related rare metabolic conditions.
Join the engine of Sanofi’s mission — where deep immunoscience meets bold, AI-powered research. In R&D, you’ll drive breakthroughs that could turn the impossible into possible for millions.
About Sanofi
We’re an R&D-driven, AI-powered biopharma company committed to improving people’s lives and delivering compelling growth. Our deep understanding of the immune system – and innovative pipeline – enables us to invent medicines and vaccines that treat and protect millions of people around the world. Together, we chase the miracles of science to improve people’s lives.
Main Responsibilities
Strategic Leadership & Program Direction
Build drug discovery programs employing a variety of therapeutic modalities (small molecule, biologics, antisense oligonucleotides, gene therapy, etc.) targeting metabolic and mitochondrial disorders
Define research strategy and drive decision-making for rare disease programs from target validation through IND-enabling studies
Serve as the scientific voice for programs in governance forums, providing strategic recommendations that shape portfolio priorities
Identify and evaluate emerging therapeutic opportunities in metabolic and mitochondrial diseases through competitive intelligence and scientific landscape analysis
Scientific Execution & Innovation
Design and oversee the execution of sophisticated in vitro and in vivo studies to elucidate disease mechanisms, validate therapeutic targets, and establish proof-of-concept for novel interventions
Drive mechanistic understanding of rare metabolic disorders
Integrate multi-omics approaches and systems biology to identify disease drivers and therapeutic intervention points
Translate preclinical findings into clinical development strategies in collaboration with translational medicine teams
Cross-Functional Collaboration & External Partnerships
Lead or contribute to cross-functional project teams spanning discovery research, translational medicine, clinical development, and regulatory affairs
Build and maintain strategic relationships with leading academic researchers, clinician-scientists, and patient advocacy organizations in the rare metabolic disease community
Manage external collaborations including CROs, academic partnerships, and biotech alliances to accelerate program advancement
Represent Sanofi's scientific leadership at conferences, advisory boards, and collaborative research forums
Scientific Communication & Documentation
Generate rigorous data analyses, interpretations, and documentation to support program milestones, regulatory submissions (IND/CTA), patent filings, and publications
Communicate complex scientific concepts clearly and persuasively to diverse audiences including senior leadership, external collaborators, and the broader scientific community
Mentor and develop junior scientists, fostering a culture of scientific excellence and innovation
About You
Required Qualifications
Ph.D. or equivalent advanced degree in biochemistry, metabolism, mitochondrial biology, molecular/cellular biology, genetics, or related discipline
Minimum of 7+ years of post-graduate experience in academic or biopharmaceutical research, with substantial focus on metabolic and/or mitochondrial disorders.
Deep expertise in neurological, neuromuscular, and/or mitochondrial disorders
Proven drug discovery leadership experience in industry with a track record of contributions to multidisciplinary teams and advancing therapeutic programs toward clinical development
Demonstrated contributions to IND/CTA-enabling activities, including target validation, mechanism-of-action studies, biomarker development, and translational research
Strong publication record in high-impact journals demonstrating scientific thought leadership in relevant disease areas
Preferred Qualifications
Established network within the academic, clinical, and patient advocacy communities focused on rare metabolic and mitochondrial diseases
Experience with relevant disease models including patient-derived cells, organoids, and animal models
Expertise designing and incorporating metabolomics, lipidomics, or other specialized experimental modalities
Familiarity with computational biology, bioinformatics, or analysis of large-scale 'omics datasets
Experience with multiple therapeutic modalities and platform technologies
Prior involvement in regulatory document preparation and interactions with health authorities
Understanding of the rare disease drug development landscape, including regulatory pathways and reimbursement considerations
Experience presenting at scientific conferences and contributing to the external scientific discourse in rare diseases
What You'll Bring
Exceptional scientific problem-solving abilities with capacity to integrate complex datasets and drive mechanistic insights
Strong experimental design skills with rigorous attention to scientific quality and reproducibility
Deep understanding of drug discovery processes from target identification through clinical candidate selection
Proven ability to lead, influence, and inspire multidisciplinary teams in a matrixed organization
Strategic mindset with capability to balance scientific rigor with business priorities and timelines
Outstanding written and verbal communication skills with ability to tailor messages for diverse audiences
Why Choose Us
Bring the miracles of science to life alongside a supportive, futurefocused 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.
Be part of a pioneering biopharma company that engages patients early in drug development and uses their insights to design studies that reflect real-world needs.
Work at the forefront of drug discovery, harnessing cutting-edge AI, data, and digital platforms to push the boundaries of science.
Help improve the lives of millions of people globally by making drugdevelopment quicker and more effective.
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.
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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.
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
Final compensation will be determined based on factors such as experience, skills, expertise, location, and others. Employees may be eligible to participate in company employee benefit programs.
Find out more about this location
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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