Senior Principal Scientist

Job title: Senior Principal Scientist Location: Cambridge, MA About the Job We are seeking a highly motivated Senior Principal Scientist to spearhead the execution and expansion of our mast cell disorders Research & Development pipeline. A successful candidate will have deep expertise in hematopoietic stem cell biology with a particular focus on mast cell disorders and related immune disorders in the context of rare diseases. This individual will work cross-functionally to identify and shepherd early-stage programs into the research pipeline, through internal and external innovation, and ensure the successful progression of development stage programs through the clinic to registration by providing deep research subject matter expertise. In parallel, the candidate will build relationships with key opinion leaders in the field and work to source disease relevant cell lines, models, and patient samples and work with research and translational sciences to expedite internal research and accelerate later-stage research programs. 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: Serve as subject matter expert for mast cell disorders and related rare immune and hematologic conditions, providing scientific leadership and strategic guidance. Drive early discovery initiatives by directing target identification, mechanistic biology research, and preclinical strategy development for first-in-class and best-in-class rare disease therapeutics. Initiate and lead new preclinical programs to strategically expand the rare disease pipeline and advance innovative treatment options. Identify and leverage cross-portfolio synergies with rare blood disorders and hematopoietic stem cell programs to maximize therapeutic opportunities and optimize resource allocation. Monitor competitive landscape and establish strategic partnerships through targeted academic collaborations and business development initiatives. Partner cross-functionally with Clinical and Business Development teams to develop indication expansion and lifecycle management strategies, supporting comprehensive portfolio development from discovery through commercialization. Contribute to organizational excellence through strategic planning, executive communications, scientific publications, and regulatory submissions that advance company objectives. About You Basic Qualifications: Earned Ph.D. in molecular biology, cellular biology, hematology, immunology, or related discipline PLUS at least 7 years research experience in biopharmaceutical setting. Experience in hematopoietic stem cell and mast cell research, including systemic mastocytosis. Experience in early and late-stage research. Preferred Qualifications: Track record of scientific publications and external visibility (e.g., scientific publications, conference presentations) Experience in translational research and drug development. The candidate is expected to have a strong network of research and clinician colleagues to leverage for collaboration and insight. Strong understanding of emerging science, leading therapeutic approaches and competitive landscapes for HSC and mast cell disorders, particularly in the rare disease space. Familiarity and/or experience with broad range of cell-based and animal models of HSC and mast cell disorders and relevant readouts. Familiarity with wide range of therapeutic modalities including biologics, small molecules, and/or genomic medicines. Familiarity with computational biology and broad range of ‘omics Experience managing studies at CROs. Experience drafting regulatory documents to support IND or CTA applications with agencies like the FDA and EMA. Skills and competencies: Ability to weigh and integrate inputs and opinions from broad range of stakeholders with diverse backgrounds. Ability to capture and distill complex data, concepts, and information into clear, well-articulated messages to guide and drive decision-making. Ability to multi-task and adapt to rapidly changing priorities and deadlines. Excellent critical thinking, analytical, and problem-solving skills. Excellent written and oral communication skills, with the ability to communicate effectively in a multidisciplinary teams as well as to senior leadership. Strong interpersonal skills, with the ability to build excellent working relationships. 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. 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. Help improve the lives of millions of people globally by making drug development quicker and more effective. Work at the forefront of drug discovery, harnessing cutting-edge AI, data, and digital platforms to push the boundaries of science. 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. #GD-SA #LI-SA #vhd #LI-Hybrid Pursue progress, discover extraordinary Better is out there. Better medications, better outcomes, better science. But progress doesn’t happen without people – people from different backgrounds, in different locations, doing different roles, all united by one thing: a desire to make miracles happen. So, let’s be those people. At Sanofi, we provide equal opportunities to all regardless of race, colour, ancestry, religion, sex, national origin, sexual orientation, age, citizenship, marital status, ability or gender identity. Watch our ALL IN video and check out our Diversity Equity and Inclusion actions at sanofi.com! US and Puerto Rico Residents Only Sanofi Inc. and its U.S. affiliates are Equal Opportunity and Affirmative Action employers committed to a culturally inclusive and diverse workforce. All qualified applicants will receive consideration for employment without regard to race; color; creed; religion; national origin; age; ancestry; nationality; natural or protective hairstyles; 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. North America Applicants Only The salary range for this position is: $148.500,00 - $214.500,00 All compensation will be determined commensurate with demonstrated experience. Employees may be eligible to participate in Company employee benefit programs. Additional benefits information can be found through the LINK. We are an R&D driven, AI-powered biopharma company committed to improving people’s lives and creating compelling growth. Our team is guided by one purpose: we chase the miracles of science to improve people’s lives. We want to build a healthier, more resilient world, and turn the impossible into the possible by discovering, developing, and delivering medicines and vaccines for millions of people around the world. Discover more about us visiting or via our movie We are Sanofi Start a career that makes a difference. Reinvention is in our DNA. It’s what drove our evolution from a small French enterprise to one of the world’s leading biopharma companies. Whether it’s using AI to shorten drug-discovery times or building trust in healthcare, you could be helping our teams make life better for patients, partners, and communities. This is where you grow your career. We open the door for you to explore new opportunities, push your limits, and connect with people who are driven by a shared purpose: we chase the miracles of science to improve people’s lives.