Pioneering Medicines: Senior Principal Scientist, In Vitro Pharmacology

About Pioneering Medicines:

Pioneering Medicines, Flagship Pioneering’s in-house drug development unit, is dedicated to conceiving and developing a broad portfolio of life-changing treatments for patients built from Flagship’s innovative platforms. Harnessing the drug development expertise of its team together with the power of Flagship's multiple scientific platforms, Pioneering Medicines explores and identifies new product concepts which are then advanced jointly with Flagship’s bioplatform companies. Within Flagship’s Innovation Supply Chain partnerships, Pioneering Medicines works with external collaborators to apply its unique approach to partners’ R&D priorities. These partnerships are highly co-creative strategic alliances that accelerate therapeutic innovation by bringing together partners spanning the full spectrum of drug discovery, development, and production.

Position Summary:
Pioneering Medicines is seeking an accomplished and highly collaborative Senior Principal Scientist, In Vitro Pharmacology to lead the development and implementation of innovative in vitro pharmacology strategies across a diverse portfolio of therapeutic programs. This role will serve as a scientific leader responsible for designing, developing, validating, and applying cell-based assays that enable lead identification, lead optimization, mechanism of action studies, and translational as well as in vivo decision-making.

The successful candidate will work closely with multiple therapeutic areas spanning Immunology, Oncology, and Metabolic diseases, as well as Translational Sciences, and In Vivo Pharmacology teams to accelerate the discovery and development of transformative therapeutics. The ideal candidate is an innovative scientist with deep expertise in assay development, mechanistic pharmacology, and matrix leadership within a fast-paced, entrepreneurial research
environment.

Key Responsibilities:

Scientific Leadership
• Lead the design, development, optimization, qualification, and implementation of robust in vitro pharmacology assays to support drug discovery programs from target validation through candidate selection.
• Develop mechanistic assays to evaluate target engagement, signaling pathways, cellular function, efficacy, and pharmacodynamic biomarkers across multiple therapeutic modalities.
• Drive innovative assay strategies utilizing primary immune cells, engineered cell lines, co-culture systems, and emerging cellular technologies.
• Establish fit-for-purpose assays that generate high-quality, reproducible data to enable critical program decisions.

Cross-functional Collaboration
• Partner closely with project teams across Immunology, Oncology, and other therapeutic areas to define pharmacology strategies aligned with
program objectives.
• Manage CROs for assay outsource, data analysis and quality control check
• Contribute scientific expertise during project reviews, portfolio discussions, and governance meetings.
• Build strong scientific partnerships across Flagship companies and external collaborators when appropriate.

Drug Discovery Support
• Design and execute pharmacology studies to characterize therapeutic candidates, including small molecules, peptides, antibodies, multi-specifics, targeted protein degraders, and other novel therapeutic modalities.
• Generate pharmacology data supporting target validation, mechanism-ofaction studies, structure-activity relationship (SAR) efforts, and candidate selection.
• Integrate in vitro pharmacology data with in vivo efficacy, PK/PD, and systems biology datasets to guide decision-making.

Innovation and Technical Excellence
• Introduce emerging technologies and state-of-the-art assay platforms that improve data quality, throughput, and biological relevance.
• Drive implementation of automation and AI-enabled data analysis where appropriate.
• Establish best practices for assay development, data analysis, quality control, and reproducibility.
• Mentor scientists and foster a culture of scientific rigor, innovation, and continuous learning.

Leadership and Mentorship
• Provide scientific mentorship and technical guidance to junior scientists and project teams.
• Influence scientific direction across multiple programs through thought leadership and strategic input.
• Promote collaboration, knowledge sharing, and technical excellence within the In Vitro Pharmacology organization.
• Represent In Vitro Pharmacology team internally and externally through scientific presentations, publications, and conference participation.

Qualifications:
Required
• Ph.D. in Immunology, Cancer Biology, Pharmacology, Cell Biology, Molecular Biology, or a related discipline with 8+ years of relevant biotechnology or pharmaceutical industry experience.
• Demonstrated expertise in developing and implementing complex cell-based pharmacology assays supporting drug discovery.
• Deep understanding of immune signaling pathways, oncology biology, and cellular mechanisms of action.
• Extensive experience working with small molecules, peptides and therapeutic antibodies and/or other advanced therapeutic modalities.
• Strong background in assay qualification, experimental design, statistical analysis, and interpretation of complex biological datasets.
• Proven ability to lead cross-functional scientific initiatives in a matrixed research environment.
• Excellent written, verbal, and presentation skills with the ability to communicate effectively across scientific disciplines.

Preferred
• Experience supporting IND-enabling pharmacology and translational biomarker strategies.
• Expertise in primary human immune cell assays, flow cytometry, multiplex cytokine analysis, high-content imaging,.
• Familiarity with computational biology, machine learning, or AI-driven approaches for pharmacology data analysis.
• Demonstrated track record of scientific innovation, publications, patents, and successful advancement of therapeutic programs.

Core Competencies
• Scientific leadership and strategic thinking
• Innovation and problem solving
• Cross-functional collaboration and influence
• Excellence in assay development and mechanistic pharmacology
• Strong project management and prioritization skills
• Mentorship and talent development
• Effective communication and stakeholder engagement
• Commitment to scientific rigor, reproducibility, and operational excellence

Why Join Pioneering Medicines:
At Pioneering Medicines, we leverage the Flagship Pioneering ecosystem to create first-in-category medicines that address unmet patient needs. As a Senior Principal Scientist, you will have the opportunity to shape scientific strategy across multiple therapeutic areas, collaborate with world-class innovators, and help translate groundbreaking biology into transformative therapies for patients

Location: Cambridge, MA

About Flagship Pioneering:

Flagship Pioneering invents and builds platform companies, each with the potential for multiple products that transform human health, sustainability and beyond. Since its launch in 2000, Flagship has originated more than 100 companies. Many of these companies have addressed humanity’s most urgent challenges: vaccinating billions of people against COVID-19, curing intractable diseases, improving human health, preempting illness, and feeding the world by improving the resiliency and sustainability of agriculture.

Flagship has been recognized twice on FORTUNE’s “Change the World” list, an annual ranking of companies that have made a positive social and environmental impact through activities that are part of their core business strategies and has been twice named to Fast Company’s annual list of the World’s Most Innovative Companies. Learn more about Flagship at

At Flagship, we accept impossible missions to enable bigger leaps. Our core values guide us through uncertainty and toward lasting impact.

We are an equal opportunity employer . All qualified applicants will be considered for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, disability, protected veteran status, or any other characteristic protected by law.

We recognize that great candidates often bring unique strengths without fulfilling every qualification . If you have some of the experience listed above but not all, please apply anyway. We are dedicated to building diverse and inclusive teams and look forward to learning more about your background and interest in Flagship.

Recruitment & Staffing Agencies : Flagship Pioneering and its affiliated Flagship Lab companies (collectively, “FSP”) do not accept unsolicited resumes from any source other than candidates. The submission of unsolicited resumes by recruitment or staffing agencies to FSP or its employees is strictly prohibited unless contacted directly by Flagship Pioneering’s internal Talent Acquisition team. Any resume submitted by an agency in the absence of a signed agreement will automatically become the property of FSP, and FSP will not owe any referral or other fees with respect thereto.

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Privacy Notice for Applicants: When you apply for a role at Flagship Pioneering or one of its portfolio companies, we collect and use personal information you provide (such as your name, contact details, work history, and application materials) to evaluate your application, communicate with you, and comply with legal obligations. Your application data is processed through Greenhouse, our applicant tracking system, and may also be reviewed using AI-assisted screening tools. We do not sell your personal information. California residents have rights under the CCPA/CPRA including to know, delete, and opt out of the sharing of their personal information. If you are located in the EU or UK, we process your data under GDPR and you have rights to access, rectify, and erase your data. To exercise your rights or for questions, contact View email address on aiapply.co.

The salary range for this role is $148,000 - $203,500. Compensation for the role will depend on a number of factors, including a candidate’s qualifications, skills, competencies, and experience. Pioneering Medicines currently offers healthcare coverage, annual incentive program, retirement benefits and a broad range of other benefits. Compensation and benefits information is based on Pioneering Medicines's good faith estimate as of the date of publication and may be modified in the future.

Privacy Notice for Applicants: When you apply for a role at Flagship Pioneering or one of its portfolio companies, we collect and use personal information you provide (such as your name, contact details, work history, and application materials) to evaluate your application, communicate with you, and comply with legal obligations. Your application data is processed through Greenhouse, our applicant tracking system, and may also be reviewed using AI-assisted screening tools. We do not sell your personal information. California residents have rights under the CCPA/CPRA including to know, delete, and opt out of the sharing of their personal information. If you are located in the EU or UK, we process your data under GDPR and you have rights to access, rectify, and erase your data. To exercise your rights or for questions, contact View email address on aiapply.co.