Pioneering Medicines: Senior Director, Head of Toxicology

Position Summary

The Senior Director, Head of Toxicology will lead and build the toxicology function within Pioneering Medicines, defining and executing nonclinical safety strategies across a diverse and rapidly evolving portfolio. This role provides scientific and strategic leadership across both investigative and regulatory toxicology, supporting a broad range of therapeutic modalities.

Working in a dynamic venture creation environment, you will collaborate closely with multidisciplinary teams to optimize candidate selection, guide preclinical development, and ensure regulatory readiness. This is a high-impact role requiring strong analytical thinking, scientific rigor, and clear communication, influencing programs from discovery through early clinical development.

• Lead, build, and scale the toxicology function, including internal team development and external partnerships
• Define fit-for-purpose operating models spanning investigative and regulatory toxicology
• Serve as the primary internal expert for nonclinical safety, ensuring quality, consistency, and scalability across the portfolio
• Define and drive toxicology strategies across multiple programs and modalities
• Translate findings into clear risk assessments, mitigation strategies, and IND/CTA-enabling plans
• Enable transparent, data-driven decision-making by articulating risks, assumptions, and trade-offs to program teams
• Oversee the design, execution, and interpretation of non-GLP and GLP toxicology studies
• Partner cross-functionally (DMPK, pharmacology, CMC, clinical) to integrate safety into development strategy
• Support diligence and evaluation of new programs within Flagship’s ecosystem
• Build and manage a high-performing CRO and consultant network, ensuring quality, timelines, and cost efficiency
• Leverage and contribute to the Flagship ecosystem, fostering knowledge sharing and collaboration across platform companies
• Lead nonclinical regulatory strategy and documentation (INDs, IBs, briefing materials)
• Ensure regulatory readiness through clear and scientifically robust safety narratives
• Represent toxicology in regulatory interactions as appropriate

• PhD, DVM, or equivalent in Toxicology, Pathology, Pharmacology, or related field
• 10-15+ years of experience in nonclinical safety in biotech/pharma
• Proven track record advancing programs through IND and into clinical development
• Experience across multiple modalities preferred
• Strong experience managing CROs and external collaborations
• Experience leading or building a toxicology function or team, including management of internal scientists and/or external partners, is a plus

• Enterprise mindset; able to operate across a portfolio in a fast-paced, collaborative environment
• Analytical and goal-oriented, with the ability to operate with urgency while maintaining high standards of scientific rigor and ethics
• Strong communicator who can translate complex toxicology into clear, audience-appropriate risk assessments, from early-stage teams to large pharma partners

The salary range for this role is $228,000 - $280,000. 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, an annual incentive program, retirement benefits, and a broad range of other benefits.