Pioneering Medicines: Senior /Executive Director, Head of Toxicology

What if... We could harness the power of Flagship’s scientific platforms and create novel treatment options that benefit more patients, sooner? 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. 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. The role provides scientific and strategic leadership across both investigative and regulatory toxicology, supporting a broad range of therapeutic modalities. Location and Travel This role can be onsite at our Cambridge, MA site or, if you are over 30 miles away, remote with travel 3–4 days per month. Key Responsibilities Functional Leadership & Capability Building 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 Portfolio & Program Strategy 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 External Partnerships & Regulatory 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 Qualifications 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 Leadership Profile 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 Salary and Benefits Salary range: $228,000 – $310,000. Compensation will depend on factors including candidate’s qualifications, skills, competencies, and experience. Pioneering Medicines offers healthcare coverage, an annual incentive program, retirement benefits, and a broad range of other benefits. #J-18808-Ljbffr Flagship Pioneering