(StealthCo) Director/Senior Director: Toxicology

About the role: A stealth mode biotech company is seeking a highly motivated Director / Senior Director to lead toxicology activities supporting the development of novel therapeutics. The successful candidate will play a key role in developing and executing the nonclinical toxicology strategy, including non-GLP NHP studies, GLP toxicology studies, and IND-enabling activities. This individual will work closely with internal teams and external CROs to design, execute, interpret, and report toxicology studies and will contribute to preparation of regulatory submissions. The position is a rare opportunity to play a pivotal role in the successful development of new drugs for patients within an early-stage therapeutics company backed by highly regarded investors. Key Responsibilities: - Lead development and execution of nonclinical toxicology strategies supporting candidate selection, GLP toxicology, IND-enabling activities, and first-in-human studies - Design and oversee non-GLP and GLP toxicology studies, including dose range-finding, repeat-dose, recovery, and other studies as appropriate for the development program - Partner with internal teams and external CROs to develop study designs, protocols, dosing strategies, endpoints, timelines, and data analysis plans - Serve as the primary scientific point of contact for external toxicology CROs, overseeing study design, study execution, data review, issue resolution, and delivery of high-quality study reports - Interpret toxicology, clinical pathology, histopathology, and other nonclinical data to identify potential target organ toxicities, exposure-response relationships, safety margins, and other development risks - Integrate toxicology findings with pharmacology, PK/PD, bioanalytical, CMC, and clinical development data to inform candidate selection, human dose selection, and overall development strategy - Support preparation and review of IND-enabling documentation, including nonclinical study reports, investigator materials, regulatory briefing documents, and IND submissions - Collaborate with regulatory and clinical teams to develop nonclinical sections of regulatory submissions and support interactions with regulatory agencies - Establish and maintain appropriate toxicology plans, timelines, budgets, and key milestones across development programs - Maintain detailed records, perform data analysis, and clearly communicate toxicology findings and recommendations to cross-functional teams and company leadership - Ensure toxicology activities are conducted in accordance with applicable GLP, animal welfare, quality, and regulatory standards - The person in this role will collaborate closely with scientists and operators in a fast-paced biotech startup environment and will be expected to operate effectively with a high degree of autonomy Qualifications: - PhD, DVM, or equivalent advanced degree in Toxicology, Pharmacology, Veterinary Medicine, or a related field with 10+ years of relevant industry experience preferred - Experience leading GLP toxicology and IND-enabling programs - Experience developing a toxicology strategy for a biologics program, including antibody or antibody-conjugate, from Discovery to First-In-Human - Strong understanding of nonclinical drug development for biologic therapeutics, including toxicology study design, safety assessment, exposure margins, and interpretation of toxicology findings - Experience managing external toxicology CROs, including small and large animal study design, site selection, protocol development, execution, data review, and final reports - Experience supporting IND submissions and regulatory interactions with the FDA and other agencies; experience with international submissions is a plus - Strong written and verbal communication skills, with the ability to synthesize complex nonclinical data and communicate clear conclusions and recommendations - Experience working in a small, fast-paced biotechnology environment and managing multiple priorities preferred What we offer: - Competitive compensation and benefits - A collaborative, small-team environment with growth opportunities - The opportunity to contribute to innovative drug development efforts and join an early-stage biotechnology company backed by highly regarded investors Location: Cambridge, MA (Hybrid)