Director, Toxicology

The Opportunity

As Director, Toxicology, you will provide scientific, strategic, and regulatory leadership for nonclinical safety activities across Praxis’s growing portfolio of novel small molecule and antisense oligonucleotide (ASO) therapies for CNS disorders.

You will own toxicology strategy for designated programs and lead nonclinical safety activities from discovery and candidate selection through IND-enabling development and toward NDA/MAA. You’ll provide hands-on scientific leadership, interpret emerging safety findings, and translate complex data into clear recommendations for program teams, leadership, and regulatory authorities.

You’ll thrive in this role if you bring deep toxicology expertise, strong regulatory judgment, and an ownership mindset. You anticipate risks, challenge assumptions, navigate ambiguity, and develop pragmatic paths forward—helping Praxis advance promising medicines to patients with speed and scientific rigor. As the function grows, the Director may assume responsibility for leading and developing direct reports by establishing clear priorities, providing scientific guidance and constructive feedback, and creating opportunities for increased ownership and professional growth.

Primary Responsibilities

• Own nonclinical safety strategy for assigned programs, ensuring toxicology plans support candidate selection, IND-enabling development, clinical progression, and later-stage regulatory milestones.
• Design and oversee discovery, exploratory, investigative, and regulatory toxicology studies, including non-GLP and GLP studies, from protocol development through interpretation and final reporting.
• Evaluate emerging safety findings, assess their relevance to human risk, and recommend clear, pragmatic paths forward for development teams.
• Lead regulatory toxicology activities, including contributions to INDs, CTAs, IBs, DSURs, NDA/MAA-related documents, and responses to FDA and other global health authority questions.
• Direct CROs, consultants, and other external partners, holding them accountable for scientific quality, compliance, timelines, and transparent communication.
• Partner across Discovery, DMPK, Bioanalytical, Clinical Pharmacology, Regulatory, Clinical, and other functions to integrate nonclinical safety into program strategy and decision-making.
• Represent Nonclinical Safety Assessment on cross-functional teams, communicate risks and recommendations clearly, and help ensure the right decisions are made with speed, rigor, and patient impact in mind.

Qualifications and Key Success Factors

• Master's degree or PhD preferred in Toxicology, Pharmacology, Pharmacy, Biology, or a related scientific discipline. DABT certification is desirable.
• 8+ years of relevant biotechnology, pharmaceutical, CRO, regulatory agency, or combined experience, with meaningful responsibility for nonclinical safety programs and significant experience directing or monitoring toxicology studies.
• Deep expertise in general toxicology and the design, conduct, interpretation, and reporting of nonclinical safety studies. Experience in reproductive toxicology, genetic toxicology, safety pharmacology, carcinogenicity, and/or abuse potential assessment is highly desirable.
• Strong command of regulatory toxicology, including working knowledge of ICH, FDA, OECD, and other applicable U.S. and international requirements and guidance. Prior experience as an FDA Pharmacology/Toxicology reviewer—or comparable experience navigating complex nonclinical interactions with global health authorities—is highly valued.
• In-depth knowledge of Good Laboratory Practices (GLP) and demonstrated ability to provide effective scientific oversight of GLP studies performed by external partners.
• Experience leading and developing toxicology talent, including setting clear expectations and priorities, providing scientific and career coaching, fostering accountability, trust, and continuous learning, and delegating meaningful ownership while remaining accessible for guidance and escalation.
• The physical and mental requirements of our roles include but are not limited to regular use of a computer, devices or other office equipment, clear communication, and occasional movement. You’ll need comfort with screen work, basic hand coordination, and focus. Reasonable accommodations may be made to enable individuals with disabilities to perform these functions.