Director, Head of Investigative Toxicology

Director, Head of Investigative Toxicology

Build Nurix’s in-house in vitro toxicology capability from the ground up. As Director, Head of Investigative Toxicology, you’ll establish the assays, infrastructure and mechanistic understanding to identify target- and modality-related safety liabilities earlier in discovery, shaping lead selection for our growing pipeline of targeted protein degrader programs. This is a hands-on, lab-based leadership role.

Position Description

The Opportunity

• Nurix Therapeutics is seeking a Head of Investigative Toxicology to establish and lead our in-house in vitro toxicology testing capability. Reporting into the Preclinical Toxicology leadership team, this individual will build the assays, infrastructure, and mechanistic understanding needed to characterize target- and modality-related safety liabilities earlier in discovery, reducing reliance on external CROs for early screening and de-risking. This is a hands-on, lab-based leadership role for a scientist who wants to build a function from the ground up, working in close partnership with Discovery Biology, Chemistry, DMPK, and Pharmacology to inform lead selection and optimization for our growing pipeline of targeted protein degrader programs. The position reports to the Senior Vice President, Nonclinical Toxicology.

In Vitro Toxicology Capability Build

• Design, establish, and validate an in-house in vitro toxicology testing platform, including assay selection, equipment procurement, protocol development, and standard operating procedures
• Develop and implement in vitro toxicology (primary and immortalized cell culture, hepatocyte and iPSC cardiomyocyte models) assays to screen for cytotoxicity and off-target liabilities
• Define the technical roadmap and prioritize which in vitro assays to bring in-house versus continue to source through CRO partners, balancing scientific value, cost, and speed
• Own day-to-day lab operations for the function, including equipment maintenance, vendor and reagent management, and data management systems

Investigative & Mechanistic Toxicology

• Serve as the in vitro/investigative toxicology representative on discovery project teams, providing mechanistic insight into target and modality-related safety findings
• Design and interpret investigative studies to elucidate mechanisms of toxicity, including neosubstrate and off-target degradation risk relevant to targeted protein degrader molecules
• Partner with DMPK, Pharmacology, and Discovery Biology to integrate in vitro toxicology data into candidate selection, structure-activity relationship (SAR), and lead optimization decisions
• Translate in vitro findings into risk assessments and clear recommendations for project teams and research leadership

Team & Culture

• Hire, mentor, and develop scientific staff as the in vitro toxicology function grows
• Represent in vitro/investigative toxicology in Research Leadership meetings and contribute to the broader nonclinical safety strategy
• Foster a collaborative, science-driven culture consistent with Nurix’s values of rigor, creativity, and patient focus

What You’ll Bring

Required Qualifications

• PhD in Toxicology, Pharmacology, Molecular Biology, or a closely related life sciences discipline; postdoctoral training preferred
• 10+ years of relevant nonclinical safety, investigative toxicology, or molecular/cellular toxicology experience in the pharmaceutical or biotechnology industry, including direct, hands-on laboratory experience with in vitro and/or complex in vitro (MPS) model systems
• Demonstrated experience building, validating, and implementing new in vitro assay platforms or laboratory capabilities in an industry setting
• Strong working knowledge of mechanisms of drug-induced toxicity and the in vitro tools used to investigate them (e.g., high content imaging, primary and immortalized cell culture, hepatocyte/cardiomyocyte models, genotoxicity assays)
• Proven ability to translate in vitro data into actionable risk assessments and communicate findings clearly to cross-functional project teams and senior leadership
• Experience managing CRO relationships and evaluating build-versus-buy decisions for laboratory capabilities

Preferred Qualifications

• Experience with targeted protein degradation (TPD) or other novel small molecule modalities, including neosubstrate/off-target degradation risk assessment
• Experience establishing or scaling a laboratory function within a growing, clinical-stage biotech
• Familiarity with New Approach Methodologies (NAMs) and organ-on-chip/microphysiological systems
• People management or mentoring experience
• Strong publication record in investigative or molecular toxicology

Salary Range: $240,100 - $281,700

The posted range applies to roles based in the San Francisco Bay Area and reflects local market conditions. Where an offer lands within that range depends on the candidate’s relevant experience, technical expertise, and how their background aligns with the role’s requirements

Location: Onsite – Brisbane, CA

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