Associate Director, Toxicology

About Parabilis Medicines Parabilis Medicines is a clinical-stage biopharmaceutical company dedicated to creating extraordinary medicines for patients with serious diseases by unlocking biologically important targets long considered undruggable. The company has pioneered a new class of alpha-helical peptides – Helicons™ – capable of modulating intracellular proteins that have historically been beyond the reach of conventional medicines. The company’s lead investigational medicine, zolucatetide, is the first and only direct inhibitor of the β-catenin:TCF interaction, a central node in the Wnt/β-catenin pathway that has eluded drug developers for decades. Zolucatetide is being evaluated in the clinic across multiple Wnt/β-catenin-driven diseases, including desmoid tumors, familial adenomatous polyposis (FAP) and a range of other solid tumor indications. Beyond zolucatetide, Parabilis is advancing additional Helicon-based programs focused on other challenging targets where we believe our medicines could have life-altering impact. For more information, visit or follow us on LinkedIn. What's the opportunity? Parabilis Medicines is seeking a highly motivated and driven Associate Director, Toxicology to lead nonclinical safety programs across a diverse pipeline built on Parabilis’ clinically validated Helicon™ pipeline. This is a hands-on scientific leadership role embedded in the discovery and early development organization, with accountability for advancing candidates from lead optimization through IND filing and beyond. The successful candidate will serve as the nonclinical safety lead on cross-functional project teams, working autonomously to define strategy, drive execution, influence candidate selection, and ensure robust safety assessment across our pipeline. Discovery-Stage / IND-Enabling Safety Engagement Partner with discovery teams during Pre-LO/LO to identify safety liabilities, design early safety profiling studies, and guide candidate selection through science-based risk assessment. Serve as the primary toxicology lead on project teams, driving alignment across multiple Research and Clinical functions to ensure integrated and timely IND readiness. Develop and communicate candidate-specific toxicology risk assessments and go/no-go recommendations to project teams and leadership. Apply knowledge of injectable formulations (subcutaneous, intravenous, intramuscular) to anticipate and address local tolerance, excipient toxicity, and route-of-administration-specific safety considerations. Design and oversee the complete IND-enabling nonclinical safety package, including acute and repeat-dose toxicology, safety pharmacology, genotoxicity, and local tolerance studies, across relevant species. In collaboration with project team, select appropriate species, routes of administration, doses, and study durations based on scientific rationale and regulatory expectations Author and own nonclinical sections of INDs and CTAs and support regulatory interactions Maintain awareness of evolving FDA, EMA, and ICH guidance and proactively apply updates to program strategy. CRO Management & Study Execution Select and manage CROs and specialty contract laboratories for GLP and non-GLP preclinical studies. Review study protocols, amendments, and final reports to ensure scientific rigor, GLP compliance, and alignment with regulatory expectations. Monitor study progress, interpret interim data, and make real-time scientific decisions to address unexpected findings or deviations. Oversee test article logistics, dose formulation preparation and stability, and chain-of-custody in coordination with CMC and Pharmaceutical Sciences. Scientific Leadership Operate with a high degree of scientific independence, defining strategy, prioritizing work, and resolving safety questions in close collaboration with project team. Communicate complex nonclinical safety data clearly and confidently to internal project teams, senior leadership, and external partners. Mentor junior scientists across the organization and contribute to scientific best practices Champion innovation in nonclinical safety tools and methodologies, including New Approach Methodologies (NAMs), organoid/microphysiological systems, and in silico predictive models, to reduce animal use and accelerate timelines. What you'll need to be successful: DVM or PhD in Toxicology, Pathology, Pharmacology, or a closely related discipline with 8+ years of industry experience in drug development. DABT certification preferred. Demonstrated, hands-on experience leading nonclinical safety programs from early discovery (lead optimization) through IND filing—not solely regulatory or late-stage development experience. Experience supporting multiple modalities, including small molecules and at least one of the following: siRNA/oligonucleotides, therapeutic peptides, PROTAC degraders, ADCs, or mRNA. Experience with injectable drug products (IV, SC, and/or IM) is required; familiarity with local tolerance study design and excipient/formulation safety assessment. Proven ability to function as an independent scientific leader on project teams, setting strategy, driving decisions, and defending nonclinical positions. Strong working knowledge of relevant ICH guidelines (M3(R2), S6(R1), S7A/B, S8, S9), GLP regulations (21 CFR Part 58), and FDA/EMA regulatory expectations for IND-enabling packages. Demonstrated CRO management experience across GLP and non-GLP studies with a track record of delivering high-quality IND-enabling packages on time. Excellent written and verbal communication skills with ability to author clear, regulatory-quality nonclinical documents and present complex data to diverse audiences. Familiarity with in vitro NAM-based safety tools (e.g., microphysiological systems, iPSC-derived models, QSAR/in silico platforms) preferred. Experience contributing to regulatory agency meetings, responding to nonclinical IND-related queries, and supporting due diligence and in-licensing evaluations preferred. Ability to work-on-site and attend in person meetings. Ability to travel up to 15%. Core Values Parabilis Medicines is a team of passionate pioneers who are trailblazing the future of precision medicine with the aim of making a meaningful difference in the lives of patients. The company is committed to promoting an inspiring and flourishing working environment for all employees across the business, in all departments, and driving innovation for patient benefit. Growth-Minded. We’re inventing a new class of medicines—one applicable to therapeutic targets that have been dreamt about, but always considered impossible to drug. Our work requires us to be curious, humble and adaptable. In(ter)dependent. We are fiercely independent as a leader in defying the limitations of current therapeutic modalities, and interdependent as a team as we work collaboratively to shift drug discovery paradigms and provide patients with better treatment options. Patient-focused. We are deeply focused on patient outcomes, and all energy in the company is focused on science as it translates to patient impact. All-In. We’re All-In on solving some of the hardest scientific challenges and delivering one of the most effective new classes of drugs in history. The base salary range for this position is $170,000-$210,000 per year, depending on experience, qualifications, and internal practices. Parabilis’s total compensation package also includes an annual target bonus, equity, and a comprehensive suite of competitive benefits designed to support our employees’ overall well-being. As an equal opportunity employer, Parabilis Medicines values an inclusive workplace and welcomes applicants of all backgrounds and experiences. All qualified applicants will receive consideration for employment without discrimination on the basis of race, color, religion, sex, sexual orientation, gender identity, national origin, protected veteran status, disability, or any other factors prohibited by law. 30 Acorn Park Drive | Cambridge, MA 02140 |