Director / Senior Director, Toxicology

The Company

Prolynx is a preclinical biotechnology company with a vision to become the industry leader in ultra-long-acting medicines that improve outcomes for patients with obesity, cardiometabolic, and other diseases. The company is developing a next-generation portfolio of incretin and non-incretin therapeutics designed for once-monthly and once-quarterly dosing.

Its proprietary, first-in-category platform uses a hydrogel-based microsphere technology with independently tunable release-linker chemistry to enable highly predictable pharmacokinetics and sustained drug exposure. Prolynx is backed by leading investors including 5AM Ventures, OrbiMed, and Monograph Capital and is based in Emeryville, CA.

Join a multidisciplinary team of talented scientists developing innovative and differentiated medicines - where we pursue purposeful science and let data and patient needs drive decisions. Prolynx provides an environment where you work, learn, and grow alongside experienced drug developers, inventive scientists, and business professionals. Bring your passion, creativity, and energy to our mission.

At Prolynx, contributions are valued regardless of title, people are trusted to own their area of expertise, and teammates readily step in to help one another. We share what we know and succeed together. If that sounds like the place for you, we’d like to meet you.

The Role

We are seeking an experienced leader in toxicology to build and direct nonclinical safety strategy as Prolynx advances its ultra-long-acting, hydrogel-based conjugate therapeutics toward and through the clinic. You will lead the toxicology function and address needs across the portfolio, addressing systemic safety of peptide payloads, and you serving as the primary nonclinical safety voice on program teams, with regulatory agencies, and with senior leadership.

Prolynx has an efficient, outsourced model for nonclinical safety. You will lead a global network of toxicology CROs and work hand in hand with expert nonclinical consulting partners to design, execute, and monitor critical studies. You will author reports and regulatory documents, ensure that all studies are designed well, conducted to GLP standards, and accepted by regulators.

As a member of the Preclinical Leadership Team, you will serve as a senior scientific voice shaping program strategy, resourcing and go/no-go decisions alongside the Chief Scientific Officer and other functional leaders.

What You Will Do

• Responsible for nonclinical safety for Prolynx's portfolio, integrating toxicology with DMPK, In Vivo Pharmacology, CMC and Clinical Development from lead selection through IND and early clinical development.
• Design, oversee and interpret GLP and non-GLP toxicology studies at CROs, including dose-range-finding, repeat-dose toxicology, safety pharmacology, genetic toxicology and local tolerance studies tailored to our unique platform.
• Lead safety assessment of the delivery platform itself, biocompatibility and clearance, alongside the systemic toxicology of each payload.
• Manage a global CRO network, including CRO selection and qualification, GLP and data-integrity oversight, contracting, budgets and timelines across sites.
• Author and review nonclinical sections of regulatory submissions, including INDs, IMPDs, Investigator's Brochures and briefing documents, and potentially represent Prolynx in meetings with FDA and other health authorities.
• Lead Project Teams for programs advancing through preclinical discovery and development.

Key Responsibilities

• Preclinical safety through stage gates
• Define stage specific safety data needed and give clear go/no-go recommendations.
• Conduct exploratory safety studies effectively in a timely manner to shape candidate selection
• Proactively build safety plans for both preclinical and clinical development.
• Design strategies and studies as appropriate and in line with regulatory guidance and the 3Rs.
• Take ownership of preclinical development activities on teams as functional team member/PTL.
• Address class effects of target payloads, such as exaggerated pharmacology limiting doses in animals, and set appropriate safety margins.
• Assess immunogenicity and hypersensitivity risks.
• Design combination toxicology strategies for pharmacokinetically matched multi-payload drugs.
• Global CRO and partner management
• Select, qualify, and audit CROs globally, confirming GLP compliance, data integrity and the acceptability of study data to FDA and other regulators.
• Manage logistics for global studies, including shipments, and on-site/remote study monitoring.
• Arrange independent pathology peer review and ensure SEND-compliant datasets for regulatory submissions.
• Work with partners, review reports and regulatory writing, and integrate with safety strategy.
• Regulatory and cross-functional leadership
• Author and critically review nonclinical safety sections of IND and IMPD filings, Investigator's Brochures and other documents, and lead pre-IND and other regulatory nonclinical interactions.
• Assess or work with DMPK to inform toxicokinetics and safety margins against projected human exposure, and work with Clinical Development colleagues on first-in-human dose selection and safety monitoring.
• Work with CMC on impurity qualification and safety of formulation and manufacturing changes.
• Present integrated safety risk assessments to executive leadership.

Who You Are

• Required
• PhD, DVM or equivalent in toxicology, pharmacology or a related discipline.
• Minimum 10 years (12+ strongly preferred) of toxicology experience in biotech or pharma industry, including leading nonclinical safety strategy for programs through clinic.
• Extensive knowledge of GLP study design, safety pharmacology and regulatory expectations for nonclinical safety packages, including ICH M3(R2), S7A/B and related guidance.
• Directly authored nonclinical sections of IND or IMPD submissions with record of participation in health authority interactions preferred.
• Managed studies at CROs international with strong record of execution and budget control.
• Set scientific strategy and influence program and portfolio decisions at a leadership level (functional leadership or leadership as a project team lead).
• Preferred
• DABT board certification.
• Experience with peptide, biologic, or controlled-release and depot drug products, including local tolerability and delivery-system biocompatibility.
• Experience with incretin, amylin or other metabolic therapies.
• Experience qualifying degradation products, impurities or PEGylated materials.
• Experience with CRO auditing and data-integrity review.
• Experience with 505(b)(2) or other bridging strategies for known active ingredients.
• Familiarity with new approaches or methodologies that reduce animal use.
• Strong statistical skills for in vivo study design and analysis, and can integrate complex data sets to inform drug development strategy.
• Hands-on PK/PD or exposure-response modeling (for example Phoenix WinNonlin, NONMEM, Monolix or R) and calculation of human dose projection.
• How you work
• Fluid, clear and articulate communication style.
• Poised working with CROs, consultants and regulators across cultures and time zones.
• Experience with diverse perspectives and working collaboratively on multidisciplinary teams.
• Demonstrated track record of scientific rigor and creativity in carrying out research.
• Excel in nimble, fast-moving and outsourced environments.

What We Offer

• Define the safety strategy for a new class of ultra-long-acting medicines.
• Opportunity to work with an innovative platform designed to make obesity medicines better tolerated with monthly to quarterly dosing.
• Base salary range: $220,000 to $250,000, plus annual bonus and equity. Title and final pay depend on experience and qualifications.
• Comprehensive medical, dental and vision benefits, a 401(k) plan and paid time off.

How to Apply

Please send your CV and a short cover letter describing your most relevant nonclinical safety programs when applying.

We are an equal opportunity employer. We do not discriminate in regard to race, color, religion, national origin, age, sex, sexual orientation, gender identity, marital status, ancestry, physical or mental disability, veteran status, or any other legally protected characteristics.

Please note that we do not accept unsolicited resumes from recruitment agencies and external recruiters. No fees will be paid for such submissions.