Associate Director, Toxicology

Carlsbad, CAFull-time$173k–$255kPosted Jun 12, 2026

Headquartered in Carlsbad, California, and with offices in Boston, Massachusetts, and Dublin, Ireland, Ionis has been at work for more than three decades discovering medical breakthroughs that have redefined life for people with serious diseases. We’re pioneers in RNA-targeted medicines, and our platform continues to revolutionize drug discovery and transform lives for patients with unmet needs. With multiple marketed medicines and a leading pipeline in neurology, cardiology and select areas of high patient needs, we continue to drive innovation in RNA therapies in addition to advancing new approaches in gene editing to provide greater value to patients and are well positioned financially to deliver on our strategic goals.

At Ionis, we pride ourselves on cultivating a challenging, motivating and rewarding environment that fosters innovation and scientific excellence. We know that our success is a direct result of the exceptional talents and dedication of our employees.

With an unprecedented opportunity to change the course of human health, we look to add diverse individuals, skill sets and perspectives to our exceptional team. We continue to invest time, money and energy into making our onsite, hybrid and remote work environments a place where solid and lasting relationships are built and where our culture and employees can thrive.

We’re building on our rich history, and we believe our greatest achievements are ahead of us. If you’re passionate about the opportunity to have meaningful impact on patients in need, we invite you to apply and join us. Experience and contribute to our unique culture while you develop and expand your career!

ASSOCIATE DIRECTOR, TOXICOLOGY

SUMMARY:

Ionis is seeking a talented and highly motivated Toxicologist to join the Preclinical Development Department and provide scientific leadership in the nonclinical safety assessment of drug candidates. The department is composed of highly collaborative scientists and offers a supportive environment that fosters professional growth and continuous learning. The expectation will be for this person to work on site in Carlsbad, CA.

RESPONSIBILITIES:

Serve as the nonclinical safety representative on cross-functional project teams, providing strategic toxicology input to support candidate selection, risk assessment, and program advancement
Design, oversee, and interpret non-GLP and GLP nonclinical pharmacology and toxicology studies
Manage outsourced toxicology studies at CROs, including study design, protocol and report review, issue resolution, and timeline management
Drive integrated nonclinical safety assessments by synthesizing pharmacology, toxicology, clinical pathology, and TK/PK data
Develop nonclinical toxicology and regulatory strategies for assigned programs
Author and review nonclinical sections of regulatory documents, including Investigator's Brochures, INDs, NDAs, DSURs, and related submissions, and represent Ionis in interactions with regulatory authorities
Assess toxicology findings and mechanisms of toxicity to determine human relevance and development impact
Communicate key nonclinical safety findings, risk assessments, and development implications to project teams and governance committees
Partner effectively with internal functional teams and external collaborators to advance programs in a matrixed development environment
Represent Ionis externally through scientific meetings, industry consortia, working groups, and professional societies
Contribute to scientific publications in high-impact, peer-reviewed journals

REQUIREMENTS:

Master’s or Doctoral degree in Toxicology or a related life sciences discipline
At least 8 years (Master’s degree) or 5 years (Ph.D.) of experience in nonclinical safety within the pharmaceutical or biotechnology industry.
Experience managing outsourced studies and working with CROs, including protocol and report development or review, as well as timeline management
Experience generating, integrating, reviewing, and interpreting toxicology data
Experience authoring regulatory documents such as IBs, INDs, CTDs, and other health authority submissions
Demonstrated ability to work effectively as a senior individual contributor in a matrixed environment, influencing without direct authority across scientific and functional teams
Proven ability to convey advanced scientific information and persuade diverse stakeholders, including project teams, senior leadership and governance committees
Commitment to lifelong learning and professional development, including building or expanding subject matter expertise

PREFERRED:

DABT certification, or a strong interest in obtaining DABT certification

Please visit our website, http://www.ionis.com for more information about Ionis and to apply for this position; reference requisition # IONIS004030

Ionis offers an excellent benefits package! Follow this link for more details: Ionis Benefits

Full Benefits Link: https://ionis.com/careers#:~:text=Highly%20competitive%20benefits

The pay scale for this position is $172,501 to $255,000

NO PHONE CALLS PLEASE. PRINCIPALS ONLY.

Ionis Pharmaceuticals, Inc. and all its subsidiaries are proud to be EEO employers.