Associate Director / Director, Toxicology

Company Summary: Korro is a biopharmaceutical company focused on developing a new class of genetic medicines for both rare and highly prevalent diseases using its proprietary RNA editing platform. Korro is generating a portfolio of differentiated programs that are designed to harness the body’s natural RNA editing process to effect a precise yet transient single base edit. By editing RNA instead of DNA, Korro is expanding the reach of genetic medicines by delivering additional precision and tunability, which has the potential for increased specificity and improved long-term tolerability. Using an oligonucleotide-based approach, Korro expects to bring its medicines to patients by leveraging its proprietary platform with precedented delivery modalities, manufacturing know-how, and established regulatory pathways of approved oligonucleotide drugs. Korro is based in Cambridge, Massachusetts.

Korro Bio is seeking a highly motivated Associate Director or Director of Toxicology to lead the design and execution of nonclinical safety studies across our RNA editing portfolio. Reporting to the Senior Director, DMPK, this individual will be a key scientific and strategic contributor responsible for building and advancing Korro’s toxicology capabilities, with an emphasis on oligonucleotide-based therapeutics. The ideal candidate brings deep experience in nonclinical development, a collaborative mindset, and a passion for bringing novel genetic medicines to patients.

Lead the design, execution, and interpretation of GLP and non-GLP toxicology studies to support target assessment, platform innovation initiatives, development candidate selection and regulatory submissions.

Serve as the toxicology subject matter expert on cross-functional program teams, contributing to overall project strategy and decision-making.

Develop and implement nonclinical safety strategies specific to oligonucleotide therapeutics, including considerations for sequence, chemistry, delivery, and off-target effects.

Experience designing, outsourcing, and overseeing nonclinical toxicology studies at external CROs, including international vendors; prior experience working with CROs in China (or broader APAC region) is highly desirable. Mandarin language skills are a plus, particularly for candidates with experience working with China based CROs.

Ensure high-quality execution of all external safety studies and timelines, including general toxicology, safety pharmacology, genetic toxicology, and immunotoxicology as needed.

Prepare reports and presentations for internal and external audiences.

Prepare and review regulatory documentation, including INDs, CTAs, Investigator’s Brochures, and responses to health authority queries.

Author and/or oversee preparation of nonclinical sections for regulatory submissions across the product lifecycle, including INDs and later-stage filings (NDA/BLA), with responsibility for Module 2 summaries, study reports, and health authority responses.

Contribute to regulatory strategy and agency interactions, with experience with accelerated development pathways and/or rare disease programs being highly desirable.

Represent Korro in regulatory interactions, including pre-IND and other milestone meetings.

Stay current on regulatory guidelines, safety assessment trends, and emerging science relevant to oligonucleotide and RNA-based therapies.

Mentor and develop junior scientists and contribute to a culture of scientific rigor, collaboration, and innovation.

PhD, DVM, or equivalent in toxicology, pharmacology, or related field; board certification (e.g., DABT) strongly preferred.

6-10+ years of relevant industry experience in toxicology, with a strong track record of supporting mechanistic toxicology and IND-enabling programs.

Deep knowledge of global regulatory expectations, ICH guidelines, and GLP principles.

Strong leadership, communication, and organizational skills, with the ability to work effectively in a fast-paced, matrixed environment.

Proven ability to influence across functions and effectively interface both internal and external stakeholders.

Hands-on experience with oligonucleotide-based therapeutics is a plus.

Mandarin language proficiency is a plus, particularly for candidates with experience collaborating with China based CROs

Familiarity with GalNAc or other delivery systems is a plus.