Principal/Senior Scientist, PK/PD Assays
Newlimit · South San Francisco · Posted Jul 2, 2026
Apply on company site Track it in JobSkout
About NewLimit
NewLimit is seeking a Scientist or Senior Scientist with deep expertise in molecular biology, pharmacokinetics and translational biomarker assay development. In this role, you will lead the design, development, and qualification of pharmacokinetic (PK) and pharmacodynamic (PD) assays that characterize the biodistribution and biological activity of our mRNA-LNP medicines in preclinical and IND enabling studies. You will serve as a technical leader within our bioanalytical function, shaping biomarker assay strategy and partnering cross-functionally to advance our therapeutic programs toward IND-enabling milestones.
What you’ll do
Own the end-to-end design, development, and qualification of PK and PD biomarker assays across various platforms to support preclinical and IND-enabling studies
Discover and validate pharmacodynamic biomarkers to support the clinical development of drugs across multiple programs
Drive data analysis, interpretation, and reporting for bioanalytical studies to support program decision-making with audit-ready data packages
Contribute to sample processing workflows including tissue harvesting, primary cell culture, and complex matrix handling
Mentor research associates, establish SOPs, and build institutional knowledge within the bioanalytical function
Requirements
PhD in molecular biology, biochemistry, cell biology, or a related field or equivalent industry experience (5+ years)
3+ years of hands-on experience in various quantitative bioanalytical assay platforms (e.g., RT-qPCR, ddPCR, ELISA, MSD, Olink, SOMAscan, NGS-based methods) in complex biological matrices (serum, plasma, tissue homogenates)
Strong working knowledge of bioanalytical method qualification/validation principles for PK/PD biomarker measurements, including familiarity with ICH M10 guidelines and fit-for-purpose frameworks
History of delivering results for bioanalytical projects -- you've discovered a PD biomarker or built an assay and solved all the problems along the way
Experience with primary cell culture and tissue-derived sample workflows
Nice to have
Track record of bioanalytical method transfer and CRO management for outsourced projects
Familiarity with preclinical drug development timelines and regulatory submissions (IND, TGA, CTD format)
Experience with mRNA-LNP biodistribution or nucleic acid–based PK assays
Experience developing products in emerging therapeutic modalities (gene therapy, nucleic acid therapies, cell therapy)
Benefits
NewLimit provides generous benefits so our team can remain focused on our mission:
Comprehensive Health, Dental, and Vision insurance
401(k) plan with company match
Paid parental leave
Industry-leading PTO: 20 days per year plus holidays
On-site meals and snacks
Salary Range: $155,000 to $200,000. Compensation for the role will depend on a number of factors, including a candidate’s qualifications, skills, competencies, and experience. NewLimit offers a competitive benefits package, which includes a 401k, healthcare coverage, and 20 days of PTO. Learn more at: https://www.newlimit.com/careers *This compensation and benefits information is based on Company's good faith estimate as of the date of publication and may be modified in the future.