Senior Bioanalytical Scientist — PK/PD & Target Engagement

Xaira Therapeutics; South San Francisco (CA); On-site; USD 110,000 - 138,000; Full time

Job summary

Xaira Therapeutics in South San Francisco is seeking a Principal Associate Scientist to join our Bioanalytical Sciences team. This hands-on, lab-based role focuses on developing ligand binding assays to support PK, PD, and target engagement across discovery programs.

You will work closely with scientists across biology and pharmacology to generate high-quality data that informs ongoing discovery efforts and candidate selection.

Qualifications

• B.S. or M.S. in Biochemistry, Immunology, Analytical Chemistry, or a related field with 7+ years of industry experience.
• Hands-on experience with ligand binding assay platforms (ELISA, MSD/ECL).
• Experience executing flow cytometry-based assays for receptor occupancy or target engagement.

Responsibilities

• Develop, optimize, and execute ligand binding assays (ELISA, MSD/ECL) and flow cytometry-based methods to support PK, PD, receptor occupancy, and target engagement studies for biologic programs
• Support assay development, qualification, and validation for non-GLP, IND-enabling GLP, and clinical studies
• Contribute to design and execution of DMPK and bioanalytical studies to generate PK/PD data for candidate selection
• Support bioanalytical method development, qualification, and validation across discovery, translational, and clinical programs
• Process and analyze samples across NHP and rodent matrices (serum, plasma, tissue)
• Generate, analyze, and document experimental data to support team decisions
• Prepare presentations and data summaries to communicate findings with internal program groups and CROs
• Maintain accurate lab records and ensure reproducibility of workflows
• Collaborate with cross-functional teams to support ongoing research programs

Skills

Ligand binding assays

Flow cytometry

PK/PD analysis

Independent troubleshooting

Data presentation

Education

B.S. or M.S. in Biochemistry, Immunology, Analytical Chemistry, or related field

Job description

Xaira Therapeutics in South San Francisco is seeking a Principal Associate Scientist to join our Bioanalytical Sciences team. This hands-on, lab-based role focuses on developing ligand binding assays to support PK, PD, and target engagement across discovery programs.

You will work closely with scientists across biology and pharmacology to generate high-quality data that informs ongoing discovery efforts and candidate selection.