Principal Scientist, Biology

About Xaira Therapeutics

Xaira is an innovative biotech startup focused on leveraging AI to transform drug discovery and development. The company is leading the development of generative AI models to design protein and antibody therapeutics, enabling the creation of medicines against historically hard-to-drug molecular targets. It is also developing foundation models for biology and disease to enable better target elucidation and patient stratification. Collectively, these technologies aim to continually enable the identification of novel therapies and to improve success in drug development. Xaira is headquartered in the San Francisco Bay Area, Seattle, and London.

About the Role Xaira Therapeutics is seeking a lab-based Principal Scientist in Inflammation and Immunology to join our Biology & Pharmacology department. This role is ideal for someone who combines hands-on research expertise with strategic program leadership, has experience working with primary human and mouse immune cells, including ex vivo tissue systems, and is excited to shape and drive therapeutic program strategy.

In this role, you will set the scientific direction for one or more therapeutic programs, generate and advance new biology target ideas, and produce actionable data that moves programs forward through cross-functional collaboration. You will also serve as a key scientific voice to senior leadership, presenting findings and recommendations that inform program and portfolio decisions.

What You’ll Do

• Drive program strategy by defining research priorities, designing and overseeing in vitro and in vivo studies, and guiding decisions on disease biology, target validation, and lead candidate development.
• Generate and advance new biology target ideas by evaluating novel targets and therapeutic strategies and building the scientific rationale to move them into active programs.
• Identify knowledge gaps, ask critical mechanistic questions to guide program direction, and shape experimental strategy across multiple workstreams.
• Translate experimental data into actionable insights and present findings and recommendations to senior leadership and cross-functional teams to inform program strategy.
• Stay hands-on at the bench, personally designing, executing, and troubleshooting key experiments, particularly for high-priority or technically challenging studies where direct expertise is needed to move a program forward.
• Establish primary cell cultures from human and mouse tissues to support downstream functional and phenotypic characterization assays, including:
• Immune profiling — via high-parameter flow cytometry (15+ colors) and complementary molecular platforms (ELISA, MSD, Luminex, qPCR, RNA-seq)
• Functional assays — including antigen presentation, immune cell activation, differentiation, proliferation, suppression, and migration
• Serve as a scientific leader and mentor within the department, contributing to the technical development of junior scientists and shaping best practices across the group, while continuing to model strong hands-on lab practice.

What We’re Looking For

• PhD in Immunology or a related field with 6+ years of relevant experience.
• Track record of impact through first-author publications, posters, and presentations at meetings
• Demonstrated ability to independently define research strategy, plan and oversee complex experiments, and interpret data to guide program direction.
• Experience generating and advancing novel target hypotheses, with the scientific judgment to prioritize among competing ideas.
• Strong expertise in in vitro and ex vivo immunology, including primary immune assays, co-culture systems, target cell depletion assays, and high-parameter flow cytometry.
• Single-cell RNA sequencing (scRNAseq), CRISPR/Cas9, and omics data analysis experience is a plus
• Proven ability to independently plan, execute, troubleshoot, and interpret experiments.
• Comfortable and enthusiastic about leveraging AI tools to support research design, data analysis, and daily workflows
• Highly organized and precise in record keeping, with the ability to manage multiple workstreams in a fast-paced environment.
• Clear, confident communicator who can distill complex data into actionable insights for senior leadership and cross-functional partners. Proven ability to work effectively in team environments
• Out-of-the-box thinker who brings a creative and innovative approach to identifying and validating novel targets, challenging conventional assumptions to uncover new opportunities

Compensation

We offer a competitive compensation and benefits package, seeking to provide an open, flexible, and friendly work environment to empower employees and provide them with a platform to develop their long-term careers. A Summary of Benefits is available for all applicants. We offer a competitive package that includes base salary, bonus, and equity. The base pay range for this position is expected to be $164,000-$205,000 annually; however, the base pay offered may vary depending on the market, job-related knowledge, skills and capabilities, and experience.

Xaira Therapeutics an equal-opportunity employer. We believe that our strength is in our differences. Our goal to build a diverse and inclusive team began on day one, and it will never end.

TO ALL RECRUITMENT AGENCIES: Xaira Therapeutics does not accept agency resumes. Please do not forward resumes to our jobs alias or employees. Xaira Therapeutics is not responsible for any fees related to unsolicited resumes.