---
title: 'Principal Scientist, Biology at Xaira Therapeutics'
canonical: 'https://feeny.ai/job/principal-scientist-biology-xaira-therapeutics-south-san-francisco-california-2azp7k7sb0b2'
type: 'job'
last_seen: '2026-09-14'
---

# Principal Scientist, Biology at Xaira Therapeutics

- **Company:** Xaira Therapeutics
- **Location:** South San Francisco California, United States
- **Posted:** 2026-09-08
- **Last confirmed live:** 2026-09-14
- **Apply:** https://job-boards.greenhouse.io/xairatherapeutics/jobs/5232474007

## Job description

## 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.

## About Xaira Therapeutics

## Company Overview
- **One-liner**: Xaira Therapeutics is an integrated biotechnology company applying artificial intelligence across the entire drug discovery and development process to design next-generation medicines.
- **Entity Type**: Private (Series A)
- **Headquarters**: South San Francisco, California, United States (with offices in Seattle, Washington, and London, UK)
- **Founded**: 2023
- **Founders**: Co-founded and incubated by ARCH Venture Partners and Foresite Labs, with foundational scientific contributions from Nobel Laureate Dr. David Baker (Institute for Protein Design, University of Washington).

## Core Business
- **Primary industry/industries**: Biotechnology, Drug Discovery & Development, Artificial Intelligence
- **Target customers**: B2B (pharmaceutical partners, biotech collaborators) and ultimately patients via its own therapeutic pipeline.
- **Mission or purpose statement**: "Pioneering the transformative artificial intelligence that will help discover and develop the next generation of life-changing medicines." [xaira.com](https://www.xaira.com/)

## Products & Services
- **AI-Powered Drug Discovery Platform**: An end-to-end platform integrating advanced AI research, expansive data generation (functional genomics, proteomics, multi-omics), and robust therapeutic product development to shift drug discovery from an empirical science to a precise engineering discipline. [xaira.com](https://www.xaira.com/our-approach)
- **Computational Protein Design**: Built on foundational work by Nobel Laureate Dr. David Baker, leveraging AI to design entirely new proteins from scratch for previously undruggable targets. [xaira.com](https://www.xaira.com/our-approach)
- **X-Cell (Virtual Cell Model)**: An AI model trained on billions of genomic data points to simulate and understand cellular biology. [xaira.com](https://www.xaira.com/)
- **Therapeutic Pipeline**: A pipeline of differentiated therapeutics across multiple modalities (small molecules, biologics, protein therapeutics) developed through an integrated AI-driven process.

## Market Standing
- **Valuation/Market Cap**: Not publicly disclosed. The company launched in 2023 with a $1 billion Series A financing, one of the largest in biotech history.
- **Key Metric**: Total Funding of $1 billion (Series A, 2023).
- **Notable Investors/Partners**: ARCH Venture Partners (co-founder and lead investor), Foresite Labs (co-founder and incubator), F-Prime Capital, and other top-tier investors. Board includes leaders from ARCH, Foresite, NEA, and Johnson & Johnson. Scientific advisors include Nobel Laureates Carolyn R. Bertozzi and David Baker, and other luminaries. [xaira.com](https://www.xaira.com/our-team)
- **Growth Signals**: Launched in 2023 with a record $1B Series A; rapidly building a world-class team across three global hubs (South San Francisco, Seattle, London); actively hiring across AI, computational biology, protein design, and drug development roles; announced X-Cell, a virtual cell model trained on billions of genomic data points. [xaira.com](https://www.xaira.com/)

## Competitive Advantages
- **Unprecedented Capital & Talent**: Launched with a $1B Series A, enabling aggressive hiring of top-tier AI and biology talent and long-term investment in infrastructure.
- **End-to-End AI Integration**: Uniquely positioned to apply AI across the entire drug discovery and development lifecycle, from target identification to clinical development, creating a powerful data flywheel.
- **World-Class Scientific Foundation**: Built on foundational AI protein design work from Nobel Laureate David Baker's lab, with a board and advisory board including multiple Nobel Laureates, former FDA commissioners, and industry leaders from Genentech, Johnson & Johnson, and top venture firms. [xaira.com](https://www.xaira.com/our-team)
- **Massive Data Generation**: Investing heavily in functional genomics and proteomics to generate proprietary, multi-dimensional datasets that fuel AI model development, creating a defensible data moat.

## Strategic Focus
- **End-to-End AI Integration**: Building predictive and agentic AI models across the complete drug discovery and development spectrum to increase probability of success, reduce timelines, and lower costs. [xaira.com](https://www.xaira.com/our-approach)
- **Data as a Core Asset**: Generating and integrating massive, multi-dimensional biological datasets (from molecular to human scales) to train and improve AI models continuously.
- **Pipeline Development**: Advancing a pipeline of differentiated therapeutics across multiple modalities (small molecules, biologics, protein therapeutics).
- **Talent Acquisition**: Aggressively hiring across AI research, engineering, computational biology, protein design, and drug development to build a world-class, interdisciplinary team.

## Why Work Here
- **Mission-Driven**: Opportunity to work at the forefront of AI and biology to fundamentally transform how medicines are discovered and developed, with the potential to impact millions of patients.
- **World-Class Team & Mentorship**: Work alongside and learn from Nobel Laureates, top AI researchers, and experienced drug developers from leading pharma and biotech companies. [xaira.com](https://www.xaira.com/our-team)
- **Interdisciplinary Culture**: A unique blend of AI/ML engineers, protein designers, computational biologists, and drug hunters all working together in a highly collaborative environment.
- **Global Hubs & Flexibility**: Offices in South San Francisco, Seattle, and London, offering multiple locations for talent.
- **Generous Resources**: Backed by a $1B Series A, providing the resources to pursue ambitious, long-term research without short-term funding pressure.
- **Job Scam Awareness**: The company has issued a warning about fraudulent job offers; all legitimate recruitment is conducted through official channels (Greenhouse) and never via Google Chat or requests for payment. [xaira.com](https://www.xaira.com/work-with-us)

## Sources
1. [xaira.com](https://www.xaira.com/)
2. [xaira.com](https://www.xaira.com/our-approach)
3. [xaira.com](https://www.xaira.com/our-team)
4. [xaira.com](https://www.xaira.com/work-with-us)
5. [greenhouse.io](https://job-boards.greenhouse.io/xairatherapeutics)

## Other roles at Xaira Therapeutics

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