Director of Biomarkers and Experimental Medicine

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 We are seeking a scientific leader to serve as our Director of Biomarkers and Experimental Medicine. This role will create and execute biomarker strategies across discovery and early development, grounded in human biology and designed to scale from target-agnostic disease understanding through program-specific development. You will work closely with Biomedical AI to use multi-modal human data to identify biomarker signals, define patient hypotheses, and establish biomarkers that guide indication choices, patient selection, and proof-of-biology. A core part of the role is building biomarker capability before programs fully crystallize. This includes defining disease-state and patient stratification frameworks, developing assay and data standards, and creating a biomarker toolkit that can be applied as targets emerge. Key Responsibilities Help create and execute strategies and incorporate human patient data to build AI models for patient stratification, target validation and biomarker discovery, in conjunction with a cross-functional team of experts including Biomedical AI Establish a target-agnostic biomarker strategy that defines disease biology, patient subgroups, and measurable signals of disease state, progression, and response potential, even before a specific therapeutic target is selected. Define biomarker hypotheses and evidence plans that connect human biology to program direction, including how biomarkers will influence indication strategy, cohort definitions, and clinical readiness. Work closely with Biomedical AI/ML to translate biomarker questions into ML-ready problem definitions, including cohort definitions, endpoints, labels, success criteria, and validation expectations. Identify and prioritize AI/ML model outputs needed for biomarker work, including patient segmentation, biomarker signal models, multi-modal integration, and response or outcome prediction where appropriate. Lead assay strategy and readiness planning, including platform choices, fit-for-purpose validation, sample strategy, and decision points that allow teams to act on biomarker results. Create standards for biomarker and model quality, reproducibility, and documentation so outputs are decision-grade and usable across programs. Build biomarker data assets and workflows that scale, including reference cohorts, baseline datasets, and repeatable analyses that can be reused as targets and indications evolve. Drive cross-functional alignment so biomarker insights consistently inform discovery priorities, program selection, and early development planning. Establish and manage an external network of biomarker experts, clinical and translational advisors, and key opinion leaders to pressure-test strategy and strengthen clinical relevance. Qualifications PhD, MD, or MD/PhD with 8+ years of experience in biomarkers, translational science, or human biology within biotech or pharma. Deep expertise in biomarker discovery and development, including experience defining biomarker strategies that support program decisions and differentiation. Strong experience with human data and multi-modal biology, including genetics and omics, and comfort operating when targets and programs are still being defined. Demonstrated ability to work closely with AI/ML teams and transla ... (truncated, view full listing at source)