Senior Scientist, Discovery Biology

Job Title: Senior Scientist, Discovery Biology

Location: Newark, CA (On-site)

Department: Discovery Biology

Protagonist Therapeutics is a clinical-stage biopharmaceutical company pioneering a new generation of peptide-based therapeutics to address unmet needs in immunology, metabolic Diseases and hematology. We leverage a powerful peptide discovery platform to design highly selective and orally delivered agents targeting validated pathways. Our Discovery Biology team plays a central role in advancing innovative molecules from concept to clinic.

We are seeking a highly motivated and scientifically rigorous Senior Scientist to join our Discovery Biology team reporting to Sr Director, Biology. The ideal candidate will have deep expertise in immunology and inflammation, and a proven ability to drive experimental research from concept to data-driven insight. This is a hands-on lab-based role with opportunities to lead key discovery-stage projects and contribute strategically to pipeline advancement.

Key Responsibilities:

• Lead Discovery Projects: Independently design and execute in vitro and in vivo studies to explore mechanisms of action and support progression of early drug candidates targeting immune pathways.
• Experimental Execution: Conduct a wide range of cellular and molecular biology assays including flow cytometry, ELISA, MSD, cell-based reporter assays, cytokine profiling, and primary cell culture.
• Data Analysis & Interpretation: Analyze complex data sets, synthesize results, and translate findings into actionable next steps for project teams.
• Cross-functional Integration: Collaborate closely with pharmacology, chemistry, DMPK, and translational science groups to guide candidate selection and optimization.
• Communication: Clearly present data and scientific rationale at team meetings, cross-functional discussions, and external conferences. Contribute to technical reports, regulatory documents, and scientific publications.
• Lab Operations: Ensure accurate documentation, inventory management, and equipment maintenance. Maintain best practices for quality, reproducibility, and compliance.
• Mentorship: Train and support junior scientists and research associates, fostering a culture of scientific excellence and collaboration.
• Innovation: Proactively identify novel approaches and contribute to the development of new assays, models, or targets within the immunology portfolio.

Qualifications & Experience:

• Ph.D. in Immunology, Cell Biology, Molecular Biology, Biochemistry, or related discipline
• 5+ years of industry experience in immunology or inflammation-focused research
• Strong expertise in immunological assays, flow cytometry, and primary immune cell handling
• Demonstrated ability to drive hypotheses and deliver impactful results in a fast-paced research setting
• Excellent organizational and communication skills
• Team-oriented, self-motivated, and intellectually curious

The base pay range for this position at commencement of employment is expected to be between $150K and $175K / year; however, base pay offered may vary depending on multiple individualized factors, including market location, job-related knowledge, skills, and experience.

Protagonist Therapeutics is a discovery through late-stage development biopharmaceutical company. Two novel peptides, icotrokinra and rusfertide, derived from Protagonist's proprietary discovery platform are currently in advanced Phase 3 clinical development, with New Drug Application submissions to the FDA expected in 2025. Icotrokinra (JNJ-2113) is a first-in-class investigational targeted oral peptide that selectively blocks the Interleukin-23 receptor ("IL-23R") which is licensed to Janssen Biotech, Inc., a Johnson & Johnson company. Following icotrokinra's joint discovery by Protagonist and Johnson & Johnson scientists pursuant to the companies' IL-23R collaboration, Protagonist was primarily responsible for development of icotrokinra through Phase 1, with Johnson & Johnson assuming responsibility for development in Phase 2 and beyond. Rusfertide, a mimetic of the natural hormone hepcidin, is currently in Phase 3 development for the rare blood disorder polycythemia vera (PV). Rusfertide is being co-developed and will be co-commercialized with Takeda Pharmaceuticals pursuant to a worldwide collaboration and license agreement entered into in 2024 under which the Company remains primarily responsible for development through NDA filing. The Company also has a number of pre-clinical stage oral drug discovery programs addressing clinically and commercially validated targets, including the IL-17 oral peptide antagonist PN-881, an oral hepcidin program, and an oral obesity program.