Senior Scientist I, Bioassay
Exelixis
Summary
The Senior Scientist I, Analytical Development, Biologics CMC will support CMC analytical development for biologic therapeutics by establishing and advancing phase-appropriate cell-based bioassay, potency, functional, and binding assay capabilities. This hands-on role will independently develop, optimize, qualify, transfer, and manage fit-for-purpose assays that reflect product mechanism of action and relevant critical quality attributes across ADCs, monoclonal antibodies, bispecifics, multispecifics, Fc-fusion proteins, VHH-Fc constructs, and other novel biologic modalities.
Job description
Summary/Job Purpose
The Senior Scientist I, Analytical Development, Biologics CMC will support CMC analytical development for biologic therapeutics by establishing and advancing phase-appropriate cell-based bioassay, potency, functional, and binding assay capabilities. This hands-on role will independently develop, optimize, qualify, transfer, and manage fit-for-purpose assays that reflect product mechanism of action and relevant critical quality attributes across ADCs, monoclonal antibodies, bispecifics, multispecifics, Fc-fusion proteins, VHH-Fc constructs, and other novel biologic modalities.
Essential Duties/Responsibilities
- Develop complex cell-based bioassays and potency assays from initial concept through optimization, qualification, and method transfer for biologic therapeutics.
- Perform hands-on mammalian cell culture, transient transfection, engineered cell model development, receptor-expression confirmation, and assay-ready cell support.
- Develop and troubleshoot functional bioassays, including reporter-gene, cytotoxicity, proliferation/inhibition, receptor blockade, ADCC/CDC, and immune-cell engagement assays.
- Apply flow cytometry, ELISA or plate-based binding assays, SPR/BLI, and other orthogonal methods to support assay development, comparability, and structure-function understanding.
- Evaluate assay performance, robustness, system suitability, relative potency, parallelism, and critical assay parameters to enable phase-appropriate method qualification and transfer.
- Author and review assay procedures, development reports, qualification or transfer documents, technical summaries, and CMC-relevant regulatory supporting materials.
- Collaborate with Discovery, Translational Sciences, Process Development, Quality, Regulatory, CDMOs, CTLs, and external partners to align assay strategy with program needs.
- Contribute to building internal bioassay capabilities, including cell culture workflows, flow cytometry practices, plate-reader methods, data analysis tools, and critical reagent management.
Supervisory Responsibilities
No direct people management responsibility is required. The incumbent may provide technical guidance, training, and work direction to junior scientists, research associates, consultants, CDMOs, CTLs, and other external partners.
Education/Experience
- Ph.D. in cell biology, immunology, molecular biology, biochemistry, bioengineering, biophysics, pharmaceutical sciences, analytical sciences, or a related life sciences discipline with relevant industry experience.
- Master's degree in a related life sciences discipline with 5+ years of relevant industry experience.
- Bachelor's degree in a related life sciences discipline with 7+ years of relevant industry experience.
- Equivalent combination of education and experience.
- Hands-on experience developing complex cell-based bioassays or functional assays from concept through optimization, qualification, troubleshooting, documentation, and method transfer.
- Experience with mammalian cell culture, assay-ready cells, transient transfection or engineered cell models, flow cytometry, plate-based assays, and functional potency readouts is strongly preferred.
Knowledge, Skills and Abilities
- Advanced knowledge of cell-based bioassay and potency assay development for biologic therapeutics, including mammalian cell culture, flow cytometry, receptor-expression analysis, functional assay design, and binding/kinetic methods such as SPR or BLI.
- Strong understanding of potency as a critical quality attribute and ability to translate product mechanism of action into scientifically justified assay strategies, biological readouts, cell models, controls, and acceptance criteria.
- Ability to develop assays with limited precedent, troubleshoot complex assay performance issues, interpret cell-based assay, flow cytometry, and binding data, and make practical CMC development recommendations.
- Working knowledge of phase-appropriate method development, qualification, comparability, method transfer, and lifecycle management for biologics.
- Technical writing skills for assay protocols, SOPs, development reports, qualification or transfer documents, comparability assessments, regulatory-supporting summaries, and investigation reports.
- Working knowledge of biologics CMC, analytical control strategy, phase-appropriate method development, and CDMO/CTL interactions is preferred.
- Effective communication, collaboration, presentation, data interpretation, organization, prioritization, and problem-solving skills in a fast-paced, cross-functional CMC environment.
- Strong ownership, scientific curiosity, attention to detail, laboratory discipline, and commitment to high-quality technical execution.
Work Environment/Physical Demands
Primarily working in laboratories and office settings. Potential exposure to laboratory materials and conditions, including biological materials, chemical reagents, hazardous materials, and extreme cold.
Requirements
- Ph.D. in cell biology, immunology, molecular biology, biochemistry, bioengineering, biophysics, pharmaceutical sciences, analytical sciences, or related life sciences discipline with relevant industry experience; or Master's degree with 5+ years relevant industry experience; or Bachelor's degree with 7+ years relevant industry experience; or equivalent combination of education and experience
- Hands-on experience developing complex cell-based bioassays or functional assays from concept through optimization, qualification, troubleshooting, documentation, and method transfer
- Advanced knowledge of cell-based bioassay and potency assay development for biologic therapeutics
- Mammalian cell culture experience
- Flow cytometry experience
- Receptor-expression analysis
- Functional assay design
- Binding/kinetic methods such as SPR or BLI
- Strong understanding of potency as a critical quality attribute
- Ability to translate product mechanism of action into scientifically justified assay strategies
- Ability to develop assays with limited precedent and troubleshoot complex assay performance issues
- Working knowledge of phase-appropriate method development, qualification, comparability, method transfer, and lifecycle management for biologics
- Technical writing skills for assay protocols, SOPs, development reports, qualification or transfer documents, comparability assessments, regulatory-supporting summaries, and investigation reports
- Effective communication, collaboration, presentation, data interpretation, organization, prioritization, and problem-solving skills
- Strong ownership, scientific curiosity, attention to detail, laboratory discipline, and commitment to high-quality technical execution
Benefits
- 401(k) Matching
- Medical, Dental & Vision
- Life & Disability Insurance
- Flexible Spending Accounts
- Discretionary Annual Bonus
- Stock Purchase Plan
- Long-Term Incentives
- 15 Vacation Days
- 17 Paid Holidays
- Up to 10 Sick Days
Company overview
Exelixis, Inc. is an oncology-focused biotechnology company headquartered in Alameda, California, that specializes in the discovery, development, and commercialization of innovative cancer treatments. Founded in 1994, the company has evolved into a multi-platform cancer organization with a proven track record in the challenging biotech sector. Exelixis is best known for its flagship molecule cabozantinib, an inhibitor of multiple tyrosine kinases including MET, AXL, VEGF receptors, and RET, which has led to several approved drugs for difficult-to-treat cancers. The company's portfolio includes four approved drugs, with two derived from cabozantinib, and it maintains a robust pipeline of next-generation cancer treatments. With approximately 1,500 employees across five continents, Exelixis operates as a publicly traded company (NASDAQ: EXEL) and has established strategic alliances with major pharmaceutical and biotechnology partners. The company's mission centers on transforming science into new treatments that give cancer patients and their families hope for the future, with every employee united in this ambitious cause.