Senior Scientist I, Bioassay

Exelixis Inc; Alameda (CA); On-site; USD 128,000 - 181,000; Full time

Benefits offered by this job

Health insurance

Job summary

Exelixis Inc in Alameda, California, is seeking a Senior Scientist I, Analytical Development, Biologics CMC to lead cell-based potency assay development for biologics including ADCs and monoclonal antibodies. This hands-on role will advance assay strategies reflecting mechanism of action and critical quality attributes across diverse modalities.

The role emphasizes regulatory readiness, lifecycle management, and collaboration with Discovery, Process Development, Quality, and Regulatory teams to

Qualifications

• 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
• Experience developing complex cell-based biosassays from concept through qualification and transfer
• Hands-on mammalian cell culture, transfection, engineered cell models, flow cytometry and functional potency readouts

Responsibilities

• Develop complex cell-based bioassays from concept through qualification and transfer
• Perform mammalian cell culture, transient transfection, and engineered cell models
• Develop and troubleshoot functional bioassays (reporter-gene, cytotoxicity, proliferation, receptor blockade, ADCC/CDC)
• Apply flow cytometry, ELISA, SPR/BLI and other methods to support assay development and structure–function
• Evaluate assay performance, qualification, and transfer to ensure phase-appropriate development

Skills

Bioassay development

Mammalian cell culture

Flow cytometry

Cell biology

Education

Ph.D. in life sciences

M.S. in life sciences

B.S. in life sciences

Tools

SPR/BLI

ELISA

Plate-based assays

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. The position exists to ensure scientifically rigorous, regulatory-relevant, cost-effective, and timely potency assay strategies through strong laboratory execution, technical ownership, and effective collaboration with Discovery, Translational Sciences, Process Development, Quality, Regulatory, CDMOs, CTLs, and external partners.

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:

• 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 cell biology, immunology, molecular biology, biochemistry, bioengineering, biophysics, pharmaceutical sciences, analytical sciences, or a related life sciences discipline with 5+ years of relevant industry experience
• Bachelor’s degree in cell biology, immunology, molecular biology, biochemistry, bioengineering, biophysics, pharmaceutical sciences, analytical sciences, or a related life sciences discipline with 7+ years of relevant industry experience
• Equivalent combination of education and experience.

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:

Environment: primarily working in laboratories and office settings. Potential exposure to laboratory materials and conditions, including biological materials, chemical reagents, hazardous materials, and extreme cold.

COMPENSATION AND BENEFITS:

#LI-MB1 Our compensation reflects the cost of labor across severalU.S. geographic markets, and we pay differently based on those defined markets. The base pay range for this positionis $127,500 - $180,500 annually. The base pay range may take into account the candidate’s geographic region, which will adjust the pay depending on the specific work location. The base pay offered will take into account the candidate’s geographic region, job-related knowledge, skills, experience and internal equity, among other factors. In addition to the base salary, as part of our Total Rewards program, Exelixis offers comprehensive employee benefits package, including a 401k plan with generous company contributions, group medical, dental and vision coverage, life and disability insurance, and flexible spending accounts. Employees are also eligible for a discretionary annual bonus program, or if field sales staff, a sales-based incentive plan. Exelixis also offers employees the opportunity to purchase company stock, and receive long-term incentives, 15 accrued vacation days in their first year, 17 paid holidays including a company-wide winter shutdown in December, and up to 10 sick days throughout the calendar year.

If you have a disability and need an accommodation in relation to the recruiting process, please email us at: [e-mail].

DISCLAIMER:

The preceding job description has been designed to indicate the general nature and level of work performed by employees within this classification. It is not designed to contain or be interpreted as a comprehensive inventory of all duties, responsibilities and qualifications required of employees assigned to the job. We are an Equal Opportunity Employer and do not discriminate against any employee or applicant for employment because of race, color, sex, age, national origin, religion, sexual orientation, gender identity, status as a veteran, and basis of disability or any other federal, state or local protected class. Every Exelixis employee is united in an ambitious cause: to launch innovative medicines that give patients and their families hope for the future. In this pursuit, we know our employees are our most valuable asset. After operating in the challenging biotech sector for 25 years, we have a proven track record of resiliency in the face of adversity. The success of our lead product has provided a solid commercial foundation allowing us to reinvigorate our research efforts, and grow our team in areas such as Drug Discovery, Clinical Development and Commercial. As we expand our global partnerships and further reinvest in R&D to help us discover the next breakthrough for difficult-to-treat cancers, we’re seeking to add talented, dedicated employees to power our mission. Cancer is our cause. Make it yours, too.