Principal Scientist (Cell Line Development)

Exelixis; Alameda (CA); On-site; USD 150,000 - 213,000; Full time

Benefits offered by this job

401(k) plan

Medical coverage

Dental coverage

Vision coverage

Life and disability insurance

Stock options

Vacation days 15 per year

Paid holidays 17

Job summary

Exelixis is seeking an experienced contributor to advance CHO-based cell line development for biologics in early manufacturing. You will design vector constructs, engineer host cells, perform transfection and single cell cloning, and verify monoclonality with imaging and analytics.

The role requires deep knowledge of mammalian expression, robust data handling, and strong communication to cross-functional teams, with emphasis on quality and regulatory readiness.

Qualifications

• Bachelor's degree with 11+ years in biotech/pharma OR
• Master's degree with 9+ years in biotech/pharma OR
• PhD with 5+ years in biotech/pharma OR
• Equivalent combination of education and experience.

Responsibilities

• Design and execute CHO-based cell line development experiments.
• Develop and optimize expression vectors and host cell lines.
• Perform transfection, single cell cloning, and monoclonality qualification.
• Generate and analyze cell line development reports and presentations.
• Ensure regulatory compliance and document technical results.

Skills

CHO cell line development

Vector construction

Transfection methods

monoclonality testing

Protein/antibody expression

Regulatory knowledge

Lab automation

Data analysis

Documentation (ELN)

Analytical techniques (HPLC/LC-MS/CE)

Communication and collaboration

Education

Bachelor's degree in life sciences

Master's degree in life sciences

PhD in molecular biology/biochemistry/biotech

Equivalent education/experience

Tools

Ambr

HPLC

LC-MS

Imaging analysis

Job description

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.

SUMMARY/JOB PURPOSE:

As a member of the Biotherapeutics group, the incumbent will play a key role in supporting the group's discovery and preclinical development efforts by possessing skills and experience in recombinant antibody and bispecific antibody production and purification/characterization. The incumbent will be responsible for delivering high performing and high-quality mammalian cell lines that enable early-phase biologics manufacturing for further development as potential therapeutic candidates or as ADCs. The ideal candidate will design and test vector constructs, engineer host cells, conduct transfection, selection and clone generation campaign in CHO cells, and apply a deep theoretical understanding of recombinant protein expression to guide the improvement of titer in stable cell lines.

ESSENTIAL DUTIES AND RESPONSIBILITIES:

• Design and execute experiments to develop CHO-based cell lines for biologic therapeutics moving into clinical development.
• Significant effort designing complex experimental approaches to improve expression systems and workflows through innovation and implementation of new technology is also an important part of this role.
• Perform therapeutic CHO cell line development processes including transfection, single cell cloning, imaging analysis to document monoclonality, clone screening and progression, characterization, and cell banking and stability assessment of cell banks using state-of-the-art equipment
• Drive innovation through the development of improved expression vectors and genetic components, host cell line engineering and/or cell line development process optimization
• Identify emerging practices for biologics therapeutic cell line development and manufacturing to shape scientific strategies and continued innovation
• Represent the cell line development team on cross‑functional projects, making decisions for cell line activities and effectively communicating results, progress and plans

• Comply with company health and safety policies and general laboratory practices.

SUPERVISORY RESPONSIBILITIES:

No supervisory responsibilities. Individual contributor role.

EDUCATION/EXPERIENCE/KNOWLEDGE & SKILLS:

Education:

• Bachelor's degree in related scientific discipline such as molecular biology, biochemistry, biology or microbiology and a minimum of eleven (11) years of experience in the biotechnology/pharmaceutical industry;
• Master's degree in related scientific discipline such as molecular biology, biochemistry, biology or microbiology and a minimum of nine (9) years of experience in the biotechnology/pharmaceutical industry;
• PhD degree in related scientific discipline such as molecular biology, biochemistry, biology or microbiology and a minimum of five (5) years of experience in the biotechnology/pharmaceutical industry;
• Equival­ent combination of education and experience.

Experience:

• The role is for an experienced incumbent who is eager, hands‑on, detail‑oriented, driven, self‑motivated and experienced to contribute with minimal onboarding or training.
• The candidate must have demonstrated proficiency in molecular biology, vector construction and genetic elements that impact recombinant antibody/bispecific expression.
• The candidate must have experience with various stable CHO expression platforms to articulate pros and cons and recommend one suitable for developing manufacturing cell lines.
• The candidate must be well versed in transfection methodologies as well as screening and selection workflows.
• The candidate must have a deep understanding about regulatory requirements with respect to demonstrating monoclonality.
• Must have experience in culturing CHO cells in different formats such as shake flasks, spin tubes, and deep‑well plate fed‑batch processes. Experience in Ambr fed‑batch processes is a plus.
• Must have experience in single cell cloning and imaging technologies to prove monoclonality.
• Experience in running titer determination and standard downstream product quality assessments.
• Author and review cell line development reports, summaries and presentations.
• Experience in analytical techniques such as HPLC, LC/MS, and/or CE is a plus.
• Familiarity with automation platforms and data analysis tools is a plus.

Knowledge/Skills:

• Solid understanding of mammalian protein/antibody expression, structure, and activity.
• Ability to set goals with an understanding of priorities and impact to program, the department and the organization.
• Ability to thrive in a high‑expectation, fast‑moving environment.
• Strong communication, organization, and documentation skills.
• Ability to design and execute activities/studies aimed at producing and characterizing recombinant antibodies and bispecifics, to interpret experimental results, and to formulate conclusions and next‑steps based on the data generated.
• Prior experience with electronic laboratory notebook documentation and workflow management is a plus.

WORKING CONDITIONS:

• Environment: primarily working in laboratories or in office.
• Exposures encountered: Potential exposure to hazardous chemicals/materials.

Our compensation reflects the cost of labor across several U.S. geographic markets, and we pay differently based on those defined markets. The base pay range for this position is $150,000 - $213,000 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 a comprehensive employee benefits package, including a 401(k) 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 application and/or recruitment process, please email us at: [e-mail].

WORKING CONDITIONS:

Our office is a modern space that fosters collaboration and creativity. Teams work closely together, sharing ideas and solutions in a supportive atmosphere. We provide all necessary equipment, including dual monitors and ergonomic chairs, to ensure a comfortable workspace.

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.