Senior Principal Scientist; Antibody Drug Conjugate

SUMMARY/JOB PURPOSE (Basic purpose of the job)

Exelixis is expanding its Antibody-Drug Conjugate (ADC) platform to advance a growing pipeline of oncology bioconjugates. We are seeking a Senior Principal Scientist with deep expertise in conjugation chemistry to serve as the technical anchor for ADC generation, from discovery-scale screening through early process development and IND-enabling tox supply. You will operate independently at the bench, shape platform strategy, and partner cross-functionally with antibody engineering, linker-payload chemistry, analytical development, DMPK, and CMC.

• Bioconjugation & Process Innovation
• Analytical Characterization
• Scientific Leadership
• Collaboration & Delivery

None.

Education:

• BS/BA degree in Chemistry, Biochemistry, Chemical Biology or related discipline and a minimum of 13 years of related experience;
• MS/MA degree in Chemistry, Biochemistry, Chemical Biology or related discipline and a minimum of 11 years of related experience;
• PhD in Chemistry, Biochemistry, Chemical Biology or related discipline and a minimum of 8 years of related experience;
• Equivalent combination of education and experience.

Experience:

Required

• Hands-on mastery of ADC conjugation chemistry from discovery through early CMC, with a track record of advancing molecules to development candidate nomination.
• Demonstrated experience in DAR control, product homogeneity optimization and formulation of bioconjugates.

Preferred

• Experience with site-specific conjugation platforms (e.g., engineered cysteine, THIOMAB, transglutaminase/AIICAP, glycan remodeling, sortase, click chemistry).
• Experience with dual-payload conjugates, bispecific ADCs or AOCs.

Required

• Working knowledge of linkers (cleavable and non-cleavable), payload classes and their MoA.
• Fluency with HIC, SEC, RP-HPLC and LC-MS for conjugate characterization.
• Rigorous scientific problem-solving, excellent written and oral communication; proven collaborator across chemistry, biology and CMC.

Preferred

• Familiarity with early process development, tech transfer, and CDMO management for GLP/GMP supply.
• Patents and peer-reviewed publications in bioconjugation.
• Working knowledge of ADC IP landscape.

• Modern, collaborative office and adjacent BSL-1/BSL-2 laboratory space at our Alameda, CA campus.
• Routine handling of proteins, organic solvents, and cytotoxic linker-payloads under standard EH&S controls.
• Travel up to 10% for conferences, CRO/CDMO site visits and collaborations.

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 $169,500 - $239,500 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.

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.