Senior Scientist II, Mass Spectrometry, Platform Biology & BioanalysisCytomX Therapeutics, Inc.

Headquarters Location: Emeryville, CA

Candidate Location: Hybrid

Travel Required: 5%

Reports To: VP, Platform Biology & Bioanalysis

Department: Platform Biology & Bioanalysis

Position Type: Full-time, Exempt

About CytomX Therapeutics: 

CytomX Therapeutics, Inc. is committed to changing the treatment of cancer with our novel PROBODY® therapeutic platform. Our commitment to transforming lives with safer, more effective therapies is driven by our curiosity and passion for innovation and our belief that by acting with integrity in an honest, respectful, ethical manner, we have the power to change lives. Our workplace embodies collaboration, open communication, celebrating our successes, and holding each other to the highest possible standards. CytomX’s robust and differentiated pipeline comprises therapeutic candidates across multiple treatment modalities including antibody-drug conjugates (“ADCs”), T-cell engagers, and immune modulators such as cytokines. CytomX’s clinical-stage pipeline includes CX-2051 and CX-801. Learn more at www.cytomX.com.  

Who You Are and What You’ll Do:

You are passionate about life sciences and making a difference to cancer patients, their families, and healthcare providers. You will serve as the in-house mass spectrometry expert supporting Platform Biology, Bioanalysis, and ADC research programs. The role will be responsible for designing and executing studies that inform molecule characterization, metabolism, catabolism, linker-payloads, biomarkers, and mechanism of action. The position will partner broadly across Research and Development to address complex analytical challenges and translate MS data into actionable program decisions. 

Job Responsibilities:

• Serve as the subject matter expert for mass spectrometry-based characterization of biologics, antibody-drug conjugates (ADCs), linker-payloads, and related biomolecules across discovery and development programs.
• Design, develop, and implement LC-MS/MS and high-resolution mass spectrometry methods to support molecule characterization, linker-payload stability, catabolism, payload release, and mechanism-of-action studies.
• Lead characterization of ADC attributes including drug-to-antibody ratio (DAR), conjugation heterogeneity, linker stability, payload-related species, and degradation products.
• Apply mass spectrometry and proteomics approaches to investigate protease biology, protease substrate specificity, and protease-mediated processing relevant to CytomX's Probody® and ADC platforms.
• Collaborate with cross-functional teams to generate analytical data that informs candidate selection, optimization, and development decisions.
• Develop innovative mass spectrometry approaches for characterization of proteins, peptides, biomarkers, and complex biological matrices.
• Provide scientific leadership in the interpretation of mass spectrometry data and communicate findings to multidisciplinary teams.
• Oversee and scientifically direct external CRO activities requiring specialized mass spectrometry expertise.
• Author technical reports, study summaries, scientific publications, and presentations.
• Mentor junior scientists and contribute to building scientific excellence across the organization.
• Stay current with emerging advancements in mass spectrometry, proteomics, and analytical technologies and evaluate opportunities for implementation at CytomX.
• Independently define and manage budget and other resources for own team and projects overseen.

Minimum Qualifications:

• Ph.D. in Analytical Chemistry, Biochemistry, Pharmaceutical Sciences, Molecular Biology, or a related discipline with 4-5+ years of relevant industry experience. Extensive hands-on experience with LC-MS/MS and mass spectrometry platforms (e.g., Orbitrap and triple quadrupole instruments) in a biotechnology, pharmaceutical, or CRO environment.
• Demonstrated expertise in mass spectrometry-based characterization of proteins, monoclonal antibodies, antibody-drug conjugates (ADCs), and/or other complex biologics.
• Experience developing, optimizing, and troubleshooting mass spectrometry workflows and interpreting complex datasets to support research and development programs.

Preferred Qualifications:

• Experience developing and applying novel mass spectrometry-based approaches to address complex biological, biochemical, and mechanistic questions.
• Experience characterizing antibody-drug conjugates (ADCs), including drug-to-antibody ratio (DAR), conjugation heterogeneity, linker-payload stability, payload release, and catabolite characterization.
• Strong understanding of protein chemistry, bioconjugation, post-translational modifications, and analytical characterization of biologics.
• Knowledge of protease biology and enzyme–substrate interactions, including cleavage-site specificity and the kinetics of proteolytic processing; experience applying it to cleavable linkers, prodrugs, or other protease-activated molecules is a plus.
• Proven ability to analyze, interpret, and communicate complex datasets to multidisciplinary scientific teams.
• Experience with advanced analytical and bioanalytical technologies, including capillary electrophoresis (CE), capillary isoelectric focusing (cIEF), ELISA/Ligand Binding Assays, CE-MS, and mass spectrometry-based approaches for characterization of biologics and ADCs.
• Experience developing novel analytical approaches to address complex biological and biochemical questions.
• Excellent communication and collaboration skills, with a demonstrated ability to work effectively in cross-functional teams.
• Experience managing external CROs and scientific collaborations.
• Demonstrated project leadership and mentoring experience in a biotechnology environment.
• Excellent written and verbal communication skills, with the ability to effectively present scientific findings to diverse audiences.
• Demonstrated ability to work independently while successfully collaborating within cross-functional teams.
• Records of scientific achievements demonstrated through publications, patents, conference presentations, or significant technical contributions.

How You Will Work:

• Demonstrates collaboration and teamwork. Works well with others and understands that collaboration leads to better results.
• Possesses strong communication skills. Communicates clearly, concisely, and professionally. Listens actively to build understanding.
• Exhibits strong interpersonal skills and self-awareness. Builds and cultivates strong and enduring relationships with others. Acts with humility and understands own strengths and weaknesses.
• Shows continuous improvement and a commitment to self-management and development. Operates with a continuous improvement mindset and continuously seeks to expand own knowledge and capabilities.
• Demonstrates a patient focus. Puts the patient first in actions and decisions taken.
• Contributes to strategy and innovation. Contributes to or leads elevating and actionable strategies. Ideates and creates unique opportunities to advance the organization.
• Demonstrates leadership and a commitment to organizational values. Takes ownership and has a strong sense of personal accountability. Consistently achieves or exceeds goals and expectations. Puts significant emphasis on living / upholding company values.
• Demonstrates ability and commitment to building effective teams. Attracts, develops, and retains diverse top talent. Aligns, mobilizes, and engages others to achieve and sustain peak performance.
• Has a track record of driving vision and purpose in teams.

Compensation, Benefits, and So Much More

• The expected salary range for this role based on the primary location for this position in California is $175,000 - $200,000 per year. Offer amounts are determined by factors such as experience, qualifications, geographic location, and other job-related factors permitted by law.
• A great environment where we work collaboratively, leverage each other’s strengths, and work toward a shared vision with our common goals of doing the best thing for patients.
• A robust and enduring approach to your development and career growth fueled by a strong learning curriculum and career guidance that helps you understand how you can grow your career at CytomX.
• A robust and highly competitive total rewards program that helps you achieve your compensation goals while supporting a great work / life balance.

Conditions of Employment 

• Background investigations are required for all positions at CytomX, consistent with applicable law.

CytomX’s Commitment to Diversity, Equity, Inclusion, and Belonging (DEIB)

CytomX believes that DEIB helps drive our success, and we encourage candidates from all identities, backgrounds, and abilities to apply. We are an equal opportunity employer committed to building an inclusive, innovative work environment with employees who reflect our values and ultimately, serve our patients. Therefore, in all aspects of the employment process, we provide employment opportunities to all qualified applicants without regard to race, color, religion, sex, disability, age, sexual orientation, gender identity or expression, pregnancy, medical condition related to pregnancy, creed, ancestry, national origin, marital status, genetic information, or military status, or any other protected status in accordance with applicable law.

Further, we are committed to the full inclusion of all qualified individuals. As part of this commitment, we (and the agencies we work with) will assist individuals who have a disability with any reasonable accommodation requests related to employment, including completing the application process, interviewing, completing any pre-employment testing, participating in the employee selection process, and/or to perform essential job functions where the requested accommodation does not impose an undue hardship.  If you have a disability and require reasonable accommodation, or need other assistance in applying for or interviewing for this position, please direct your inquiries to Human Resources, at hr@cytomx.com 

Notice to Recruiters/Staffing Agencies

Recruiters and staffing agencies should not contact CytomX Therapeutics through this page. We require that all Recruitment Vendors (e.g., search firms, recruitment agencies and staffing companies) have a fully executed, formal written agreement on file with CytomX prior to submitting candidates. Any resumes submitted through the website or directly by Recruitment Vendors will be considered unsolicited.  Unsolicited vendor submissions do not constitute any actual or implied contract with CytomX, and CytomX will not be responsible for any purported fees. For more information, please contact our HR team at hr@cytomx.com

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