Scientist, Mass Spectrometry

Xilio Therapeutics

Waltham, MA, US
  • Job Type: Full-Time
  • Function: Research Sci/Assoc/Mgr
  • Post Date: 04/21/2021
  • Website:
  • Company Address: 828 Winter Street, Waltham, MA, 02451

About Xilio Therapeutics

Xilio Therapeutics is a biopharmaceutical company focused on developing highly-potent, targeted immuno-oncology therapeutics.

Job Description

Xilio Therapeutics is a development-stage biotechnology company advancing next-generation cancer immunotherapies designed to improve patient outcomes by unleashing the power of the immune system selectively at the site of the tumor. The company’s tumor-selective immunotherapies are based on its proprietary technology, which maximizes the potency of proven immuno-oncology therapies and restricts their activity to the tumor to minimize peripheral side effects. The broad applicability of these therapies across cancer types means that all patients could benefit from these potentially curative medicines.

Xilio was founded in 2016 and closed a $95M Series C financing from blue chip venture investors in February 2021. Xilio is headquartered in Waltham, MA.


We are looking for a highly energetic and motivated Scientist to join our Mass Spectrometry Team. Their primary responsibility will be LC-MS analysis of therapeutic proteins, particularly antibody and Fc fusion proteins. The Scientist will have tremendous opportunities within a dynamic, enthusiastic, highly interdisciplinary and collaborative team.


    Utilize LC-MS to perform non-GLP bioanalytical quantitation method development, qualification and sample analysis for therapeutic proteins to support non-GLP PK/PD studies.
    Perform LC-MS characterization of therapeutic proteins to support Biologics Discovery/ Production including but not limited to intact mass analysis, peptide mapping and PTM profiling.
    Prepare samples to be tested by LC-MS and LC-MSMS from various sources, i.e., purified protein products, biological matrix (plasma, serum, and tissues, etc).
    Assist in managing outsourced work from characterization to bioanalysis at CROs.  
    Maintain and troubleshoot LC-MS systems.
    Mentor and train junior colleagues.
    Identify and integrate technologies that improve or expand the ability to LC-MS analysis by working with teammates, collaborators, vendors, and staying abreast of the literature.
    Enter all data into electronic laboratory notebooks and databases on a daily basis, generate weekly summary reports for management review.
    Actively participate and present data and analyses at project team and department meetings.



    Ph.D. in Chemistry or Biochemistry or a relevant scientific discipline with 2+ years of biopharma experience with therapeutic protein LC-MS analysis or MS with 5+ years of biopharma experience with therapeutic protein LC-MS analysis.
    Essential to possess technical expertise in the LC-MS analysis of proteins, which may range from protein characterization, protein bioanalytical quantitation, and proteomics.
    Hands-on experiences are necessary, including sample preparation (deglycosylation, reduction, and in-solution/in-gel digestion), LC-MS operation, basic maintenance and troubleshooting.
    Skills with the following are a plus: extraction and enrichment techniques (Affinity Capture, SPE, Protein Precipitation), SDS-PAGE, and HPLC (IEX, SEC etc).
    Experience with immune oncology and/or protease biology is a plus.
    A track record of innovation and scientific rigor, strong problem solving and troubleshooting skills, and ability to contribute constructively to discussions.
    Goal oriented, organized, capable of prioritizing and working on multiple projects, and able to execute to timelines that meet company goals.
    Work well in a cross functional team environment, both independently as well as be willing to help others.
    Good verbal and written communication skills.
    Driven by a desire to create the next generation of immunotherapy-based cancer therapeutics and the vision to offer cancer patients efficacious and tolerable new therapies that extend and improve their lives.

Xilio offers the opportunity to work in an innovation driven, exciting biotechnology company doing ground-breaking work in the field of immuno-oncology. We offer a competitive compensation package including a base salary, annual bonus potential, stock options, 401k, healthcare benefits and paid time-off.

POSITION: Full-Time, Exempt

EEOC Statement: Xilio Therapeutics believes in a diverse environment and is committed to equal employment opportunity for all its employees and qualified applicants. We do not discriminate in recruitment, hiring, training, promotion or any other employment practices for reasons of race, color, religion, gender, national origin, age, sexual orientation, marital or veteran status, disability, or any other legally protected status. Xilio will make reasonable accommodations for qualified individuals with known disabilities, in accordance with applicable law.

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Disclaimer: Local Candidates Only
This company does NOT accept candidates from outside recruiting firms. Agency contacts are not welcome.