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Principal Scientist, Discovery Biology

Cambridge, MA

About Theseus

Theseus Pharmaceuticals is passionately committed to improving the lives of cancer patients by working to outsmart cancer resistance. Led by a team of targeted oncology pioneers with a proven track record developing and commercializing cancer therapeutics, we are developing the next generation of tyrosine kinase inhibitors (TKIs): “pan-variant” targeted therapies that address all known drug resistant mutations. We believe a pan-variant approach is the only way to address cancer resistance. Our lead program, THE-630, is a pan-variant KIT inhibitor for patients with advanced gastrointestinal stromal tumors (GIST), whose cancer has developed resistance to earlier lines of kinase inhibitor therapy. We are also developing a fourth-generation, selective epidermal growth factor receptor (EGFR) inhibitor to address C797S-mediated resistance to first- or later-line osimertinib treatment in patients with non-small cell lung cancer (NSCLC). For more information, visit theseusrx.com or follow the company on LinkedIn.

Role Description

We are looking for an experienced and passionate biologist who is excited to leverage the latest advances in biology, chemistry, and computation to help us discover new medicines. The successful candidate will be directly responsible for target validation, assay development, and analysis of all in vitro and in vivo data, and will be a key member of the team that selects our next clinical candidate(s).


  • Partner with leadership to plan and prioritize biology strategy and workflows
  • Select, design, and validate appropriate assays, and design all studies and analyze data for programs using external resources
  • Provide guidance in identifying and validating biomarkers and indication selection for clinical development
  • Manage external CROs focusing on preclinical mechanism of action studies, compound screening, in vivo efficacy experiments, reagent generation, assay development / validation and computational biology activities
  • Leverage a network of external scientific advisors and consultants to execute research activities covering preclinical and clinical programs


  • Ph.D. and post-doctoral fellowship in relevant field of biomedical research and 5+ years of relevant industry experience, or B.A/B.S, or M.S., with 10-12+ years of relevant industry experience, including project leadership
  • Strong background in oncology/cancer research, with a thorough understanding of signaling pathways implicated in disease and the mechanism of action of targeted therapies; experience developing kinase inhibitors is a plus
  • A very high level of motivation and a proven record of accomplishment (eg, a strong publication record)
  • Experience performing and analyzing a broad array of molecular and cell biology experiments
  • Track-record of adopting highly innovative approaches to answering complex biological questions and helping to drive drug discovery programs to successful development candidate selection
  • Experience working extensively with external CROs to accomplish drug discovery objectives
  • Excellent interpersonal skills, leadership abilities, and oral and written communication

Candidates should be aware that Theseus Pharmaceuticals requires all employees to be fully vaccinated against COVID-19. Newly hired employees must be vaccinated prior to their employment start date. Theseus is an equal opportunity employer and will provide reasonable accommodation to those unable to be vaccinated where it is not an undue hardship to the company to do so as provided under federal, state, and local law.

Theseus Pharmaceuticals is an equal employment opportunity employer and does not discriminate against any applicant because of race, creed, color, age, national origin, ancestry, religion, gender, sexual orientation, disability, genetic information, veteran status, military status, application for military service or any other class protected by state or federal law.

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