Senior Scientist Diagnostics

Our client is a leading and well-funded clinical-stage biopharmaceutical company located in the Greater Seattle Area. The company specializes in developing innovative cancer treatments using established drug development platforms, with a focus on bi-specific and multi-specific antibodies, as well as antibody-drug conjugates (ADCs). Our client has multiple assets in various stages of clinical trials for solid tumor and hematologic indications. In addition to ongoing clinical programs, the company maintains a robust preclinical pipeline of potential cancer therapeutics in discovery and IND-enabling stages, representing cutting-edge biologics development. This is an opportunity to learn, grow, and make meaningful contributions to the organization's success. We are seeking a Scientist or Senior Scientist to lead and support immunohistochemistry (IHC) assay development for companion diagnostic (CDx) kits supporting oncology drug development. This role is responsible for end-to-end IHC assay development, including antibody selection, assay optimization, analytical validation, and clinical trial implementation, with a clear development path from RUO/LDT to IVD CDx commercialization. The ideal candidate will bring strong expertise in pathology, IHC assay development, and CDx regulatory expectations, and will be able to collaborate effectively across R&D, clinical, regulatory, quality assurance, and external CROs and central laboratories. Key Responsibilities IHC Assay & CDx DevelopmentLead development of IHC-based CDx assays from biomarker discovery through assay optimization and validation.Select and evaluate primary antibodies, detection systems, and staining platforms.Optimize assay parameters, including epitope retrieval, antibody dilution, detection chemistry, and staining conditions.Establish scoring algorithms, cut-off strategies, and interpretation guidelines in collaboration with pathologists.Support biomarker strategies for patient selection and stratification in clinical trials.Analytical Validation & PerformanceDesign and oversee analytical performance studies, including:Sensitivity and specificityPrecision and reproducibility (intra-run, inter-run, inter-site)Accuracy and robustnessLinearity and limit of detection, where applicablePrepare, review, and approve validation protocols, reports, and SOPs in alignment with CDx expectations.Clinical Trial & Central Lab SupportSupport implementation of IHC assays in clinical trials, including:Central laboratory qualification and oversightPathologist training and alignmentSlide logistics, staining consistency, and scoring harmonizationCollaborate with clinical teams on sample strategy, feasibility studies, and biomarker cut-off justification.Regulatory & Quality CollaborationWork closely with Regulatory Affairs and Quality Assurance to ensure compliance with:FDA CDx guidance (US)NMPA/CDE requirements (China), where applicableIVDR (EU), as relevantSupport preparation of regulatory documentation, including:IDE/IND biomarker sectionsCDx bridging strategies (RUO/LDT to IVD)Analytical and clinical performance summariesEnsure assay development aligns with QMS requirements, design controls, and document traceability.Cross-Functional & External CollaborationServe as a technical subject-matter expert, interacting with CROs, central laboratories, IVD partners, antibody vendors, and staining platform providers.Provide scientific input to project teams, governance meetings, and external collaborations.Mentor junior scientists and contribute to team capability building, as appropriate.Qualifications EducationPhD in Pathology, Molecular Biology, Immunology, Oncology, or a related fieldMS or BS with significant CDx or IVD industry experience may also be consideredExperience3-5+ years of hands-on experience in IHC assay development, preferably in a CDx or IVD settingDirect experience supporting oncology biomarkers and clinical trialsExperience across the CDx development lifecycle, from RUO/LDT through IVD readinessStrong understanding of IHC scoring methodologies such as TPS, H-score, and CPSFamiliarity with analytical validation and regulatory expectations for CDxDemonstrated ability to work effectively in cross-functional teamsSoft SkillsStrong scientific rigor with excellent documentation and data interpretation skillsAbility to operate in a fast-paced, matrixed environmentClear and effective communication with both technical and non-technical stakeholdersExperience working with global teams is a plusPreferred QualificationsPrior experience with late-stage or FDA-approved CDx programsExperience developing and justifying biomarker cut-off strategiesFamiliarity with NSCLC, GI cancers, or other solid tumorsExperience interacting with health authorities or supporting regulatory meetingsCompensation and Benefits The expected base salary range for this position is $95,000 - $140,000 annually. Actual compensation will be based on a variety of factors, including but not limited to a candidate's qualifications, level, experience, and skills. Estimated Min Rate: $98000.00 Estimated Max Rate: $140000.00What's In It for You?We welcome you to be a part of the largest and legendary global staffing companies to meet your career aspirations. Yoh's network of client companies has been employing professionals like you for over 65 years in the U.S., UK and Canada. Join Yoh's extensive talent community that will provide you with access to Yoh's vast network of opportunities and gain access to this exclusive opportunity available to you. Benefit eligibility is in accordance with applicable laws and client requirements. Benefits include:Medical, Prescription, Dental & Vision Benefits (for employees working 20+ hours per week)Health Savings Account (HSA) (for employees working 20+ hours per week)Life & Disability Insurance (for employees working 20+ hours per week)MetLife Voluntary BenefitsEmployee Assistance Program (EAP)401K Retirement Savings PlanDirect Deposit & weekly epayrollReferral Bonus ProgramsCertification and training opportunitiesNote: Any pay ranges displayed are estimations. Actual pay is determined by an applicant's experience, technical expertise, and other qualifications as listed in the job description. All qualified applicants are welcome to apply.Yoh, a Day & Zimmermann company, is an Equal Opportunity Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, disability, or status as a protected veteran.Visit to contact us if you are an individual with a disability and require accommodation in the application process.For California applicants, qualified applicants with arrest or conviction records will be considered for employment in accordance with the Los Angeles County Fair Chance Ordinance for Employers and the California Fair Chance Act. All of the material job duties described in this posting are job duties for which a criminal history may have a direct, adverse, and negative relationship potentially resulting in the withdrawal of a conditional offer of employment.It is unlawful in Massachusetts to require or administer a lie detector test as a condition of employment or continued employment. 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Created: 2026-04-15