Scientist/Senior Scientist, Companion Diagnostics (CDx) - IHC Development

SystImmune is a leading and well-funded clinical-stage biopharmaceutical company located in Bothell, WA and Princeton, NJ. It specializes in developing innovative cancer treatments using its established drug development platforms, focusing on bi-specific, multi-specific antibodies, and antibody-drug conjugates (ADCs). SystImmune has multiple assets in various stages of clinical trials for solid tumor and hematologic indications. Alongside ongoing clinical trials. SystImmune has a robust preclinical pipeline of potential cancer therapeutics in the discover and IND-enabling stages, representing cutting-edge biologics development. We offer an opportunity for you to learn and grow while making significant contributions to the company'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 has strong expertise in pathology, IHC assay development, and CDx regulatory expectations, and can work effectively across R&D, clinical, regulatory, QA, and external CROs and central laboratories.

Key Responsibilities

IHC Assay & CDx Development

• Lead development of IHC-based CDx assays, from biomarker discovery through assay optimization and validation.
• Select and evaluate primary antibodies, detection systems, and staining platforms (e.g., Ventana, Dako, Leica).
• 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 & Performance

• Design and oversee analytical performance studies, including:
  • Sensitivity and specificity
  • Precision and reproducibility (intra-run, inter-run, inter-site)
  • Accuracy and robustness
  • Linearity and limit of detection, where applicable
• Prepare, review, and approve validation protocols, reports, and SOPs in alignment with CDx expectations.

Clinical Trial & Central Lab Support

• Support implementation of IHC assays in clinical trials, including:
  • Central laboratory qualification and oversight
  • Pathologist training and alignment
  • Slide logistics, staining consistency, and scoring harmonization
• Collaborate with clinical teams on sample strategy, feasibility studies, and biomarker cut-off justification.
• Regulatory & Quality Collaboration
• Work closely with Regulatory Affairs and Quality Assurance to ensure compliance with:
  • FDA CDx guidance (US)
  • NMPA/CDE requirements (China), where applicable
  • IVDR (EU), as relevant
• Support preparation of regulatory documentation, including:
  • IDE/IND biomarker sections
  • CDx bridging strategies (RUO/LDT → IVD)
  • Analytical and clinical performance summaries
• Ensure assay development aligns with QMS requirements, design controls, and document traceability.

Cross-Functional & External Collaboration

• Serve as a technical subject-matter expert, interacting with:
  • CROs, central laboratories, and 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

Education

• PhD in Pathology, Molecular Biology, Immunology, Oncology, or a related field
• MS or BS with significant CDx or IVD industry experience may be considered

Experience

• 3–5+ years of hands-on experience in IHC assay development, preferably in a CDx or IVD setting
• Direct experience supporting oncology biomarkers and clinical trials
• Experience across the CDx development lifecycle (RUO/LDT through IVD readiness)
• Strong understanding of IHC scoring methodologies (e.g., TPS, H-score, CPS)
• Familiarity with analytical validation and regulatory expectations for CDx
• Demonstrated ability to work effectively in cross-functional teams

Soft Skills

• Strong scientific rigor with excellent documentation and data interpretation skills
• Ability to operate in a fast-paced, matrix environment
• Clear and effective communication with both technical and non-technical stakeholders
• Experience working with global teams is a plus

Preferred Qualifications

• Prior experience with late-stage or FDA-approved CDx programs
• Experience developing and justifying biomarker cut-off strategies
• Familiarity with NSCLC, GI cancers, or other solid tumors
• Experience interacting with health authorities or supporting regulatory meetings

Why Join Us

• Opportunity to shape next-generation CDx programs linked to innovative oncology therapeutics
• High-visibility role with direct impact on patient selection and drug approval
• Collaborative environment bridging pathology, translational science, and regulatory strategy

Compensation and Benefits:
The expected base salary range for this position is $90,000 - $140,000 annually. Actual compensation will be based on a variety of factors, including but not limited to a candidate’s qualifications, level of the position , experience, and skills.

While most offers typically fall within the low to mid-point of the range, we may extend an offer toward the higher end for exceptional candidates whose background and expertise exceeds the requirements of the role.
 
SystImmune is a leading and well-funded biotech company with a bright future. We offer an opportunity for you to learn and grow while making significant contributions to the company’s success. SystImmune offers a comprehensive benefits package including: 100% paid employee premiums for medical/dental/vision, also STD, LTD, a 401(k) plan with a 50% company match of up to 3% and a vesting schedule of only 5 years, 15 PTO days per year, sick leave, plus 11 paid holidays and MORE.
 
We offer an opportunity for you to learn and grow while making significant contributions to the company’s success.
 
SystImmune is an Equal Opportunity Employer. We welcome diverse talent and encourage all qualified applicants to apply.