Scientist​/Senior Scientist, Companion Diagnostics; CDx - IHC Development

Position: Scientist/Senior Scientist, Companion Diagnostics (CDx) - IHC Development
Syst Immune is a leading and well-funded clinical-stage biopharmaceutical company located in Redmond, 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). Syst Immune has multiple assets in various stages of clinical trials for solid tumor and hematologic indications. Alongside ongoing clinical trials.

Syst Immune 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…