Principal Scientist, Translational Lead

Who We Are

Arcellx is a public, clinical-stage biotechnology company reimagining cell therapy by engineering innovative immunotherapies for patients with cancer and other incurable diseases. We believe that cell therapies are one of the forward pillars of medicine and our mission is to destroy cancer and advance humanity by developing cell therapies that are safer, more effective, and more broadly accessible.

Our team members are made up of talented innovators and dreamers working from our offices in Rockville, Maryland, and Redwood City, California. At Arcellx, we hire exceptional people and create a fun, diverse, supportive, and informal environment that allows everyone to do their best work.

What Matters to Us

Living our core values is essential to maintaining a work environment that is high-performing, inclusive, and collaborative. We look for candidates who demonstrate strong values alignment and bring different backgrounds, viewpoints, and abilities to the team.

Arcellx Core Values

• Start with authenticity: We foster an inclusive environment where each person can bring their authentic self to work.

• Think ‘we’ before ‘me’: We prioritize collective success, collaborating and supporting one another to achieve our shared goals.

• Embrace the challenge: We deliver exceptional results by working with shared determination and a commitment to doing what’s right.

How You’ll Make a Difference

We are seeking a dynamic, scientifically rigorous Principal Scientist, Translational Lead to drive translational strategy and execution across early-stage clinical programs. This cross-functional role combines biological insight, data fluency, and operational pragmatism, ideally suited for a candidate with a strong translational medicine background who is also comfortable performing hands-on analytics and drafting infrastructure requirements.

The successful candidate will lead the integration of high-dimensional biomarker and clinical data—including flow cytometry, transcriptomics, and proteomics—to inform mechanism-of-action, pharmacodynamics, and patient stratification. This role requires the ability to independently generate and execute data analysis plans and to specify compliant infrastructure requirements to support analytics workflows. The role will not own infrastructure buildout but must be able to define what is needed for scalable, auditable translational research.

The “Fine Print” – What You’ll Do

• Drive translational strategy for early-phase clinical programs, incorporating biomarker hypotheses, patient selection, and endpoint optimization.

• Serve as the lead for biomarker components in clinical protocols, IND submissions, and regulatory engagements.

• Align translational goals with key clinical milestones and trial objectives.

• Design and execute analysis plans for high-dimensional datasets including flow cytometry, RNA-seq, single-cell, and spatial omics.

• Lead integration of molecular and clinical data to uncover pharmacodynamic signals, stratification markers, and mechanisms of resistance.

• Automate and analyze complex flow cytometry and CyTOF datasets using tools such as FlowJo, R (e.g., flowCore, CytoML, ggcyto), or Python-based pipelines.

• Apply modern statistical and machine learning methods to uncover actionable insights, ensuring analytic reproducibility and compliance.

• Contribute to governance meetings, internal reviews, and external scientific communications (e.g., manuscripts, abstracts).

• Provide thought leadership at the interface of clinical development and translational science.

• Evaluate new biomarker platforms and external datasets to expand translational capabilities.

• Mentor junior scientists and cultivate a high-performing, collaborative translational culture.

Skills and Experience We Look For

• PhD in Bioinformatics, Computational Biology, Immunology, Molecular Biology, or related discipline.

• 8+ years of industry experience in translational medicine, biomarkers, or bioinformatics in oncology, immunology, or rare disease.

• Proficiency in automated flow cytometry analysis, including multicolor panel data interpretation and integration with other biomarker modalities.

• Hands-on fluency in R and/or Python for statistical modeling, data visualization, and reproducible bioinformatics.

• Demonstrated ability to design and execute translational analysis plans and influence clinical development.

• Experience contributing to INDs or regulatory filings involving biomarker or flow cytometry data.

• Familiarity with early-phase trials in cell therapy, immuno-oncology, or engineered therapeutics.

• Experience working in GCP/GxP-regulated environments or defining analytics/compliance workflows.

• Exposure to tools such as FlowJo, Cytobank, Spectre, or Bioconductor-based cytometry packages.

• Background in small biotech or matrixed R&D settings with high execution ownership.

Rewards at Arcellx

Our people are our greatest asset, and supporting their well-being is an essential part of delivering on our mission and impacting the lives of patients. Putting this belief into practice means offering strong compensation and benefits.

The base salary range for this position is $150,000 - $177,000 per year. Where a candidate falls within that range is determined by factors such as years of experience. Our compensation package also includes an annual bonus based on company goals and an equity (RSU) grant. We do offer relocation assistance for roles if required.

Our market-leading benefits package includes: 100% coverage for medical, dental and vision for team members and dependents, unlimited vacation, a 3-day weekend every month, fully-paid parental leave for up to 6 months, tuition reimbursement, 401k employer contribution and more.

Join us in our quest to reimagine cell therapy and destroy cancer. For more on our technology, culture, and team, go to www.arcellx.com.

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