Cmc Bioassay Development Jobs (NOW HIRING)

Drug development shouldn’t be guesswork, not when patients are waiting.

Pathos is building a next-generation biotech with AI at the core. Not as a feature, but as the operating system for how medicines get developed. We believe most drugs don't fail because the science was wrong. They fail because they were tested in the wrong patients, with the wrong assumptions, in trials that couldn't answer the real question: who benefits, and why?

Pathos exists to change that. We're building the largest foundation model in oncology and pairing it with proprietary AI systems, deep oncology expertise, and 200+ petabytes of multimodal data linked to patient outcomes, so we can make development decisions with more precision, much earlier.

This is not theoretical. We’re well-capitalized and have the leadership to build a generational company. We invest in and advance our own clinical-stage programs, using our AI platform to sharpen trial design, patient selection and biomarker strategy. So therapies reach the patients most likely to benefit, sooner.

How We Build

Pathos does not operate like a traditional biotech. There is no middle management. There are no layers of approval. The company is designed, from the ground up, around small teams of 2–4 subject matter experts who each command hundreds of AI agents to do the work that used to require dozens of people.

Everyone builds. Everyone ships. Every function at Pathos — from clinical execution to asset selection to the foundation model itself — runs on this model. Our product velocity delivers meaningful outcomes in hours instead of weeks. This is not a future aspiration. It is how we operate today.

The people who thrive here are operators: deep experts who can specify what needs to happen, orchestrate AI agents to execute at scale, and make high-judgment calls that compound over time. If you have spent your career building and shipping AI systems at scale, this is the environment where that experience becomes a superpower.

We are seeking a Director, CMC – Biologics & ADC to lead the chemistry, manufacturing, and controls strategy for our antibody and antibody-drug conjugate (ADC) oncology programs. This individual will own upstream and downstream process development, analytical development, and ADC conjugation/manufacturing — from early clinical supply through late-stage development — ensuring phase-appropriate quality, robust and scalable processes, and regulatory-ready documentation. This is a foundational hire on the Pathos CMC/Technical Operations team. You will help build and scale the chemistry, manufacturing, and controls function from an early stage, working shoulder-to-shoulder along with the Head of CMC with Research, Clinical, Regulatory, and Quality colleagues in a fast-moving, resource-conscious environment. You are equally comfortable rolling up your sleeves on technical detail and operating strategically across a portfolio.

What You Will Do

• Define and execute the end-to-end biologics/ADC CMC strategy for one or more oncology programs, spanning antibody drug substance, conjugation, and drug product.
• Serve as the CMC program lead and single point of accountability, representing CMC on cross-functional program teams alongside Research, Clinical, Regulatory, and Quality.
• Translate program goals and timelines into phase-appropriate development plans, budgets, and risk-mitigation strategies.

Upstream & Downstream Process Development

• Expert in biologics cell line and drug substance development.
• Lead upstream process development for antibodies — cell line development oversight, media/feed optimization, and fed-batch/perfusion bioreactor processes from bench through scale-up.
• Lead downstream process development — harvest/clarification, Protein A and polishing chromatography, viral clearance, ultrafiltration/diafiltration, and formulation.
• Apply QbD and risk-based approaches to establish robust, scalable, and controllable processes and control strategies.

ADC Conjugation & Manufacturing

• Direct ADC-specific CMC activities including linker-payload strategy, conjugation process development, and drug-to-antibody ratio (DAR) control.
• Oversee ADC drug substance and drug product manufacturing, including handling of high-potency payloads and appropriate containment (OEB) controls.
• Coordinate the multi-component supply chain (antibody intermediate, linker-payload, conjugated drug substance, and drug product) across specialized CDMOs.
• Experience with high-concentration development is a plus
• Lyophilization experience is a plus

Analytical Development & Characterization

• Own the analytical strategy for antibodies and ADCs — method development, qualification/validation, specifications, and stability.
• Direct product characterization and comparability, including purity/impurities, aggregation, charge variants, glycosylation, potency/bioassays, DAR, free-drug, and other ADC‑critical quality attributes.
• Design and execute studies to assess protein stability, aggregation, degradation pathways, viscosity, and developability under relevant formulation conditions.

External Manufacturing, Regulatory & Quality

• Select, manage, and technically oversee CDMOs for antibody and ADC manufacture, leading tech transfer, scale-up, engineering, and GMP campaigns.
• Ensure timely, phase‑appropriate clinical supply (Phase 1–3) and lead process performance/validation to support late‑stage development and commercialization.
• Author and review CMC sections of regulatory filings (IND, IMPD, briefing documents, and later BLA/MAA modules) and support health‑authority interactions.
• Partner with Quality to ensure GMP compliance, manage deviations and change control, and support audits.

Who You Are

Required Qualifications

• Ph.D. in Biochemistry, Chemical/Biochemical Engineering, Biotechnology, or a related field (or an M.S./B.S. with commensurate additional experience).
• 8–10+ years of biopharmaceutical CMC experience with demonstrated depth in antibody upstream AND downstream process development and analytics.
• Hands‑on experience with ADC manufacturing — conjugation chemistry, linker‑payload handling, DAR control, and high‑potency containment.
• Direct experience in oncology drug development.
• Proven track record across the full development lifecycle: phase‑appropriate development for Phase 1–3 as well as hands‑on experience with late‑stage development.
• Experience in BOTH a small/emerging biotech and a large pharma environment, with the versatility to operate effectively in each.
• Demonstrated success managing CDMOs and leading technical transfer, scale‑up, and GMP manufacturing for biologics and/or ADCs.
• Strong command of ICH, FDA, and EMA guidance for biologics/ADCs and phase‑appropriate GMP expectations, with experience authoring CMC regulatory submissions.

Preferred Qualifications

• Experience taking a biologic or ADC oncology asset through pivotal/late‑stage development and toward registration (BLA/MAA).
• Familiarity with site‑specific/next‑generation conjugation, novel payload classes, or bispecific antibody formats.
• Experience with comparability strategies and control of ADC‑specific critical quality attributes across process changes.
• Comfort operating in a data‑and‑technology‑forward organization; interest in leveraging AI/ML to accelerate CMC decision‑making.

What Success Looks Like

• Reliable, phase‑appropriate clinical supply of antibody and ADC material that never gates the clinical program.
• Robust, scalable processes and well‑controlled critical quality attributes that de‑risk late‑stage development.
• Clean, defensible CMC regulatory submissions and successful health‑authority interactions.

Location

This is a hybrid role, requiring 3 days per week onsite, in our NYC Headquarters.

The pay range for this role is:

210,000 - 250,000 USD per year (New York Office - ACLS East Tower)