Postdoc API Process Development

Postdoc/Scientist – Advanced Therapies API Process Development

JnJ Innovative Medicines is committed to developing first‑in‑class or best‑in‑class medication for some of the world’s most life‑threatening diseases. In Leiden, we have a workforce of 350 scientists and support staff focusing on the development of Advanced Therapies. We partner with many of the world’s leading experts, academic and clinical institutions, and other pharmaceutical companies for the early development of production processes.

The API (Active Pharmaceutical Ingredients) Process Development department is responsible for designing scalable, pharmaceutical‑grade production processes. Our main focus is the early‑stage development of process steps for Advanced Therapies manufacturing, ranging from viral seed generation and cell culturing to purification. Innovative technologies are employed to ensure that all processes meet safety, reliability, scalability, and cost‑efficiency standards. Once developed, these production processes are transferred to GMP manufacturing facilities for clinical batch production and further scaled for commercial operations. All activities are conducted in close collaboration with other departments.

We are looking for a motivated scientist/postdoc to execute a two‑year R&D project to improve the robustness, scalability, and manufacturability of a transient transfection process for viral vector production. This position is part of the Discovery, Product Development & Supply (DPDS) Postdoctoral Scholar program.

Based in Leiden and working closely with cross‑functional stakeholders (including a partner site in the United States), you will translate development needs into an experimental strategy, execute laboratory studies, and drive data‑informed decisions to strengthen process consistency and product quality. Travel to the United States is anticipated and may include periods of extended stay.

This project operates at the interface between process development, automation, process engineering, and equipment design with the aim of introducing an optimized transfection process in GMP manufacturing. The candidate will gain a thorough insight into how transfection process parameters affect the quality attributes of resulting viral vectors. Additionally, the candidate will develop and implement near real‑time biophysical monitoring strategies (inline, online, or at‑line) to track critical quality attributes, deepen mechanistic product understanding, and accelerate process development. This position will require hands‑on lab work, while offering ample scientific leadership and personal growth opportunities through training, mentoring and R&D‑wide connectivity.

This position is full‑time and primarily on‑site, with limited hybrid working possible. We are looking for a candidate who enjoys combining hands‑on laboratory work with scientific problem‑solving, data analysis, and stakeholder management.

• Translate technical concepts into a practical, end‑to‑end transient transfection solution.
• Plan and execute experiments.
• Establish fit‑for‑purpose analytical methods and readouts in collaboration with internal experts.
• Apply statistical methods and Design of Experiments (DoE) to define parameter setpoints.
• Identify automation strategies with a view to future GMP implementation.
• Communicate progress clearly to stakeholders.
• Analyze data and document results.
• Contribute to internal knowledge building and, where appropriate, scientific publications and IP/patent activities.
• Drive the development of an optimized transient transfection process in a GMP manufacturing environment.

• PhD (or equivalent experience) in a relevant field such as biochemistry, cell biology, biochemical engineering, virology, biotechnology, bioprocess design, or related field.
• Experience with transient transfection systems, mammalian cell culture, and viral vectors.
• Affinity with process engineering.
• Hands‑on and collaborative working style; comfortable working across departments and disciplines.
• Excellent communication skills, with the ability to explain complex ideas clearly to diverse audiences.
• Demonstrated rigor in both experimental design and data analysis, with the capacity to develop innovative solutions to scientific challenges.
• Experience with (in‑line) biophysical methods (preferred).
• Experience with process automation (preferred).