287: Why the Cell Line Is the CMC Decision You Don't Get to Undo with Sigma Mostafa - Part 1

A breakthrough in drug discovery can be derailed in an instant if manufacturability is left as an afterthought. Too many biotech programs hit bottlenecks at scale-up because key decisions in cell line and process development get kicked down the road. On the Smart Biotech Scientist Podcast, David Brühlmann spoke with Sigma Mostafa, Chief Scientific and Technology Officer at KBI Biopharma. She’s spent 25+ years converting early-stage discoveries into commercial biomanufacturing success and she’s adamant: manufacturability decisions belong at the candidate selection stage, not after. Topics discussed: Why manufacturability should be assessed at the candidate selection stage, not later (03:02) Sigma’s background in bringing math and biology together and her path into bioprocess engineering (04:18) The "art" and complexity of bioprocess development, especially with new molecule types (05:54) A case study of how switching cell lines revealed hidden manufacturability issues (07:33) Key properties affecting manufacturability, such as aggregation and thermal stability (10:10) Reasons companies delay manufacturability assessments—timing pressure, costs, and lack of early deep characterization (11:02) Why CMC should be integrated from day one and concerns with treating scalability as 'just' engineering (12:08) Critical decisions and pitfalls in cell line development, including robustness, media choices, and adapting after the master cell bank is made (12:48) Regulatory aspects of cell line development: demonstrating clonality, avoiding animal source materials, and documentation requirements (15:04) Smart insight: Manufacturability is not just a box for the CMC team. It’s a proactive mindset, to be embraced from day one. Early, cross-functional scrutiny—examining both molecule and cell line—preempts disasters during scale-up and accelerates timelines to market while minimizing costly surprises. This episode unpacks what that means in practice and where speed and robustness pull against each other. If it resonated, these conversations expand the picture: how to spot manufacturable candidates early, how in silico tools predict stability and aggregation before the lab, and which early CMC decisions quietly become permanent. Episodes 123 - 124: Manufacturability: Why Most Protein Candidates Fail (And How to Pick Winners Early) with Susan Sharfstein Episodes 213 - 214: From Developability to Formulation: How In Silico Methods Predict Stability Issues Before the Lab with Giuseppe Licari Episodes 231 - 232: From IND to BLA: The Biologics CMC Decisions That Determine Regulatory Success with Henri Kornmann Episodes 103 - 104: One-Stop Shop vs. Specialist CDMO: A Scientist's Guide to CDMO Selection with Sigma Mostafa Connect with Sigma Mostafa: Linkedin: https://www.linkedin.com/in/sigma-mostafa-79180817 KBI website: https://www.kbibiopharma.com Free 5-day email course, The CMC Failure Chain: the five recurring CMC mistakes that put your promising program at risk → Get it here Support the show