288: Why the Cell Line Is the CMC Decision You Don't Get to Undo with Sigma Mostafa - Part 2

Manufacturability challenges in biotech are becoming more complex as therapies become more potent, formats diversify, and timelines compress across the industry.

On this episode, David Brühlmann sits down with Sigma Mostafa, Chief Scientific and Technology Officer at KBI Biopharma. Sigma brings deep expertise in early-stage CMC decision-making and has guided countless programs—from upstart startups to established pipelines—through the traps and trade-offs of process development. Her ground-floor perspective spans in silico modeling, innovative cell line engineering, and the gritty realities of tech transfer.

Key topics discussed:

• Practical advice for startups on selecting robust cell lines and avoiding long-term lock-in to problematic platforms (03:07)
• Managing risks in process development, such as high oxygen demand and filter loading, before tech transfer to manufacturing (04:47)
• The value of pressure testing bioprocesses at scale and identifying potential failure modes, including filter clogging and narrow feeding windows (07:41)
• Balancing speed, robustness, and regulatory expectations when advancing new molecules (09:23)
• How fast-tracking from transfection to IND is changing timelines, and the associated risks of accelerated development (09:54)
• Trends and caution in applying AI and in silico tools to protein and process modeling, and the limits of digital solutions (12:01)
• What first-time founders need to get right, including early analysis of molecular issues and careful cell line selection (15:48)
• Shifting modality trends—growing numbers of ADCs/XDCs, more complexity, and the move toward smaller scale and more potent molecules (16:55)
• The overarching lesson: invest early in the areas you cannot change later—especially cell line and understanding of molecule challenges (18:23)

Smart insight: Startup founders often wonder which fires to fight first. Sigma’s advice: focus on deep molecular assessment and making informed, scalable cell line choices above all else. These are the “few things you cannot change later” and the investments that separate enduring programs from cautionary tales.

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

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