Month: September 2026

Biosimilar Cell Line Development After FDA’s Push to Streamline Approvals

Biosimilar Cell Line Development After FDA’s Push to Streamline Approvals Biosimilar cell line development just gained new strategic weight. In October 2025, FDA issued draft guidance on comparative efficacy studies. It proposed that these studies no longer be the default for most therapeutic protein biosimilars. Instead, the agency would rely more on comparative analytical data, … Continue reading Biosimilar Cell Line Development After FDA’s Push to Streamline Approvals

Potency Assay Development Starts With the Cell Line

Potency Assay Development Starts With the Cell Line FDA reopened the potency conversation this summer. Consequently, potency assay development is back on many CMC timelines. On August 20, 2026, the agency published a draft guidance, Potency Assessment of Active Immunotherapy Products, under docket FDA-2026-D-8561. Comments close November 18, 2026. The draft addresses active immunotherapy products, … Continue reading Potency Assay Development Starts With the Cell Line

When to Walk Away from a Cell Line: Signs Your Clone Is Not Worth Developing Further

When to Walk Away from a Cell Line: Signs Your Clone Is Not Worth Developing Further Knowing when to walk away from a cell line is one of the most valuable, and least discussed, judgment calls in cell line development. Every project begins with optimism. However, at some point the data starts telling you that … Continue reading When to Walk Away from a Cell Line: Signs Your Clone Is Not Worth Developing Further

Passage Number in Cell Culture: How to Control It and Why It Matters

Passage Number in Cell Culture: How to Control It and Why It Matters Passage number in cell culture is one of the most underestimated drivers of variability in mammalian cell systems. Most protocols specify a passage range. Many labs and production programs treat it as background bookkeeping rather than an active experimental variable. The result … Continue reading Passage Number in Cell Culture: How to Control It and Why It Matters

HEK293 Cell Line Development: A Practical Guide to Stable Expression

HEK293 Cell Line Development: A Practical Guide to Stable Expression HEK293 cell line development is one of the most requested expression projects in early-stage biologics, research protein production, and gene therapy applications. Originally derived from human embryonic kidney cells, HEK293 cells produce proteins with human-like post-translational modifications, transfect efficiently, and scale from small plates to … Continue reading HEK293 Cell Line Development: A Practical Guide to Stable Expression