Dr. Yashas Rajendra, Research Scientist of Bio-TDR Cell Culture at Eli Lilly and Company, and a speaker
at the upcoming “Optimizing Cell Culture Technology Conference” shares insight on streamlining the
discovery process by minimizing the risk when molecules move forward in the portfolio.
Dr. Rajendra obtained his Bachelor of Engineering in
Biotechnology in India and Master of Science in
Molecular Biotechnology in Stockholm. His research career
started in 2009 with Ph.D. thesis work at EPFL, Switzerland
under the expert guidance of Prof. Florian Wurm. He has
been working as a
Research Scientist at Lilly Research Laboratories, Eli Lilly since 2013.
His area of expertise mainly
encompasses - mammalian cell culture; transient gene expression in
CHO and HEK293 cells; stable CHO pool and cell line generation.
Harmonizing Transient and Stable CHO Expression
Platforms for Early-Phase Drug Discovery
Dr. Yashas Rajendra, Research Scientist of Bio-TDR Cell Culture at Eli Lilly and Company

How do you go about streamlining your processes?
Typically, most companies still rely on HEK293 transient transfection platforms
for early phase drug discovery of complex biopharmaceuticals.
However, this can greatly increase the risk of surprises when molecules
are advanced in the portfolio and are eventually expressed in CHO cells.
Our goal from day one has been to develop a transient CHO expression
platform that can mimic product quality attributes coming from stable
CHO expression platform.
This allows us to streamline the discovery process by minimizing the risk
when molecules move forward in the portfolio.

What are the differences you see between your
transient and stable expression platforms?
We have been successful in developing a transient CHO platform based
on the same cell line, media package, and DNA expression cassette that
is used for stable CHO expression platform, which puts us in a unique
position.
This has minimized the differences in product quality observed for therapeutics
between our transient and stable expression platforms.
However, there are still some unavoidable differences, for ex. the mode
of expression (plasmid mediated vs integrated gene), duration of expression
(1 week for transient expression vs 2 weeks for stable expression)
and the expression levels which can all contribute to molecular attributes.

Have you observed product quality surprises when
moving a molecule form transient to stable
expression?
In the past, our transient platform was based on HEK293 cells and we
have had a few cases of product quality surprises when the molecules
were expressed in CHO cells, leading to project delays.
Recently, we have developed a transient CHO platform that closely
mimics product quality attributes of proteins generated from stable CHO
platform, and so we have minimized such surprises.
However, with biopharmaceuticals increasing in complexity with each
passing day, we will have to closely monitor and gather further data to
elucidate and manage any significant differences.
To learn more about his presentation and The Bioprocessing Summit, visit www.bioprocessingsummit.com/Cell-Culture/