The EWG had a lot of debate about this particular subject and really didn’t come up with a
particularly good analogy for fermentation. Is it really the cell lines used in production? Is it the
media and media components that make up the source material? What exactly is it? We also had
this discussion with the CTD working group because they were trying to define the same thing,
and I don’t think there was ever a plausible resolution to this. So what we came up with is nicely
illustrated as part of the chart, and we thought it was a more workable solution, was instead of
trying to define something as a source material, what we would do is try to show the processes in
parallel. And that is one of the reasons we chose to start with fermentation because that seemed
like a good starting point for the process for both biotech and classical fermentation. So the
answer is we realized that trying to define the source material for these processes was a difficult
task and it was one that ultimately we did not resolve.
