The FDA has long considered that even minor changes in the production of biological drugs--including exactly the same isolation and purification procedures applied at significantly larger scale than previously--yield a distinct and new drug that must undergo an independent demonstration of safety and efficacy.

FORBES: Commentary

After obtaining from Genentech, Inc. the recombinant E. coli bacteria that contained the genetic blueprint for and that synthesized human insulin, they developed processes for the large-scale cultivation of the organism (in huge fermenters similar to those that make wine or beer) and for the purification and formulation of the insulin.

FORBES: When Genetic Engineering Came Of Age