The introduction of a gene that affects some characteristic is not the same as the administration of a drug. A more apposite model is the approach taken by the FDA's food regulator, the Center for Food Safety and Applied Nutrition, which does not perform case-by-case reviews of every new product but limits them to products with characteristics that suggest they pose non-negligible risk. This approach has worked quite well over many years.
The FDA's existing approach to foods should have been applied to genetically engineered animals. But characteristically, regulators chose the most risk-averse and burdensome approach. The result has been an entire innovative business sector burdened with a policy that inflates research and development costs, inhibits innovation and deprives consumers of health-promoting and less-expensive products. Not surprisingly, very few companies are willing to brave the regulatory thicket.