Approved treatment
At least one medicine using this approach has been authorised by a national regulator for this use.
Simple explanation
Waxy corn produces starch of a particular composition used in food processing and adhesives. Editing disabled one enzyme to produce it directly, rather than breeding for it over many seasons. In 2016 the USDA confirmed it would not regulate the result as a genetically modified organism, because nothing foreign had been added. It was one of the first such determinations anywhere.
Go deeper
Waxy corn developed by DuPont Pioneer using CRISPR-Cas9 to knock out the waxy allele received a USDA determination in 2016 that it fell outside biotechnology regulation, an early precedent for product-based regulation of edited crops. Subsequent programmes target drought tolerance, disease resistance and improved nitrogen use efficiency.