FDA denies 5-year exclusivity to “stable esters” and confirms structure-based approach to exclusivity

For sponsors developing new chemical structures based on previously approved active ingredients, two new FDA decisions offer a clear – though hardly satisfying – standard for determining whether a new structure will be awarded 5-year “new chemical entity” (NCE) exclusivity. In two letter decisions issued on the same day, the agency firmly explained that NCE exclusivity will not be awarded to a new structure that relies on an ester bond to link a new appendage to a previously approved active ingredient.

Read: "FDA denies 5-year exclusivity to “stable esters” and confirms structure-based approach to exclusivity"


Download PDF Share Back To Listing
Loading data