Regulatory Open Forum

New chemical entity (NCE) is, according to the US FDA, a drug that contains no active moiety that has been approved by the FDA in any other application submitted under section 505(b) of the Federal Food, Drug, and Cosmetic Act

A new molecular entity (NME) is a drug that contains an active moiety that has never been approved by the FDA or marketed in the US.

New Chemical Entity (NCE) by the FDA, the product receives five years of market exclusivity after approval in the United States, regardless of the patent situation (sometimes referred to as Hatch-Waxman exclusivity). 

NME product receives a 3 year period of market "data exclusivity" if it contains an active moiety that has been previously approved but has been the subject of new clinical investigation by the sponsor that were essential for approval. 

When a company submits new clinical investigation data for a therapeutic indication for the product which has an active moiety (already approved by the FDA) will be called as NME. If it has no active moiety then it will be NCE.

"Active moiety is "the molecule or ion, excluding those appended portions of the molecule that cause the drug to be an ester, salt . . . , or other noncovalent derivative . . . of the molecule, responsible for the physiological or pharmacological action of the drug substance."