new chemical entity

A new chemical entity is a molecule the world has genuinely never used as a medicine before, a truly fresh structure rather than a tweak of an existing pill. It is the difference between inventing a new key and merely re-cutting an old one.

Defined formally, it is a novel active molecule never before approved or marketed as a drug. Because it is unprecedented, it must go through the full battery of safety and efficacy testing, and it can earn strong patent protection and regulatory exclusivity that reward the risk of inventing it.

The term is sometimes used loosely, but regulators apply specific criteria to decide what counts as new, often relating to whether the active moiety has been approved before. Reformulating, combining, or making a new salt of an existing drug usually does not qualify as a new chemical entity.