Like hypotheses, concepts are important to our understanding and point the direction for actions and tests. The concept of me-too drugs is simple and powerful and misleadingly deemphasizes the value of these drugs for patients and physicians. The term me-too drug has been used in several ways, by some even to mean a generic drug.1
However, the term is historically and most accurately used to describe a drug with a mechanism of action similar to a drug already on the market. Although chemically distinct, the me-too drug will usually have a chemical structure that is similar to the first-to-market drug, which is viewed as having established the therapeutic category. These category-creating drugs are also called innovator or breakthrough drugs. Corticosteroids, retinoids, and antihistamines are examples familiar to dermatologists.
Eaglstein WH. Me-Too Drugs and Me-Too People. JAMA Dermatol. 2013;149(12):1375-1376. doi:10.1001/jamadermatol.2013.6759