Cereblon E3 ligase modulators, also known as immunomodulatory imide drugs (IMiDs), are a class of immunomodulatory drugs (drugs that adjust immune responses) containing an imide group. The IMiD class includes thalidomide and its analogues (lenalidomide, pomalidomide, mezigdomide 
and iberdomide). These drugs may also be referred to as Cereblon modulators. Cereblon (CRBN) is the protein targeted by this class of drugs.
The name "IMiD" alludes to both "IMD" for "immunomodulatory drug" and the forms imide, imido-, imid-, and imid.
The development of analogs of thalidomide was precipitated by the discovery of the anti-angiogenic and anti-inflammatory properties of the drug yielding a new way of fighting cancer as well as some inflammatory diseases after it had been banned in 1961. The problems with thalidomide included teratogenic side effects, high incidence of other adverse reactions, poor solubility in water and poor absorption from the intestines.
In 1998 thalidomide was approved by the U.S. Food and Drug Administration (FDA) for use in newly diagnosed multiple myeloma (MM) under strict regulations. This has led to the development of a number of analogs with fewer side effects and increased potency which include lenalidomide and pomalidomide, which are currently marketed and manufactured by Celgene.