Recent developments in the medicinal chemistry of NK2 receptor antagonists

The search for new NK2 receptor antagonists have resulted in the discovery of several different classes of compounds with promise to have clinical utility. Clearly, the first reported non-peptide NK2 receptor antagonist (SR-48,968) has inspired a lot of effort in the area, but over the years other approaches have also been fruitful. These include optimisation of hits from random screening and modifying compounds with NK3 receptor antagonistic properties into selective NK2 receptor antagonists. This is also an area where cyclic peptides and derivatives have been extensively examined. So far, no NK2 receptor antagonist has reached the market, but several clinical trials are in progress.