A novel water soluble LHRH antagonist (EP 24332 - Antarelix) is descri
bed. Its activity in vitro and in vivo in several animal models is giv
en. Antarelix (Ac-D-Nal, D-Cpa, D-Pal, Ser, Tyr, D-Hci, Leu, Lys-(iPr)
, Pro, D-Ala-NH2) in view of its potency, modest histamine - liberatin
g activity and high water solubility has been selected for further dev
elopment.