The novel NK1 receptor antagonist MK-0869 (L-754,030) and its water soluble phosphoryl prodrug, L758,298, inhibit acute and delayed cisplatin-inducedemesis in ferrets

The anti-emetic profile of the novel brain penetrant tachykinin NK, recepto r antagonist MK-0869 (L-754,030) 2-(R)-(1-(R)(3 5-bis (trifluoromethyl)phen ylethoxy)-3-(S)-(4-fluoro)phenyl-4-(3-oxo-1,2,4-triazol-5-yl)methylmorpholi ne and its water soluble prodrug, L-758,298, has been examined against emes is induced by cisplatin in ferrets. In a 4 h observation period, MK-0869 an d L-758,298 (3 mg/kg i.v. or p.o.) inhibited the emetic response to cisplat in (10 mg/kg i,v,), The anti-emetic protection afforded by MK-0869 (0.1 mg/ kg i.v.) was enhanced by combined treatment with either dexamethasone (20 m g/kg i.v,) or the 5-HT3, receptor antagonist ondansetron (0.1 mg/kg i.v.). In a model of acute and delayed emesis, ferrets were dosed with cisplatin ( 5 mg/kg i.p.) and the retching and vomiting response recorded for 72 h. Pre treatment with MK-0869 (4-16 mg/kg p.o,) dose-dependently inhibited the eme tic response to cisplatin. Once daily treatment with MK-0869 (2 and 4 mg/kg p.o,) completely prevented retching and vomiting in all ferrets tested. Fu rther when daily dosing began at 24 h after cisplatin injection, when the a cute phase of emesis had already become established, MK-0869 (4 mg/kg p.o, at 24 and 48 h after cisplatin) prevented retching and vomiting in three ou t of four ferrets. These data show that MK-0869 and its prodrug, L-758,298, have good activity against cisplatin-induced emesis in ferrets and provide d a basis for the clinical testing of these agents for the treatment of eme sis associated with cancer chemotherapy, (C) 2000 Elsevier Science Ltd. All rights reserved.