title: Orally active fibrinogen receptor antagonists. 2. Amidoximes as prodrugs of amidines.
abstract: The potent and selective GP IIb-IIIa antagonist lamifiban (1, Ro 44-9883) is currently in clinical development as an injectable antithrombotic agent for treating and preventing acute coronary syndromes. However, for secondary prevention of thrombotic occlusions, orally active inhibitors are needed. By means of a prodrug strategy, the modest oral absorption of 1 in mice was improved by a factor of 9. In addition, these studies demonstrated that an amidoxime group can serve as a prodrug functionality for an amidino group. Application of this principle to the structurally related amidino carboxylate 13 led to the amidoxime ester 18 which was absorbed approximately 20 times better, after oral administration to mice, than 13. Due to the modification of the amidino group as well as of the carboxylate group, 18 completely lost its ability to interact with purified platelet GP IIb-IIIa. After oral administration of 18 to rats, dogs, and rhesus monkeys, the bioavailability of the active derivative 13 was 26 +/- 5, 25 +/- 6, and 33 +/- 6%, respectively, and the elimination half-life was 4.1 +/- 1.7, 11.4 +/- 1.1, and 5.1 +/- 1.4 h, respectively. On the basis of these properties, the orally active 18 (Ro 48-3657), a double prodrug of the potent and selective non-peptide GP IIb-IIIa antagonist 13 (Ro 44-3888), was selected as clinical candidate for evaluation as a prophylactic agent in patients at high risk for arterial thrombosis.
authors: Pharma Division, F. Hoffmann-La Roche Ltd., Basel, Switzerland.
authors: T
authors: T
authors: Weller
authors: L
authors: L
authors: Alig
authors: M
authors: M
authors: Beresini
authors: B
authors: B
authors: Blackburn
authors: S
authors: S
authors: Bunting
authors: P
authors: P
authors: Hadváry
authors: M H
authors: MH
authors: Müller
authors: D
authors: D
authors: Knopp
authors: B
authors: B
authors: Levet-Trafit
authors: M T
authors: MT
authors: Lipari
authors: N B
authors: NB
authors: Modi
authors: M
authors: M
authors: Müller
authors: C J
authors: CJ
authors: Refino
authors: M
authors: M
authors: Schmitt
authors: P
authors: P
authors: Schönholzer
authors: S
authors: S
authors: Weiss
authors: B
authors: B
authors: Steiner
mesh_terms: D000085:Acetates / Q000494:pharmacology; D000284:Administration, Oral; D000578:Amidines / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology*; D000818:Animals; D000925:Anticoagulants / Q000008:administration & dosage / Q000138:chemical synthesis / Q000493:pharmacokinetics / Q000494:pharmacology; D004285:Dogs; D008253:Macaca mulatta; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D051379:Mice; D015394:Molecular Structure; D010091:Oximes / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology*; D010880:Piperidines / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology*; D010974:Platelet Aggregation / Q000187:drug effects; D010975:Platelet Aggregation Inhibitors / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology*; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000037:antagonists & inhibitors*; D011355:Prodrugs / Q000008:administration & dosage / Q000138:chemical synthesis / Q000493:pharmacokinetics / Q000494:pharmacology*; D051381:Rats; D014443:Tyrosine / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: D000085:Acetates; D000578:Amidines; D000925:Anticoagulants; D010091:Oximes; D010880:Piperidines; D010975:Platelet Aggregation Inhibitors; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; D011355:Prodrugs; C100916:Ro 44-3888; D014443:Tyrosine; C084062:lamifiban; C100917:sibrafiban