Document Report Card

ID: ALA1145460

Journal: J Med Chem

Title: Novel vanilloid receptor-1 antagonists: 3. The identification of a second-generation clinical candidate with improved physicochemical and pharmacokinetic properties.

Authors: Wang HL, Katon J, Balan C, Bannon AW, Bernard C, Doherty EM, Dominguez C, Gavva NR, Gore V, Ma V, Nishimura N, Surapaneni S, Tang P, Tamir R, Thiel O, Treanor JJ, Norman MH.

Abstract: Based on the previously reported clinical candidate, AMG 517 (compound 1), a series of related piperazinylpyrimidine analogues were synthesized and evaluated as antagonists of the vanilloid 1 receptor (VR1 or TRPV1). Optimization of in vitro potency and physicochemical and pharmacokinetic properties led to the discovery of (R)-N-(4-(6-(4-(1-(4-fluorophenyl)ethyl)piperazin-1-yl)pyrimidin-4-yloxy)benzo[d]thiazol-2-yl)acetamide (16p), a potent TRPV1 antagonist [rTRPV1(CAP) IC50 = 3.7 nM] with excellent aqueous solubility (>or=200 microg/mL in 0.01 N HCl) and a reduced half-life (rat t1/2 = 3.8 h, dog t1/2 = 2.7 h, monkey t1/2 = 3.2 h) as compared to AMG 517. In addition, compound 16p was shown to be efficacious at blocking a TRPV1-mediated physiological response in vivo (ED50 = 1.9 mg/kg, p.o. in the capsaicin-induced flinch model in rats) and was also effective at reducing thermal hyperalgesia induced by complete Freund's adjuvant in rats (MED = 1 mg/kg, p.o). Based on its improved overall profile, compound 16p (AMG 628) was selected as a second-generation candidate for further evaluation in human clinical trials as a potential new treatment for chronic pain.

CiteXplore: 17585751

DOI: 10.1021/jm070191h