RESUMEN
The relevance of the melanocortin system to sexual activity is well established, and nonselective peptide agonists of the melanocortin receptors have shown evidence of efficacy in human sexual dysfunction. The role of the MC4 receptor subtype has received particular scrutiny, but the sufficiency of its selective activation in potentiating sexual response has remained uncertain owing to conflicting data from studies in preclinical species. We describe here the discovery of a novel series of small-molecule MC4 receptor agonists derived from library hit 2. The addition of methyl substituents at C3 and C5 of the 4-phenylpiperidin-4-ol ring was found to be markedly potency-enhancing, enabling the combination of low nanomolar potencies with full rule-of-five compliance. In general, the series shows only micromolar activity at other melanocortin receptors. Our preferred compound 40a provided significant systemic exposure in humans on both sublingual and oral administration and was safe and well tolerated up to the maximum tested dose. In a pilot clinical study of male erectile dysfunction, the highest dose of 40a tested (200 mg) provided a similar level of efficacy to sildenafil.
Asunto(s)
Disfunción Eréctil/tratamiento farmacológico , Piperidinas/síntesis química , Pirrolidinas/síntesis química , Receptor de Melanocortina Tipo 4/agonistas , Administración Intranasal , Administración Oral , Administración Sublingual , Animales , Disponibilidad Biológica , Ensayos Clínicos Fase I como Asunto , Cristalografía por Rayos X , Perros , Hepatocitos/metabolismo , Humanos , Técnicas In Vitro , Masculino , Microsomas Hepáticos/metabolismo , Modelos Moleculares , Piperidinas/farmacocinética , Piperidinas/farmacología , Pirrolidinas/farmacocinética , Pirrolidinas/farmacología , Ensayos Clínicos Controlados Aleatorios como Asunto , Ratas , Estereoisomerismo , Relación Estructura-ActividadRESUMEN
We prepared three discreet cohorts of potent non-nucleoside HIV reverse transcriptase inhibitors (NNRTIs) based on the recently reported 3-cyanophenoxypyrazole lead 3. Several of these compounds displayed very promising anti-HIV activity in vitro, safety, pharmacokinetic and pharmaceutical profiles. We describe our analysis and conclusions leading to the selection of alcohol 5 (UK-453,061, lersivirine) for clinical development.