Discovery and Optimization of 4-(8-(3-Fluorophenyl)-1,7-naphthyridin-6-yl)transcyclohexanecarboxylic Acid, an Improved PDE4 Inhibitor for the Treatment of Chronic Obstructive Pulmonary Disease (COPD).
Press NJ, Taylor RJ, Fullerton JD, Tranter P, McCarthy C, Keller TH, Arnold N, Beer D, Brown L, Cheung R, Christie J, Denholm A, Haberthuer S, Hatto JD, Keenan M, Mercer MK, Oakman H, Sahri H, Tuffnell AR, Tweed M, Trifilieff A.
Herein we describe the optimization of a series of PDE4 inhibitors, with special focus on solubility and pharamcokinetics, to clinical compound 2, 4-(8-(3-fluorophenyl)-1,7-naphthyridin-6-yl)transcyclohexanecarboxylic acid. Although compound 2 produces emesis in humans when given as a single dose, its exemplary pharmacokinetic properties enabled a novel dosing regime comprising multiple escalating doses and the resultant achievement of high plasma drug levels without associated nausea or emesis.