Development of a Series of Kynurenine 3-Monooxygenase Inhibitors Leading to a Clinical Candidate for the Treatment of Acute Pancreatitis

Recently, we reported a novel role for KMO in the pathogenesis of acute pancreatitis (AP). A number of inhibitors of kynurenine 3-monooxygenase (KMO) have previously been described as potential treatments for neurodegenerative conditions and particularly for Huntington’s disease. However, the inhibitors reported to date have insufficient aqueous solubility relative to their cellular potency to be compatible with the intravenous (iv) dosing route required in AP. We have identified and optimized a novel series of high affinity KMO inhibitors with favorable physicochemical properties. The leading example is exquisitely selective, has low clearance in two species, prevents lung and kidney damage in a rat model of acute pancreatitis, and is progressing into preclinical development

Discovery of a Rapidly Metabolized, Long-Acting β₂ Adrenergic Receptor Agonist with a Short Onset Time Incorporating a Sulfone Group Suitable for Once-Daily Dosing

A series of novel, potent, and selective human β₂ adrenoceptor agonists incorporating a sulfone moiety on the terminal right-hand-side phenyl ring of (<i>R</i>)-salmeterol is presented. Sulfone <b>10b</b> had salmeterol-like potency and selectivity profile, long duration of action on guinea pig trachea, and longer than salmeterol duration of action in vivo, suitable for once-daily dosing. It had lower than salmeterol oral absorption in rat, lower bioavailability in rat and dog, and a high turnover in human hepatocytes. It was metabolized in human hepatocytes by hydroxylation, oxidation, cleavage, and conjugation; most of the metabolites would be expected to have reduced or no β₂ activity. The 4-biphenylsulfonic acid was identified as a crystalline, non-hygroscopic salt of <b>10b</b>, suitable for inhaled delivery. Furthermore, it was free of any genetic toxicity issues and was considered as a backup to vilanterol