A structurally novel series of adenosine 5'-triphosphate-sensitive potassium (K(ATP)) channel openers is described. As part of our efforts directed toward identifying novel, bladder-selective potassium channel openers (KCOs) targeted for urge urinary incontinence (UUI), we found that bioisosteric replacement of the N-cyanoguanidine moiety of pinacidil (1, Figure 1) with a diaminocyclobutenedione template afforded squaric acid analogue 2, the prototype of a novel series of K(ATP) channel openers with unique selectivity for bladder smooth muscle in vivo. Further modification of the heterocyclic ring to give substituted aryl derivatives (3) afforded potent KCOs that possessed the desired detrusor selectivity when administered orally. The effects of these potassium channel agonists on bladder contractile function was studied in vitro using isolated rat detrusor strips. Potent relaxants were evaluated in vivo in a rat model of bladder instability. Lead compounds were evaluated concomitantly in normotensive rats for their effects on mean arterial blood pressure (MAP) and heart rate as a measure of in vivo bladder selectivity. (R)-4-[3,4-Dioxo-2-(1,2, 2-trimethyl-propylamino)-cyclobut-1-enylamino]-3-ethyl-benzo nitrile (79) met our potency and selectivity criteria and represents an attractive development candidate for the treatment of UUI. Electrophysiological studies using isolated rat bladder detrusor myocytes have demonstrated that compound 79 produces significant hyperpolarization which is glyburide-reversed, thus consistent with the activation of K(ATP). The design, synthesis, structure-activity relationships (SAR), and pharmacological activity associated with this series of novel KCOs will be discussed.

A series of potent hydroxyethyl amine (HEA) derived inhibitors of β-site APP cleaving enzyme (BACE1) was optimized to address suboptimal pharmacokinetics and poor CNS partitioning. This work identified a series of benzodioxolane analogues that possessed improved metabolic stability and increased oral bioavailability. Subsequent efforts focused on improving CNS exposure by limiting susceptibility to Pgp-mediated efflux and identified an inhibitor which demonstrated robust and sustained reduction of CNS β-amyloid (Aβ) in Sprague–Dawley rats following oral administration.

A series of naphthyl-based compounds were synthesized as potential inhibitors of vascular endothelial growth factor (VEGF) receptors. Investigations of structure-activity relationships led to the identification of a series of naphthamides that are potent inhibitors of the VEGF receptor tyrosine kinase family. Numerous analogues demonstrated low nanomolar inhibition of VEGF-dependent human umbilical vein endothelial cell (HUVEC) proliferation, and of these several compounds possessed favorable pharmacokinetic (PK) profiles. In particular, compound 48 demonstrated significant antitumor efficacy against established HT29 human colon adenocarcinoma xenografts implanted in athymic mice. A full account of the preparation, structure-activity relationships, pharmacokinetic properties, and pharmacology of analogues within this series is presented.

A structure- and property-based drug design approach was employed to identify aminooxazoline xanthenes as potent and selective human β-secretase inhibitors. These compounds exhibited good isolated enzyme, cell potency, and selectivity against the structurally related aspartyl protease cathepsin D. Our efforts resulted in the identification of a potent, orally bioavailable CNS penetrant compound that exhibited in vivo efficacy. A single oral dose of compound 11a resulted in a significant reduction of CNS Aβ40 in naive rats.

There has been significant interest in developing a transient receptor potential A1 (TRPA1) antagonist for the treatment of pain due to a wealth of data implicating its role in pain pathways. Despite this, identification of a potent small molecule tool possessing pharmacokinetic properties allowing for robust in vivo target coverage has been challenging. Here we describe the optimization of a potent, selective series of quinazolinone-based TRPA1 antagonists. High-throughput screening identified 4, which possessed promising potency and selectivity. A strategy focused on optimizing potency while increasing polarity in order to improve intrinsic clearance culminated with the discovery of purinone 27 (AM-0902), which is a potent, selective antagonist of TRPA1 with pharmacokinetic properties allowing for >30-fold coverage of the rat TRPA1 IC50 in vivo. Compound 27 demonstrated dose-dependent inhibition of AITC-induced flinching in rats, validating its utility as a tool for interrogating the role of TRPA1 in in vivo pain models.

A novel series of benzylamine, potassium channel openers (KCOs) is presented as part of our program toward designing new, bladder-selective compounds for the treatment of urge urinary incontinence (UUI). We have found that the in vitro potency of (R)-4-[3,4-dioxo-2-(1,2, 2-trimethyl-propylamino)-cyclobut-1-enylamino]-3-ethyl-benzo nitrile 1 in the relaxation of precontracted rat detrusor strips can also be obtained with cyanobenzylamine derivative 4 (IC(50) = 0.29 microM) (Figure 3). Addition of a 2-Cl substituted benzylamine moiety and changing the alkylamino substituent of 4 to a t-Bu amine gives 31 (IC(50) = 0.14 microM)-a compound with similar in vitro potency as 4 as well as relaxant activity on bladder smooth muscle in vivo when administered orally (31, ED(50) = 3 mg/kg) in a rodent model of bladder instability. Further modifications, particularly the replacement of the t-Bu amino substituent with a tert-amylamine, gave a similarly active compound 60 (IC(50) = 0.10 microM) which shows excellent in vivo efficacy (ED(50) = 0.6 mg/kg). Moreover, 60, 3-(2,4-dichloro-6-methyl-benzylamino)-4-(1, 1-dimethyl-propylamino)-cyclobut-3-ene-1,2-dione (WAY-151616), shows excellent tissue selectivity for bladder K channels over arterial tissue (60, MAP ED(20) = 100 mg/kg; selectivity: MAP ED(20)/bladder ED(50) = 166). Other manipulations of the benzylamino cyclobutenediones, acylation of the benzylamine, conversion of the benzylamine substituent to a benzamide, homologation of the benzylamine to a phenethylamine, and incorporation of a methyl group at the benzyl carbon, all led to substantial loss of in vitro activity, although some in vivo activity was maintained in the acylated analogues. Compound 60 represents an attractive candidate for development in the treatment of UUI.

Because of its strong genetic validation, Na1.7 has attracted significant interest as a target for the treatment of pain. We have previously reported on a number of structurally distinct bicyclic heteroarylsulfonamides as Na1.7 inhibitors that demonstrate high levels of selectivity over other Na isoforms. Herein, we report the discovery and optimization of a series of atropisomeric quinolinone sulfonamide inhibitors [ Bicyclic sulfonamide compounds as sodium channel inhibitors and their preparation . WO 2014201206, 2014 ] of Na1.7, which demonstrate nanomolar inhibition of Na1.7 and exhibit high levels of selectivity over other sodium channel isoforms. After optimization of metabolic and pharmacokinetic properties, including PXR activation, CYP2C9 inhibition, and CYP3A4 TDI, several compounds were advanced into in vivo target engagement and efficacy models. When tested in mice, compound 39 (AM-0466) demonstrated robust pharmacodynamic activity in a Na1.7-dependent model of histamine-induced pruritus (itch) and additionally in a capsaicin-induced nociception model of pain without any confounding effect in open-field activity.

Angiogenesis is vital for solid tumor growth, and its prevention is a proven strategy for the treatment of disease states such as cancer. The vascular endothelial growth factor (VEGF) pathway provides several opportunities by which small molecules can act as inhibitors of endothelial proliferation and migration. Critical to these processes is signaling through VEGFR-2 or the kinase insert domain receptor (KDR) upon stimulation by its ligand VEGF. Herein, we report the discovery of 2,3-dihydro-1,4-benzoxazines as inhibitors of intrinsic KDR activity (IC 50 < 0.1 microM) and human umbilical vein endothelial cell (HUVEC) proliferation with IC 50 < 0.1 microM. More specifically, compound 16 was identified as a potent (KDR: < 1 nM and HUVEC: 4 nM) and selective inhibitor that exhibited efficacy in angiogenic in vivo models. In addition, this series of molecules is typically well-absorbed orally, further demonstrating the 2,3-dihydro-1,4-benzoxazine moiety as a promising platform for generating kinase-based antiangiogenic therapeutic agents.