David S. Carter

Identification and SAR of novel diaminopyrimidines. Part 1: The discovery of RO-4, a dual P2X3/P2X2/3 antagonist for the treatment of pain

P2X purinoceptors are ligand-gated ion channels whose endogenous ligand is ATP. Both the P2X(3) and P2X(2/3) receptor subtypes have been shown to play an important role in the regulation of sensory function and dual P2X(3)/P2X(2/3) antagonists offer significant potential for the treatment of pain. A high-throughput screen of the Roche compound collection resulted in the identification of a novel series of diaminopyrimidines; subsequent optimization resulted in the discovery of RO-4, a potent, selective and drug-like dual P2X(3)/P2X(2/3) antagonist.

Identification and SAR of novel diaminopyrimidines. Part 2: The discovery of RO-51, a potent and selective, dual P2X3/P2X2/3 antagonist for the treatment of pain

The purinoceptor subtypes P2X(3) and P2X(2/3) have been shown to play a pivotal role in models of various pain conditions. Identification of a potent and selective dual P2X(3)/P2X(2/3) diaminopyrimidine antagonist RO-4 prompted subsequent optimization of the template. This paper describes the SAR and optimization of the diaminopyrimidine ring and particularly the substitution of the 2-amino group. The discovery of the highly potent and drug-like dual P2X(3)/P2X(2/3) antagonist RO-51 is presented.

Discovery and optimization of RO-85, a novel drug-like, potent, and selective P2X3 receptor antagonist

Despite the extensive literature describing the role of the ATP-gated P2X(3) receptors in a variety of physiological processes the potential of antagonists as therapeutic agents has been limited by the lack of drug-like selective molecules. In this paper we report the discovery and optimization of RO-85, a novel drug-like, potent and selective P2X(3) antagonist. High-throughput screening of the Roche compound collection identified a small hit series of heterocyclic amides from a large parallel synthesis library. Rapid optimization, facilitated by high-throughput synthesis, focusing on increasing potency and improving drug-likeness resulted in the discovery of RO-85.

Novel 3,3-disubstituted pyrrolidines as selective triple serotonin/norepinephrine/dopamine reuptake inhibitors

A series of 3,3-disubstituted pyrrolidine monoamine triple reuptake inhibitors were discovered. Analogues with low nanomolar potency, good human in vitro microsomal stability and in vitro permeability, and low drug-drug interaction potential are described. One example showed in vivo anti-depressant-like effects in the mouse tail suspension assay with a minimum effective dose of 30 mg/kg i.p.

2-Substituted N-aryl piperazines as novel triple reuptake inhibitors for the treatment of depression

Recently a class of compounds known as triple reuptake inhibitors has emerged as a new strategy for the treatment of depression. These compounds work by simultaneously inhibiting the synaptic reuptake of serotonin, norepinephrine and dopamine. In this Letter we describe the optimization of a novel series of 2-substituted N-aryl piperazine based triple reuptake inhibitors.

Design, synthesis, and biological evaluation of new monoamine reuptake inhibitors with potential therapeutic utility in depression and pain

Two new series of monoamine triple reuptake inhibitors (TRIs) have been discovered through scaffold homologation of our recently reported series of 3,3-disubstituted pyrrolidine TRIs. The regioisomeric 2- and 3-ketopyrrolidines demonstrated high levels of potency against all three monoamine transporters as well as good human in vitro stability, low drug-drug interaction potential and a decreased propensity for hERG channel binding. Representative compounds from these series displayed good in vivo pharmacokinetics and high monoamine receptor occupancies which are indicators of good brain penetration.

Discovery of N-[4-[6-tert-Butyl-5-methoxy-8-(6-methoxy-2-oxo-1H-pyridin-3-yl)-3-quinolyl]phenyl]methanesulfonamide (RG7109), a Potent Inhibitor of the Hepatitis C Virus NS5B Polymerase

In the past few years, there have been many advances in the efforts to cure patients with hepatitis C virus (HCV). The ultimate goal of these efforts is to develop a combination therapy consisting of only direct-antiviral agents (DAAs). In this paper, we discuss our efforts that led to the identification of a bicyclic template with potent activity against the NS5B polymerase, a critical enzyme on the life cycle of HCV. In continuation of our exploration to improve the stilbene series, the 3,5,6,8-tetrasubstituted quinoline core was identified as replacement of the stilbene moiety. 6-Methoxy-2(1H)-pyridone was identified among several heterocyclic headgroups to have the best potency. Solubility of the template was improved by replacing a planar aryl linker with a saturated pyrrolidine. Profiling of the most promising compounds led to the identification of quinoline 41 (RG7109), which was selected for advancement to clinical development.

(R)-3-(6-CHLORO-1-ISOPROPYLBENZIMIDAZOLE-4-CARBOXAMIDO)QUINUCLIDINE : A HIGH AFFINITY LIGAND FOR THE (R)-ZACOPRIDE BINDING SITE

Abstract The (R)-3-amido quinuclidine 6 (RS-16566) was found to be a high affinity ligand for the (R)-zacopride binding site.

Novel, achiral aminoheterocycles as selective monoamine reuptake inhibitors

A variety of novel aminoheterocycle scaffolds as selective monoamine reuptake inhibitors have been prepared and one of these scaffolds is achiral. The main elements responsible for hERG channel, CYP2D6 and CYP3A4 inhibition were identified.