Identification of a Novel Sulfonamide Non-Nucleoside Reverse Transcriptase Inhibitor by a Phenotypic HIV-1 Full Replication Assay

<div><p>Classical target-based, high-throughput screening has been useful for the identification of inhibitors for known molecular mechanisms involved in the HIV life cycle. In this study, the development of a cell-based assay that uses a phenotypic drug discovery approach based on automated high-content screening is described. Using this screening approach, the antiviral activity of 26,500 small molecules from a relevant chemical scaffold library was evaluated. Among the selected hits, one sulfonamide compound showed strong anti-HIV activity against wild-type and clinically relevant multidrug resistant HIV strains. The biochemical inhibition, point resistance mutations and the activity of structural analogs allowed us to understand the mode of action and propose a binding model for this compound with HIV-1 reverse transcriptase.</p></div

HIV infection assay development.

<p>A. Measurement of GFP reporter activity, using Victor 3 and Opera reader, in CEMx 174-LTR-GFP CG8 cells upon HIV-1_LAI infection. B. Infection of CEMx 174-LTR-GFP CG8 and HeLa-LTR-GFP cells: Opera-acquired images showed infected (Panel b and d), unlike uninfected (Panel a and c) cells, carried the GFP reporter gene. Syncytia are indicated by red circles. C. Assay validation upon antiretroviral treatment: reference drugs were tested to evaluate the assay performance using an Opera reader. CEMx 174-LTR-GFP CG8 cells infected by HIV-1_LAI were treated with AZT (Panel b), nevirapine (Panel c) and saquinavir (Panel d). Images show nucleus detection in red and infected cells in green (Panel a: DMSO).</p

Identification of IPK1 as a potent antiretroviral hit compound.

<p>A. Chemical structure of the <b>IPK1</b> compound. B. Dose-response curve of <b>IPK1</b> and comparison to reference anti-HIV drugs. The IC₅₀ value was characterized in CEMx 174-LTR-GFP CG8 cells infected by HIV-1_LAI. C. <b>IPK1</b> activity defined by IC₅₀ characterization in HeLa-LTR-GFP cells upon HIV-1_LAI infection. D. <b>IPK1</b> activity against the multidrug resistant virus HIV-1_RTMDR/MT-2 in CEMx 174-LTR-GFP CG8.</p

Anti-reverse transcriptase activity of the IPK1 compound and nevirapine.

<p>The IC₅₀ value was determined <i>in vitro</i> using purified enzyme.</p

Table of calculated docking energy and IC₅₀ characterization of the IPK1 compound and analogs.

<p>Table of calculated docking energy and IC₅₀ characterization of the IPK1 compound and analogs.</p

IC₅₀ characterization of IPK1 and TMC125.

<p>Antiviral activity of <b>IPK1</b> and TMC125 compounds against defined reverse transcriptase resistant mutations using the Monogram Bioscience experimental assay.</p

Lead Optimization of a Novel Series of Imidazo[1,2‑<i>a</i>]pyridine Amides Leading to a Clinical Candidate (Q203) as a Multi- and Extensively-Drug-Resistant Anti-tuberculosis Agent

A critical unmet clinical need to combat the global tuberculosis epidemic is the development of potent agents capable of reducing the time of multi-drug-resistant (MDR) and extensively-drug-resistant (XDR) tuberculosis therapy. In this paper, we report on the optimization of imidazo­[1,2-<i>a</i>]­pyridine amide (IPA) lead compound <b>1</b>, which led to the design and synthesis of Q203 (<b>50</b>). We found that the amide linker with IPA core is very important for activity against Mycobacterium tuberculosis H37Rv. Linearity and lipophilicity of the amine part in the IPA series play a critical role in improving in vitro and in vivo efficacy and pharmacokinetic profile. The optimized IPAs <b>49</b> and <b>50</b> showed not only excellent oral bioavailability (80.2% and 90.7%, respectively) with high exposure of the area under curve (AUC) but also displayed significant colony-forming unit (CFU) reduction (1.52 and 3.13 log₁₀ reduction at 10 mg/kg dosing level, respectively) in mouse lung

Discovery of Phenylaminopyridine Derivatives as Novel HIV-1 Non-nucleoside Reverse Transcriptase Inhibitors

We identified a novel class of aryl-substituted triazine compounds as potent non-nucleoside reverse transcriptase inhibitors (NNRTIs) during a high-throughput screening campaign that evaluated more than 200000 compounds for antihuman immunodeficiency virus (HIV) activity using a cell-based full replication assay. Herein, we disclose the optimization of the antiviral activity in a cell-based assay system leading to the discovery of compound <b>27</b>, which possessed excellent potency against wild-type HIV-1 (EC₅₀ = 0.2 nM) as well as viruses bearing Y181C and K103N resistance mutations in the reverse transcriptase gene. The X-ray crystal structure of compound <b>27</b> complexed with wild-type reverse transcriptase confirmed the mode of action of this novel class of NNRTIs. Introduction of a chloro functional group in the pyrazole moiety dramatically improved hERG and CYP inhibition profiles, yielding highly promising leads for further development