Kenneth Simmen

Efficacy of Re-treatment With TMC435 as Combination Therapy in Hepatitis C Virus–Infected Patients Following TMC435 Monotherapy

In the TMC435-C101 study, 6 patients infected with hepatitis C virus genotype 1 were treated with the protease inhibitor TMC435 (200 mg once daily) as monotherapy for 5 days. Approximately 1.5 years later, 5 of these patients were re-treated with TMC435 (200 mg once daily) plus pegylated interferon alfa-2a and ribavirin (PegIFNα-2a and RBV) for 4 weeks, followed by PegIFNα-2a and RBV until week 48 (in the Optimal Protease inhibitor Enhancement of Response to therApy [OPERA-1] study). TMC435-resistant variants, which emerged in all 5 patients during the TMC435-C101 study, were no longer detected at the beginning of the OPERA-1 study based on virus population sequencing. During the OPERA-1 study, 3 patients had a sustained virologic response; deep sequencing indicated low-level persistence of resistant variants in the remaining 2 patients, which might have affected their response to re-treatment.

Synthesis and SAR of potent inhibitors of the Hepatitis C virus NS3/4A protease: Exploration of P2 quinazoline substituents

Novel NS3/4A protease inhibitors comprising quinazoline derivatives as P2 substituent were synthesized. High potency inhibitors displaying advantageous PK properties have been obtained through the optimization of quinazoline P2 substituents in three series exhibiting macrocyclic P2 cyclopentane dicarboxylic acid and P2 proline urea motifs. For the quinazoline moiety it was found that 8-methyl substitution in the P2 cyclopentane dicarboxylic acid series improved on the metabolic stability in human liver microsomes. By comparison, the proline urea series displayed advantageous Caco-2 permeability over the cyclopentane series. Pharmacokinetic properties in vivo were assessed in rat on selected compounds, where excellent exposure and liver-to-plasma ratios were demonstrated for a member of the 14-membered quinazoline substituted P2 proline urea series.

Finger-loop inhibitors of the HCV NS5b polymerase. Part 1: Discovery and optimization of novel 1,6- and 2,6-macrocyclic indole series

Novel conformationaly constrained 1,6- and 2,6-macrocyclic HCV NS5b polymerase inhibitors, in which either the nitrogen or the phenyl ring in the C2 position of the central indole core is tethered to an acylsulfamide acid bioisostere, have been designed and tested for their anti-HCV potency. This transformational route toward non-zwitterionic finger loop-directed inhibitors led to the discovery of derivatives with improved cell potency and pharmacokinetic profile.

Synthesis and evaluation of novel HCV replication inhibitors

Direct acting antiviral agents to cure hepatitis C virus (HCV) infection has emerged as the gold standard therapy. Along with protease inhibitors, nucleoside polymerase inhibitors and non-nucleoside polymerase inhibitors, the inhibition of NS5a has proved to be an effective way to treat HCV patients. Here we report on novel HCV NS5a inhibitors which were synthesized and evaluated in the HCV replicon assay. A series of inhibitors were formed by a cycloaddition reaction in parallel to establish new leads and explore the effects of unsymmetrical cap substitution. This led to the identification of several triazoles with picomolar potency in vitro against hepatitis C virus.Graphical Abstract