2-Alkyloxazoles as potent and selective PI4KIIIß inhibitors demonstrating inhibition of HCV replication.

Synthesis and SAR of 2-alkyloxazoles as class III phosphatidylinositol-4-kinase beta (PI4KIIIß) inhibitors is described. These compounds demonstrate that inhibition of PI4KIIIß leads to potent inhibition of HCV replication as observed in genotype (GT) 1a and 1b replicon and GT2a JFH1 virus assays in vitro.

A macrocyclic HCV NS3/4A protease inhibitor interacts with protease and helicase residues in the complex with its full-length target.

Hepatitis C virus (HCV) infection is a global health burden with over 170 million people infected worldwide. In a significant portion of patients chronic hepatitis C infection leads to serious liver diseases, including fibrosis, cirrhosis, and hepatocellular carcinoma. The HCV NS3 protein is essential for viral polyprotein processing and RNA replication and hence viral replication. It is composed of an N-terminal serine protease domain and a C-terminal helicase/NTPase domain. For full activity, the protease requires the NS4A protein as a cofactor. HCV NS3/4A protease is a prime target for developing direct-acting antiviral agents. First-generation NS3/4A protease inhibitors have recently been introduced into clinical practice, markedly changing HCV treatment options. To date, crystal structures of HCV NS3/4A protease inhibitors have only been reported in complex with the protease domain alone. Here, we present a unique structure of an inhibitor bound to the full-length, bifunctional protease-helicase NS3/4A and show that parts of the P4 capping and P2 moieties of the inhibitor interact with both protease and helicase residues. The structure sheds light on inhibitor binding to the more physiologically relevant form of the enzyme and supports exploring inhibitor-helicase interactions in the design of the next generation of HCV NS3/4A protease inhibitors. In addition, small angle X-ray scattering confirmed the observed protease-helicase domain assembly in solution.

The Safety and Antiviral Activity of BZF961 with or without Ritonavir in Patients Infected with Hepatitis C Virus: A Randomized, Multicenter Trial.

PURPOSE: Infection with hepatitis C virus is the leading cause of infectious disease mortality in the United States. BZF961 is a novel small molecule inhibitor of the hepatitis C virus NS3-4A protease. Here we present the results of a randomized, double-blinded, placebo-controlled, multicentered study in treatment-naïve patients with chronic hepatitis C virus genotype-1 infection. METHODS: Patients were enrolled sequentially in 2 parts and treated for 3days. BZF961 was administered as monotherapy (500mg BID for 3 days) or in combination with the cytochrome P450 3A4 inhibitor ritonavir to boost its exposure (BZF961 10, 20, or 50mg QD or BID). FINDINGS: BZF961 was safe and well tolerated in the patients studied with no serious adverse events. There were no appreciable differences in adverse events among patients who received BZF961, BZF961 with ritonavir, or placebo. There was a significant, clinically meaningful reduction in viral load from baseline in patients treated either with BZF961 500mg every 12hours alone or BZF961 50mg every 12hours in combination with ritonavir. Activity against the hepatitis C virus of the lower-dose regimens was apparent but more modest. There were no relevant changes from baseline viral loads in placebo-treated patients. IMPLICATIONS: Coadministration of ritonavir with BZF961 boosted BZF961 exposure (including Cmin, which is the clinically relevant parameter associated with antiviral activity) in a therapeutic range with less variability compared with BZF961 alone. For strategic reasons, BZF961 is no longer under development.

A Diacylglycerol Transferase 1 Inhibitor Is a Potent Hepatitis C Antiviral in Vitro but Not in Patients in a Randomized Clinical Trial.

Hepatitis C virus (HCV) infection is a significant cause of liver disease affecting 80-150 million people globally. Diacylglycerol transferase 1 (DGAT-1), a triglyceride synthesis enzyme, is important for the HCV life cycle in vitro. Pradigastat, a potent DGAT-1 inhibitor found to lower triglycerides and HgbA1c in patients, was investigated for safety and efficacy in patients with HCV. This was a two-part study. In the in vitro study, the effect of pradigastat on virus production was evaluated in infected cells in culture. In the clinical study ( https://clinicaltrials.gov/ct2/show/NCT01387958 ), 32 patients with HCV infection were randomized to receive pradigastat or placebo (26:6) once daily for 14 days. Primary efficacy outcomes were serum viral RNA and alanine aminotransferase levels. In vitro, pradigastat significantly reduced virus production, consistent with inhibition of viral assembly and release. However, the clinical study was prematurely terminated for lack of efficacy. There was no significant change in serum viral RNA levels after dosing with pradigastat or placebo for 14 days. Pradigastat was safe and well-tolerated in this population. Most treatment-emergent adverse events were gastrointestinal; there were no hepatic adverse events. Although pradigastat had a potent antiviral effect in vitro, no significant antiviral effect was observed in patients at predicted efficacious exposures.

Synthesis, structure, and activity of diclofenac analogues as transthyretin amyloid fibril formation inhibitors.

Twelve analogues of diclofenac (1), a nonsteroidal antiinflammatory drug and known inhibitor of transthyretin (TTR) amyloid formation, were prepared and evaluated as TTR amyloid formation inhibitors. High activity was exhibited by five of the compounds. Structure-activity relationships reveal that a carboxylic acid is required for activity, but changes in its position as well as the positions of other substituents are tolerated. High-resolution X-ray crystal structures of four of the active compounds bound to TTR were obtained. These demonstrate the significant flexibility with which TTR can accommodate ligands within its two binding sites.

Identification and characterization of 4-aryl-3,4-dihydropyrimidin-2(1H)-ones as inhibitors of the fatty acid transporter FATP4.

Several potent, cell permeable 4-aryl-dihydropyrimidinones have been identified as inhibitors of FATP4. Lipophilic ester substituents at the 5-position and substitution at the para-position (optimal groups being -NO(2) and CF(3)) of the 4-aryl group led to active compounds. In two cases racemates were resolved and the S enantiomers shown to have higher potencies.