Prakash Raman

2-Alkyloxazoles as potent and selective PI4KIIIβ inhibitors demonstrating inhibition of HCV replication.

Synthesis and SAR of 2-alkyloxazoles as class III phosphatidylinositol-4-kinase beta (PI4KIIIβ) inhibitors is described. These compounds demonstrate that inhibition of PI4KIIIβ leads to potent inhibition of HCV replication as observed in genotype (GT) 1a and 1b replicon and GT2a JFH1 virus assays in vitro.

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.

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.