Virus Protease Inhibitors Boceprevir Research Articles

An orally bioavailable SARS-CoV-2 main protease inhibitor exhibits improved affinity and reduced sensitivity to mutations.

Inhibitors of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) main protease (Mpro) such as nirmatrelvir (NTV) and ensitrelvir (ETV) have proven effective in reducing the severity of COVID-19, but the presence of resistance-conferring mutations in sequenced viral genomes raises concerns about future drug resistance. Second-generation oral drugs that retain function against these mutants are thus urgently needed. We hypothesized that the covalent hepatitis C virus protease inhibitor boceprevir (BPV) could serve as the basis for orally bioavailable drugs that inhibit SARS-CoV-2 Mpro more efficiently than existing drugs. Performing structure-guided modifications of BPV, we developed a picomolar-affinity inhibitor, ML2006a4, with antiviral activity, oral pharmacokinetics, and therapeutic efficacy similar or superior to those of NTV. A crucial feature of ML2006a4 is a derivatization of the ketoamide reactive group that improves cell permeability and oral bioavailability. Last, ML2006a4 was found to be less sensitive to several mutations that cause resistance to NTV or ETV and occur in the natural SARS-CoV-2 population. Thus, anticipatory design can preemptively address potential resistance mechanisms to expand future treatment options against coronavirus variants.

Comparative effectiveness of the hepatitis C virus protease inhibitors boceprevir and telaprevir in a large U.S. cohort

Limited data exist on the effectiveness of boceprevir and telaprevir in routine practice. To assess the comparative effectiveness of boceprevir and telaprevir regimens. In this observational, intent-to-treat cohort analysis of hepatitis C genotype 1-infected veterans initiated on peginterferon/ribavirin and boceprevir (n=661) or telaprevir (n=198), we determined sustained virological response (SVR), treatment discontinuation rates and adverse haematological events. Inverse probability-of-treatment weighting (IPTW) was used to estimate the effect of one drug over the other, with matched pairs and unweighted logistic regression on the entire cohort for comparison. Of 835 veterans, SVR occurred in 50% and 52% receiving boceprevir- and telaprevir-based treatment, respectively (P=0.72). No significant differences occurred among subgroups: cirrhotics (37% vs. 39%, P=0.94), null responders (23% vs. 18%, P=0.81), partial responders (39% vs. 58%, P=0.15) and relapsers (60% vs. 77%, P=0.11). Early discontinuation rates for boceprevir and telaprevir, respectively, were 31% and 28% by week 24 (P=0.46) and 54% and 45% by 48weeks (in those completing at least 28weeks) (P=0.14). Choice of telaprevir over boceprevir was significantly associated with SVR in multivariate models (IPTW OR: 1.57, 95% CI: 1.10-2.25, P=0.01; matched-pairs OR: 1.91, 95% CI: 1.23-3.00, P=0.004; unweighted OR: 1.50 95% CI: 1.05-2.14, P=0.02). Rates of haematological adverse events in boceprevir- and telaprevir-treated patients were as follows: anaemia 59% vs. 51%, P=0.30, thrombocytopenia 41% vs. 48%, P=0.26, neutropenia 41% vs. 27%, P=0.04. Sustained virological response was more likely with telaprevir-based regimens compared with boceprevir-based regimens in routine medical practice, after accounting for patient differences. Early discontinuation and haematological events, however, were similar.

Pharmacokinetic Evaluation of the Interaction between Hepatitis C Virus Protease Inhibitor Boceprevir and 3-Hydroxy-3-Methylglutaryl Coenzyme A Reductase Inhibitors Atorvastatin and Pravastatin

Boceprevir is a potent orally administered inhibitor of hepatitis C virus and a strong, reversible inhibitor of CYP3A4, the primary metabolic pathway for many 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors. Thus, the aim of the present study was to investigate drug-drug interactions between atorvastatin or pravastatin and boceprevir. We conducted a single-center, open-label, fixed-sequence, one-way-crossover study with 20 healthy adult volunteers. Subjects received single-dose atorvastatin (40 mg) or pravastatin (40 mg) on day 1, followed by boceprevir (800 mg three times daily) for 7 to 10 days. Repeat single doses of atorvastatin or pravastatin were administered in the presence of steady-state boceprevir. Atorvastatin exposure increased in the presence of boceprevir, with atorvastatin area under the concentration-time curve from time zero to infinity after single dosing (AUC(inf)) increasing 2.3-fold (90% confidence interval [CI], 1.85, 2.90) and maximum observed concentration in plasma (Cmax) 2.7-fold (90% CI, 1.81, 3.90). Pravastatin exposure was slightly increased in the presence of boceprevir, with pravastatin AUC(inf) increasing 1.63-fold (90% CI, 1.03, 2.58) and C(max) 1.49-fold (90% CI, 1.03, 2.14). Boceprevir exposure was generally unchanged when the drug was coadministered with atorvastatin or pravastatin. All adverse events were mild and consistent with the known safety profile of boceprevir. The observed 130% increase in AUC of atorvastatin supports the use of the lowest possible effective dose of atorvastatin when coadministered with boceprevir, without exceeding a maximum daily dose of 40 mg. The observed 60% increase in pravastatin AUC with boceprevir coadministration supports the initiation of pravastatin treatment at the recommended dose when coadministered with boceprevir, with close clinical monitoring.

Pharmacokinetic interaction between the hepatitis C virus protease inhibitor boceprevir and cyclosporine and tacrolimus in healthy volunteers

The hepatitis C virus protease inhibitor boceprevir is a strong inhibitor of cytochrome P450 3A4 and 3A5 (CYP3A4/5). Cyclosporine and tacrolimus are calcineurin inhibitor immunosuppressants used to prevent organ rejection after liver transplantation; both are substrates of CYP3A4. This two-part pharmacokinetic interaction study evaluated boceprevir with cyclosporine (part 1) and tacrolimus (part 2). In part 1, 10 subjects received single-dose cyclosporine (100 mg) on day 1, single-dose boceprevir (800 mg) on day 3, and concomitant cyclosporine/boceprevir on day 4. After washout, subjects received boceprevir (800 mg three times a day) for 7 days plus single-dose cyclosporine (100 mg) on day 6. In part 2A, 12 subjects received single-dose tacrolimus (0.5 mg). After washout, they received boceprevir (800 mg three times a day) for 11 days plus single-dose tacrolimus (0.5 mg) on day 6. In part 2B, 10 subjects received single-dose boceprevir (800 mg) and 24 hours later received boceprevir (800 mg) plus tacrolimus (0.5 mg). Coadministration of boceprevir with cyclosporine/tacrolimus was well tolerated. Concomitant boceprevir increased the area under the concentration-time curve from time 0 to infinity after single dosing (AUC(inf) ) and maximum observed plasma (or blood) concentration (C(max) ) of cyclosporine with geometric mean ratios (GMRs) (90% confidence interval [CI]) of 2.7 (2.4-3.1) and 2.0 (1.7-2.4), respectively. Concomitant boceprevir increased the AUC(inf) and C(max) of tacrolimus with GMRs (90% CI) of 17 (14-21) and 9.9 (8.0-12), respectively. Neither cyclosporine nor tacrolimus coadministration had a meaningful effect on boceprevir pharmacokinetics. Dose adjustments of cyclosporine should be anticipated when administered with boceprevir, guided by close monitoring of cyclosporine blood concentrations and frequent assessments of renal function and cyclosporine-related side effects. Administration of boceprevir plus tacrolimus requires significant dose reduction and prolongation of the dosing interval for tacrolimus, with close monitoring of tacrolimus blood concentrations and frequent assessments of renal function and tacrolimus-related side effects.

Design and synthesis of deuterated boceprevir analogs with enhanced pharmacokinetic properties

As part of an ongoing effort to apply the Deuterated Chemical Entity Platform (DCE Platform™) to clinically validated drugs, the synthesis of deuterated analogs of the hepatitis C virus protease inhibitor boceprevir was carried out. The devised synthetic routes allowed for site‐selective deuterium incorporation with high levels of isotopic purity. Application of the DCE Platform™ to boceprevir enabled the identification of several deuterated analogs that display marked levels of in vitro metabolic stabilization. Most notably, analog 1g exhibits a near doubling of in vitro half‐life in human liver microsomal assays. The details of the convergent synthetic route to the boceprevir isotopologs and the results of the metabolic stability assays are described herein.

Highly sensitive determination of HCV protease inhibitors boceprevir (SCH 503034) and telaprevir (VX 950) in human plasma by LC–MS/MS

The purpose of this study was to develop a specific and highly sensitive method based on fast sample preparation and LC–MS/MS techniques for the determination of the HCV protease inhibitors boceprevir (SCH 503034) and telaprevir (VX 950) in human plasma. Boceprevir, telaprevir and the internal standard dimethylcelecoxib were separated on a Luna C18 column (150 mm × 2.0 mm I.D., 5 μm particle size) under gradient conditions with a mobile phase A consisting of water/ammonia solution (25%) (100:0.05, v/v) and mobile phase B consisting of methanol/ammonia solution (25%) (100:0.05, v/v) and a chromatographic run time of 11 min. The lower limit of quantification (LLOQ) of boceprevir and telaprevir is 0.25 pg on column (25 pg/mL at injection volume of 10 μL). The method possesses a reliable calibration range of 0.025–2.5 ng/mL. Due to the dilution of real life plasma samples by a factor of 10 during the precipitation process the method is suitable to quantify boceprevir and telaprevir at a concentration range of 0.25–25 ng/mL. Variations in accuracy and intraday and interday precision ( n = 6 for each concentration) were <15% over the whole range of calibration. For the first time, a rapid, specific, sensitive, accurate and reproducible LC–MS/MS method in human plasma has been developed and validated. It is suitable to quantify the concentrations of the hepatitis C virus protease inhibitors boceprevir and telaprevir in human plasma.