Efficacy and safety of telaprevir with pegylated interferon α-2a and ribavirin in Japanese patients

The Alpha Keto Amide Moiety as a Privileged Motif in Medicinal Chemistry: Current Insights and Emerging Opportunities

Over the years, researchers in drug discovery have taken advantage of the use of privileged structures to design innovative hit/lead molecules. The α-ketoamide motif is found in many natural products, and it has been widely exploited by medicinal chemists to develop compounds tailored to a vast range of biological targets, thus presenting clinical potential for a plethora of pathological conditions. The purpose of this perspective is to provide insights into the versatility of this chemical moiety as a privileged structure in drug discovery. After a brief analysis of its physical-chemical features and synthetic procedures to obtain it, α-ketoamide-based classes of compounds are reported according to the application of this motif as either a nonreactive or reactive moiety. The goal is to highlight those aspects that may be useful to understanding the perspectives of employing the α-ketoamide moiety in the rational design of compounds able to interact with a specific target.

Eltrombopag enables initiation and completion of pegylated interferon/ribavirin therapy in Japanese HCV-infected patients with chronic liver disease and thrombocytopenia

To investigate the efficacy of eltrombopag for the treatment of thrombocytopenia in patients with chronic hepatitis C, a phase II, single-arm, open-label study with a 9-week pre-antiviral phase was conducted, followed by a 48-week antiviral phase and a 24-week follow-up phase. The proportion of patients who achieved a platelet count threshold, the proportion of patients who maintained a platelet count >50,000/µl, sustained virological response (SVR) rates and safety parameters were evaluated. Of the 45 enrolled patients (median age, 59 years; median platelet count, 63,000/µl; 98% with Child-Pugh class A), 43 (96%) achieved the platelet count threshold during the pre-antiviral phase. A total of 13 patients (29%) experienced ≥1 adverse event (AE), of which headache and vomiting were the most common, and 41 patients (mostly receiving eltrombopag 12.5 mg or 25 mg) entered the antiviral phase, of which 36 (88%) maintained the platelet count threshold; no patient platelet count decreased below 25,000/µl. Nine patients (22%) achieved an SVR at the 24-week follow-up. Grade ≥3 AEs occurred in 25 patients (61%). A total of 8 serious AEs occurred in five patients (12%). No mortality, thromboembolic events (TEEs), or cataract progression were reported. Eltrombopag increased the platelet count in chronic hepatitis C virus-infected patients with cirrhosis and thrombocytopenia and enabled them to initiate and complete interferon-based antiviral therapy (NCT01636778; first submitted: July 05, 2012).

Efficacy and safety of telaprevir with natural human interferon-β and ribavirin in Japanese chronic hepatitis C patients with depression

AIM

To assess the efficacy and safety of telaprevir (TVR) when used in combination with natural human interferon-β (IFN-β) and ribavirin (RBV) for genotype 1 patients with depression compared to IFN-β/RBV therapy in Japan. We also examined the efficacy of the TVR/IFN-β/RBV therapy in treatment failure genotype 2 patients with depression.

METHODS

For the genotype 1 patients, 30 patients received TVR (750 mg every 8 h) for 12 weeks combined with IFN-β and RBV for 24 weeks (Group A), and 30 received IFN-β and RBV for 48 weeks (Group B). For the genotype 2 patients, 14 patients were dosed only with the TVR-based regimen.

RESULTS

The sustained virologic response (SVR) rates for Group A and Group B were 63.3% and 20.0%, respectively (P = 0.001, likelihood ratio test). The SVR rate for genotype 2 patients previously treated with pegylated IFN and/or RBV was 71.4%. No patient dropped out due to exacerbation of depression. The trend of platelet counts after the drugs were given was similar in the TVR/IFN-β/RBV therapy group and the IFN-β/RBV therapy group. Common resistance-associated variants of TVR were identified in 4 of the 13 patients who did not achieve SVR.

CONCLUSION

This study showed that an addition of TVR to IFN-β/RBV therapy raised SVR in previously treated and untreated genotype 1 patients and previously treated genotype 2 patients with chronic hepatitis C and depression.

Safety of direct antiviral agents for treatment of hepatitis C virus infection

Antiviral drugs for treatment of hepatitis C have grown dramatically in recent years. The emergence of direct antiviral agents (DAAs) is a major advance in hepatitis C treatment. Since the first generation DAAs appeared in 2011, two more generations of DAAs have been approved by the Food and Drug Administration in only five years. With the advantages of coverage of all genotypes, high availability and easy administration, DAAs have been widely used worldwide in recent years. DAAs have nearly solved the main problems encountered in hepatitis C antiviral therapy. However, adverse events associated with DAAs use have been reported constantly, and the safety of DAAs has attracted more and more attention. According to recent reports, the adverse reactions of DAAs have been gradually reduced from the first generation to the third generation. When combined with other drugs, the drug-drug interactions (DDIs) need special attention. In addition, the usage of DAAs in special patient groups should be cautious. In this paper, we will summarize the adverse effects and DDIs of DAAs as well as their usage in the general population and special patient groups.

The Safety Profile of Telaprevir-Based Triple Therapy in Clinical Practice: A Retrospective Cohort Study

This study was designed to evaluate the safety profile of adding telaprevir to therapy using pegylated interferon-alfa-2b and ribavirin (PR) using real world patient data obtained from a nationwide Japanese interferon database. This retrospective cohort study compared telaprevir-based triple therapy (T/PR) with PR therapy. The study population comprised patients with genotype 1 chronic hepatitis C represented in the database between December 2009 and August 2015. The primary endpoint was dropout from treatment due to adverse events during the relevant standard treatment duration based on guidelines from the Japan Society of Hepatology. The dropout odds ratio (OR) and 95% confidence interval (95% CI) were calculated using univariate logistic regression analysis. Covariates were detected using a stepwise logistic regression analysis, and the adjusted OR and 95% CI were calculated. A total of 25989 patients were registered, and 4619 patients (T/PR: 1334, PR: 3285) were appropriate for primary endpoint analysis. The dropout rate due to adverse events was lower in the T/PR group (13.4%) than in the PR group (22.6%) (OR: 0.530; 95% CI, 0.444-0.633). After adjustment for the covariates detected by stepwise selection, the OR was 0.529 (95% CI, 0.441-0.634). Our study showed that there was a difference in dropout rate between real world T/PR and PR therapy in Japan. Although the addition of telaprevir to PR therapy may improve treatment continuity under the care of hepatologists, this study could not fully determine which therapy was safer or the factors influencing this result. Therefore, additional research will be required to confirm this.