By W. Kliff. Notre Dame College of Ohio.
What is the comparative effectiveness of regimens of peginterferon alfa-2a plus ribavirin versus peginterferon alfa-2b plus ribavirin for treatment of chronic hepatitis C virus infection? How does duration of treatment or dosing protocols (including weight-based or maintenance dosing or dosing of ribavirin) affect estimates of comparative effectiveness? Pegylated interferons for hepatitis C Page 7 of 65 Final Report Drug Effectiveness Review Project 2 order silvitra 120 mg on line. What is the comparative tolerability and safety of peginterferon alfa-2a plus ribavirin versus peginterferon alfa-2b plus ribavirin for treatment of chronic hepatitis C virus infection? Does the comparative effectiveness or tolerability and safety of peginterferon alfa-2a plus ribavirin versus peginterferon alfa-2b plus ribavirin vary in patient subgroups defined by demographics (age cheap 120 mg silvitra visa, racial groups, gender, genotype, markers of disease severity), use of other medications, or presence of co-morbidities (such as HIV infection)? Pegylated interferons for hepatitis C Page 8 of 65 Final Report Drug Effectiveness Review Project METHODS Literature Search To identify articles relevant to each key question, we searched Medline (1966 to July Week 4 2006), the Cochrane Central Register of Controlled Trials (3rd Quarter 2006), the Cochrane Database of Systematic Reviews (2nd Quarter 2006), and the Database of Abstracts of Reviews of Effects (3rd Quarter 2006) (See Appendix A for search strategies). We also searched reference lists of included review articles for additional citations. Pharmaceutical manufacturers were invited to submit dossiers, including citations. All citations were imported into an electronic database (Endnote 9. Study Selection All citations were reviewed for inclusion using the criteria shown in Table 3. Full-text articles of potentially relevant citations were retrieved and inclusion criteria were re-applied. Title and abstract review was conducted by two independent reviewers (Carson and Care); review of full-text articles was conducted by one reviewer (Carson) and checked by a second (Chou). Study inclusion criteria Populations • Non-pregnant adult outpatients with chronic Hepatitis C infection Subgroups include: • HIV-infected persons • Non-responders or relapsers (including re-treatment) • Based on gender, race, or age • Based on genotype • Based on viral load • Based on liver function test abnormalities • Based on degree of fibrosis, inflammation, or cirrhosis on liver biopsy • Based on other co-morbid conditions, including obesity, addiction, psychiatric illness Treatments • Pegylated interferon alfa-2a plus ribavirin • Pegylated interferon alfa-2b plus ribavirin Effectiveness outcomes • Sustained virologic response (SVR) • Normalization of liver enzyme abnormalities (sustained biochemical response, or SBR) • Improvement in inflammation or fibrosis on liver biopsy • Cirrhosis • Hepatocellular carcinoma • Need for liver transplant • Quality of life Pegylated interferons for hepatitis C Page 9 of 65 Final Report Drug Effectiveness Review Project • Mortality • Early virologic response (only for head-to-head trials) Safety outcomes • Overall adverse effects • Withdrawals due to adverse effects • Serious adverse events (including depression, suicidality) • Specific adverse events (including myalgias, flu-like symptoms, fevers, chills, neutropenia, dose reduction) Study designs • For assessment of effectiveness in general, controlled clinical trials and good-quality systematic reviews were included. We defined a sustained virologic response (SVR) as the absence of detectable HCV RNA 21 in the serum six months after the end of a course of therapy. SVR is the best short-term predictor of long-term virologic remission rates and is associated with improvements in fibrosis 22 and inflammation. End-of-treatment response (ETR) was defined as no detectable virus at the end of a course of therapy. We did not consider ETR a primary outcome since it is not as reliable as SVR for predicting long-term remission. Some trials also measure early virologic response (EVR), which is usually defined as absence of detectable HCV RNA in serum or >2. Although assessing EVR is helpful for determining whether to complete a full course of therapy (patients without an EVR are unlikely to achieve an SVR), it is less accurate than ETR for predicting long-term remission. We included head-to-head trials reporting EVR because no head-to-head trials reporting longer- term outcomes are currently available. We defined a sustained biochemical response (SBR) as normalization of liver transaminases six months after the end of a course of therapy. Some trials also report end-of- treatment biochemical response. Definitions for histological response are less standardized than definitions for reporting virologic outcomes, however traditionally a histologic response has been defined as a 2-point or greater decrease in the inflammatory score or fibrosis score, or a 1-point 21 decrease in the fibrosis score. Because dual therapy with pegylated interferon has only been available since 2001 and assessment of effects on rates of cirrhosis, hepatocellular cancer, need for liver transplant, and mortality would require studies with extended (a decade or more) follow-up, we believed studies evaluating these outcomes would probably not be available. However, we did search for studies reporting these important clinical outcomes. We included non-randomized studies as well as randomized trials reporting adverse events (withdrawal due to adverse events, serious adverse events, overall adverse events, hematologic adverse events, flu-like symptoms, and depression) associated with dual therapy with pegylated interferon. Pegylated interferons for hepatitis C Page 10 of 65 Final Report Drug Effectiveness Review Project Data Abstraction The following data were abstracted from included trials: study design, setting, population characteristics (including sex, age, ethnicity, and HCV genotype), eligibility and exclusion criteria, and interventions (dose and duration); numbers screened, eligible, enrolled, and lost to follow-up; method of outcome ascertainment; and results for each outcome (including SVR, ETR, SBR, histological response rates, quality of life, other clinical outcomes, and adverse events). We recorded intention-to-treat results when available.
Overview of boosted protease inhibitors in treatment-experienced HIV-infected patients silvitra 120 mg without prescription. It is involved in the integration of the viral DNA into the host genome and is essential for the replication of HIV (Nair 2002) trusted silvitra 120mg. It is of note that there is no integrase in human cells so selective inhibition of this enzyme that does not induce side effects seems possible. There are at least four steps leading to the integration of viral DNA (Review: Lataillade 2006). All these steps may be theoretically inhibited by different integrase inhibitors. Binding of the integrase enzyme to viral DNA within the cytoplasm. This results in a stable viral DNA-integrase binding complex (pre-integration complex, PIC). This step can be inhibited by binding inhibitors such as pyrano-dipyrimides. The integrase removes a dinucleotide at each end of the viral DNA producing new 3’ hydroxyl ends within the PIC. This step can be inhibited by 3’ processing inhibitors such as diketo acids. After the transport of the PIC from the cytoplasm through a nuclear pore into the cell’s nucleus, integrase binds to the host chromosomal DNA. By doing this, integrase mediates irreversible binding of viral and cellular DNA. This step can be inhibited by integrase strand transfer inhibitors (INSTIs). The combination of viral and cellular DNA is a gapped intermediate product. The gap repair is done by host cell DNA repair enzymes. Integrase seems not to be necessary in this last step, which can be inhibited by gap repair inhibitors such as methylxanthines. For almost a decade, the development of integrase inhibitors was slow. This was largely because of a lack of good lead compounds and reliable in vitro screening assays that incorporate each of the integration steps (Lataillade 2006). Only after 2000 did development progress and the principle of strand transfer was elucidated (Hazuda 2000). Since 2005, numerous clinical studies have evaluated integrase inhibitors (mainly strand transfer inhibitors). In December 2007, raltegravir was licensed as the first integrase inhibitor for the treatment of HIV+ patients. Today, three integrase inhibitors are on the market, namely raltegravir, elvitegravir and dolutegravir. Given the good tolerability and the high potency of this drug class, INSTIs now play a major role in HIV medicine. As with other antiretroviral drug classes, however, some questions remain unan- swered. Although very well-tolerated during the first years of therapy, little is known about long-term toxicity of integrase inhibitors. There is no experience with long- term use beyond 5–10 years. Genetic resistance barriers, relatively low with ralte- gravir and elvitegravir, may also be an important issue. Increased viral rebound rates were observed with treatment-experienced patients on boosted PIs (viral load below the limit of detection) when switching to raltegravir, especially in those with pre- existing resistance (Eron 2009). As soon as integrase inhibitor resistance develops, the agent should be stopped. This way, further resistance mutations (Wirden 2009) can be avoided, as well as unnec- essary costs.
A prevalence of more than 20% has been observed in large US cities with significant populations of MSM and a long history of access to antiretroviral treatment silvitra 120mg lowest price. Data on the incidence and prevalence of primary drug resistance pub- lished before 2007 should be interpreted with caution silvitra 120 mg discount, since a consensus definition of transmitted genotypic drug resistance had not been established. In 2007 (update 2009), an international research group agreed upon criteria defining mutations indicative for transmitted drug resistance (Bennett 2009). This standardization allows for comparisons of epidemiological data across geographic regions and periods of time. In a systemic review of 215 studies with a total of 43,170 patients until 2009 trans- mission of resistance was most prevalent in North America (12. The most 308 ART significant increase was observed in Asia and Africa. Changes with respect to specific drug classes were generally seen over time. Resistance to NRTIs decreased signifi- cantly over time in North America, Europe and Latin America, while NNRTI-resis- tance increased (Frentz 2012). In the German Seroconverter Study, the prevalence of any resistance mutation was 12. Whereas the total prevalence remained stable during the observation period, NRTI-resistant virus populations (mainly TAMs) decreased to 6. The most frequently reported PI muta- tions were M46L and L90M (Kuecherer 2013). In chronically infected patients of the German RESINA study, the proportion with primary resistance was 10. European-wide data from the years 2006–2007 derive from SPREAD (Strategy to Control Spread of HIV Drug Resistance), a program established to monitor primary resistance in newly infected patients and ART-naïve patients. In total, at least one resistance-associated mutation was found in 9. Two- class resistance was present in less than one percent (Hofstra 2013). Ultrasensitive methods such as allele-specific real-time PCR (AS PCR) or ultra-deep sequencing detect resistance mutations more often than conventional sequencing methods. A study from Atlanta found minor resistance mutations in 34 of 205 patients (17%), in which only wild-type virus was identified using conventional sequencing (Johnson 2008). In a British study investigating 165 samples from the years 2003–2006, drug resistance was detected in 13% of samples when using the standard assay compared to 19% when using an assay more sensitive for K103N, Y181C or M184V. In particular, the proportion of M184V isolates increased from 0. The prevalence of drug resistance was almost similar for treatment naïve patients with either primary or chronic HIV infection (19% and 20%) confirming data showing that primary resistance can persist for a long time (Buckton 2011, Pao 2004). In 2010, the transmission of a virus resistant to INSTIs was reported for the first time. The virus also harbored NRTI, NNRTI and PI resistance mutations. The authors recommended sequencing the integrase gene in cases of transmitted mul- tidrug resistance (Young 2010). Table 6: Prevalence of resistance prior to initiation of therapy (a selection) Author Country or region Time period Patient population N Prevalence (study) Kücherer 2013 Germany 1996–2012 Seroconverter 2,060 12. For ethical reasons, studies that prospectively examine the benefits of resistance analysis, especially in pre-treated patients for regimens including drug classes such as integrase inhibitors or CCR5 antagonists, are no longer justifiable. A resistance test before ART initiation is part of routine diagnosis in regions where the transmission of resistant HIV viruses is seen. The impact of transmitted HIV resistance on the initial success of ART was investigated in a retrospective analysis of the Eurocoord-CHAIN project. Of 10,458 patients initiated on ART in 1998, blood samples before therapy were retrospectively examined for resistance.