AIDS Clinical Research in Spain-Large HIV Population, Geniality of Doctors, and Missing Opportunities

The first cases of AIDS in Spain were reported in 1982. Since then over 85,000 persons with AIDS have been cumulated, with 60,000 deaths. Current estimates for people living with HIV are of 145,000, of whom 20% are unaware of it. This explains the still high rate of late HIV presenters. Although the HIV epidemic in Spain was originally driven mostly by injection drug users, since the year 2000 men having sex with men (MSM) account for most new incident HIV cases. Currently, MSM represent over 80% of new yearly HIV diagnoses. In the 80s, a subset of young doctors and nurses working at Internal Medicine hospital wards became deeply engaged in attending HIV-infected persons. Before the introduction of antiretrovirals in the earlier 1990s, diagnosis and treatment of opportunistic infections was their major task. A new wave of infectious diseases specialists was born. Following the wide introduction of triple combination therapy in the late 1990s, drug side effects and antiretroviral resistance led to built a core of highly devoted HIV specialists across the country. Since then, HIV medicine has improved and currently is largely conducted by multidisciplinary teams of health care providers working at hospital-based outclinics, where HIV-positive persons are generally seen every six months. Antiretroviral therapy is currently prescribed to roughly 75,000 persons, almost all attended at clinics belonging to the government health public system. Overall, the impact of HIV/AIDS publications by Spanish teams is the third most important in Europe. HIV research in Spain has classically been funded mostly by national and European public agencies along with pharma companies. Chronologically, some of the major contributions of Spanish HIV research are being in the field of tuberculosis, toxoplasmosis, leishmaniasis, HIV variants including HIV-2, drug resistance, pharmacology, antiretroviral drug-related toxicities, coinfection with viral hepatitis, design and participation in clinical trials with antiretrovirals, immunopathogenesis, ageing, and vaccine development.

Influence of Ribavirin Serum Levels on Outcome of Antiviral Treatment and Anemia in Hepatitis C Virus Infection

BACKGROUND

Ribavirin blood levels vary considerably between patients with standard weight-based dosing. Their impact on sustained virological response (SVR) with pegylated interferon and ribavirin is controversial, but has mostly been studied before the IL28b gene polymorphism as a possible confounder was discovered.

METHODS

The impact of serum ribavirin trough levels at week 4, at the end of treatment and of mean levels across the entire antiviral treatment with pegylated interferon and ribavirin on relapse, SVR rates and anemia was retrospectively studied by univariate and multivariable logistic regression analyses in 214 patients with HCV genotype 1-4 infection, including 88 patients with available IL28b genotyping.

RESULTS

Mean ribavirin levels varied between 0.68-5.65 mg/l and significantly differed between patients with or without SVR. By multivariable regression including age, sex, HCV viral load, HCV genotype, liver fibrosis stage, prior treatments, immunosuppression and IL28b genotype, ribavirin levels consistently displayed significant influence on SVR and relapse without indication for a specific importance of higher concentrations early or late in the treatment course. Although hemoglobin decline was on average more pronounced in patients with higher ribavirin levels, hemoglobin remained relatively stable in a significant proportion of these, indicating that ribavirin levels alone are insufficient to predict anemia.

CONCLUSION

While data are scarce to draw conclusions applicable for modern DAA therapies, these results support ribavirin treatment based on serum levels instead of purely weight-based dosing in combination with pegylated interferon.

A meta-analysis platform methodology for determining the comparative effectiveness of antihepatitis C virus regimens

AIM

Many hepatitis C virus regimens are unlikely to be compared head to head. In more difficult to treat populations where there is no standard of care, trials are single arm. We describe a flexible meta-analysis platform in this setting.

METHODS

Our meta-analysis is literature based. We illustrate our methodology and show how inference can be extended to single-arm trials.

RESULTS

As an example, in the single arm setting, a regimen with response rates of 84, 72 and 54% in genotype 1a across treatment naive, previous partial responders and previous null responders, respectively, would have 95% probability of superiority to IFN-α + RBV + TPV.

CONCLUSION

This is a rigorous approach to comparative effectiveness that accounts for varying patient populations and plans for the incorporation of emerging treatments.

Cost-effectiveness of sofosbuvir in the treatment of patients with hepatitis C

In France, 190,306 patients were suffering from chronic hepatitis C in 2012. These patients have a decreased life expectancy and are susceptible to complications associated with chronic hepatitis. Current treatments are poorly tolerated and their effectiveness varies depending on the genotype of the virus. Sofosbuvir, a new class of treatment, has demonstrated in five phase III trials sustained viral response (SVR) rates of over 90% across genotypes, higher than current treatments and has a tolerance profile similar to placebo. The objective was to determine the cost-effectiveness of using sofosbuvir in the treatment of chronic HCV infection. A Markov model was used to compare treatment strategies with and without sofosbuvir. The model simulated the natural history of HCV infection. SVR rates were based on data from clinical trials. Utilities associated with different stages of disease were based on data from the literature. French direct medical costs were used. Price for sofosbuvir was the price used in the early access program for severe fibrosis stages. The incremental cost-effectiveness ratio for sofosbuvir versus current reference treatments was € 16,278/QALY and varied from 40,000 €/QALY for F0 stages to 12,080 €/QALY for F4 stages. The sensitivity analyses carried out confirmed the robustness of this result. Sofosbuvir is a cost-effective treatment option for patients with hepatitis C.

Telaprevir and ribavirin interaction: higher ribavirin levels are not only due to renal dysfunction during triple therapy

A higher incidence of anemia has been observed during the treatment of hepatitis C virus genotype 1 (HCV-1) infection with pegylated alpha interferon (pegIFN-α), ribavirin, and telaprevir. We assessed the impacts that concomitant administration of telaprevir and changes in the glomerular filtration rate have on ribavirin plasma levels. The minimum concentrations of ribavirin in plasma (ribavirin Cmin) determined during triple therapy including telaprevir were compared with those observed after telaprevir withdrawal and those observed in the same subjects and in a large cohort during a previous course of pegIFN-α plus ribavirin. Intensive pharmacokinetic sampling for ribavirin was performed at steady state during the triple-therapy phase. Ribavirin levels were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Twenty-seven HCV-1/HIV-coinfected patients were enrolled. The median ribavirin Cmin for triple therapy (4.08 μg/ml; range, 2.14 to 5.56 μg/ml) was higher than that observed after telaprevir withdrawal (1.96 μg/ml; range, 0.41 to 3.45 μg/ml) (P < 0.001) and that observed for 125 HCV-1/HIV-coinfected patients treated only with pegIFN-α plus ribavirin (1.65 μg/ml; range, 0.41 to 5.56 μg/ml) (P < 0.001). The estimated glomerular filtration rate (eGFR) decreased >20% from the baseline value in 11 of 27 patients and became normal after telaprevir removal in almost all cases. There was a negative correlation between eGFR and ribavirin clearance (r(2) = 0.257; P = 0.064) but not the ribavirin area under the concentration-time curve from 0 to 12 h (AUC0-12) (r(2) = 0.001; P = 0.455). Thus, there is a significant pharmacokinetic interaction between telaprevir and ribavirin that results in very high ribavirin levels, which explains the excess of toxicity observed with this drug combination. A blockade of the proximal tubular transporters might be implicated in both the increase in plasma creatinine and the high ribavirin levels. (This study has been registered at ClinicalTrials.gov under registration no. NCT01818856.).

The ARRIBA concept: adequate resorption of ribavirin

BACKGROUND

Adequate ribavirin exposure is essential for optimal sustained virological response (SVR) rates in chronic HCV treatment. It has been proposed that the area under the concentration-time curve up to 4 h after intake of ribavirin (AUC0-4 h) of the first weight-based ribavirin dose should be ≥1.755 mg•h/l to guarantee the highest chance of SVR. Our ARRIBA concept comprises a test dose of ribavirin to select the optimal starting dose to achieve adequate exposure. This study aims to evaluate whether adequate exposure can be achieved after dose advice based on the AUC0-4 h of a single weight-based ribavirin test dose.

METHODS

(Formerly) HCV-infected subjects received a single weight-based ribavirin test dose (<75 kg: 400 mg; ≥75 kg: 600 mg) and the AUC0-4 h was calculated. If ribavirin AUC0-4 h was ≥1.755 mg•h/l, subjects received the same dose 4 weeks later; if the AUC0-4 h was <1.755 mg•h/l, an adjusted dose was administered. The ribavirin AUC0-4 h was recorded again. The primary outcome was the proportion of subjects with an AUC0-4 h ≥1.755 mg•h/l after the second dose.

RESULTS

A total of 26 subjects were included. The geometric mean (95% CI) ribavirin AUC0-4 h was 1.67 (1.44-1.92) mg•h/l with 9 subjects (35%) reaching the target AUC on day 1. Thus, on day 29, 17 subjects (65%) received an adjusted dose. The geometric mean (95% CI) AUC0-4 h increased to 1.90 (1.62-2.21) mg•h/l and then 16 subjects (62%) had an AUC0-4 h ≥1.755 mg•h/l, which is significantly higher than day 1 (P<0.05).

CONCLUSIONS

Our ARRIBA concept of a ribavirin test dose, with dose adjustment if necessary, leads to an increased proportion of patients with an AUC≥1.755 mg•h/l compared to traditional weight-based ribavirin dosing.

OPERA: responses to peginterferon and ribavirin therapy in a subgroup of interferon-naïve patients with HIV/HCV genotype 2/3 co-infection in Italy

BACKGROUND & AIMS

Hepatitis C virus (HCV) genotype 3 (G3) is common among HIV/HCV co-infected individuals and associated with moderate sustained virological response (SVR) rates with pegylated interferon (PEG-IFN) plus ribavirin (RBV) therapy, while G2 is less frequent and associated with higher SVR. To determine SVR and other response rates, identify SVR predictors and analyse differences between G2 and G3 with PEG-IFN/RBV in a large HIV/HCV G2/3 patient population.

METHODS

This subgroup analysis of the prospective, observational OPERA (Optimized Pegylated interferon Efficacy and anti-Retroviral Approach) study was conducted between 2005 and 2011 in Italy in PEG-IFN/RBV-naïve HIV/HCV patients. The primary efficacy endpoint was SVR rate (HCV RNA <50 IU/ml or undetectable 24 weeks after end-of-treatment).

RESULTS

Five hundred and fifty-six HCV G2/3 patients (G2 n = 60; G3 n = 496) were treated with PEG-IFN alfa-2a 180 μg/week or PEG-IFN alfa-2b 1.5 μg/kg, + RBV 13.6 ± 2.3 (mean ± SD) mg/kg/day for median 47 (26-54) weeks. SVR rates were 57.7%, 68.3% and 56.5% for G2/3, G2 and G3 respectively) and RVR rates were 53.2%, 57.1% and 45.8% respectively. Independent SVR predictors were undetectable baseline HIV RNA [adjusted odds ratio (AOR), 2.64; 95% CI: 1.523-4.565, P = 0.0005], age (AOR 0.95 per year; 95% CI: 0.908-0.994, P = 0.0258) and anti-HCV treatment duration (AOR 1.034 per week; 95% CI: 1.013-1.057, P = 0.0019).

CONCLUSIONS

Undetectable HIV RNA, longer anti-HCV treatment adherence and younger age were independent SVR predictors in treatment-naïve HIV/HCV G2/3 patients receiving PEG-IFN/RBV. Suppressing HIV RNA replication before anti-HCV therapy and increasing adherence to PEG-IFN/RBV treatment SVR rates may improve SVR.

Hepatitis C virus infection in patients with HIV-1: epidemiology, natural history and management

Hepatitis C virus (HCV)-related liver diseases have contributed to increased morbidity and mortality in HIV-1-infected individuals in the era of effective antiretroviral therapy. HCV transmission patterns have changed among the HIV co-infected population during the last decade, with acute HCV infection emerging worldwide. HIV infection accelerates the progression of HCV-related liver diseases and consequently cirrhosis, liver failure, and hepatocellular carcinoma. However, the current standard treatment of HCV infection with pegylated interferon plus ribavirin results in only a limited viral response. Furthermore, cumbersome pill regimens, antiretroviral related hepatotoxicity, and drug interactions of HCV and HIV regimens complicate therapy strategies. Fortunately, in the near future, new direct-acting anti-HCV agents will widen therapeutic options for HCV/HIV co-infection. Liver transplantation is also gradually accepted as a therapeutic option for end stage liver disease of HCV/HIV co-infected patients.

Impact of the peginterferon-α 2a and ribavirin plasma levels on viral kinetics and sustained virological response in genotype 1 HCV/HIV-co-infected patients with the unfavourable non-CC IL28B genotypes

Studies on the association between the peginterferon-α and ribavirin levels and sustained virological response (SVR) have shown yielded conflicting results, but most of them were performed before the influence of IL28B polymorphisms was known. Our aim was to assess the effects of peginterferon-α 2a and ribavirin plasma levels on viral kinetics and SVR in hepatitis C virus genotype 1 HCV-1/HIV-co-infected patients according to IL28B genotype. This was a cohort study of HCV-1/HIV-co-infected patients who were HCV-treatment naïve and for whom the efficacy of peginterferon-α 2a plus ribavirin was evaluated by per-protocol analysis. The peginterferon-α 2a and ribavirin levels were measured by ELISA and HPLC-UV, respectively. The relationships among host and viral factors, the trough drugs levels and virological responses were analysed by multivariate regression analyses. A total of 131 Caucasian patients were included (cirrhosis:38.9%). Overall, SVR rate was 39.6%. In patients with CC IL28B genotype, SVR was related neither to peginterferon-α 2a nor to ribavirin plasma levels, while higher levels of both drugs were the only variables independently associated with SVR in individuals with CT/TT IL28B genotypes (OR, 5.02; CI95 , 1.45-17.1; P = 0.001 and 4.0; CI95 , 1.08-14.7; P = 0.038, respectively). Moreover, faster viral declines were observed in CT/TT patients when pegIFN-α 2a and ribavirin plasma levels were greater than 3400 pg/mL and 1.6 μg/mL, respectively. In contrast to the results for CC patients, the results in patients carrying the unfavourable CT/TT IL28B genotypes showed that plasma levels of both drugs have significant effects on viral kinetics and SVR.

Towards hepatitis C eradication from the HIV-infected population

Around 10-15% of the 35 million people living with HIV worldwide have chronic hepatitis C virus (HCV) infection and are prone to develop liver-related complications. Exposure to HCV is almost universal among injecting drug users and is on the rise among homosexual men. Response to peginterferon-ribavirin therapy is generally lower in coinfection compared to HCV monoinfection. For this reason, the advent of direct-acting antivirals (DAA) is eagerly awaited for this population. The results of trials using DAA in coinfection show that treatment response rates are similar to those obtained in HCV monoinfection. Thus, HIV should no longer be considered as a "special" population, as long as antiretroviral therapy is given and drug interactions are taken into account. Envisioning HCV eradication from the HIV population faces major challenges ahead, including identification of the large number of undiagnosed individuals, and ensuring wide access to the best but often expensive HCV medications. This article forms part of a symposium in Antiviral Research on "Hepatitis C: next steps toward global eradication".

Optimizing treatment in HIV/HCV coinfection

Sustained virological response (SVR) to anti-hepatitis C virus (HCV) treatment is an outcome that can improve life expectancy in persons with human immunodeficiency virus (HIV) infection. Results of anti-HCV treatment are poor, and less than 50% of treated patients show SVR to peginterferon plus ribavirin combination therapy; in infections from HCV genotype 1 this proportion is less than 40%. Pilot studies have demonstrated that Boceprevir or Telaprevir in combination with peginterferon plus ribavirin are able to increase the SVR rate from 45% to 74% with Telaprevir, and from 26% to 61% with Boceprevir in persons never treated for hepatitis C. Interim data seem to indicate a high rate of HCV RNA undetectability on treatment also in patients without sustained response to peginterferon plus ribavirin. Both Telaprevir and Boceprevir have drug-drug interactions with antiretrovirals, and options for concurrent antiretroviral therapy are restricted. There are also several new anti-HCV drugs under study with the potential for more tolerable effective future regimens. The indication for treatment in a patient with HCV/HIV coinfection should take into account the priority of treatment, the probability of sustained response, the potential toxicities, the concurrent antiretroviral therapy options, the patient's motivation, and the sustainability of current and future therapies.

Hepatitis C therapy: highlights from the 2012 annual meeting of the European Association for the Study of the Liver

The results from clinical trials testing new direct-acting antivirals (DAAs) for chronic hepatitis C were the major focus of interest at the 2012 annual meeting of the European Association for the Study of the Liver. Besides triple combinations, in which any one of the new DAAs is given along with peginterferon-α/ribavirin, clinical trials exploring interferon-free oral regimens combining several DAAs attracted major attention. The good tolerance, broad hepatitis C virus (HCV) genotype activity, and high resistance barrier of sofosbuvir make this nucleotide analogue one of the most promising DAAs. Among HCV protease inhibitors, the safety, potency, and convenient dosing of simeprevir, asunaprevir, faldaprevir, and ABT-450/r were particularly highlighted. Among NS5A inhibitors, the good performance of daclatasvir encourages further clinical development. Finally, intriguing results were released about the role of interleukin 28B (IL-28B) polymorphisms using interferon-free regimens, indirectly supporting the role of innate immunity for clearing HCV definitively.

Management of hepatitis C in HIV and/or HBV co-infected patients

Co-infection with either HIV or HBV in chronic hepatitis C patients is common, since all these viruses share transmission routes and geographical distribution. Interaction between these viruses generally amplifies liver damage, increasing the risk of developing end-stage liver disease and hepatocellular carcinoma. HIV-HCV co-infection is associated with poorer response to antiviral therapy. New antivirals against HCV are eagerly awaited for this population. HBV-HCV dual infections are less common. The principles guiding indication of therapy in monoinfected patients should be followed considering which virus replicates in persons with serological markers of dual HBV-HCV infection. Although there is growing evidence supporting the use of direct acting antivirals (DAA) in dually infected patients with active HCV replication, prospective trials should be conducted to demonstrate their benefit, assessing carefully the rate and clinical consequences of HBV rebounds.