Treating HCV in HIV 2013: on the cusp of change

Modelling the impact of deferring HCV treatment on liver-related complications in HIV coinfected men who have sex with men

BACKGROUND & AIMS

Hepatitis C (HCV) is a leading cause of morbidity and mortality in people who live with HIV. In many countries, access to direct acting antiviral agents to treat HCV is restricted to individuals with advanced liver disease (METAVIR stage F3 or F4). Our goal was to estimate the long term impact of deferring HCV treatment for men who have sex with men (MSM) who are coinfected with HIV and often have multiple risk factors for liver disease progression.

METHODS

We developed an individual-based model of liver disease progression in HIV/HCV coinfected MSM. We estimated liver-related morbidity and mortality as well as the median time spent with replicating HCV infection when individuals were treated in liver fibrosis stages F0, F1, F2, F3 or F4 on the METAVIR scale.

RESULTS

The percentage of individuals who died of liver-related complications was 2% if treatment was initiated in F0 or F1. It increased to 3% if treatment was deferred until F2, 7% if it was deferred until F3 and 22% if deferred until F4. The median time individuals spent with replicating HCV increased from 5years if treatment was initiated in F2 to almost 15years if it was deferred until F4.

CONCLUSIONS

Deferring HCV therapy until advanced liver fibrosis is established could increase liver-related morbidity and mortality in HIV/HCV coinfected individuals, and substantially prolong the time individuals spend with a replicating HCV infection.

Daclatasvir and Sofosbuvir Versus Sofosbuvir and Ribavirin in Patients with Chronic Hepatitis C Coinfected with HIV: A Matching-adjusted Indirect Comparison

PURPOSE

Our aim was to compare the efficacy and tolerability of daclatasvir plus sofosbuvir (DCV+SOF) versus SOF plus ribavirin (SOF+R) in patients coinfected with HIV and hepatitis C virus (HCV).

METHODS

A systematic literature review of Phase III clinical trials identified 2 trials of SOF+R-PHOTON-1 (A Phase 3, Open-Label Study to Investigate the Efficacy and Safety of GS-7977 Plus Ribavirin in Chronic Genotype 1, 2 and 3 Hepatitis C Virus [HCV] and Human Immunodeficiency Virus [HIV] Co-Infected Subjects) and PHOTON-2 (A Phase 3, Open-Label Study to Investigate the Efficacy and Safety of Sofosbuvir Plus Ribavirin in Chronic Genotype 1, 2, 3 and 4 Hepatitis C Virus [HCV] and Human Immunodeficiency Virus [HIV] Co-Infected Subjects) suitable for comparison with the trial of DCV+SOF in patients coinfected with HIV and HCV-ALLY-2 (A Phase 3 Evaluation of Daclatasvir Plus Sofosbuvir in Treatment-naïve and Treatment-experienced Chronic Hepatitis C [Genotype 1, 2, 3, 4, 5, or 6] Subjects Coinfected With Human Immunodeficiency Virus [HIV]). Individual patient data from ALLY-2 were available; published summary data were extracted and pooled for the PHOTON trials. To adjust for cross-trial differences, ALLY-2 patients were subject to the inclusion and exclusion criteria reported in the PHOTON trials and were weighted to match all available summary baseline characteristics reported in both PHOTON trials. Sustained virologic response at week 12 post-treatment (SVR12) discontinuation due to adverse events (AEs) and rates of AEs were compared.

FINDINGS

The SVR12 rate was significantly higher among patients treated with DCV+SOF (n = 91) than among those treated with SOF+R (n = 455) both before (96.7% vs 84.6%; P = 0.002) and after (99.9% vs 84.6%; P < 0.001) adjusting for baseline characteristics. After adjustment, compared with patients treated with SOF+R, patients receiving DCV+SOF had a significantly lower rate of discontinuation due to AEs and significantly lower rates of the following specific AEs: cough, diarrhea, insomnia, nasopharyngitis, upper respiratory tract infection, and hemoglobin <10 g/dL.

IMPLICATIONS

After adjustment for cross-trial differences in baseline characteristics, DCV+SOF was associated with a significantly higher SVR12 rate and lower rate of discontinuation due to AEs than SOF+R in patients coinfected with HIV and HCV.

Impact of physiological, pathological and environmental factors on the expression and activity of human cytochrome P450 2D6 and implications in precision medicine

With only 1.3-4.3% in total hepatic CYP content, human CYP2D6 can metabolize more than 160 drugs. It is a highly polymorphic enzyme and subject to marked inhibition by a number of drugs, causing a large interindividual variability in drug clearance and drug response and drug-drug interactions. The expression and activity of CYP2D6 are regulated by a number of physiological, pathological and environmental factors at transcriptional, post-transcriptional, translational and epigenetic levels. DNA hypermethylation and histone modifications can repress the expression of CYP2D6. Hepatocyte nuclear factor-4α binds to a directly repeated element in the promoter of CYP2D6 and thus regulates the expression of CYP2D6. Small heterodimer partner represses hepatocyte nuclear factor-4α-mediated transactivation of CYP2D6. GW4064, a farnesoid X receptor agonist, decreases hepatic CYP2D6 expression and activity while increasing small heterodimer partner expression and its recruitment to the CYP2D6 promoter. The genotypes are key determinants of interindividual variability in CYP2D6 expression and activity. Recent genome-wide association studies have identified a large number of genes that can regulate CYP2D6. Pregnancy induces CYP2D6 via unknown mechanisms. Renal or liver diseases, smoking and alcohol use have minor to moderate effects only on CYP2D6 activity. Unlike CYP1 and 3 and other CYP2 members, CYP2D6 is resistant to typical inducers such as rifampin, phenobarbital and dexamethasone. Post-translational modifications such as phosphorylation of CYP2D6 Ser135 have been observed, but the functional impact is unknown. Further functional and validation studies are needed to clarify the role of nuclear receptors, epigenetic factors and other factors in the regulation of CYP2D6.

HIV-hepatitis C virus co-infection in the era of direct-acting antivirals

Approximately one-third of patients infected with human immunodeficiency virus (HIV) are concomitantly infected with hepatitis C virus (HCV). As a result, liver disease remains a major source of morbidity and mortality in HIV patients. Prior to 2011, treatments of HCV lacked efficacy in clinical trials in HIV/HCV co-infected patients. Fortunately, several direct-acting antivirals (DAAs) have now entered clinical practice and others have reached advanced stages of clinical development. These therapies offer significant benefits such as improved rates of sustained virologic response (SVR), shortened durations of treatment, and compatibility with HIV antiretroviral therapies. Treatments such as sofosbuvir (SOF) have received approval for HIV/HCV co-infected patients. Moreover, interferon-free options exist for HIV/HCV co-infected patients who may be ineligible or intolerant of interferon. Despite these improvements, physicians must be aware of the differences between these DAAs, the patient characteristics that play a role on the effectiveness of these medications, and the drug-drug interactions these DAAs may have with existing HIV antiretroviral therapies. The aim of this review is to discuss the prevalence and incidence of HIV/HCV co-infection, critical factors related to patient evaluation, current treatment options, and new developments in the management of HIV/HCV co-infected patients.

Using patient-reported outcomes to improve the management of co-infection with HIV and HCV: the ANRS CO13 HEPAVIH cohort

The management of co-infection with HIV and hepatitis C virus (HCV) is complicated by viral and drug-drug interactions, treatment-related side effects, and the poor response to therapy of certain HCV genotypes. Current or past drug use may also have a negative impact. HEPAVIH (ANRS CO13) is an ongoing French cohort study of co-infected individuals which combines medical and socio-behavioral follow-up. This cohort study aims at analyzing the course of HCV infection and access to HCV treatment in HIV-HCV co-infected patients, using both clinical and patient-reported outcomes. This article documents the main lessons learned to date from the HEPAVIH data and published literature, while describing research prospects and needs requiring further investigation in the field of patient-reported outcomes.