Hepatitis C and substance use: new treatments and novel approaches

Primary Care-Based Hepatitis C Treatment Outcomes With First-Generation Direct-Acting Agents

OBJECTIVES

Vulnerable, urban populations with a history of substance use disorders have a high prevalence of hepatitis C virus (HCV). Primary care-based treatment has been proposed to improve access to care. In this study, we present outcomes from our urban, primary care-based HCV treatment program in patients treated with telaprevir or boceprevir in combination with pegylated-interferon and ribavirin ("triple therapy").

METHODS

We collected data from 126 consecutive patients with genotype 1 HCV monoinfection seen in our treatment program (2011-2013). Among the 40 who initiated treatment, we analyzed factors associated with achieving a sustained viral response (SVR).

RESULTS

During the study period, 40 patients initiated triple therapy (32%), 80% with recent or past substance use disorders. Patients initiating treatment were younger than untreated patients (P = 0.002), but otherwise did not differ demographically, or in the severity of their liver fibrosis (P > 0.05). An SVR was achieved in 18 patients (45%) and was less likely in patients with recent or past substance use disorders or psychiatric illness (both P < 0.01).

CONCLUSIONS

Nearly one third of patients initiated triple therapy with SVR rates comparable to other HCV treatment settings, despite a significant burden of mental illness and substance dependence. Our experience demonstrates that a primary care-based practice can successfully deliver HCV care to a vulnerable population. Additional interventions may be needed to improve outcomes in patients with recent or past substance use disorders or psychiatric illness.

[In Process Citation]

Approximately 70,000 people are infected with hepatitis C virus in Hungary, and more than half of them are not aware of their infection. From the point of infected individuals early recognition and effective treatment of related liver injury may prevent consequent advanced liver diseases and complications (liver cirrhosis, liver failure and liver cancer) and can increase work productivity and life expectancy. From a socioeconomic aspect, this could also prevent further spread of the virus as well as reduce substantially long term financial burden of related morbidity. Pegylated interferon + ribavirin dual therapy, which is available in Hungary since 2003, can clear the virus in 40-45% of previously not treated (naïve), and in 5-21% of previous treatment-failure patients. Addition of a direct acting first generation protease inhibitor drug (boceprevir or telaprevir) to the dual therapy increases the chance of sustained viral response to 63-75% and 59-66%, respectively. These two protease inhibitors are available and financed for a segment of Hungarian patients since May 2013. Between 2013 and February 2015, other direct acting antiviral interferon-free combination therapies have been registered for the treatment of chronic hepatitis C, with a potential efficacy over 90% and typical short duration of 8-12 weeks. Indication of therapy includes exclusion of contraindications to the drugs and demonstration of viral replication with consequent liver injury, i.e., inflammation and / or fibrosis in the liver. Non-invasive methods (elastography and biochemical methods) are accepted and preferred for staging liver damage (fibrosis). For initiation of treatment as well as for on-treatment decisions, accurate and timely molecular biology tests are mandatory. Eligibility for treatment is a subject of individual central medical review. Due to budget limitations therapy is covered only for a proportion of patients by the National Health Insurance Fund. Priority is given to those with urgent need based on a Hungarian Priority Index system reflecting primarily the stage of liver disease, and considering also additional factors, i.e., activity and progression of liver disease, predictive factors of treatment and other special issues. Approved treatments are restricted to the most cost-effective combinations based on the cost per sustained viral response value in different patient categories with consensus between professional organizations, National Health Insurance Fund and patient organizations. More expensive therapies might be available upon co-financing by the patient or a third party. Interferon-free treatments and shorter therapy durations preferred as much as financially feasible. A separate budget is allocated to cover interferon-free treatments for the most-in-need interferon ineligible/intolerant patients, and for those who have no more interferon-based therapy option. Orv. Hetil., 2015, 156(Suppl. 1), 3-23.

[Diagnosis, treatment, and follow-up of hepatitis C-virus related liver disease. Hungarian national consensus guideline]

Approximately 70 000 people are infected with hepatitis C virus in Hungary, more than half of whom are not aware of their infection. Early recognition and effective treatment of related liver injury may prevent consequent advanced liver diseases (liver cirrhosis and liver cancer) and its complications. In addition, it may increase work productivity and life expectancy of infected individual, and can prevent further viral transmission. Early recognition can substantially reduce the long term financial burden of related morbidity from socioeconomic point of view. Pegylated interferon + ribavirin dual therapy, which is available in Hungary since 2003, can kill the virus in 40-45% of previously not treated (naïve), and in 5-21% of previous treatment-failure patients. Addition of two direct acting first generation protease inhibitor drugs (boceprevir and telaprevir) to the dual therapy increased the chance of sustained clearance of virus to 63-75% and 59-66%, respectively. These two protease inhibitor drugs are available and financed for a segment of Hungarian patients since May 2013. Indication of therapy includes exclusion of contraindications to the drugs and demonstration of viral replication with consequent liver injury, i.e., inflammation and/or fibrosis in the liver. For initiation of treatment as well as for on-treatment decisions accurate and timely molecular biology tests are mandatory. Staging of liver damage (fibrosis) non-invasive methods (transient elastography and biochemical methods) are acceptable to avoid concerns of patients related to liver biopsy. Professional decision for treatment is balanced against budget limitations in Hungary, and priority is given to those with urgent need using a national Priority Index system reflecting stage of liver disease as well as additional factors (activity and progression of liver disease, predictive factors and other special circumstances). All naïve patients are given a first chance with dual therapy. Those with genotype 1 infection and with on-treatment or historic failure to dual therapy are eligible to receive protease inhibitor based triple therapy provided, they reach financial cutoff eligibility based on Priority Index. Duration of therapy is usually 48 weeks in genotype 1 with a response-guided potential to reduce duration for non-cirrhotic patients. Patients with non-1 genotypes are treated with dual therapy (without protease inhibitors) for a genotype and response driven duration of 16, 24, 48, or 72 week. Careful monitoring for early recognition and management of side-effects as well as viral response and potential breakthrough during protease-inhibitor therapy are recommended.

Natural killer cell activity and function in chronic HCV-infected patients during peg interferon and ribavirin: early effects of active substance use

In Western countries, chronic hepatitis C virus (HCV)-infection mostly affects former and active substance users. The effect of active substance use on interferon (IFN)-responsiveness and therapy efficacy is not well understood. In this study, we compared natural killer (NK) cell activity and function in healthy controls and chronic HCV-infected patients with and without active substance use, as well as the early effects of antiviral therapy with peg-IFN and ribavirin. No differences were observed between chronic HCV patients and healthy individuals in the number and frequencies of CD56(dim) and CD56(bright) NK cells. Also, IL-12/18-induced IFN-gamma production by NK cells was comparable between all groups, whereas the cytotoxic ability of NK cells (granzyme and CD107a levels) was more potent in HCV-infected patients as compared to healthy controls, and highest in non-substance users. Moreover, at baseline, the activation of NK cells was significantly lower in HCV-infected patients who used substances, when compared to healthy individuals. Therapy-induced viral load reduction assessed early at day 7 showed a similar decline in substance users and non-substance use HCV patients, with 25% substance users and 17% non-substance users testing HCV-RNA negative at day 7. Furthermore, early during IFN-based therapy, NK cells from HCV patients remained responsive to IFN, and only a minor decline in the degree of STAT-1 phosphorylation was observed irrespective of substance use. These findings were further supported by comparable in vitro p-STAT-1 induction in all three experimental groups. Despite subtle differences at baseline between healthy individuals and chronic HCV patients, we observed that active substance use in chronic HCV-infected patients did not affect the immune responsiveness to IFN early after start of treatment, and thus, we found no evidence - from an immunological point of view - that antiviral therapy of our cohort of HCV-infected patients with active substance use is less efficient.