Alimentary Pharmacology & Therapeutics
Review Article: The Treatment of Genotype 1 Chronic Hepatitis C Virus Infection in Liver Transplant Candidates and Recipients
D. Joshi, I. Carey, K. Agarwal
Disclosures
Aliment Pharmacol Ther. 2013;37(7):659-671.
Abstract and Introduction
Abstract
Background Recently, the therapeutic landscape with regard to anti-HCV therapy has changed dramatically. The new directly acting anti-virals (DAAs) have demonstrated improved sustained virological response (SVR) compared with pegylated-interferon and ribavirin.
Aim To examine and present the latest data with regard to anti-viral therapy in genotype 1 HCV-positive transplant candidates and recipients.
Methods An electronic search using Medline was performed. Search terms included 'HCV, DAA and protease inhibitor' in combination with 'treatment pre-transplantation' and 'treatment post-transplantation'.
Results Patients with advanced fibrosis and cirrhosis have inferior SVR rates compared with patients with minimal fibrosis. A low accelerating dose regimen (LADR) of pegylated interferon and ribavirin (PR) appears to be a safe therapeutic option. Side effects also appear to be more pronounced in patients with advanced disease. Data from the large registration studies with triple therapy (boceprevir or telaprevir plus PR) demonstrated improved SVR rates even in patients with advanced disease, although virological relapse rates were highest amongst these patients. In transplant recipients, initial data are being reported on the use of triple therapy, and although no SVR data are available, promising results are accruing. The drug–drug interactions appear to be manageable. Side effects in particular anaemia appear to be markedly increased in the posttransplant setting.
Conclusions The use of the new DAAs in patients with advanced fibrosis/cirrhosis pretransplant and posttransplant appears possible, with manageable side effects and drug–drug interactions, and improved early virological response rates. We recommend that these patients are managed in centres with the appropriate expertise.
Introduction
Hepatitis C virus (HCV) infection is a global epidemic and a leading cause of chronic liver disease.[1] Data from the World Health Organisation (WHO) estimate that 3–4 million individuals are infected with HCV every year.[2] Currently, chronic HCV is the leading cause of death from liver disease and the leading indication for liver transplantation (LT) in the United States and Western Europe.[3–5]
Spontaneous clearance of HCV post-LT is rare and re-infection of the liver allograft is universal in individuals with HCV viraemia at the time of transplantation. Compared with other aetiologies, patient and graft survival rates are inferior due to progressive fibrosis driven by HCV recurrence.[6, 7] Several strategies have therefore emerged to help improve outcomes post-LT including optimal donor, recipient and immunosuppression selection. Another potential strategy is exposure to anti-viral therapy (AVT) pre-LT for those on the transplant waiting list to achieve an undetectable HCV viral load at the time of LT.[8]
This review addresses treatment of HCV in patients with advanced fibrosis or cirrhosis who are transplant candidates, and transplant recipients posttransplant in genotype 1 patients. We highlight important predictors of response, the increased side effect profile and the increasing experience of the use of the new protease inhibitors and directly acting anti-virals (DAAs) both pre- and posttransplant.
Search Strategy and Selection Criteria
We searched Medline (1 Jan 1966 to 1 September 2012) with the search term 'HCV and protease inhibitor' in combination with 'treatment pre-transplantation' and 'treatment post-transplantation'. Publications were reviewed by DJ and KA, and were selected predominately from the last 5 years. Given the rapidly evolving landscape with regard to the newer DAAs, we also included abstracts from recent conferences. Older seminal publications were not excluded. Reference lists of articles identified by this search strategy were reviewed. Our reference list was also modified on the basis of comments from peer reviewers.
Pre Liver Transplant
Treatment in Patients With Advanced Fibrosis and Cirrhosis
Virological response rates are lower in patients with cirrhosis; sustained virological response (SVR) rates ranging between 40% and 50% for Child-Pugh (CP) class A and between 7 and 26% for CP class C.[9–12] Poorer SVR rates are also evident in genotype 1 and 4 patients compared with genotype 2 and 3 patients with advanced fibrosis (51% vs. 61%) and cirrhosis (33% vs. 57%).[12] A marked step-wise reduction in SVR is apparent according to fibrosis stage in genotype-1 patients; no fibrosis (70%) vs. cirrhosis (10%), P < 0.0001.[12] Irrespective of viral genotype, a rapid virological response (RVR) remains the strongest on treatment predictor of SVR.[12] Although data from the IDEAL study would suggest that treatment with either PEG-IFN alpha 2a or 2b is equally efficacious, more recent data would suggest hypo-responsiveness to PEG-IFN alpha 2b and ribavirin in patients with cirrhosis.[13, 14]
Treatment of patients with CP-A and early CP-B (score 7) disease can result in attenuation of disease progression, development of hepatocellular carcinoma and potentially end in clinical remission with avoidance for the need for LT altogether. The aim of treating patients with advanced fibrosis or cirrhosis who are listed for LT is to potentially allow the patient to enter transplantation with an undetectable HCV viral load and therefore reduce the chance of recurrence posttransplantation. The latter observation was based on the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) Liver Transplant Database study, which demonstrated that patients with lower titres of HCV (<1 × 106 viral copies/mL) before transplantation had improved mortality and graft survival.[15] Current EASL guidelines[16] are shown in Table 1. Patients who are listed for LT based on HCC who are not undergoing local-regional therapy should also be considered for AVT. AVT is poorly tolerated in patients with advanced fibrosis/cirrhosis and can precipitate hepatic decompensation. Long-term, maintenance therapy with PEG-IFN in patients with advanced fibrosis or cirrhosis who fail to achieve an SVR with conventional therapy is currently not advocated.[17, 18]
Treatment on the Transplant Waiting List
Initial data with the use of interferon (IFN) mono-therapy in small cohorts of patients demonstrated that AVT was feasible in cirrhotic patients albeit with an increased side effect profile.[19–22] Studies evaluating the role of AVT in patients with cirrhosis and undergoing liver transplantation are summarised in Table 2.
Patients who present with a living donor represent an ideal patient group in whom AVT can be timed so that ideally these patients enter transplantation with an undetectable HCV viral load. Given the poorer tolerability of AVT amongst cirrhotic patients and the possibility of hepatic decompensation, the concept of a low accelerating dose regimen (LADR) was introduced.[8] An LADR essentially involves commencing patients on reduced doses of pegylated interferon (PEG-IFN) and ribavirin (PR) and then incrementing doses every 2 weeks to achieve maximally tolerated or target standard doses.
A recent multi-centre, randomised study further evaluated the efficacy and safety of pretransplant AVT for the prevention of HCV recurrence posttransplant.[23] Although this study was not limited to genotype 1 patients only, a total of 59 patients listed for either living donation or HCC with MELD exception underwent treatment with an LADR and were compared with 20 untreated patients. A total of 57 patients subsequently underwent transplantation (44 treated and 13 controls): 26 (59%) treated patients had undetectable HCV RNA at the time of transplant with 11 (42%) patients demonstrating HCV RNA negativity 24 weeks posttransplant; 13 (50%) patients subsequently relapsed posttransplantation. Predictors of an undetectable HCV RNA 12 weeks posttransplantation included PR treatment duration >16 weeks, but not viral genotype. No increase in serious adverse events (SAEs) was noted in treated group (68% vs. 55%, P = 0.3), although the number of SAEs per patient was higher (2.7 vs. 1.3, P = 0.003).[23]
Side Effects
Data available would suggest a significant side effect profile in patients with advanced fibrosis or cirrhosis undergoing AVT.[8, 19–22] Side effects are more common in patients with CP class C and MELD >18. In addition, dose reductions are more common in patients with cirrhosis. The development of neutropenia, thrombocytopenia along with anaemia is common, necessitating dose reductions in both PR doses, although the majority of tolerability issues relate to the pegylated interferon component. A retrospective case–control study also demonstrated an increased incidence of bacterial infections particularly in CP-B and -C patients undergoing AVT (17 vs. 3 episodes, P = 0.002).[22] In the same study, an increased incidence of spontaneous bacterial peritonitis in patients undergoing AVT not receiving norfloxacin prophylaxis was also demonstrated.[22] The incidence of hepatic decompensation in patients with compensated cirrhosis is between 0% and 3%, although these data may be an underestimation due to patient selection within clinical trials.[24–26]
Triple Therapy; Protease Inhibitor + Pegylated Interferon and Ribavirin
In 2011, the first generation of protease inhibitors (PI), boceprevir and telaprevir, were released and approved for patients with genotype 1 HCV disease only. Boceprevir is a linear peptidomimetic keto-amide serine protease inhibitor that reversibly binds to the HCV nonstructural 3 (NS3) active site whilst telaprevir inhibits the NS3/4A HCV protease.[27, 28] Triple therapy (PI + PR) is now regarded as standard of care for genotype 1 patients. Overall SVR rates in treatment-naïve patients were increased significantly to between 68% and 75% and in previously treatment-experienced patients to between 59% and 88%.[29–33]
Protease Inhibitors in Treatment-naïve Genotype 1 Patients With Advanced Fibrosis or Cirrhosis
The SPRINT-2 (serine protease inhibitor therapy 2) trial was a phase III study conducted in treatment-naïve patients using boceprevir.[29] A total of 1097 patients were included, 100 patients (9%) having either advanced fibrosis (n = 47) or cirrhosis (n = 53). All patients received a lead-in of PR for 4 weeks before being randomised into 3 groups: Group 1, PR for 44 weeks; Group 2 (response-guided therapy group, RGT), boceprevir and PR for 24 weeks (those with detectable HCV RNA between 8 weeks and 24 weeks received PR for further 20 weeks); and Group 3, boceprevir and PR for 44 weeks. Overall, SVR rates were higher in the boceprevir treatment groups in particular amongst patients with minimal fibrosis, although a benefit was evident in patients with either advanced fibrosis or cirrhosis (Figure 1). Relapse rates were, however, higher amongst patients with advanced fibrosis or cirrhosis compared with patients with minimal fibrosis (12–18% vs. 9%). The absence of cirrhosis was identified as a baseline predictor of SVR with boceprevir and PR (OR: 2.5, 95% CI: 1.4–4.6, P = 0.003). On treatment, viral kinetics remained an important predictor of SVR; RVR (undetectable HCV RNA at week 8) allowed shortened treatment duration amongst patients with minimal fibrosis only. An RVR, however, was less common amongst patients with advanced fibrosis or cirrhosis. In conclusion, the authors recommended that treatment-naïve patients with advanced fibrosis or cirrhosis should receive a fixed duration of therapy (boceprevir and PR for 48 weeks in total).
Figure 1.
This blog is all about current FDA approved drugs to treat the hepatitis C virus (HCV) with a focus on treating HCV according to genotype, using information extracted from peer-reviewed journals, liver meetings/conferences, and interactive learning activities.
Risk Of Developing Liver Cancer After HCV Treatment
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