Peginterferon Alfa-2a Plus Ribavirin for the Treatment of Dual Chronic Infection With Hepatitis B and C Viruses
Gastroenterology Feb 2009
Interim results of this trial were presented at the 49th International Association for the Study of the Liver meeting, September 7-11, 2006, Cairo, Egypt; at the 42nd European Association for the Study of the Liver meeting, April 11-15, 2007, Barcelona, Spain; at the 58th American Association for the Study of the Liver Meeting, November 1-5, 2007, Boston, MA; at the 17th Asian Pacific Association for the Study of the Liver meeting, March 25-28, 2007, Kyoto, Japan; at the 18th Asian Pacific Association for the Study of the Liver meeting, March 23-26, 2008, Seoul, South Korea; and at the 43rd European Association for the Study of the Liver meeting, April 23-27, 2008, Milan, Italy.
Chun-Jen Liu, Wan-Long Chuang, Chuan-Mo Lee, Ming-Lung Yu, Sheng-Nan Lu, Shun-Sheng Wu_, Li-Ying Liao, Chi-Ling Chen, Hsing-Tao Kuo#, You-Chen Chao, Shui-Yi Tung, Sien-Sing Yang, Jia-Horng Kao, Chen-Hua Liu, Wei-Wen Su_, Chih-Lin Lin, Yung-Ming Jeng, Pei-Jer Chen, Ding-Shinn Chen
Background & Aims
Dual chronic infection with hepatitis C virus (HCV) and hepatitis B virus (HBV) is common in areas endemic for either virus. Combination therapy with ribavirin and pegylated interferon (peginterferon) is the standard of care for patients with HCV monoinfection. We investigated the effects of combination therapy in patients infected with both HBV and HCV (genotypes 1, 2, or 3).
The study included 321 Taiwanese patients with active HCV infection; 161 also tested positive for hepatitis B surface antigen (HBsAg) and 160 were HBsAg-negative (controls). Patients with HCV genotype 1 infection received peginterferon alfa-2a (180 _g) weekly for 48 weeks and ribavirin (1000-1200 mg) daily. Patients with HCV genotypes 2 or 3 received peginterferon alfa-2a weekly for 24 weeks and ribavirin (800 mg) daily. At 24 weeks posttreatment, patient samples were examined for a sustained virologic response (SVR) against HCV (serum HCV levels decreased to <25 IU/mL).
In patients with HCV genotype 1 infection, the SVR was 72.2% in dually infected patients vs 77.3% in monoinfected patients after treatment. For patients with HCV genotype 2/3 infections, the SVR values were 82.8% and 84..0%, respectively, after treatment. Serum HBV DNA eventually appeared in 36.3% of 77 dual-infected patients with undetectable pretreatment levels of HBV DNA; this was not accompanied by significant hepatitis. Posttreatment HBsAg clearance was observed in 11.2% of 161 dual-infected patients.
Combination therapy with peginterferon alfa-2a and ribavirin is equally effective in patients with HCV monoinfection and in those with dual chronic HCV/HBV infection.
In areas where hepatitis B virus (HBV) or hepatitis C virus (HCV) infection is endemic, a substantial number of patients are infected with both viruses.1, 2, 3 Those dually infected with HCV and HBV have been reported to carry a significantly higher risk of developing advanced liver diseases and hepatocellular carcinoma than those with either infection alone.3, 4, 5, 6 There is currently no approved treatment for this important patient group.
Small studies have shown that interferon alone was not effective in clearing HCV or HBV in dually infected patients.7, 8, 9 Combining interferon with ribavirin improved response rates in patients monoinfected with HCV,10, 11, 12 suggesting that combination therapy also might be more effective than interferon alone in dually infected patients. We therefore used conventional interferon alfa plus ribavirin to treat dually infected patients in a series of pilot studies.13, 14, 15 The 24-week combination regimen cleared HCV in 64% of the patients with dual HCV/HBV infection, comparable with results in patients with chronic hepatitis C monoinfection.. These results subsequently were confirmed by others.16 However, we found that sustained virologic response (SVR) was much less common in those patients with HBV/HCV genotype 1 infection than in those with HBV/HCV genotype 2 infection (44% vs 85%; P < .05). We also found that after a prolonged follow-up period of more than 2 years posttreatment, a significant portion (21%) of the successfully treated patients also cleared hepatitis B surface antigen (HBsAg).17
In the treatment of chronic hepatitis C monoinfection, pegylated interferon (peginterferon) has been shown to be superior to conventional interferon,18, 19, 20 and combination with ribavirin has become the standard of care for HCV monoinfection.21, 22, 23 We therefore hypothesized that the treatment of dually infected patients also might be enhanced with peginterferon plus ribavirin.
This large multicenter clinical trial was a further investigation into the efficacy of peginterferon plus ribavirin in dually infected patients with HCV genotypes 1, 2, and 3. Because occult HBV infection has been shown to reduce HCV SVR,24, 25 we addressed the issue through inclusion of this subpopulation. We also explored the effect of therapy on HBsAg clearance, the ultimate goal of anti-HBV therapy, and the interactions between HCV and HBV13, 14, 26, 27 during and after treatment.
This study in Taiwanese patients showed that, using peginterferon and ribavirin, a sustained HCV clearance rate of 72% was achieved in the difficult-to-treat patients dually infected with HCV genotype 1 and HBV. The results proved our hypothesis that HCV-SVR rates would be similar in dually infected patients and in HCV monoinfected patients. Contrary to previous reports,24, 25 a co-existing occult HBV infection was not found to influence the HCV SVR.
In the present study, the rate of SVR achieved with peginterferon alfa-2a plus ribavirin therapy in those infected with HCV genotype 1 appears to be higher than that reported in Caucasian patients, but is in keeping with rates seen using combination therapy in previous Taiwanese studies.23, 32, 33 The better SVR rates in our patients may be owing to a lower pretreatment HCV-RNA level and a lower mean body weight in the Taiwanese patients as compared with the Caucasian patients. Overall, 143 (44.5%) of our patients had low serum HCV-RNA levels, which indeed was shown to correlate with HCV SVR. Besides, higher average doses of peginterferon and ribavirin on body weight basis in Taiwanese patients have been shown to contribute to higher rates of rapid and early virologic response.21, 33, 34 This also may account for the high HCV SVR. Nevertheless, the HCV SVR in genotype 2/3-infected patients was not improved in this clinical trial. We thus speculated that there are still some unidentified host or viral factors that could not be overcome by the current peginterferon plus ribavirin-based combination therapy.
In retrospective analyses of randomized trials on chronic hepatitis C, assessment of HCV RNA at 4 and 12 weeks of treatment has been identified as a useful early predictor of SVR.35 The protocol of our study was designed before the introduction of such practice, and thus these virologic data were not available in the present study. In addition, dose reductions of peginterferon alfa-2a or ribavirin owing to adverse effects or decrease of cell counts during therapy are not uncommon, and may have a negative impact on SVR (supplementary Table 4; see supplementary material online at www.gastrojournal.org). Regarding this, administration of erythropoietin might be beneficial. Further studies are needed to clarify these important issues.
Co-existing HBV infection has been shown to influence the clearance of HCV in HCV and HBV dually infected patients treated with interferon monotherapy.7, 8, 9 The addition of ribavirin to interferon and the use of pegylated interferon appears to overcome this obstacle, as predicted from our previous pilot study13 and confirmed here in a large patient population.. Our findings indicated that in dually infected patients with predominant hepatitis C, the same genotype-dependent treatment recommendations for chronic hepatitis C also are applicable.36
Serum ALT activities in chronic hepatitis C usually return to normal when HCV is eradicated. In our patient population we found that about 24% of the dually infected patients with HCV SVR still had abnormal serum ALT activity. Further examination revealed that 76% of these patients had detectable serum HBV DNA posttreatment. We therefore speculated that in these patients residual chronic hepatitis B might account for the persistent hepatitis activity after the clearance of HCV. From another aspect, eradication of one hepatitis virus may lead to increased titer and pathogenicity of the other. Examination of HBV antigens and HCV replication in the liver compartment is required to confirm this. Because only 26 (8.1%) patients underwent a posttreatment liver biopsy in this study, we could not clarify these issues.
Regarding safety of the combination regimen in dually infected patients, there were no unexpected safety issues and adverse events such as those typically associated with interferon-based therapy.
During treatment of dual hepatitis C and B infection, virologic response of HBV to peginterferon and the possible reappearance of HBV after the control of HCV are 2 major clinical issues that need to be addressed. We found that HBV virologic response was obtained in 56% of the dually infected patients with pretreatment hepatitis B viremia. Intriguingly, in keeping with the results of our previous pilot study,17 posttreatment HBsAg clearance was noted in 11% of the dually infected patients in the present study. The ability to induce HBsAg clearance in HCV/HBV dually infected patients is of particular significance because this represents the closest outcome to cure chronic hepatitis B and is associated with a favorable clinical outcome and improved survival. This figure is far beyond the spontaneous or treatment-induced HBsAg clearance, which is only around 0%-3% annually in previous reports,31, 37, 38, 39 and thus it would be appropriate to study the mechanisms of HBsAg clearance in this unique cohort. On the other hand, 28 (36%) of the 77 dually infected patients whose pretreatment serum HBV DNA were undetectable had a reappearance of HBV (Table 4). Nevertheless, the reappearance of HBV did not result in clinically evident hepatitis. The significance of the reappearance of HBV after effective treatment of hepatitis C in patients with dually chronic HCV/HBV infection needs further study. In case of need, hepatitis B antiviral therapy should be given.40
Although our study showed that peginterferon alfa-2a plus ribavirin is effective in eradicating hepatitis C in patients chronically infected with both HBV and HCV, it remains to be determined whether this regimen also is suitable for dually infected patients who are positive for HBeAg and have a higher hepatitis B viral load.
In conclusion, combination therapy of peginterferon alfa-2a and ribavirin appears to be just as effective and safe for the treatment of HBsAg-positive patients chronically infected with active chronic hepatitis C as it is in patients with HCV monoinfection. The treatment recommendations regarding therapy duration according to genotype in HCV monoinfected patients appear to be applicable also for this patient group.
Demographic and Baseline Characteristics
All patients were naive to interferon-based therapy. None was positive for antibody against hepatitis D virus. The mean age of the HCV genotype 1 monoinfected patients was slightly younger than that of the genotype 1 dually infected patients (P = .04) (Table 1). Male sex predominated in all subgroups of patients except in the HCV genotype 2/3 monoinfected group (P = .04). Serum HCV-RNA level was lower in genotype 2/3 monoinfected patients than that in genotype 2/3 dually infected patients (P = .03). Twenty-nine (9%) of the 321 patients had cirrhosis. Fibrosis was more advanced in the HCV/HBV dually infected patients than in the HCV monoinfected patients (P < .001).
Before treatment, serum HBV DNA was detectable in 76 (47.2%) of the 161 dually infected patients. In addition, we found active HBeAg-negative chronic hepatitis B in 40 patients (24.8%) and inactive HBsAg carriers in 121 patients (75.2%). Finally, occult HBV infection, defined by the presence of serum HBV DNA in HBsAg-seronegative patients, was noted in 10 (6.3%) of the 160 HCV monoinfected patients (serum hepatitis B core antibody positive in 6 and serum antibody to HBsAg positive in 8). The median serum HBV-DNA level of the 10 patients was 1831 IU/mL (range, 478-12,000 IU/mL).
HCV SVR in each arm is shown in Figure 2. By intent-to-treat analysis, 72.2% of the patients with HCV genotype 1/HBV dual infection achieved an HCV SVR with a comparable SVR rate (77.3%) in HCV genotype 1 monoinfected patients. Only lower serum HCV-RNA level and absence of cirrhosis correlated significantly with an HCV SVR by multiple logistic regression analysis (Table 2). In HCV genotype 2/3 dually infected patients, SVR rates were similar in dually (82.8%) and monoinfected patients (84.0%).
Serum HCV-RNA level 400,000 IU/mL has been suggested as the cut-off value for low and high HCV-RNA levels, and this low HCV-RNA level was found to be a predictor of SVR. To address this issue, an HCV-RNA level of 400,000 IU/mL or higher vs less than 400,000 IU/mL instead of linear serum HCV-RNA level also was put into both univariate and multivariate analyses. Consistently, we found that lower serum HCV-RNA level was associated significantly with SVR (supplementary Table 1; see supplementary material online at www.gastrojournal.org).
The response to HCV therapy and the histology may differ between 2 subgroups of dually infected patients with HBeAg-negative chronic HBV infection. We thus further analyzed the HCV SVR and histologic findings between these 2 subgroups. We found that the serum HBV-DNA level did not correlate with the HCV SVR (77.5% in the active HBeAg-negative chronic hepatitis B subgroup and 76.9% in the inactive HBsAg carrier subgroup; P = .95). Histologically, the serum HBV-DNA level also did not correlate with the stage of liver fibrosis (P = .64) (supplementary Table 2; see supplementary material online at www.gastrojournal.org).
All 10 of the HCV monoinfected patients with occult HBV infection achieved HCV SVR.
HBV serologic responses
Peginterferon alfa-2a is approved for the treatment of chronic hepatitis B.31 In our study, clearance of HBsAg was documented in 19 (11.8%) and 18 (11.2%) of the dually infected patients at the end of treatment and at the end of the follow-up period, respectively. In addition, seroconversion to anti-HBs was observed in 7 (36.8%) of the 19 patients at the end of treatment and in 8 (44.4%) of the 18 patients at the end of the follow-up period. Among many variables analyzed, only low pretreatment serum HBsAg titer correlated significantly with the clearance of HBsAg at the end of treatment (P < .001) and at the end of the follow-up period (P < .001) (Table 3).
HBV virologic response and reappearance
Of the 145 dually infected patients who completed the treatment and posttreatment follow-up evaluation, we examined the HBV virologic responses. Of them, 68 (46.9%) had detectable serum HBV DNA pretreatment. HBV virologic response, defined by a posttreatment reduction of serum HBV DNA to an undetectable level, was obtained in 47 (69.1%) of the 68 patients at the end of treatment and in 38 (55.9%) at the end of the follow-up period (Table 4, Table 5).
Of the remaining 77 patients with undetectable pretreatment serum HBV DNA, reappearance of HBV DNA, defined by an increase of serum HBV DNA to 200 IU (1000 copies)/mL or greater, was found in 28 (36.4%) patients, either at the end of treatment (n = 16) or at the end of the follow-up period (n = 17). The rate of HBV reappearance was not significantly different between patients with an HCV SVR and those without (36% vs 40%; P = .95). Reappearance of serum HBV DNA was not associated with clinically evident hepatitis and the increase of serum ALT never exceeded 200 IU/L (supplementary Figure 1; see supplementary material online at www.gastrojournal.org).
Serum HBV DNA became undetectable after treatment in all 10 HCV monoinfected patients with pretreatment occult HBV infection. Furthermore, none of the remaining HCV monoinfected patients had detectable serum HBV DNA after the end of treatment.
Rates of serum ALT normalization vs HCV SVR at the end of the follow-up period are shown in Figure 3. Notably, 29 (23.6%) of the 123 dually infected patients with HCV SVR still had abnormal serum ALT levels (range, 56-102 IU/L). To clarify the possible contribution of HBV activity to ALT abnormality in these patients we looked for the presence of serum HBV DNA. Detectable serum HBV DNA was found in 22 (75.9%) of the 29 patients.
The patterns and severity of adverse effects in the dually infected patients were similar to those seen in HCV monoinfected patients. A total of 17 patients experienced serious adverse events, of which 4 events (thrombocytopenia, urinary tract infection, diabetes mellitus, and hypoglycemia) were regarded as possibly related to the study drug by the investigators who took care of these patients. Twenty-six patients (8.1%) withdrew from the study. The rate of withdrawal was not significantly different among the 4 patient groups (supplementary Table 3; see supplementary material online at www.gastrojournal.org). Noncompliance (30.8%), skin rashes (30.8%), and constitutional symptoms (15.4%) were the most common.
Patients and Methods
This was an open-label, comparative, multicenter study (National Institutes of Health registration number: NCT00361179) to show the efficacy and safety of peginterferon alfa-2a (Pegasys; F. Hoffman-La Roche Ltd, Basel, Switzerland) plus ribavirin (Robatrol; F. Hoffman-La Roche Ltd) for HCV SVR in HCV/HBV dually infected patients with active hepatitis C (study group) (Figure 1). For comparison, we also enrolled patients with active hepatitis C but seronegative for HBsAg (control group). Because our strategy aimed at eradication of HCV in dually infected patients and the designed regimen was not primarily for hepatitis B e antigen (HBeAg)-positive chronic hepatitis B, those dually infected patients positive for HBeAg were not enrolled.
Eligibility of Patients
The study group (either sex, age ≥18 y) comprised HCV and HBV dually infected patients with active hepatitis C and HBeAg-negative chronic HBV infection. Dual infection was defined by seropositivity for both antibodies to HCV (anti-HCV) and HBsAg for more than 6 months together with a serum HCV-RNA level of 200 IU/mL or higher (1000 copies/mL).
HBeAg-negative chronic HBV infection was defined further into 2 categories: those with high HBV DNA (≥2000 IU/mL or 10,000 copies/mL) who were considered to have active HBeAg-negative chronic hepatitis B and those with low or undetectable HBV DNA (<2000 IU/mL or 10,000 copies/mL) who were considered to be inactive HBsAg carriers.
Other eligibility criteria included the following: (1) treatment naive or failure to previous interferon monotherapy; (2) increased serum alanine aminotransferase (ALT) levels at least 1.5 times and below 10 times the upper limit of normal within 6 months before enrollment; and (3) adequate hematopoietic function (hemoglobin level, >12 g/dL; platelet count, >90,000/mm3), compensated liver function (Child-Pugh score, <6), and renal function (serum creatinine level, <1.5 mg/dL). Patients with human immunodeficiency virus infection or evidence of hepatocellular carcinoma were excluded.
The control group consisted of patients monoinfected with HCV who fulfilled the same eligibility criteria except that they were negative for HBsAg.
Patient Recruitment, Study Medications, and Visit Schedules
This investigator-initiated study was conducted at 9 medical centers in Taiwan. From June 2004 to February 2006, 321 patients were enrolled consecutively, 161 patients had dual infections and 160 had HCV infection only. During the screening process of the dually infected subjects, 311 patients positive for HBsAg, positive for anti-HCV, and negative for HBeAg were evaluated. Of them, 150 patients were excluded because of serum HCV-RNA levels less than 200 IU/mL in 95 patients, the presence of contraindicated comorbidity in 40 patients, and no informed consent in 15 patients.. As for the enrollment of the HCV monoinfected patients, 253 patients negative for HBsAg and positive for anti-HCV were screened. Of them, 93 patients were excluded because of serum HCV-RNA levels less than 200 IU/mL in 55 patients, contraindicated comorbidity in 30 patients, and no informed consent in 8 patients.
Patients with HCV genotype 1 infection received 48 weeks of combination therapy with peginterferon alfa-2a 180 _g weekly plus daily ribavirin. Those with HCV genotype 2/3 infection were treated for 24 weeks. Ribavirin was dosed according to HCV genotype and body weight: 800 mg daily for HCV genotype 2/3; for genotype 1, 1000 mg daily for patients whose body weight was less than 75 kg and 1200 mg for patients whose body weight was 75 kg or greater.
Clinical assessments were performed at baseline, and monthly during the treatment period and the posttreatment follow-up period. Serum HCV-RNA level was determined at recruitment, the end of treatment, and 6 months after the end of treatment. Serum HBsAg and HBV-DNA level were determined at recruitment, the end of treatment, and 6 months after the end of treatment in dually infected patients.
Efficacy and Safety Evaluation
Primary efficacy was determined by the results of serum HCV RNA at the end of treatment and at 6 months after the end of treatment. HCV SVR was defined as HCV RNA undetectable using a commercial quantitative real-time polymerase chain reaction (PCR) assay (COBAS TaqMan HCV Test version 2.0; Roche Diagnostics GmbH, Mannheim, Germany; lower detection of limit, 25 IU/mL) both at end of treatment and at end of posttreatment follow-up period.
Secondary efficacy was determined by the results of serum ALT, serum HBsAg, and serum HBV DNA. The safety variables included the following: (1) safety laboratory data, (2) clinical adverse events, and (3) evaluation of withdrawal cases.
Hepatitis Virus Markers and Virologic Assays
Pretreatment HBsAg, HBeAg, and anti-HCV were tested with commercial kits at each study site. Antibody against hepatitis D virus was screened with a commercial kit in a central laboratory (Hepatitis Research Center, National Taiwan University Hospital). HBsAg at the end of treatment and at the end of the follow-up period also was measured in the central laboratory using a standard quantitative Chemiluminescent Microparticle Immunoassay (ARCHITECT HBsAg; Abbott Diagnostics Division, Wiesbaden, Germany; sensitivity; 0.07 IU/mL).
Quantification and Genotyping of Serum HBV DNA and HCV RNA
We used an in-house real-time PCR assay for quantification and genotyping of HBV DNA as previously described.28 The detection limit of this assay for HBV DNA was 103 copies (or 200 IU) per mL.
Pretreatment serum HCV-RNA level and genotype were determined by an in-house real-time PCR assay. Serum HCV-RNA level at the end of therapy and at the sixth month of the posttreatment follow-up period was determined in a central laboratory (Hepatitis Research Center, National Taiwan University Hospital) by a commercial real-time PCR assay (COBAS TaqMan HCV Test version 2.0; Roche Diagnostics).
Grading of the hepatic necroinflammation and staging of fibrosis were assessed according to the Metavir scoring system.29 The histologic assessment in these patients was performed by various pathologists in each study site and not scored in a blinded way.
The clinical trial protocol and subsequent amendments were reviewed and approved by the Department of Health in Taiwan, as well as the Institutional Review Boards at each medical center. The study was conducted according to the 1975 Declaration of Helsinki and Good Clinical Practice. All patients gave written informed consent.
Sample Size Estimation and Statistical Analysis
The primary hypothesis that HCV-SVR rates in dually infected patients were similar to those in HCV monoinfected patients was tested against the alternative that the efficacy of peginterferon alfa-2a plus ribavirin in HCV monoinfected patients was at least 30% better than in dually infected patients. The planned enrollment of 100 HCV genotype 1-infected patients and 50 genotype 2/3-infected patients assumed an SVR rate of 60% for HCV genotype 1 and 80% for genotype 2/3, a statistical power of the study of greater than 80%, and a one-sided significance level of 0.05.30
All categoric and continuous variables were analyzed by the chi-square test and the Student t test, respectively. For continuous variables with outliers, nonparametric tests were used. Univariate and multiple logistic regression analyses were used to identify all factors possibly predictive of an HCV SVR.
The primary efficacy parameter was analyzed using the intent-to-treat analysis (by C.-L.C.). The HCV response rate was calculated as the number of patients with HCV SVR divided by the number of patients who received at least one dose of the study medication. Per-protocol analysis also was performed in those patients who took 12 or more injections of peginterferon and whose total ribavirin therapy was 84 days or more. Safety analysis included any patient who received at least one dose of the study medication.
All analyses were performed by using Stata statistical software (version 8.2; Stata Corp, College Station, TX).