Abstract

Background & Aims: The aim of this study was to evaluate the long-term sustainability of response in patients with hepatitis B e antigen (HBeAg)-positive chronic hepatitis B treated with pegylated interferon (PEG-IFN) α-2b alone or in combination with lamivudine. Methods: All 266 patients enrolled in the HBV99-01 study were offered participation in a long-term follow-up (LTFU) study. Patients were treated with PEG-IFN α-2b (100 μg/wk) alone or in combination with lamivudine (100 mg/day) for 52 weeks. Initial response was defined as HBeAg negativity at 26 weeks posttreatment. For the LTFU study, patients had one additional visit after the initial study (mean interval, 3.0 ± 0.8 years). Results: Of 266 patients enrolled in the initial study, 172 (65%) participated in the LTFU study. At LTFU, HBeAg and hepatitis B surface antigen (HBsAg) negativity were observed in 37% and 11% of 172 patients, respectively. Sixty-four patients were classified as initial responders and 108 as nonresponders. Among the initial responders, sustained HBeAg negativity and HBsAg loss were observed in 81% and 30%, respectively. Significantly higher rates of HBeAg negativity were observed in genotype A–infected initial responders compared with those with genotype non-A (96% vs 76%; P = .06) as well as HBsAg loss (58% vs 11%; P 1.0 × 105 copies/mL. Major exclusion criteria were antiviral therapy within 6 months before randomization, viral coinfections, preexisting cytopenia, or decompensated liver disease. For the LTFU study, patients were reevaluated by one additional visit at the local participating center. The local investigator assessed clinical signs and symptoms of liver disease, complications of liver disease (hepatocellular carcinoma, ascites, variceal bleeding, encephalopathy, or jaundice), liver transplantation, mortality, and administration of (other) antiviral therapy after the initial study according to predefined criteria on standardized questionnaires. If the patient had been re-treated, local data before re-treatment were also collected. Patients were enrolled in the LTFU study after they gave informed consent according to the standards of the local ethics committees. Follow-up time was calculated from the end of the initial study (week 78) to the visit for the LTFU study. The primary outcome for the LTFU study was sustainability of HBeAg negativity. Secondary outcome measures were HBV DNA levels 5.0 × 103 copies/mL after HBeAg loss were tested for the presence of core promoter (A1762T/G1764A) and precore mutations (G1896A) by sequence analysis. Testing for HBeAg, anti-HBe, HBsAg, and anti-HBs for the LTFU study was performed with the commercially available enzyme-linked immunosorbent assays of DiaSorin (DiaSorin SpA, Saluggia, Italy). For the comparison of frequencies between or within groups, χ2 test, Fisher exact test, and McNemar test were used where appropriate. Student t test and Mann–Whitney test were used to compare means between groups. The Kaplan–Meier method was used to estimate cumulative response rates, and differences between groups were compared by log-rank testing. Four-year cumulative response rates were used, because an adequate proportion of patients were still at risk at this time point. This method was used in addition to a cross-sectional analysis because the timing of the LTFU visit was different for the patients enrolled. A cross-sectional analysis alone could overestimate or underestimate response rates due to the differences in duration of follow-up after the initial study. Cox regression analysis was used for the identification of factors influencing HBeAg relapse in responders. The hazard ratio (HR) and 95% confidence interval (CI) are given for factors associated with HBeAg relapse. Patients with missing data and patients who were re-treated were considered nonresponders. A P value of .05 was considered statistically significant (all 2-sided). Statistical analysis was performed with the SPSS 14.0 program (SPSS Inc, Chicago, IL). Of 266 patients from 41 centers participating in the HBV99-01 study, 172 patients (65%) from 28 centers (68%) were enrolled in the LTFU study. The LTFU study overview is shown in Figure 1. Patients were followed up for a mean of 3.0 ± 0.8 years (range, 1.6–5.0 years) after the end of the initial study. The majority of the 94 patients who were not enrolled in the LTFU study did not participate because the local study site did not, for variable reasons, take part in this study (n = 52; 55%) or because the patient was lost to follow-up (n = 23; 24%). Three patients died after the initial study, and all 3 were nonresponders. Baseline characteristics and outcome at the end of the initial study of patients who did not participate in the LTFU study (n = 94) and those who were included in the LTFU study (n = 172) were comparable except for mean baseline ALT level (3.7 ± 2.1 vs 4.7 ± 4.0 U/L; P = .03). Baseline characteristics and outcome at the end of the initial study for patients enrolled in the LTFU study (n = 172) and all patients from the initial study (n = 266) are shown in Table 1. The patient groups were similar in terms of baseline demographics and disease characteristics. Ninety-one patients treated with PEG-IFN α-2b alone and 81 patients treated with PEG-IFN α-2b in combination with lamivudine were included in the LTFU study. Outcome at the end of the initial study was comparable between the 2 patient groups.Table 1Baseline Characteristics and Outcome at 26 Weeks PosttreatmentInitial study (n = 266)LTFU study (n = 172)P valueBaseline (start of treatment)PEG-IFN monotherapy, n (%)136 (51)91 (53).72Age (y), mean ± SD35.0 ± 12.935.5 ± 13.3.66Male, n (%)207 (78)137 (80).65Ethnicity, n (%).88 White196 (74)124 (72) Asian53 (20)35 (20) Other17 (6)13 (8)ALT level (U/L), mean ± SD4.3 ± 3.54.7 ± 4.0.36Log HBV DNA (copies/mL), mean ± SD9.1 ± 0.99.0 ± 0.9.72HBV genotype, n (%).83 A90 (34)53 (31) B23 (9)13 (8) C39 (15)32 (19) D103 (39)66 (38) Other11 (4)8 (5)Necroinflammation (median)5 (1–10)5 (1–10).91Fibrosis (median)3 (0–6)3 (0–6).95Previous IFN, n (%)55 (21)40 (23).52Previous lamivudine, n (%)33 (12)22 (13).9226 weeks posttreatment (end of initial study)HBeAg loss, n (%)95 (36)64 (37).75HBeAg seroconversion, n (%)77 (29)53 (31).68Log HBV DNA (copies/mL), mean ± SD6.8 ± 2.66.7 ± 2.6.95HBV DNA 1.0 × 104 copies/mL at LTFU and in 9 of 37 patients (24%) with an HBV DNA level 1.0 × 104 copies/mL at LTFU and in those with HBV DNA below this level. We previously showed that anti-HBe negativity at the end of treatment was the strongest predictor of HBeAg relapse within 6 months posttreatment.23Flink H.J. Buster E.H. Merican I. et al.Relapse after treatment with peginterferon alpha-2b alone or in combination with lamivudine in HBeAg positive chronic hepatitis B.Gut. 2007; 56: 1485-1486Crossref PubMed Scopus (6) Google Scholar In this study, however, we found no relation between anti-HBe status at 6 months posttreatment and the risk of HBeAg relapse during LTFU. In patients who still have undetectable HBeAg after a 6-month treatment-free interval, presence of anti-HBe seems thus of less importance for the long-term sustainability of HBeAg negativity. Studies comparing the outcome of responders to standard IFN with nonresponders found that patients who cleared HBeAg had better survival free of hepatic complications, in particular patients with cirrhosis.13van Zonneveld M. Honkoop P. Hansen B.E. et al.Long-term follow-up of alpha-interferon treatment of patients with chronic hepatitis B.Hepatology. 2004; 39: 804-810Crossref PubMed Scopus (303) Google Scholar, 14Niederau C. Heintges T. Lange S. et al.Long-term follow-up of HBeAg-positive patients treated with interferon alfa for chronic hepatitis B.N Engl J Med. 1996; 334: 1422-1427Crossref PubMed Scopus (803) Google Scholar, 24Lau D.T. Everhart J. Kleiner D.E. et al.Long-term follow-up of patients with chronic hepatitis B treated with interferon alfa.Gastroenterology. 1997; 113: 1660-1667Abstract Full Text Full Text PDF PubMed Scopus (284) Google Scholar, 25Fattovich G. Giustina G. Realdi G. et al.European Concerted Action on Viral Hepatitis (EUROHEP)Long-term outcome of hepatitis B e antigen-positive patients with compensated cirrhosis treated with interferon alfa.Hepatology. 1997; 26: 1338-1342Crossref PubMed Scopus (212) Google Scholar In our study, the limited number of hepatic complications precluded valid analysis for these end points. Previous studies in IFN-treated patients from our group and others that showed improved long-term outcome in responders compared with nonresponders typically had a longer duration of follow-up after therapy than our study.13van Zonneveld M. Honkoop P. Hansen B.E. et al.Long-term follow-up of alpha-interferon treatment of patients with chronic hepatitis B.Hepatology. 2004; 39: 804-810Crossref PubMed Scopus (303) Google Scholar, 15Lau G.K. Piratvisuth T. Luo K.X. et al.Durability of response and occurrence of late response to peginterferon alpha-2a (40KD) one year post-treatment in patients with HBeAg-positive chronic hepatitis B.J Hepatol. 2006; 44: S23Abstract Full Text PDF PubMed Google Scholar Delayed clearance of HBsAg has been observed in 12%–65% of patients within 5 years after IFN-induced HBeAg loss, although this seems to occur particularly in non-Asian populations.10Pas S.D. Fries E. De Man R.A. et al.Development of a quantitative real-time detection assay for hepatitis B virus DNA and comparison with two commercial assays.J Clin Microbiol. 2000; 38: 2897-2901PubMed Google Scholar, 14Niederau C. Heintges T. Lange S. et al.Long-term follow-up of HBeAg-positive patients treated with interferon alfa for chronic hepatitis B.N Engl J Med. 1996; 334: 1422-1427Crossref PubMed Scopus (803) Google Scholar, 24Lau D.T. Everhart J. Kleiner D.E. et al.Long-term follow-up of patients with chronic hepatitis B treated with interferon alfa.Gastroenterology. 1997; 113: 1660-1667Abstract Full Text Full Text PDF PubMed Scopus (284) Google Scholar, 25Fattovich G. Giustina G. Realdi G. et al.European Concerted Action on Viral Hepatitis (EUROHEP)Long-term outcome of hepatitis B e antigen-positive patients with compensated cirrhosis treated with interferon alfa.Hepatology. 1997; 26: 1338-1342Crossref PubMed Scopus (212) Google Scholar, 26Carreno V. Castillo I. Molina J. et al.Long-term follow-up of hepatitis B chronic carriers who responded to interferon therapy.J Hepatol. 1992; 15: 102-106Abstract Full Text PDF PubMed Scopus (74) Google Scholar, 27Korenman J. Baker B. Waggoner J. et al.Long-term remission of chronic hepatitis B after alpha-interferon therapy.Ann Intern Med. 1991; 114: 629-634Crossref PubMed Scopus (380) Google Scholar, 28Lin S.M. Sheen I.S. Chien R.N. et al.Long-term beneficial effect of interferon therapy in patients with chronic hepatitis B virus infection.Hepatology. 1999; 29: 971-975Crossref PubMed Scopus (421) Google Scholar, 29Lok A.S. Chung H.T. Liu V.W. et al.Long-term follow-up of chronic hepatitis B patients treated with interferon alfa.Gastroenterology. 1993; 105: 1833-1838PubMed Google Scholar In HBeAg-negative patients treated with PEG-IFN α-2a, 6% of responders had loss of HBsAg and appearance of anti-HBs at 2 years posttreatment.30Marcellin P. Bonino F. Lau G.K.K. et al.The majority of patients with HBeAg-negative chronic hepatitis B treated with peginterferon alfa-2a (40KD) [Pegasys®] sustain responses 2 years post-treatment.J Hepatol. 2006; 44: S275Abstract Full Text PDF PubMed Google Scholar In these HBeAg-negative patients, loss of HBsAg occurred significantly more often in genotype A–infected patients (28%) than in those with genotype D (0%; P = .05).30Marcellin P. Bonino F. Lau G.K.K. et al.The majority of patients with HBeAg-negative chronic hepatitis B treated with peginterferon alfa-2a (40KD) [Pegasys®] sustain responses 2 years post-treatment.J Hepatol. 2006; 44: S275Abstract Full Text PDF PubMed Google Scholar In our study, HBsAg loss was observed in 11% of the overall group and in 30% of the initial HBeAg responders. High HBsAg loss rates were observed in genotype A–infected patients (28%), while HBsAg loss hardly occurred in those with genotype B, C, or D infection (3%). PEG-IFN α-2b should therefore particularly be considered as first-line therapy in genotype A–infected HBeAg-positive patients, while for the other genotypes the potential risks and benefits should be more carefully balanced. A caveat of the current study was the fact that patients had their additional LTFU visit at different time points after the initial study. The observed response rates at LTFU may therefore overestimate or underestimate actual response rates. However, Kaplan–Meier estimates of 4-year cumulative HBeAg and HBsAg response seem comparable to observed response rates at LTFU. Furthermore, in retrospect, a relatively low dosage of PEG-IFN α-2b may have been used in this study (100 μg/wk starting dosage, reduced to 50 μg/wk after 32 weeks). Adding lamivudine to PEG-IFN therapy has been reported to result in higher response rates at the end of therapy, but not after treatment discontinuation.7Janssen H.L. van Zonneveld M. Senturk H. et al.Pegylated interferon alfa-2b alone or in combination with lamivudine for HBeAg-positive chronic hepatitis B: a randomised trial.Lancet. 2005; 365: 123-129Abstract Full Text Full Text PDF PubMed Scopus (1032) Google Scholar, 8Lau G.K. Piratvisuth T. Luo K.X. et al.Peginterferon Alfa-2a, lamivudine, and the combination for HBeAg-positive chronic hepatitis B.N Engl J Med. 2005; 352: 2682-2695Crossref PubMed Scopus (1379) Google Scholar We also found that HBeAg loss occurred equally in patients treated with PEG-IFN α-2b alone and those with added lamivudine. However, patients in the combination therapy group were more likely to have undetectable HBV DNA compared with patients treated with PEG-IFN α-2b alone at LTFU. Adding lamivudine to PEG-IFN α-2b therapy might thus be beneficial in the long-term. Future studies with long duration of follow-up after treatment with PEG-IFN α-2b and newer (more potent) nucleos(t)ide analogues may clarify this observation. Because lamivudine was discontinued after 1 year of therapy both in this study as in other large randomized studies investigating the effects of added lamivudine to PEG-IFN therapy,7Janssen H.L. van Zonneveld M. Senturk H. et al.Pegylated interferon alfa-2b alone or in combination with lamivudine for HBeAg-positive chronic hepatitis B: a randomised trial.Lancet. 2005; 365: 123-129Abstract Full Text Full Text PDF PubMed Scopus (1032) Google Scholar, 8Lau G.K. Piratvisuth T. Luo K.X. et al.Peginterferon Alfa-2a, lamivudine, and the combination for HBeAg-positive chronic hepatitis B.N Engl J Med. 2005; 352: 2682-2695Crossref PubMed Scopus (1379) Google Scholar, 30Marcellin P. Bonino F. Lau G.K.K. et al.The majority of patients with HBeAg-negative chronic hepatitis B treated with peginterferon alfa-2a (40KD) [Pegasys®] sustain responses 2 years post-treatment.J Hepatol. 2006; 44: S275Abstract Full Text PDF PubMed Google Scholar it is unknown whether continuing a nucleos(t)ide analogue after PEG-IFN α-2b may be beneficial in the long-term. We conclude that HBeAg response to PEG-IFN α-2b alone or in combination with lamivudine is durable in the majority of patients and is associated with an increase in HBsAg loss. This study further emphasizes the importance of HBV genotype in PEG-IFN α-2b therapy, also in the long-term, with clearance of HBsAg in more than one fourth of genotype A–infected patients but rarely in those with other genotypes.