Chronic hepatitis B is a major cause of end-stage

Transcription

1 Predictors of HBeAg Loss After Lamivudine Treatment for Chronic Hepatitis B Robert P. Perrillo, 1 Ching-Lung Lai, 2 Yun-Fan Liaw, 3 Jules L. Dienstag, 4 Eugene R. Schiff, 5 Solko W. Schalm, 6 E. Jenny Heathcote, 7 Nathaniel A. Brown, 8 Mark Atkins, 9 Mary Woessner, 10 and Stephen D. Gardner 10 Elevated alanine transaminase (ALT) levels and low serum hepatitis B virus (HBV) DNA predict a higher likelihood of hepatitis B e antigen (HBeAg) loss in patients with chronic hepatitis B treated with interferon. Predictors of HBeAg loss in patients treated with lamivudine are not known. The objective of this analysis of 4 lamivudine-controlled Phase III trials was to determine patient-dependent or laboratory variables that predict HBeAg loss. Predictors of HBeAg loss in patients treated with interferon, lamivudine plus interferon, or placebo are also described. A total of 805 adults with chronic hepatitis B were treated either with lamivudine (n 406), matching placebo (n 196), interferon (n 68), or the combination of lamivudine plus interferon (n 135). Demographic and baseline disease characteristics were used in stepwise multivariate analyses to identify features that were predictive of lamivudine-induced HBeAg loss. HBeAg loss correlated with increased pretreatment ALT levels in all groups. The rate of HBeAg loss was highest among patients with pretreatment ALT levels greater than 5 times the upper limit of normal (ULN) and was most pronounced in the lamivudine group (56%). Multivariate modeling indicated that elevated baseline ALT levels (P <.001) and histologic activity index (HAI) score (P <.001) were important predictors of HBeAg loss in response to lamivudine. The effect of pretreatment ALT levels on HBeAg loss was similar for Asians and Caucasians. In conclusion, elevated pretreatment ALT levels and/or active histologic disease were the most important predictors of lamivudine-induced HBeAg loss. Asians and Caucasians had similar rates of response to lamivudine at comparable ALT levels. (HEPATOLOGY 2002;36: ) Chronic hepatitis B is a major cause of end-stage liver disease and mortality resulting from cirrhosis-related liver failure or hepatocellular carcinoma. 1 Interferon-alfa was the first drug specifically Abbreviations: HBV, hepatitis B virus; HBeAg, hepatitis B e antigen; HBsAg, hepatitis B s antigen; ALT, alanine transaminase; ULN, upper limit of normal; HAI, histologic activity index. From the 1 Section of Gastroenterology and Hepatology, Ochsner Clinic Foundation, New Orleans, LA; 2 Department of Medicine, Queen Mary Hospital, Hong Kong, China; 3 Liver Research Unit, Chang Gung Memorial Hospital, Chang Gung University, Taipei, Taiwan; 4 Gastrointestinal Unit (Medical Services) and Liver- Biliary-Pancreas Center, Massachusetts General Hospital, and the Department of Medicine, Harvard Medical School, Boston, MA; 5 Center for Liver Diseases, University of Miami Medical Center and the Veteran Affairs Medical Center, Miami, FL; 6 Department of Hepatology and Gastroenterology, Erasmus University Hospital Rotterdam, Rotterdam, the Netherlands; 7 Division of Gastroenterology, Toronto Western Hospital, Toronto, Canada; 8 Novirio Pharmaceuticals Inc., Cambridge, MA; 9 Glaxo Wellcome Research and Development, Greenford, Middlesex, England; 10 Glaxo Wellcome Inc., Research Triangle Park, NC. Received December 12, 2001; accepted April 21, Supported by Glaxo Wellcome. Additional support was provided by a Clinical Research Center Grant (MO1RR01066) to the Massachusetts General Hospital from the National Institutes of Health. Address reprint requests to: Robert P. Perrillo, M.D., Section of Gastroenterology and Hepatology, Ochsner Clinic Foundation, 1514 Jefferson Highway, New Orleans, LA rperrillo@ochsner.org; fax: Copyright 2002 by the American Association for the Study of Liver Diseases /02/ $35.00/0 doi: /jhep licensed to treat chronic hepatitis B. 2,3 Lamivudine is an oral nucleoside analogue that has recently been licensed to treat this condition. It has been found to suppress hepatitis B virus (HBV) replication consistently, and Phase III clinical trials have shown histologic, biochemical, and virologic improvements in Asian and Western patients The virologic endpoints of treatment have been the sustained disappearance of serum HBV DNA by a conventional hybridization assay and either the disappearance of hepatitis B e antigen (HBeAg) from serum (HBeAg loss) or the loss of HBeAg accompanied by the detection of anti-hbe (HBeAg seroconversion) At a recent consensus conference on the management of hepatitis B it was concluded that HBeAg loss in conjunction with nondetectable serum HBV-DNA levels by a conventional assay are reasonable virologic endpoints by which to measure the efficacy of antiviral treatment, and seroconversion to anti-hbe may not provide further assurances that a virologic response will be sustained. 11 Disappearance of HBV DNA and HBeAg can occur spontaneously in the natural course of the disease or in response to interferon or lamivudine therapy. The undetectability of these markers of viral replication is considered an indicator of a patient s transition to a state of 186

2 HEPATOLOGY, Vol. 36, No. 1, 2002 PERRILLO ET AL. 187 substantially lower HBV replication, which when maintained is likely to be associated with improved long-term clinical outcomes. 12,13 Serum transaminases tend to normalize quickly after viral replication subsides, reflecting reductions in underlying liver inflammation, and some patients ultimately lose all serologic markers of HBV infection and become hepatitis B s antigen (HBsAg) seronegative on prolonged follow-up In patients treated with lamivudine, improvement in liver histology correlates with the disappearance of serum HBV DNA by direct hybridization assays. 7,8,10 Interferon and lamivudine studies have used the additional endpoint of HBeAg loss because this has been found to be associated with a lasting virologic response. 2,3,8,11 This is a particularly important consideration when the efficacy of lamivudine monotherapy is evaluated because the loss of HBeAg alone is considerably more likely to occur when compared with HBeAg seroconversion in response to 52 weeks of treatment. High serum alanine transaminase (ALT) levels and low serum HBV-DNA levels pretreatment were independently associated with an increased rate of HBeAg responses (HBeAg loss and HBeAg seroconversion) to interferon. 2,3,15,16 Pretreatment serum HBV-DNA level (below 100 pg/ml by the solution hybridization assay) was the most important independent predictive factor for HBeAg response in a U.S. multicenter trial of interferon alfa-2b. 3 The importance of HBV DNA as a predictor of response was also confirmed in other studies conducted in Western Europe and Australia. 15,16 In contrast, Lok et al. 17 and Hoofnagle et al. 2 found that pretreatment serum aminotransferase level was the most significant predictor of response in Chinese and American patients, respectively, who were treated with alfa interferon. At present, limited information is available on the association between pretreatment variables and HBeAg loss in patients with hepatitis B who are treated with lamivudine. An analysis of a subset of data in the reported Asian multicenter study 7 indicated that pretreatment ALT level was the strongest predictor of HBeAg response, though the investigators cautioned that the analysis should be considered exploratory because of the relatively small number of patients who seroconverted. 18 Moreover, this study did not analyze the impact that patient- and laboratory-related variables had on the more frequent HBeAg loss. Accordingly, in the current study we report predictors of lamivudine-induced HBeAg loss after 1 year of treatment by using the combined data from 4 lamivudine Phase III trials involving 406 adults who were treated with lamivudine. Predictors of HBeAg loss in an additional 399 adults who were treated with interferon, lamivudine plus interferon, or placebo are also described. Patients and Methods Patient Group. The 4 lamivudine Phase III clinical trials analyzed in the current study were conducted in Asia, North America, Europe, Israel, South Africa, Australia, and New Zealand All studies were approved by the Human Studies Committees of the respective institutions in accordance with the 1975 Declaration of Helsinki. All patients gave informed consent before entering the trials. Patients entering these trials had HBeAg-positive chronic hepatitis B and were either interferon and lamivudine naive (3 studies) or interferon nonresponders (1 study), as previously described Patients were adult men or women ( 16 y) with compensated liver disease, and all had evidence of chronic hepatitis B infection (documented HBsAg positive 6 mo) with ongoing HBV replication (HBeAg and HBV-DNA positive). In 3 of the trials, entry ALT levels at the screening visit were required to be in the range of 1.3 to 10 times the upper limit of the normal (ULN) reference range. A fourth trial (in Asia, as described later) enrolled patients with normal ALT levels as well as those with elevations up to 10 times the ULN. All patients entering these studies had histologic features consistent with chronic hepatitis B in pretreatment liver biopsy specimens. Study Designs and End Points. Patients in the 4 clinical trials were treated with either lamivudine 100 mg orally once daily, matching placebo once daily, interferon 10 million units (MU) subcutaneously 3 times weekly for 16 weeks, or the combination of lamivudine plus an identical regimen of interferon. These treatment groups were used in all analyses. In the U.S. trial (study 1), previously untreated patients were randomly assigned to receive lamivudine versus placebo for 52 weeks. 8 In the Asian trial (study 2), patients were randomized to receive lamivudine versus placebo, each given for 52 weeks (a third treatment arm in which patients were randomized to receive lamivudine 25 mg once daily was not included in the current analysis). 7 In the trial conducted in Europe, Canada, South Africa, Australia, and New Zealand (study 3), previously untreated patients were randomized to receive 1 of the 3 following treatment regimens: (1) combination treatment 8 weeks of lamivudine followed by 16 weeks of lamivudine and interferon alfa-2b (Intron A; Schering- Plough, Kenilworth, NJ) and then follow-up to week 52; (2) interferon monotherapy 8 weeks of oral placebo followed by 16 weeks of placebo and interferon and then follow-up to week 52; and (3) lamivudine monotherapy for 52 weeks. 10 In the trial conducted in North America, Europe, and Israel (study 4), patients who had failed to respond to previous treatment with interferon were randomized to receive 1 of the 3 following treatment regi-

3 188 PERRILLO ET AL. HEPATOLOGY, July 2002 mens: (1) lamivudine monotherapy for 52 weeks; (2) combination treatment lamivudine for 8 weeks followed by lamivudine plus interferon alfa-2b (Intron A) for 16 weeks, and then follow-up to week 52; and (3) daily placebo for 52 weeks. 9 Histologic response at week 52, defined as a reduction of at least 2 points in the Knodell Histologic Activity Index (HAI) 19 in the posttreatment biopsy as compared with pretreatment, was the primary efficacy endpoint in 3 of the 4 trials (studies 1, 2, and 4). Three independent histopathologists evaluated the liver biopsy specimens. Each histopathologist reviewed 1 of the studies in its entirety (1 pathologist did studies 1 and 4) and all assessments were conducted in a blinded fashion with respect to treatment and sequence (baseline, week 52) HBeAg loss (loss of detectable levels of HBeAg in serum irrespective of HBV-DNA status) and HBeAg seroconversion (loss of detectable levels of HBeAg and HBV DNA in serum and the appearance of antibody to HBeAg) were prospectively defined endpoints for all of the trials. Consistency of the data for serologic parameters, including ALT levels and virologic assessments, was aided by the use of a single, centralized reference laboratory for each of the studies. Serum levels of HBV DNA were measured in all 4 studies with a conventional solution hybridization assay (Abbott Laboratories, Abbott Park, IL), which had been used in previous interferon trials. 3 This HBV-DNA assay had a lower limit of detection of 1.6 pg/ml at the U.S. reference laboratory and 3.0 pg/ml at the European reference laboratory (equivalent to approximately 10 6 copies/ml). HBeAg, anti-hbe, HBsAg, and anti-hbs were assessed with standard, commercially available enzyme immunoassays (Abbott Laboratories). Statistical Evaluation. Data from the 4 trials with similar patient populations, baseline characteristics, and treatment endpoints were combined to identify pretreatment characteristics that were associated with HBeAg loss (prognostic variables). All patients with confirmed chronic hepatitis B (defined as HBsAg detectable for 6 months and HAI score 2 or elevated ALT level at study entry) randomized to treatment (intent to treat), regardless of whether the study drug was actually taken or if the patient completed the planned duration of the study, were included. A small number of patients across the 4 treatment groups (n 11) were excluded based on a failure to meet the definition of confirmed chronic hepatitis B. The last observation carried forward method of imputing data was used for missing HBeAg assessment. Data were summarized as the proportion of patients with response at the end of 52 weeks with the results displayed by treatment groups. The primary focus of this analysis was to compare the lamivudine- and placebo-treated patients. The other treatment groups (interferon and lamivudine in combination with interferon) are presented herein for comparison. For ALT level assessments, the value was divided by the ULN range for the 4 central laboratories. This adjustment allowed for differences in the normal ranges between the laboratories as well as differences associated with the sex-specific ranges. Exploratory analyses with prospectively defined covariates of interest were used to evaluate potential predictors of HBeAg loss. For these analyses, only patients treated with lamivudine (n 406) or placebo (n 196) were included. The baseline factors included were age, sex, race, body mass index, weight, ALT, HBV DNA, HAI score, and presence of cirrhosis. Sex, race, and presence of cirrhosis were included as categoric variables, whereas age, body mass index, weight, ALT, HBV DNA, and HAI score were included as continuous variables in the models. Initially, univariate analyses were conducted by using logistic regression to investigate the pattern of covariation of response (HBeAg loss) with individual baseline characteristics adjusted for treatment effect. Next, multivariate analysis was used to investigate the pattern of covariation of multiple factors with response. A stepwise logistic model was used, with generous P values for entry (P.20) and exit (P.25) criteria to control for those characteristics that had a marginal association. This analysis was used to identify prognostic variables (those related to outcome), and to provide a more precise estimation of treatment efficacy after allowing for any association of these baseline characteristics. Once these characteristics were identified, subgroup analyses were prepared to show response rates across different levels of these baseline characteristics. The Mantel-Haenszel test was used to describe differences across baseline levels within a group. The statistical analysis software used was SAS Software (SAS Institute, Cary, NC) version 6.08 running under a VAX/VMS environment. Results Patient Population. The treatment groups were generally well matched with regard to demographics and baseline disease characteristics with significant differences between the treatment groups noted only for ethnicity and pretreatment HAI scores (Table 1). The patients were predominantly men and ranged in age from 15 to 76 years. A lower proportion of patients receiving interferon or the combination of lamivudine plus interferon were of Asian descent (26% and 13%, respectively), reflecting the Western geographic locations where patients in these

4 HEPATOLOGY, Vol. 36, No. 1, 2002 PERRILLO ET AL. 189 Table 1. Baseline Characteristics of the Patients Placebo n 196 Lamivudine n 406 Interferon n 68 Lamivudine Interferon n 135 P Value Age (y).588 Median Range Male Sex (%) Weight (kg).588 Median Range Race (%) White Asian Black Other/unknown Route of HBV acquisition (%).185 Intravenous drug use Perinatal Sexual Transfusion Other Unknown HAI Score* Median Range Cirrhosis (%) Serum HBV DNA (pg/ml).437 Median Range LLOD-1,150 LLOD-2,264 LLOD-1,322 LLOD-786 Serum ALT ( ULN).414 Median Range Abbreviation: LLOD, lower limit of detection. *Pretreatment biopsy specimen may have been obtained up to 6 months before the baseline visit. Although patients were required to have HBV-DNA levels LLOD and ALT levels 1.3 to 10 times the ULN reference range at the screening visit, baseline values obtained approximately 4 weeks later may have varied. treatment groups were enrolled. No difference was apparent in the probable route of acquisition with the exception that fewer patients treated with either interferon or the combination regimen were reported to have perinatally acquired HBV. Patients given interferon or the combination regimen had lower median pretreatment HAI scores, but the frequency of cirrhosis was similar in all treatment groups. Baseline serologic and biochemical markers of HBV infection were also comparable. Pretreatment median HBV-DNA values did not appear to differ across the treatment groups, and pretreatment ALT levels as a multiple of the ULN were similar across the treatment groups ranging from 2.2 to 2.4 times the ULN. HBeAg Response. Table 2 depicts the frequency of Table 2. HBeAg Loss and Seroconversion by Treatment Group and Pretreatment ALT Level HBeAg Loss HBeAg Seroconversion Pretreatment ALT Level Placebo Lamivudine Interferon Lamivudine Interferon Placebo Lamivudine Interferon Lamivudine Interferon n % n % n % n % n % n % n % n % 1 ULN 0/25 0 2/55 4 1/2 50 0/4 0 0/25 0 1/53 2 1/2 50 0/ ULN 4/ / / / /59 5 8/ /22 9 5/ ULN 9/ / / / / / / / ULN 7/ / / / / / / /20 45 P value Overall 20/ / / / / / / / NOTE. Differences in patient denominators between HBeAg loss and HBeAg seroconversion are owing to the baseline criteria in each of these definitions: (1) HBeAg loss loss of detectable levels of HBeAg in serum irrespective of HBV-DNA status at baseline or week 52; and (2) HBeAg seroconversion loss of detectable levels of HBeAg and HBV DNA in serum and the appearance of antibody to HBeAg. P value based on Mantel-Haenszel test comparing response/nonresponse by baseline ALT category ( 1-2 ULN, 2-5 ULN, 5 ULN).

5 190 PERRILLO ET AL. HEPATOLOGY, July 2002 HBeAg loss and seroconversion according to baseline ALT level. The frequency of HBeAg loss and seroconversion was similar in all active treatment groups and greater than that observed in placebo-treated patients. HBeAg response rates in the active treatment groups increased with the level of pretreatment ALT. A similar but less pronounced trend was observed for patients receiving placebo. Among patients with pretreatment ALT levels greater than 1 to 2 times the ULN or less, HBeAg loss occurred in approximately 13% to 15% of the patients in the 3 active treatment groups, as compared with 7% for placebo-treated patients. The rate of HBeAg loss increased further in the actively treated patients with pretreatment ALT levels greater than 2 to 5 times the ULN or less, and this occurred in 28% of the lamivudine patients, 22% of the interferon patients, and 32% of the combination-regimen patients at this level of ALT level abnormality compared with 11% for placebo-treated patients. The rate of HBeAg loss was highest among patients with pretreatment ALT levels greater than 5 times the ULN, occurring in more than 50% of the patients treated with lamivudine. Similar trends were observed with HBeAg seroconversion, though seroconversion occurred less frequently than HBeAg loss. An even more stringent analysis of HBeAg loss in which missing data were input as no response revealed similar response rates and conclusions regarding ALT levels. Pretreatment Factors Influencing HBeAg Loss. As can be seen in Table 3, univariate analysis of individual baseline characteristics showed that treatment with lamivudine (P.001), pretreatment ALT level (P.001), HAI score (P.001), HBV-DNA level (P.008), cirrhosis (P.009), and ethnicity (P.02) were each predictive of HBeAg loss. ALT level and HAI score were positively correlated with response, whereas HBV-DNA level was negatively correlated. Patients with cirrhosis were more likely to experience HBeAg loss, whereas patients with Asian ethnicity were less likely to experience loss. After controlling for treatment, there was no apparent association with the other characteristics: race, age, sex, weight, and body mass index. In the stepwise regression modeling, ALT level (P.001) and HAI score (P.001) were the most important predictors of HBeAg loss, with HBV-DNA level (P.07) selected in the model, but appearing less important when considered with ALT and HAI score (Table 4). The effects seen with cirrhosis, which is derived from the HAI score, and ethnicity did not appear in the more comprehensive multivariate model. The original impact of ethnicity in the univariate model may in part be caused by the subset of patients who entered the Asian study (study 2) with normal ALT levels because these patients had a lower rate of HBeAg loss. Table 3. Odds Ratios of HBeAg Loss for Potential Prognostic Factors Univariate Analyses Response Rates by Factor Responders n % Odds Ratio* 95% CI P Value Treatment Lamivudine 101/ Placebo 20/ Baseline ALT level (U/L) 90 43/ / Baseline HAI / / / / Baseline HBV-DNA level (pg/ml) / / / / Cirrhosis.009 Absent 95/ Present 19/ Weight / / / / Ethnic origin.020 Other 16/ Caucasian 65/ Asian** 40/ Body mass index (kg/m 2 ) / / / / Age (y) / / / / Sex.794 Women 26/ Men 94/ *Odds ratios adjusted for treatment effect. Rates presented are actual rates for each subgroup. P values are based on a logistic regression model adjusted for treatment effect. Age, weight, baseline HAI, ALT level, and HBV-DNA level were fitted as continuous variables, but are displayed as categoric variables in this table for clearer description of relationship to response. HAI according to Chien et al. 18 Cirrhosis is indicated by a score of 4 on the fibrosis component of the HAI score. Ethnic origin Other includes Black, non-asians, and Hispanics. **Includes patient set with normal ALT levels at baseline. This analysis provided an estimate of the treatment effect of lamivudine on HBeAg loss after controlling for these variables; the unadjusted analysis was significant (P.001; odds ratio 2.96; 95% confidence interval, ; Table 3) and remained significant after adjust-

6 HEPATOLOGY, Vol. 36, No. 1, 2002 PERRILLO ET AL. 191 Table 4. Odds Ratios of HBeAg Loss for Potential Prognostic Factors Multivariate Analyses Factor Odds Ratio* P Value Treatment (lamivudine vs. placebo) 3.93 ( ) HAI score (per 1-unit increase) 1.17 ( ) ALT level (per 10-unit increase) 1.04 ( ) HBV-DNA level (per 10-unit increase) 0.99 ( ).07 *Each odds ratio adjusted for other variables in the table. ing for these baseline characteristics (P.001; odds ratio 3.93; 95% confidence interval, ; Table 4). Similar results were seen in these analyses for HBeAg seroconversion with regard to the set of predictors (data not shown). Other Factors Potentially Influencing HBeAg Loss. The rate of HBeAg loss was uniformly low across the 3 active treatment groups (range, 9%-15%) for patients with minimal necroinflammatory activity on the pretreatment liver biopsy as reflected by a pretreatment HAI score of less than 5 (Table 5). For patients with higher pretreatment HAI scores (5-9 or 10), correspondingly higher rates of HBeAg loss occurred. With HAI scores of 10 or greater, approximately one third of the patients in all 3 active treatment groups experienced HBeAg loss. For patients treated with placebo, higher pretreatment HAI scores did not appear to increase the likelihood of HBeAg loss. HAI scores and the corresponding rate of HBeAg loss were also examined in the subgroup of patients with normal or minimally elevated pretreatment ALT levels ( 1.5 times the ULN) treated with either placebo or lamivudine (Table 6). Once again, the rate of HBeAg loss with lamivudine was noticeably increased in patients with pretreatment HAI scores of 10 or greater (Table 6). HBeAg Loss by Ethnic Origin. For patients treated with lamivudine, the effect of pretreatment ALT level on HBeAg loss appeared similar for Asian and Caucasian patients, the 2 major ethnic groups in the 4 trials (Fig. 1). In both ethnic groups, there was a progressive increase in HBeAg loss as pretreatment ALT levels increased. A similar observation was made when HBeAg seroconversion was evaluated in Asian and Caucasian patients in relation to baseline ALT levels (data not shown). Table 6. HBeAg Loss by Pretreatment HAI Categories in Patients With Normal or Minimally Elevated Pretreatment ALT Level (<1.5 Times the ULN) Pretreatment HAI Score Temporal Patterns of HBeAg Loss. Fig. 2 displays the time to HBeAg loss over the study period by pretreatment ALT level and treatment. HBeAg loss tended to occur earlier in patients with higher pretreatment ALT levels. This trend was particularly noticeable when ALT levels were greater than 5 times the ULN. Discussion Placebo (n 50) Lamivudine (n 110) n % n % 0-4 0/18 0 1/ /21 5 1/ /11 0 6/29 21 NOTE. Primarily derived from Asian patients in study 2. The current study represents the most definitive analysis to date of the pretreatment factors associated with a virologic response (HBeAg loss) to lamivudine. Multivariate analysis identified pretreatment ALT levels and HAI score to be the best independent predictors of HBeAg loss with or without seroconversion to anti-hbe. The observations with regard to pretreatment ALT levels and response to lamivudine were not apparent in the original analyses of study 1, 8 probably because subject numbers were too small, but the current study confirmed the findings of a retrospective analysis of one of the other treatment populations (study 2). 18 Combining the patients in all 4 efficacy trials provided an opportunity to better evaluate the baseline characteristics in which the individual studies were limited based on the number of patients with response in each study. Moreover, the incorporation of interferon- and combination-treated patients in the current study allowed comparisons to be made with regard to the effect that pretreatment ALT level and HAI score had on HBeAg loss with these other forms of treatment. Table 5. HBeAg Loss by Treatment Group and Pretreatment HAI Score Pretreatment HAI Score Placebo Lamivudine Interferon Lamivudine Interferon n % n % n % n % 0-4 3/ /95 9 4/ / / / / / / / / /45 36 Fig. 1. HBeAg loss by pretreatment ALT level and ethnic origin in patients treated with lamivudine. *Includes patients with normal ALT levels.

7 192 PERRILLO ET AL. HEPATOLOGY, July 2002 Fig. 2. Proportion of patients with HBeAg loss over time according to pretreatment ALT level. (}) LAM, lamivudine-treated patients; ( ) IFN, patients treated with 8 weeks of placebo preceding 16 weeks of interferon; ( ) PBO, placebo-treated patients; ( ) LAM/IFN, patients treated with 8 weeks of lamivudine preceding 16 weeks of lamivudine and interferon. The effect that progressively higher levels of pretreatment ALT had on HBeAg loss in the current study was striking. Among patients with pretreatment ALT levels greater than 2 to 5 times the ULN or less, 28% of the lamivudine patients and 32% of the combination-regimen patients experienced HBeAg loss. At the highest ALT level ( 5 times the ULN), approximately one half of the patients receiving lamivudine or the combination experienced HBeAg loss. A slightly lower response rate (40%) was observed in patients treated with interferon alone. Although pretreatment ALT level has also been shown to be an independent predictor of response to interferon, the finding that HBeAg loss occurs earlier in patients with high pretreatment ALT levels has not been described in interferon-treated patients. The overall rate of HBeAg loss and HBeAg seroconversion observed for placebo-treated patients in the current study (10% and 7%, respectively) is consistent with published rates for spontaneous events of this nature. 3,20 When compared with the active treatment groups, there was a more modest increase in HBeAg response in the placebo-treated patients as pretreatment ALT levels increased. At all levels of ALT, response frequency in placebo-treated patients was well below that observed in patients receiving lamivudine, interferon, or the combination regimen. In lamivudine-treated patients, the effect of pretreatment ALT level on HBeAg responses was similar for Asians and Caucasians. HBeAg loss rates were remarkably similar for these 2 ethnic groups when compared across the pretreatment ALT categories. Other investigators have also observed that Asians receiving interferon had HBeAg response rates similar to those in Caucasians when stratified by pretreatment ALT level and they noted that the response rate was poor for Asians with normal ALT levels. 18,21 The observation that the rate of HBeAg loss was higher for the active treatment groups when pretreatment HAI scores were 10 or greater is consistent with other data that indicate the response to interferon is more likely for patients who show increased necroinflammatory activity on liver biopsy, presumably indicative of an active immune response against HBV. 3,15 Interestingly, for patients treated with placebo, higher pretreatment HAI scores did not appear to increase the likelihood of HBeAg loss, suggesting that treatment offered an additional additive benefit, perhaps by inducing a more appropriate immune response to HBV Of interest also was the finding in the relatively small subgroup of Asian patients with normal or minimally elevated pretreatment ALT levels that the rate of HBeAg loss was low overall but was increased in patients with pretreatment HAI scores of 10 or greater who received lamivudine. This finding suggests that the likelihood of having an HBeAg response may be increased in the patient with normal or minimally elevated ALT levels if the pretreatment liver biopsy shows moderate to severe inflammation. These data, however, require confirmation in prospective studies with larger numbers of patients. In contrast, the rate of HBeAg loss was uniformly low across the 3 active treatment groups for patients with both low pretreatment ALT levels and minimal necroinflammatory activity on the liver biopsy and only marginally higher than that observed in the placebo group. This subgroup of patients would generally have a good prognosis without treatment and are unlikely to have a favorable response to lamivudine or interferon. 3,18 It is important to note that the significant effect of pretreatment HBV DNA on the rate of HBeAg loss in the univariate model became less evident after controlling for the contribution of other variables in the multivariate analysis. This may be caused in part by the correlation between the baseline ALT and HBV-DNA level that may

8 HEPATOLOGY, Vol. 36, No. 1, 2002 PERRILLO ET AL. 193 make the latter variable appear less important in the model. These findings differ from a large multicenter trial of alfa-interferon conducted in the United States that described pretreatment HBV-DNA level to be an important predictor of response. 3 Although the reasons for these discrepancies remain unclear, it is possible that this reflects substantially greater inhibition of viral replication provided by lamivudine. The predictors of HBeAg loss identified in this analysis were derived from patients who had received a 52-week course of lamivudine. Consequently, it is not known if these predictors would still be applicable for patients receiving a longer course of therapy. However, higher cumulative rates of HBeAg seroconversion were observed in patients with elevated baseline levels ( 1 times the ULN vs. ALT 2 times the ULN) receiving 3 years of lamivudine treatment. 25 Likewise, this analysis does not address the long-term durability of virologic response or the baseline characteristics associated with a durable response because the design of the 52-week treatment trials only allowed for a limited assessment of posttreatment durability ( 4 months). However, in this limited period of time, most HBeAg responses were sustained with the durability of HBeAg loss similar to that observed for HBeAg seroconversion. 8,10 Conclusion In conclusion, analyses of a large series of patients with chronic hepatitis B treated for 1 year revealed that pretreatment ALT level was a significant predictor of HBeAg loss secondary to lamivudine treatment. As pretreatment ALT levels increased, HBeAg loss became more frequent and the rate of HBeAg loss was markedly higher among patients with pretreatment ALT levels greater than 5 times the ULN. The rates of HBeAg loss appeared similar for Asians and Caucasians treated with lamivudine across all ALT groups. Analyses using both univariate and multivariate techniques suggested that the patients most likely to experience HBeAg loss in response to treatment with lamivudine were patients with active liver disease as evidenced by elevated pretreatment levels of ALT and/or a significant level of necroinflammatory activity on pretreatment liver biopsy. Taken together, the association of baseline ALT level with response and high baseline HAI activity reaffirm the importance of the immune response to HBV in affecting a sustained suppression of viral replication. Acknowledgment: The authors acknowledge Bharat Thakrar, Ph.D., Randy Davis, Dr.P.H., and Judy Barber, MSc, for contributions to statistical analysis, and Susan McMullen, M.A., for contributions to the preparation of the article. References 1. Mast EE, Alter MJ. Epidemiology of viral hepatitis: an overview. Sem Virol 1993;4: Hoofnagle JH, Peters M, Mullen KD, Jones DB, Rustgi V, Di Bisceglie A, Hallahan C, et al. Randomized, controlled trial of recombinant human -interferon in patients with chronic hepatitis B. Gastroenterology 1988; 95: Perrillo RP, Schiff ER, Davis GL, Bodenheimer HC, Lindsay K, Payne J, Dienstag JL. A randomized, controlled trial of interferon alfa-2b alone and after prednisone withdrawal for the treatment of chronic hepatitis B. N Engl J Med 1990;323: Dienstag JL, Perrillo RP, Schiff ER, Bartholomew M, Vicary C, Rubin M. A preliminary trial of lamivudine for chronic hepatitis B infection. N Engl J Med 1995;333: Lai C-L, Ching C-K, Tung AK-M, Li E, Young J, Hill A, Wong BC. Lamivudine is effective in suppressing hepatitis B virus DNA in Chinese hepatitis B surface antigen carriers: a placebo-controlled trial. HEPATOL- OGY 1997;25: Nevens F, Main J, Honkoop P, Tyrrell DL, Barber J, Sullivan MT, Fevery J. Lamivudine therapy for chronic hepatitis B: a six month randomized dose-ranging study. Gastroenterology 1997;113: Lai C-L, Chien R-N, Leung NWY, Chang T-T, Guan R, Tai D-I, Ng KY. A one-year trial of lamivudine for chronic hepatitis B. N Engl J Med 1998;339: Dienstag JL, Schiff ER, Wright TL, Perrillo RP, Hann H-W, Goodman Z, Crowther L. Lamivudine as initial treatment for chronic hepatitis B in the United States. N Engl J Med 1999;341: Schiff E, Karayalcin S, Grimm I, Perrillo RP, Dienstag JL, Husa P, Schalm S. A placebo controlled study of lamivudine and interferon alpha-2b in patients with chronic hepatitis B who previously failed interferon therapy [Abstract]. HEPATOLOGY 1998;28(Suppl):388A. 10. Schalm SW, Heathcote J, Cianciara J, Farrell G, Sherman M, Willems B, Dhillon A. Lamivudine and alpha interferon combination treatment of patients with chronic hepatitis B infection: a randomized trial. Gut 2000; 46: Lok A, Heathcote J, Hoofnagle J. Management of hepatitis B: summary of a workshop. Gastroenterology 2001;120: Niederau C, Heintges T, Lange S, Goldmann G, Niederau CM, Mohr L, Haussinger D. Long-term follow-up of HBeAg-positive patients treated with interferon alfa for chronic hepatitis B. N Engl J Med 1996;334: Lau DT, Everhart J, Kleiner DE, Park Y, Vergalla J, Schmid P, Hoofnagle JH. Long-term follow-up of patients with chronic hepatitis B treated with interferon alfa. Gastroenterology 1997;113: Korenman J, Baker B, Waggoner J, Everhart JE, Di Bisceglie AM, Hoofnagle JH. Long-term remission of chronic hepatitis B after alphainterferon therapy. Ann Intern Med 1991;114: Brook MG, Karayiannis P, Thomas HC. Which patients with chronic hepatitis B virus infection will respond to -interferon therapy? A statistical analysis of predictive factors. HEPATOLOGY 1989;10: Hope AH, Craig PI, Grierson JM, Bilous M, Williams SJ, Farrell GC. Interferon alfa for chronic active hepatitis B. Long-term follow-up of 62 patients: outcomes and predictors of response. Med J Aust 1995;162: Lok ASF, Wu P-C, Lai C-L, Lau JYN, Leung EKY, Wong LSK, Ma OC. A controlled trial of interferon with or without prednisone priming for chronic hepatitis B. Gastroenterology 1992;102: Chien R-N, Liaw Y-F, Atkins M. Pretherapy alanine transaminase level as a determinant for hepatitis B e antigen seroconversion during lamivudine therapy in patients with chronic hepatitis B. HEPATOLOGY 1999;30: Knodell RG, Ishak KG, Black WC, Chen TS, Craig R, Kaplowitz N, Kiernan TW. Formulation and application of a numerical scoring system

9 194 PERRILLO ET AL. HEPATOLOGY, July 2002 for assessing histological activity in asymptomatic chronic active hepatitis. HEPATOLOGY 1981;1: Seeff LB, Koff RS. Evolving concepts of the clinical and serologic consequences of hepatitis B virus infection. Semin Liver Dis 1986;6: Lok ASF, Wu P-C, Lai C-L, Leung EKY. Long-term follow-up in a randomized controlled trial of recombinant alpha-interferon in Chinese patients with chronic hepatitis B infection. Lancet 1988;2: Boni C, Bertoletti A, Penna A, Cavalli A, Pilli M, Urbani S, Scognamiglio P. Lamivudine treatment can restore T cell responsiveness in chronic hepatitis B. J Clin Invest 1998;102: Peters M. Mechanisms of action of interferons. Semin Liver Dis 1989;9: Chen L-K, Mathieu-Mahul D, Bach FH, Dausset J, Bensussan A, Sasportes M. Recombinant interferon alpha can induce rearrangement of T cell antigen receptor alpha genes and maturation to cytotoxicity in T lymphocytes clones in vitro. Proc Natl Acad Sci USA1986;83: Leung NWY, Lai C-L, Chang T-T, Guan R, Lee C-M, Ng K-Y, Lim S-G, et al. Extended lamivudine treatment in patients with chronic hepatitis B enhances hepatitis B e antigen seroconversion: results after 3 years of therapy. HEPATOLOGY 2001;33: