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Famciclovir treatment in transplant recipients with HBV-related liver disease: disappointing results
THE AMERICAN JOURNAL OF GASTROENTEROLOGY © 2001 by Am. Coll. of Gastroenterology Published by Elsevier Science Inc.
Vol. 96, No. 2, 2001 ISSN 0002-9270/01/$20.00 PII S0002-9270(00)02347-9
Famciclovir Treatment in Transplant Recipients With HBV-Related Liver Disease: Disappointing Results Marina Berenguer, M.D., Martin Prieto, M.D., Miguel Rayo´n, M.D., Marco Bustamante, M.D., Domingo Carrasco, M.D., Angel Moya, M.D., Miguel A. Pastor, M.D., Miguel Gobernado, M.D., Jose´ Mir, M.D., and Joaquı´n Berenguer, M.D., Hepatogastroenterology Service, Pathology Service, Microbiology Service, and Liver Transplantation and Surgery Unit, Hospital Universitario La Fe, Valencia, Spain
OBJECTIVE: Long-term administration of hepatitis B immune globulin is effective as prophylaxis for hepatitis B virus (HBV) reinfection but is limited by cost, side effects, availability and a failure rate of 20%. Famciclovir has been shown to be effective in the treatment of hepatitis B in the immunocompetent patient. Fewer data exist in the liver transplant setting, particularly regarding its efficacy in de novo HBV infection. The aims of this pilot study were to determine the effectiveness and safety of long-term administration of famciclovir in recurrent (n ⫽ 3) and de novo (n ⫽ 3) HBV infection after liver transplantation. METHODS: Six patients with postransplant HBV infection (positivity of serum HBsAg and HBV DNA), four of whom were HBeAg positive, were treated with famciclovir (500 mg, 3 times a day) with a minimum follow-up period of 12 months. Biochemical, serological, virological (HBV DNA by hybridization assays and polymerase chain reaction), and histological (including HBV immunostaining) endpoints were evaluated. RESULTS: None of the patients had a complete biochemical response, with a near complete normalization of ALT levels being observed in 3/6 patients. There was a lack of correlation between virological and biochemical responses. None of the patients seroconverted to anti-HBs or anti-HBe. A virological clearance was observed in only two patients, whereas a moderate reduction in HBV DNA levels was present in one. HBV DNA levels were higher than levels during pretreatment in the three remaining patients. Histological improvement was only observed in one patient. CONCLUSION: Famciclovir alone appears of limited efficacy in the treatment of HBV infection after liver transplantation. (Am J Gastroenterol 2001;96:526 –533. © 2001 by Am. Coll. of Gastroenterology)
INTRODUCTION Chronic HBV infection has historically been a relative contraindication to liver transplantation because of increased
graft loss and reduced patient survival due to disease recurrence (1). Although immunoprophylaxis with hepatitis B immunoglobulin (HBIg) has substantially improved the survival of HBsAg-positive patients undergoing liver transplantation (2), treatment is expensive, supplies of HBIg are limited, and unrecognized side effects from long-term therapy may exist. Moreover, HBIg monotherapy does not prevent universally recurrent infection. Approximately 20% of the patients treated with HBIg have a “breakthrough” while on HBIg despite good anti-HBs trough levels and develop recurrent disease (3). Moreover, HBIg has little benefit in treatment of posttransplantation recurrence. Drugs that are currently being used for the treatment of recurrent HBV disease or de novo HBV infection include interferon alpha (4) and the new nucleoside analogs, lamivudine and famciclovir. Experience with interferon is limited, and concerns exist as to the potential of precipitating allograft rejection (4). Although extensive experience is available in both the transplant and nontransplant setting with lamivudine (5– 8), it is more limited with famciclovir (9 –14). Both drugs are potent anti-HBV agents that are admininistered orally and are well tolerated. Lamivudine is effective at suppressing HBV replication in patients with chronic HBV, those with hepatic decompensation awaiting transplantation (5), and those with posttransplantation recurrence (6 – 8). However, lamivudine monotherapy is associated with development of genetic resistance in 10 –25% and in therapeutic failure in 20% (5, 6, 8). Famciclovir is a guanosine analog that has also been used for the treatment of HBV infection (9). The suppressive effect of famciclovir against HBV replication appears to be less than that of lamivudine, and as with lamivudine, this effect is transient in the majority. Experience with famciclovir in the transplant setting is nonetheless more limited, and most of the data come from case reports with few patients included in each study (10, 12–14). We report the results of famciclovir in the treatment of HBV infection after liver transplantation in six patients with either HBV recurrence (n ⫽ 3) or de novo HBV infection
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(n ⫽ 3) with a minimum follow-up period of 12 months. Detailed information is given regarding virological, serological, biochemical, clinical, and histological parameters.
MATERIALS AND METHODS Patients Six patients with HBV infection after liver transplantation were treated with famciclovir on a compassionate basis. HBV infection was defined as positivity of serum surface HBV antigen (HBsAg) and detectability of HBV DNA in serum by hybridization assays. Three patients had de novo HBV infection posttransplantation, and the remaining three patients had HBV recurrence despite the use of HBIg. No patient had clinical, biochemical, or histological signs of rejection when treatment with famciclovir was started. Patients were followed for a minimum period of 12 months after starting treatment with famciclovir. Endpoints The efficacy of famciclovir was evaluated in terms of the following criteria: 1) viral suppression, both quantitatively (reduction in HBV DNA levels) and qualitatively (viral clearance or undetectability of HBV DNA in serum by polymerase chain reaction—PCR); 2) biochemical response (normalization of serum ALT values); 3) histological improvement; and 4) clinical improvement. Each patient situation at the end of follow-up was compared with the baseline situation. A patient was classified as a responder if HBV DNA in serum became undetectable by the PCR method. Immunosuppression The same induction immunosuppression protocol was used for all transplant recipients, consisting of triple therapy with cyclosporine, azathioprine, and prednisone. When famciclovir was started, all patients but one were on monotherapy with cyclosporine. In one patient (patient 5), azathioprine was continued during 3 additional months. Prednisone was tapered in all cases several months before starting famciclovir treatment to decrease viral replication and thus diminish the risk of treatment failure. Treatment Famciclovir was given at a dose of 500 mg three times daily. In one patient (patient 2), a reduced dosage (250 mg three times a day) was administered during the first 3 months of therapy because of renal impairment. Samples Blood samples were obtained before initiation of therapy and monthy thereafter. Biochemical, hematological, serological (HBsAg, HBeAg, anti-HBe, anti-HBs), and virological (HBV DNA levels) parameters were measured at every timepoint. HBV DNA levels were measured by viral DNA hybridization assays (Digene Diagnostics, Gaithersburg, MD). The limit of detection of the assay is 10 pg/ml. PCR
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was only performed in case of negativity of the hybridization assay. Histology Liver biopsies were performed at baseline and at the end of the study period in all patients. All specimens were assessed by the same pathologist (M.R.) and assigned an histology activity index. Immunoperoxidase staining for HBsAg and HBcAg was performed in all samples. Staining for HBV antigens was scored as follows: negative, none or occasional staining; 1⫹, 1–10% of cells; 2⫹, 10 – 40% of cells; 3⫹, 40 – 60% of cells; and 4⫹, ⬎60% of cells.
RESULTS Baseline Features of the Study Group Six liver transplant recipients with HBV infection after transplantation were included. Liver transplantation had been performed in all cases between November 1991 and December 1993. End-stage liver disease was the indication for liver transplantation in all cases. In three of them, HBV infection occurred de novo, presumably acquired from the donor. The indications for liver transplantation in these cases were HCV-related cirrhosis in one, primary biliary cirrhosis in one, and alcoholic cirrhosis in one. The remaining three patients had recurrent HBV infection at 1, 3, and 10 months after transplantation, despite the use of HBIg. Two patients were infected with the HBV e-minus mutant (patients 2 and 3). Two patients were infected with HCV pretransplantation (patients 3 and 4). Recurrence of HCV infection defined by virological means was evidenced in the two patients who were infected with HCV pretransplantation, with detection of HCV RNA in serum as soon as one month post-transplantation. See Table 1. Effects of Famciclovir on HBV DNA Levels The individual changes in DNA levels during follow-up are described in Figures 1 to 6, and in Table 2. At baseline, HBV DNA levels ranged from 116 pg/ml to 9705 pg/ml with a median of 1312 pg/ml. Viral clearance occurred in only two patients (patients 1 and 2). A slight reduction in HBV DNA levels was observed in one additional patient (patient 4). The remaining three patients (patients 3, 5, and 6) ended the study with higher DNA levels compared with baseline values, although an initial decline was observed early after the onset of therapy. The drop in HBV DNA occurred early after initiation of therapy and was more evident in the two responder-group patients (patients 1 and 2). After 2 yr of therapy, HBV DNA has become detectable in serum (by PCR) in one of the two initial virological responder-group patients (patient 2; data not shown). Effects of Famciclovir on HBV Serological Markers At baseline, all patients were seropositive for HBsAg, and four patients were also seropositive for HBeAg. During therapy, none of the patients seroconverted to anti-HBs or anti-HBe (in the four HBeAg-positive patients). See Table 2.
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Table 1. Baseline Features of the Six Liver Transplant Recipients Treated With Famciclovir
Patient No.
Age/Sex
Transplant Date
1
29/M
10/29/91
2 3
40/M 48/M
01/25/93 12/06/93
4 5 6
55/F 53/F 40/M
02/10/92 10/02/91 02/01/93
Indication Cirrhosis HBV ⫹ delta Cirrhosis HBV Cirrhosis HBV ⫹HCV Cirrhosis HCV PBC Alcoholic cirrhosis
Infection Type
Delay Between Transplantation and Infection* (Months)
Delay Between Infection* And Treatment† (Months)
Recurrent
3
40
Recurrent Recurrent
10 1
17 25
De novo De novo De novo
22 47 3
18 3 24
M ⫽ male, F ⫽ female, PBC ⫽ primary biliary cirrhosis * Infection was defined by the positivity of HBsAg and HBV DNA in serum. † Treatment was only initiated once biochemical and histological hepatitis were evidenced.
Effects of Famciclovir on ALT Levels Individual changes in ALT levels are shown in Figures 1 to 6. Also see Table 2. At baseline, median ALT levels were 155 U/l (range, 64 –315). At the last available follow-up, three patients had a near-complete normalization of ALT values (patients 2, 3, and 6), whereas no significant changes were observed in the remaining three patients. There was a lack of correlation between virological and biochemical responses. One of two virological respondergroup patients had abnormal ALT values at the end of follow-up despite negativization of HBV DNA in serum by PCR (patient 2). Effects of Famciclovir on Histological and Immunohistochemical Findings Baseline biopsy was compatible with chronic hepatitis in all patients except one (patient 5), who developed acute HBV hepatitis 3 months before starting therapy with famciclovir.
Among patients with chronic hepatitis, the Knodell Index score ranged between 6 and 14 (Table 3). Histological improvement was only observed in one of the patients treated, with a decrease in the Knodell Index from 6 to 3 (patient 6). That patient was a nonvirological responder with higher HBV DNA levels at the end of the study compared with baseline. In contrast, none of the three patients with a decrease in HBV DNA levels during therapy showed an improvement in histological parameters. A decrease in HBV antigens (HBsAg and HBcAg) staining was observed in one of the two responder-group patients (patient 2) in parallel with the decrease in serum HBV DNA levels. The remaining patients had minimum changes in staining. Effects of Famciclovir on Clinical Situation The clinical condition of two patients (patient 2 and 4), including one of the virological responders (patient 2),
Figure 1. Effects of famciclovir on HBV DNA and ALT levels during follow-up. Evolution of patient 2 with recurrent HBV infection.
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Figure 2. Effects of famciclovir on HBV DNA and ALT levels during follow-up. Evolution of patient 1 with recurrent HBV infection.
continued to deteriorate despite famciclovir therapy, with the onset of ascites in both and spontaneous bacterial peritonitis in one. The remaining patients maintained a stable clinical condition throughout the study period. No significant adverse effects were noted during the follow-up.
DISCUSSION Chronic viral hepatitis is a common cause of end-stage liver disease and accounts for approximately 40% of diagnoses in patients undergoing liver transplantation (15). Unfortunately, unless specific precautions are taken, viral recurrence is universal and can result in significant morbidity and
mortality (1, 16, 17). Until recently, hepatitis B virus (HBV) infection was considered a relative contraindication to transplantation because of high rates of recurrences and, when infection recurred, reduced survival (1). Furthermore, in patients with active replication before transplantation (HBeAg and HBV DNA positive), HBV infection was considered an absolute contraindication to liver transplantation in many centers because survival was reduced even further compared with those who were HBeAg negative (17). To improve this outcome, three main approaches may be implemented in the patient with HBV infection undergoing liver transplantation. The first one, prevention of progressive liver disease before transplantation so that liver transplantation may be avoided, should be considered the major
Figure 3. Effects of famciclovir on HBV DNA and ALT levels during follow-up. Evolution of patient 3 with recurrent HBV infection.
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Figure 4. Effects of famciclovir on HBV DNA and ALT levels during follow-up. Evolution of patient 4 with de novo HBV infection.
goal. Unfortunately, no drug has yet proved in a controlled trial to stop clinical progression of decompensated liver disease nor reduce need for transplantation. Exciting preliminary results are being reported with lamivudine (5). The second strategy, prevention of recurrent infection after transplantation by administration of agents before, at the time of, and subsequent to transplantation, is currently considered the “standard of care,” with the use of prophylactic HBIg and/or nucleoside analogs. Finally, a third approach is the treatment of disease when it occurs. This approach is the only alternative in case of de novo HBV infection, as occurred in three of the patients included in this study. Most of the experience in preventing recurrent HBV infection has been with polyclonal hepatitis B immunoglob-
ulin (HBIg) (2, 3). The presumed mode of action of this HBIg is to neutralize circulating virus, thereby preventing infection of the transplanted liver. However, despite adequate anti-HBs titers, approximately 20% of patients fail HBIg and become HBsAg positive, and an additional percentage develops liver disease while remaining HBsAg negative (3). Other major limitations of prophylactic HBIg are the high cost and limited availability. Finally, HBIg has no proven efficacy once recurrent disease develops. For many years, interferon was considered the only therapeutic alternative in case of HBV-related liver disease after transplantation (4). Interferon, however, should be used with caution in the setting of transplantation, as allograft rejection is a potential adverse effect of this drug.
Figure 5. Effects of famciclovir on HBV DNA and ALT levels during follow-up. Evolution of patient 5 with de novo HBV infection.
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Figure 6. Effects of famciclovir on HBV DNA and ALT levels during follow-up. Evolution of patient 6 with de novo HBV infection.
Significant gains have been made in recent years with the availability of new oral agents for the treatment of HBVrelated liver disease. Most of the experience in both the transplant and nontransplant setting is with two oral nucleoside analogs, lamivudine and famciclovir. Both drugs have potent anti-HBV activity, and both are administered orally. Famciclovir, the prodrug for penciclovir, is a guanosine analog that inhibits HBV DNA and viral protein synthesis (9). In contrast to other drugs within the family of guanosine analogues, such as acyclovir and ganciclovir, famciclovir has good bioavailability after oral administration (about 80%). In a recent phase IIB multicenter dose-finding study, 333 patients with chronic hepatitis B, “historically considered difficult to treat (on baseline, low ALT levels and high HBV DNA levels),” 41% of whom had previously received interferon therapy, were randomized to receive 16-wk treatment with famciclovir (500 mg, 250 mg, 125 mg, or placebo, three times daily). All doses resulted in a rapid, dose-dependent reduction in both HBV DNA and transaminase levels, with 500-mg famciclovir being the superior dose. Seroconversion from HBeAg to anti-HBe occurred in 14% of the 500-mg famciclovir–treated patients versus only 3% in the placebo group (18). Data on famciclovir for the treatment of hepatitis B after liver transplantation are, however, scarce and come mainly
from case reports, with few patients included in each study (10, 12–14). Results from these studies suggest that famciclovir, given at doses of 500 mg three times daily, adjusted for renal function and given for periods of time ranging from 4 wk to 50 months, is well tolerated and suppresses HBV replication. However, although a significant reduction in HBV DNA levels (⬃80%), usually seen within the first 2– 4 wk of treatment, occurs in half of the patients, HBV DNA clearance by hibridization assays is a rare event (⬃25– 45%). Furthermore, as with lamivudine, genotypic resistence to famciclovir has also been reported (19, 20), and its clinical significance is being determined. We have reported here our experience with famciclovir in the treatment of hepatitis B after liver transplantation. Even though the number of patients included in this pilot study is small, patients are very well characterized, with at least 12 months of follow-up, and histological assessment before and at the end of therapy is available in all patients. Our study supports the results that have previously been reported, that is, a rapid drop in HBV DNA levels, seen within 3 months of starting therapy in 50% of the patients treated, with 30% of HBV DNA clearance by hybridization assays and PCR. However, despite HBV DNA clearance, histological, clinical and/or biochemical improvement were absent in the vast majority of patients treated, and immunostaining showed
Table 2. Long-Term Follow-Up Results After Famciclovir Therapy HBeAg
HBV DNA (pg/mL)
Serum ALT (U/L)
Patient No.
Pre
Post
Pre
Post†
% Difference
Pre
Post†
% Difference
1 2 3 4 5 6
⫹ ⫺ ⫺ ⫹ ⫹ ⫹
⫹ ⫺ ⫺ ⫹ ⫹ ⫹
116 162 2863 39.5 2202 2490
⬍10* ⬍10* 5274 30.3 9705 3113
100 100 0 23 0 0
315 146 85 157 165 64
272 51 48 109 197 58
24 65 43 30 0 11
* PCR negative. † Values refer to the last available follow-up.
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Table 3. Histologic Evolution After Famciclovir Treatment
Patient No. 1 2 3 4 5 6
Activity Grade* Pre Post
Fibrosis Stage Pre Post
Cytoplasmic HBsAg Staining Pre Post
10 13 7 14 NA 5
3 3 0 3 NA 1
⫹⫹ ⫹⫹ ⫹⫹⫹ ⫹⫹⫹⫹ ⫹⫹ ⫹⫹
10 9 5 14 1 3
4 4 1 4 3 0
⫹⫹⫹ Neg. ⫹⫹⫹⫹ ⫹⫹⫹ ⫹⫹⫹ ⫹⫹
Nuclear HBcAg Staining Pre Post ⫹⫹⫹ ⫹ ⫹⫹ ⫹⫹ ⫹⫹⫹⫹ ⫹⫹⫹
⫹ Neg. ⫹⫹ ⫹⫹ ⫹⫹⫹⫹ ⫹⫹⫹⫹
Cytoplasmic HBcAg Staining† Pre Post 90% Neg. 30% Neg. 90% Neg.
Neg. Neg. 30% Neg. 90% Neg.
NA ⫽ Not available. Neg. ⫽ negative. * Activity grade based on Knodell’s Activity Index. † Expressed as percentage of cells with cytoplasmic HBcAg staining.
only minor changes with treatment. A lack of correlation was observed both between virological and biochemical response and between virological and histological response, suggesting that a complete response was never achieved. There are several reasons that may explain these disappointing results: 1) a third of our patients were infected with the e-minus mutant, a strain historically associated with a poorer response to antivirals; 2) the median time from diagnosis of HBV infection to therapy was longer than that previously reported, with an average of 21 months (range: 3– 40); 3) half of the patients had de novo HBV infection, a situation that could potentially affect the response to therapy (in fact, none of the patients with de novo HBV infection cleared HBV DNA from serum); and 4) coinfection with other viruses may alter the response to therapy, and a third of the patients were coinfected with HCV. In these cases, recurrence of HCV infection with subsequent graft injury is the norm (16), adding further difficulty to the evaluation of both the biochemical and histological response. An interesting finding is the increase in HBV DNA levels in three of the patients after 7, 10, and 11 months of initiating famciclovir, respectively. Development of resistance due to the appearance of mutant strains is an important issue regarding the use of any antiviral therapy (21). In most studies performed to date, mutations tend to occur late in therapy, probably because of the continuous and prolonged selection pressure on minute amounts of virus present in serum, not detectable by conventional hybridization assays but by more sensitive assays such as PCR. Although genotypic analysis was not performed in this study, the rise in HBV DNA levels late in the course of therapy, after an initial response, suggests that resistance to famciclovir may have developed. In conclusion, results of this pilot study were disappointing. Larger controlled studies are needed to draw valid conclusions regarding the efficacy of famciclovir in the treatment of HBV-related liver disease after liver transplantation. Finally, combination therapy with famciclovir and an additional antiviral agent may be an alternative, the rationale behind that being the same as has been proposed for the treatment of HIV infection: that is, attempt to maximize antiviral activity by using drugs that act synergistically, and attempt to minimize genetic viral resistance by combining
drugs for which viral mutations conferring resistance do not overlap.
Reprint requests and correspondence: Marina Berenguer, Servicio de Hepatogastroenterologı´a, Hospital Universitario La FE, Avda Campanar 21, Valencia, 46009, Spain. Received Jan. 26, 2000; accepted Aug. 25, 2000.
REFERENCES 1. Todo S, Demetris A, Van Thiel D, et al. Orthotopic liver transplantation for patients with hepatitis B virus-related liver disease. Hepatology 1991;13:619 –26. 2. Samuel D, Bismuth A, Mathieu D, et al. Passive immunoprophylaxis after liver transplantation in HBsAg-positive patients. Lancet 1991;337:813–5. 3. Terrault N, Zhou S, Combs C, et al. Prophylaxis in liver transplant recipients using a fixed dosing schedule of hepatitis B immunoglobulin. Hepatology 1996;24:1327–33. 4. Terrault N, Holland CC, Ferrell L, et al. Interferon alfa for recurrent hepatitis B infection after liver transplantation. Liver Transplant Surg 1996;2:132– 8. 5. Bain VG, Kneteman NM, Ma MM, et al. Efficacy of lamivudine in chronic hepatitis B patients with active viral replication and decompensated cirrhosis undergoing liver transplantation. Transplantation 1996;62:1456 – 62. 6. Grellier L, Mutimer D, Ahmed M, et al. Lamivudine prophylaxis against reinfection in liver transplantation for hepatitis B cirrhosis. Lancet 1996;348:1212–5. 7. Nery JR, Weppler D, Rodriguez M, et al. Multicenter study of lamivudine therapy for hepatitis B after liver transplantation. Hepatology 1999;29:1581–1586. 9. Cirelli R, Herne K, McCrary M, et al. Famciclovir: review of clinical efficacy and safety. Antiviral Res 1996;29:141–51. 10. Haller GW, Bechstein WO, Neuhaus R, et al. Famciclovir therapy for recurrent hepatitis B virus infection after liver transplantation. Transpl Int 1996;9(suppl):S210 –2. 11. Singh N, Gayowski T, Wannstedt CF, et al. Pretransplant famciclovir as prophilaxis for hepatitis B virus recurrence after liver transplantation. Transplantation 1997;63:1415–9. 12. Rabinovitz M, Dodson F, Rakela J. Famciclovir for recurrent hepatitis B (HBV) infection after liver transplantation (OLTX). Hepatology 1996;24:282A (abstract). 13. Han SH, Kinkhabwala M, Martin P, et al. Resolution of recurrent hepatitis B in two liver transplant recipients treated with famciclovir. Am J Gastroenterol 1998;93:2245–7. 14. Kruger M, Tillmann HL, Trautwein C, et al. Famciclovir
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treatment of hepatitis B virus recurrence after liver transplantation: a pilot study. Liver Transpl Surg 1996;2:253– 62. 15. Prieto M, Berenguer M, Rimola A, et al. Liver transplantation in hepatitis C. A Spanish multicentre experience. Eur J Gastroenterol Hepatol 1998;10:771– 6. 16. Prieto M, Berenguer M, Rayo´n M, et al. High incidence of allograft cirrhosis in hepatitis C virus genotype 1b infection following transplantation: relationship with rejection episodes. Hepatology 1999;29:250 – 6. 17. Samuel D, Muller R, Alexander G, et al. Liver transplantation in European patients with the hepatitis B surface antigen. N Engl J Med 1993;329:1842–7.
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18. Trepo C, Jezek P, Atkinson GF, et al. Famciclovir in chronic hepatitis B: results of a dose-finding study. J Hepatol 2000; 32:1011– 8. 19. Locarnini S, Aye TT, Shaw T, et al. The emergence of famciclovir resistant mutations in the hepatitis B virus polymerase during therapy in patients following liver transplantation. Hepatology 1997;26:368A (abstract). 20. Aye TT, Bartholomeusz A, Shaw T, et al. Hepatitis B virus polymerase mutations during antiviral therapy in a patient following liver transplantation. J Hepatol 1997;26:1148 –53. 21. Locarnini S. Hepatitis B virus surface antigen and polymerase gene variants: potential virological and clinical significance. Hepatology 1998;27:294 –7.
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Famciclovir Treatment in Transplant Recipients With HBV-Related Liver Disease: Disappointing Results Marina Berenguer, M.D., Martin Prieto, M.D., Miguel Rayo´n, M.D., Marco Bustamante, M.D., Domingo Carrasco, M.D., Angel Moya, M.D., Miguel A. Pastor, M.D., Miguel Gobernado, M.D., Jose´ Mir, M.D., and Joaquı´n Berenguer, M.D., Hepatogastroenterology Service, Pathology Service, Microbiology Service, and Liver Transplantation and Surgery Unit, Hospital Universitario La Fe, Valencia, Spain
OBJECTIVE: Long-term administration of hepatitis B immune globulin is effective as prophylaxis for hepatitis B virus (HBV) reinfection but is limited by cost, side effects, availability and a failure rate of 20%. Famciclovir has been shown to be effective in the treatment of hepatitis B in the immunocompetent patient. Fewer data exist in the liver transplant setting, particularly regarding its efficacy in de novo HBV infection. The aims of this pilot study were to determine the effectiveness and safety of long-term administration of famciclovir in recurrent (n ⫽ 3) and de novo (n ⫽ 3) HBV infection after liver transplantation. METHODS: Six patients with postransplant HBV infection (positivity of serum HBsAg and HBV DNA), four of whom were HBeAg positive, were treated with famciclovir (500 mg, 3 times a day) with a minimum follow-up period of 12 months. Biochemical, serological, virological (HBV DNA by hybridization assays and polymerase chain reaction), and histological (including HBV immunostaining) endpoints were evaluated. RESULTS: None of the patients had a complete biochemical response, with a near complete normalization of ALT levels being observed in 3/6 patients. There was a lack of correlation between virological and biochemical responses. None of the patients seroconverted to anti-HBs or anti-HBe. A virological clearance was observed in only two patients, whereas a moderate reduction in HBV DNA levels was present in one. HBV DNA levels were higher than levels during pretreatment in the three remaining patients. Histological improvement was only observed in one patient. CONCLUSION: Famciclovir alone appears of limited efficacy in the treatment of HBV infection after liver transplantation. (Am J Gastroenterol 2001;96:526 –533. © 2001 by Am. Coll. of Gastroenterology)
INTRODUCTION Chronic HBV infection has historically been a relative contraindication to liver transplantation because of increased
graft loss and reduced patient survival due to disease recurrence (1). Although immunoprophylaxis with hepatitis B immunoglobulin (HBIg) has substantially improved the survival of HBsAg-positive patients undergoing liver transplantation (2), treatment is expensive, supplies of HBIg are limited, and unrecognized side effects from long-term therapy may exist. Moreover, HBIg monotherapy does not prevent universally recurrent infection. Approximately 20% of the patients treated with HBIg have a “breakthrough” while on HBIg despite good anti-HBs trough levels and develop recurrent disease (3). Moreover, HBIg has little benefit in treatment of posttransplantation recurrence. Drugs that are currently being used for the treatment of recurrent HBV disease or de novo HBV infection include interferon alpha (4) and the new nucleoside analogs, lamivudine and famciclovir. Experience with interferon is limited, and concerns exist as to the potential of precipitating allograft rejection (4). Although extensive experience is available in both the transplant and nontransplant setting with lamivudine (5– 8), it is more limited with famciclovir (9 –14). Both drugs are potent anti-HBV agents that are admininistered orally and are well tolerated. Lamivudine is effective at suppressing HBV replication in patients with chronic HBV, those with hepatic decompensation awaiting transplantation (5), and those with posttransplantation recurrence (6 – 8). However, lamivudine monotherapy is associated with development of genetic resistance in 10 –25% and in therapeutic failure in 20% (5, 6, 8). Famciclovir is a guanosine analog that has also been used for the treatment of HBV infection (9). The suppressive effect of famciclovir against HBV replication appears to be less than that of lamivudine, and as with lamivudine, this effect is transient in the majority. Experience with famciclovir in the transplant setting is nonetheless more limited, and most of the data come from case reports with few patients included in each study (10, 12–14). We report the results of famciclovir in the treatment of HBV infection after liver transplantation in six patients with either HBV recurrence (n ⫽ 3) or de novo HBV infection
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(n ⫽ 3) with a minimum follow-up period of 12 months. Detailed information is given regarding virological, serological, biochemical, clinical, and histological parameters.
MATERIALS AND METHODS Patients Six patients with HBV infection after liver transplantation were treated with famciclovir on a compassionate basis. HBV infection was defined as positivity of serum surface HBV antigen (HBsAg) and detectability of HBV DNA in serum by hybridization assays. Three patients had de novo HBV infection posttransplantation, and the remaining three patients had HBV recurrence despite the use of HBIg. No patient had clinical, biochemical, or histological signs of rejection when treatment with famciclovir was started. Patients were followed for a minimum period of 12 months after starting treatment with famciclovir. Endpoints The efficacy of famciclovir was evaluated in terms of the following criteria: 1) viral suppression, both quantitatively (reduction in HBV DNA levels) and qualitatively (viral clearance or undetectability of HBV DNA in serum by polymerase chain reaction—PCR); 2) biochemical response (normalization of serum ALT values); 3) histological improvement; and 4) clinical improvement. Each patient situation at the end of follow-up was compared with the baseline situation. A patient was classified as a responder if HBV DNA in serum became undetectable by the PCR method. Immunosuppression The same induction immunosuppression protocol was used for all transplant recipients, consisting of triple therapy with cyclosporine, azathioprine, and prednisone. When famciclovir was started, all patients but one were on monotherapy with cyclosporine. In one patient (patient 5), azathioprine was continued during 3 additional months. Prednisone was tapered in all cases several months before starting famciclovir treatment to decrease viral replication and thus diminish the risk of treatment failure. Treatment Famciclovir was given at a dose of 500 mg three times daily. In one patient (patient 2), a reduced dosage (250 mg three times a day) was administered during the first 3 months of therapy because of renal impairment. Samples Blood samples were obtained before initiation of therapy and monthy thereafter. Biochemical, hematological, serological (HBsAg, HBeAg, anti-HBe, anti-HBs), and virological (HBV DNA levels) parameters were measured at every timepoint. HBV DNA levels were measured by viral DNA hybridization assays (Digene Diagnostics, Gaithersburg, MD). The limit of detection of the assay is 10 pg/ml. PCR
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was only performed in case of negativity of the hybridization assay. Histology Liver biopsies were performed at baseline and at the end of the study period in all patients. All specimens were assessed by the same pathologist (M.R.) and assigned an histology activity index. Immunoperoxidase staining for HBsAg and HBcAg was performed in all samples. Staining for HBV antigens was scored as follows: negative, none or occasional staining; 1⫹, 1–10% of cells; 2⫹, 10 – 40% of cells; 3⫹, 40 – 60% of cells; and 4⫹, ⬎60% of cells.
RESULTS Baseline Features of the Study Group Six liver transplant recipients with HBV infection after transplantation were included. Liver transplantation had been performed in all cases between November 1991 and December 1993. End-stage liver disease was the indication for liver transplantation in all cases. In three of them, HBV infection occurred de novo, presumably acquired from the donor. The indications for liver transplantation in these cases were HCV-related cirrhosis in one, primary biliary cirrhosis in one, and alcoholic cirrhosis in one. The remaining three patients had recurrent HBV infection at 1, 3, and 10 months after transplantation, despite the use of HBIg. Two patients were infected with the HBV e-minus mutant (patients 2 and 3). Two patients were infected with HCV pretransplantation (patients 3 and 4). Recurrence of HCV infection defined by virological means was evidenced in the two patients who were infected with HCV pretransplantation, with detection of HCV RNA in serum as soon as one month post-transplantation. See Table 1. Effects of Famciclovir on HBV DNA Levels The individual changes in DNA levels during follow-up are described in Figures 1 to 6, and in Table 2. At baseline, HBV DNA levels ranged from 116 pg/ml to 9705 pg/ml with a median of 1312 pg/ml. Viral clearance occurred in only two patients (patients 1 and 2). A slight reduction in HBV DNA levels was observed in one additional patient (patient 4). The remaining three patients (patients 3, 5, and 6) ended the study with higher DNA levels compared with baseline values, although an initial decline was observed early after the onset of therapy. The drop in HBV DNA occurred early after initiation of therapy and was more evident in the two responder-group patients (patients 1 and 2). After 2 yr of therapy, HBV DNA has become detectable in serum (by PCR) in one of the two initial virological responder-group patients (patient 2; data not shown). Effects of Famciclovir on HBV Serological Markers At baseline, all patients were seropositive for HBsAg, and four patients were also seropositive for HBeAg. During therapy, none of the patients seroconverted to anti-HBs or anti-HBe (in the four HBeAg-positive patients). See Table 2.
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Table 1. Baseline Features of the Six Liver Transplant Recipients Treated With Famciclovir
Patient No.
Age/Sex
Transplant Date
1
29/M
10/29/91
2 3
40/M 48/M
01/25/93 12/06/93
4 5 6
55/F 53/F 40/M
02/10/92 10/02/91 02/01/93
Indication Cirrhosis HBV ⫹ delta Cirrhosis HBV Cirrhosis HBV ⫹HCV Cirrhosis HCV PBC Alcoholic cirrhosis
Infection Type
Delay Between Transplantation and Infection* (Months)
Delay Between Infection* And Treatment† (Months)
Recurrent
3
40
Recurrent Recurrent
10 1
17 25
De novo De novo De novo
22 47 3
18 3 24
M ⫽ male, F ⫽ female, PBC ⫽ primary biliary cirrhosis * Infection was defined by the positivity of HBsAg and HBV DNA in serum. † Treatment was only initiated once biochemical and histological hepatitis were evidenced.
Effects of Famciclovir on ALT Levels Individual changes in ALT levels are shown in Figures 1 to 6. Also see Table 2. At baseline, median ALT levels were 155 U/l (range, 64 –315). At the last available follow-up, three patients had a near-complete normalization of ALT values (patients 2, 3, and 6), whereas no significant changes were observed in the remaining three patients. There was a lack of correlation between virological and biochemical responses. One of two virological respondergroup patients had abnormal ALT values at the end of follow-up despite negativization of HBV DNA in serum by PCR (patient 2). Effects of Famciclovir on Histological and Immunohistochemical Findings Baseline biopsy was compatible with chronic hepatitis in all patients except one (patient 5), who developed acute HBV hepatitis 3 months before starting therapy with famciclovir.
Among patients with chronic hepatitis, the Knodell Index score ranged between 6 and 14 (Table 3). Histological improvement was only observed in one of the patients treated, with a decrease in the Knodell Index from 6 to 3 (patient 6). That patient was a nonvirological responder with higher HBV DNA levels at the end of the study compared with baseline. In contrast, none of the three patients with a decrease in HBV DNA levels during therapy showed an improvement in histological parameters. A decrease in HBV antigens (HBsAg and HBcAg) staining was observed in one of the two responder-group patients (patient 2) in parallel with the decrease in serum HBV DNA levels. The remaining patients had minimum changes in staining. Effects of Famciclovir on Clinical Situation The clinical condition of two patients (patient 2 and 4), including one of the virological responders (patient 2),
Figure 1. Effects of famciclovir on HBV DNA and ALT levels during follow-up. Evolution of patient 2 with recurrent HBV infection.
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Figure 2. Effects of famciclovir on HBV DNA and ALT levels during follow-up. Evolution of patient 1 with recurrent HBV infection.
continued to deteriorate despite famciclovir therapy, with the onset of ascites in both and spontaneous bacterial peritonitis in one. The remaining patients maintained a stable clinical condition throughout the study period. No significant adverse effects were noted during the follow-up.
DISCUSSION Chronic viral hepatitis is a common cause of end-stage liver disease and accounts for approximately 40% of diagnoses in patients undergoing liver transplantation (15). Unfortunately, unless specific precautions are taken, viral recurrence is universal and can result in significant morbidity and
mortality (1, 16, 17). Until recently, hepatitis B virus (HBV) infection was considered a relative contraindication to transplantation because of high rates of recurrences and, when infection recurred, reduced survival (1). Furthermore, in patients with active replication before transplantation (HBeAg and HBV DNA positive), HBV infection was considered an absolute contraindication to liver transplantation in many centers because survival was reduced even further compared with those who were HBeAg negative (17). To improve this outcome, three main approaches may be implemented in the patient with HBV infection undergoing liver transplantation. The first one, prevention of progressive liver disease before transplantation so that liver transplantation may be avoided, should be considered the major
Figure 3. Effects of famciclovir on HBV DNA and ALT levels during follow-up. Evolution of patient 3 with recurrent HBV infection.
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Figure 4. Effects of famciclovir on HBV DNA and ALT levels during follow-up. Evolution of patient 4 with de novo HBV infection.
goal. Unfortunately, no drug has yet proved in a controlled trial to stop clinical progression of decompensated liver disease nor reduce need for transplantation. Exciting preliminary results are being reported with lamivudine (5). The second strategy, prevention of recurrent infection after transplantation by administration of agents before, at the time of, and subsequent to transplantation, is currently considered the “standard of care,” with the use of prophylactic HBIg and/or nucleoside analogs. Finally, a third approach is the treatment of disease when it occurs. This approach is the only alternative in case of de novo HBV infection, as occurred in three of the patients included in this study. Most of the experience in preventing recurrent HBV infection has been with polyclonal hepatitis B immunoglob-
ulin (HBIg) (2, 3). The presumed mode of action of this HBIg is to neutralize circulating virus, thereby preventing infection of the transplanted liver. However, despite adequate anti-HBs titers, approximately 20% of patients fail HBIg and become HBsAg positive, and an additional percentage develops liver disease while remaining HBsAg negative (3). Other major limitations of prophylactic HBIg are the high cost and limited availability. Finally, HBIg has no proven efficacy once recurrent disease develops. For many years, interferon was considered the only therapeutic alternative in case of HBV-related liver disease after transplantation (4). Interferon, however, should be used with caution in the setting of transplantation, as allograft rejection is a potential adverse effect of this drug.
Figure 5. Effects of famciclovir on HBV DNA and ALT levels during follow-up. Evolution of patient 5 with de novo HBV infection.
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Figure 6. Effects of famciclovir on HBV DNA and ALT levels during follow-up. Evolution of patient 6 with de novo HBV infection.
Significant gains have been made in recent years with the availability of new oral agents for the treatment of HBVrelated liver disease. Most of the experience in both the transplant and nontransplant setting is with two oral nucleoside analogs, lamivudine and famciclovir. Both drugs have potent anti-HBV activity, and both are administered orally. Famciclovir, the prodrug for penciclovir, is a guanosine analog that inhibits HBV DNA and viral protein synthesis (9). In contrast to other drugs within the family of guanosine analogues, such as acyclovir and ganciclovir, famciclovir has good bioavailability after oral administration (about 80%). In a recent phase IIB multicenter dose-finding study, 333 patients with chronic hepatitis B, “historically considered difficult to treat (on baseline, low ALT levels and high HBV DNA levels),” 41% of whom had previously received interferon therapy, were randomized to receive 16-wk treatment with famciclovir (500 mg, 250 mg, 125 mg, or placebo, three times daily). All doses resulted in a rapid, dose-dependent reduction in both HBV DNA and transaminase levels, with 500-mg famciclovir being the superior dose. Seroconversion from HBeAg to anti-HBe occurred in 14% of the 500-mg famciclovir–treated patients versus only 3% in the placebo group (18). Data on famciclovir for the treatment of hepatitis B after liver transplantation are, however, scarce and come mainly
from case reports, with few patients included in each study (10, 12–14). Results from these studies suggest that famciclovir, given at doses of 500 mg three times daily, adjusted for renal function and given for periods of time ranging from 4 wk to 50 months, is well tolerated and suppresses HBV replication. However, although a significant reduction in HBV DNA levels (⬃80%), usually seen within the first 2– 4 wk of treatment, occurs in half of the patients, HBV DNA clearance by hibridization assays is a rare event (⬃25– 45%). Furthermore, as with lamivudine, genotypic resistence to famciclovir has also been reported (19, 20), and its clinical significance is being determined. We have reported here our experience with famciclovir in the treatment of hepatitis B after liver transplantation. Even though the number of patients included in this pilot study is small, patients are very well characterized, with at least 12 months of follow-up, and histological assessment before and at the end of therapy is available in all patients. Our study supports the results that have previously been reported, that is, a rapid drop in HBV DNA levels, seen within 3 months of starting therapy in 50% of the patients treated, with 30% of HBV DNA clearance by hybridization assays and PCR. However, despite HBV DNA clearance, histological, clinical and/or biochemical improvement were absent in the vast majority of patients treated, and immunostaining showed
Table 2. Long-Term Follow-Up Results After Famciclovir Therapy HBeAg
HBV DNA (pg/mL)
Serum ALT (U/L)
Patient No.
Pre
Post
Pre
Post†
% Difference
Pre
Post†
% Difference
1 2 3 4 5 6
⫹ ⫺ ⫺ ⫹ ⫹ ⫹
⫹ ⫺ ⫺ ⫹ ⫹ ⫹
116 162 2863 39.5 2202 2490
⬍10* ⬍10* 5274 30.3 9705 3113
100 100 0 23 0 0
315 146 85 157 165 64
272 51 48 109 197 58
24 65 43 30 0 11
* PCR negative. † Values refer to the last available follow-up.
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Table 3. Histologic Evolution After Famciclovir Treatment
Patient No. 1 2 3 4 5 6
Activity Grade* Pre Post
Fibrosis Stage Pre Post
Cytoplasmic HBsAg Staining Pre Post
10 13 7 14 NA 5
3 3 0 3 NA 1
⫹⫹ ⫹⫹ ⫹⫹⫹ ⫹⫹⫹⫹ ⫹⫹ ⫹⫹
10 9 5 14 1 3
4 4 1 4 3 0
⫹⫹⫹ Neg. ⫹⫹⫹⫹ ⫹⫹⫹ ⫹⫹⫹ ⫹⫹
Nuclear HBcAg Staining Pre Post ⫹⫹⫹ ⫹ ⫹⫹ ⫹⫹ ⫹⫹⫹⫹ ⫹⫹⫹
⫹ Neg. ⫹⫹ ⫹⫹ ⫹⫹⫹⫹ ⫹⫹⫹⫹
Cytoplasmic HBcAg Staining† Pre Post 90% Neg. 30% Neg. 90% Neg.
Neg. Neg. 30% Neg. 90% Neg.
NA ⫽ Not available. Neg. ⫽ negative. * Activity grade based on Knodell’s Activity Index. † Expressed as percentage of cells with cytoplasmic HBcAg staining.
only minor changes with treatment. A lack of correlation was observed both between virological and biochemical response and between virological and histological response, suggesting that a complete response was never achieved. There are several reasons that may explain these disappointing results: 1) a third of our patients were infected with the e-minus mutant, a strain historically associated with a poorer response to antivirals; 2) the median time from diagnosis of HBV infection to therapy was longer than that previously reported, with an average of 21 months (range: 3– 40); 3) half of the patients had de novo HBV infection, a situation that could potentially affect the response to therapy (in fact, none of the patients with de novo HBV infection cleared HBV DNA from serum); and 4) coinfection with other viruses may alter the response to therapy, and a third of the patients were coinfected with HCV. In these cases, recurrence of HCV infection with subsequent graft injury is the norm (16), adding further difficulty to the evaluation of both the biochemical and histological response. An interesting finding is the increase in HBV DNA levels in three of the patients after 7, 10, and 11 months of initiating famciclovir, respectively. Development of resistance due to the appearance of mutant strains is an important issue regarding the use of any antiviral therapy (21). In most studies performed to date, mutations tend to occur late in therapy, probably because of the continuous and prolonged selection pressure on minute amounts of virus present in serum, not detectable by conventional hybridization assays but by more sensitive assays such as PCR. Although genotypic analysis was not performed in this study, the rise in HBV DNA levels late in the course of therapy, after an initial response, suggests that resistance to famciclovir may have developed. In conclusion, results of this pilot study were disappointing. Larger controlled studies are needed to draw valid conclusions regarding the efficacy of famciclovir in the treatment of HBV-related liver disease after liver transplantation. Finally, combination therapy with famciclovir and an additional antiviral agent may be an alternative, the rationale behind that being the same as has been proposed for the treatment of HIV infection: that is, attempt to maximize antiviral activity by using drugs that act synergistically, and attempt to minimize genetic viral resistance by combining
drugs for which viral mutations conferring resistance do not overlap.
Reprint requests and correspondence: Marina Berenguer, Servicio de Hepatogastroenterologı´a, Hospital Universitario La FE, Avda Campanar 21, Valencia, 46009, Spain. Received Jan. 26, 2000; accepted Aug. 25, 2000.
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treatment of hepatitis B virus recurrence after liver transplantation: a pilot study. Liver Transpl Surg 1996;2:253– 62. 15. Prieto M, Berenguer M, Rimola A, et al. Liver transplantation in hepatitis C. A Spanish multicentre experience. Eur J Gastroenterol Hepatol 1998;10:771– 6. 16. Prieto M, Berenguer M, Rayo´n M, et al. High incidence of allograft cirrhosis in hepatitis C virus genotype 1b infection following transplantation: relationship with rejection episodes. Hepatology 1999;29:250 – 6. 17. Samuel D, Muller R, Alexander G, et al. Liver transplantation in European patients with the hepatitis B surface antigen. N Engl J Med 1993;329:1842–7.
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18. Trepo C, Jezek P, Atkinson GF, et al. Famciclovir in chronic hepatitis B: results of a dose-finding study. J Hepatol 2000; 32:1011– 8. 19. Locarnini S, Aye TT, Shaw T, et al. The emergence of famciclovir resistant mutations in the hepatitis B virus polymerase during therapy in patients following liver transplantation. Hepatology 1997;26:368A (abstract). 20. Aye TT, Bartholomeusz A, Shaw T, et al. Hepatitis B virus polymerase mutations during antiviral therapy in a patient following liver transplantation. J Hepatol 1997;26:1148 –53. 21. Locarnini S. Hepatitis B virus surface antigen and polymerase gene variants: potential virological and clinical significance. Hepatology 1998;27:294 –7.