Fatal hepatic decompensation in a patient with hepatitis B cirrhosis following famciclovir withdrawal

Hepatitis B virus (HBV) infection is a major cause of chronic liver disease worldwide. Famciclovir is a nucleoside analogue with potent antiviral activity that appears promising in the management of patients with HBV infection. No data exist regarding the safety of nucleoside analogue withdrawal in patients treated for HBV cirrhosis. The authors describe a 41-year-old man with compensated HBV cirrhosis who developed fatal hepatic decompensation due to a rebound in viral replication within six weeks of discontinuing famciclovir therapy. Although several mutations in the HBV DNA polymerase gene have been documented, none has been associated with famciclovir resistance or adverse clinical outcomes. Clinicians should consider the risk of inducing serious flares in hepatic inflammation as a result of abrupt nucleoside analogue withdrawal. Until further data are available regarding the safety of withdrawal of these agents, indefinite treatment may be required in patients with established cirrhosis.

A randomized, placebo-controlled study to evaluate the efficacy of 12-month famciclovir treatment in patients with chronic hepatitis B e antigen-positive hepatitis B

We conducted a randomized, placebo-controlled clinical study evaluating famciclovir (500 mg 3 times daily and 1.5 g once daily) for 1 year (6 months post-treatment follow-up) in patients with chronic hepatitis B e antigen (HBeAg)-positive hepatitis B virus (HBV) infection. The study was conducted in 80 centers in North America, Europe, and Australia/New Zealand. A total of 417 patients with histologically documented chronic hepatitis B (histologic activity index [HAI] 9.5-11.0) received famciclovir (500 mg 3 times daily or 1.5 g once daily) or placebo. Famciclovir 500 mg 3 times daily significantly reduced HBV DNA and median HAI scores versus placebo. By week 8, median HBV DNA decreased from 1,645 to 283 MEq/mL (famciclovir 500 mg 3 times daily) and from 1,147 to 304 MEq/mL (famciclovir 1.5 g once daily), while increasing for placebo (1,617 to 1,685 MEq/mL). Median change in HBV DNA at the end of therapy was -76% (famciclovir 500 mg 3 times daily; P <.01) and -60% (famciclovir 1.5 g once daily; P =.25) versus -37% for placebo. Median change in HAI was -1.5 points (famciclovir 500 mg 3 times daily; P =.02) and -1.0 point (famciclovir 1.5 g once daily; P =.35) and zero for placebo. Fifty percent of patients receiving famciclovir 500 mg 3 times daily (P =.07) and 43% receiving 1.5 g once daily (P =.41) experienced >/=2 points improvement in HAI versus 37% for placebo. Nine percent of patients treated with famciclovir 500 mg 3 times daily underwent anti-HBeAg seroconversion with undetectable HBV DNA at end of follow-up versus 3% in the placebo group (P =.05). Famciclovir was well tolerated; the incidence of post-treatment alanine transaminase (ALT) elevations was comparable with placebo. In conclusion, famciclovir 500 mg 3 times daily gave modest suppression of viral replication, but translated into significant histologic improvement in median HAI score at 1 year.

Efficacy and safety of famciclovir for treating mucocutaneous herpes simplex infection in HIV-infected individuals. Collaborative Famciclovir HIV Study Group

OBJECTIVE

To compare the efficacy and safety of 7 days' treatment with famciclovir 500 mg twice a day versus acyclovir 400 mg five times a day, for mucocutaneous herpes simplex virus (HSV) infection in HIV-infected individuals.

DESIGN

Randomized, double-blind, parallel-group study to demonstrate equivalence for the primary efficacy parameter.

SETTING

Forty-eight hospital-based or specialist public-health clinics in 12 countries.

PATIENTS

Two-hundred and ninety-three HIV-positive patients with recurrent HSV infection (orolabial or genital) starting treatment within 48 h of first appearance of herpetic lesions.

MAIN OUTCOME MEASURES

Proportion of patients developing new lesions during treatment (primary outcome measures); Time to complete healing of lesions, time to cessation of viral shedding, time to loss of lesion-associated symptoms, number of withdrawals due to treatment failure (secondary outcome measures).

RESULTS

Equivalence was defined prospectively and famciclovir was equivalent to acyclovir in preventing new lesion formation: new lesions occurred in 16.7% and 13.3% of patients, respectively [difference, 3.4%; 95% confidence interval (CI), -4.8-11.5]. The groups were comparable in time to complete healing (median 7 days for both groups; hazard ratio, 1.01; 95% CI, 0.79-1.29; P = 0.95), cessation of viral shedding (median of 2 days [hazard ratio = 0.93; 95% C.I. 0.68, 1.27; p = 0.64]), and loss of lesion-associated symptoms (median 4 days; hazard ratio, 0.99; 95% CI, 0.75-1.30; P = 0.93). Similar numbers in each group withdrew because of treatment failure. There were no differences between groups in the incidence of adverse events.

CONCLUSIONS

Famciclovir given twice a day is as effective and well tolerated as high-dose acyclovir for mucocutaneous HSV infections in HIV-infected individuals, and has the convenience of less frequent dosing.

Famciclovir in chronic hepatitis B: results of a dose-finding study

BACKGROUND/AIMS

Famciclovir, an orally available nucleoside analogue with potent in vitro activity against HBV, is being investigated for treatment of chronic hepatitis B.

METHODS

A dose-finding study was conducted in patients with hepatitis B e antigen present in serum. Patients received famciclovir 125 mg, 250 mg, 500 mg three times daily (tid) or placebo for 16 weeks, followed by 8 months post-treatment observation, and 16 weeks open-label treatment. More than 90% of patients had previously received alpha-interferon or had baseline characteristics indicating a high likelihood of poor response to alpha-interferon.

RESULTS

Famciclovir induced rapid, dose-dependent suppression of viral replication and reduction in alanine aminotransferase (ALT), with greatest efficacy in the 500-mg tid treatment group. HBV DNA reduction was maintained throughout the treatment period. ALT also steadily declined during the treatment period. Approximately 40% of patients with pretreatment ALT>upper limit of normal (ULN) receiving famciclovir 500 mg tid, experienced sustained normalization of ALT at the end of the 8-month follow-up. Anti-HBe seroconversion occurred more frequently in patients receiving famciclovir 500 mg tid compared with placebo (p=0.04). Famciclovir was generally well tolerated; the incidence of adverse events was comparable to placebo. Exacerbation of liver disease or serious ALT flares were not observed.

CONCLUSION

Famciclovir 500 mg three times daily may offer an alternative to alpha-interferon for treatment for chronic hepatitis B. Anti-HBe seroconversion in the famciclovir 500-mg tid group suggests that 16 weeks treatment has the potential for HBV clearance. Further studies with a longer treatment duration are warranted.

Combination treatment with famciclovir and a topical corticosteroid gel versus famciclovir alone for experimental ultraviolet radiation-induced herpes simplex labialis: a pilot study

To investigate the efficacy of corticosteroids for the treatment of herpes labialis, we compared famciclovir (Famvir, 500 mg 3x/day po [per os] for 5 days) and topical fluocinonide (0.05% Lidex Gel 3x/day for 5 days) with famciclovir and topical vehicle control for experimental ultraviolet radiation-induced herpetic recurrences. We irradiated 49 volunteers, and 29 (60%) of 48 developed signs or symptoms of a recurrence. They self-initiated treatment, and we were able to evaluate them. There was a trend in the combination group toward more aborted lesions, compared with those who received antiviral therapy alone (7 [41%] of 17 vs. 1 [8%] of 12; P=.09). Combination therapy significantly reduced the median maximum lesion size (48 vs. 162 mm(2); P=.02) and the number of patients who experienced lesion pain (10 [59%] of 17 vs. 12 [100%] of 12; P=.02). Adverse events were minimal. Corticosteroids in combination with an antiviral agent may be safe and beneficial for episodic treatment of herpes labialis. Larger studies are needed to confirm these findings.

Famciclovir update. Chronic hepatitis B

The growing body of preclinical data, as well as clinical data from the phase II doseranging study in immunocompetent patients and from liver transplant recipients participating in the compassionate use program, indicates that famciclovir offers the promise of safe and convenient oral treatment of chronic hepatitis B infection. The results of phase III pivotal studies are eagerly awaited. Denavir is a trademark of SmithKline Beecham plc.

Peroral famciclovir in the treatment of experimental ultraviolet radiation-induced herpes simplex labialis: A double-blind, dose-ranging, placebo-controlled, multicenter trial

Three doses of famciclovir were tested for treatment of experimental ultraviolet radiation (UVR)-induced herpes labialis. Patients received 125, 250, or 500 mg of famciclovir or placebo 3 times a day for 5 days beginning 48 h after UVR exposure, a model of early episodic intervention. Of 248 patients irradiated, 102 developed lesions while on treatment. There were no significant differences between groups in the number of lesions. The mean maximal lesion size was reduced in a dose-proportional manner: 139, 105, 77, and 55 mm2 for the placebo and 125-, 250-, and 500-mg famciclovir groups, respectively (P=.040, linear regression). Median time to healing was faster in the 500-mg famciclovir group than in the placebo group, both by investigator (4 vs. 6 days, 33% reduction, P=.010) and patient assessment (3.0 vs. 5.8 days, 48% reduction, P=.008) analyses. These findings suggest that evaluation of higher drug doses for herpes labialis treatment is warranted.

Oral famciclovir for the suppression of recurrent genital herpes: a randomized controlled trial. Collaborative Famciclovir Genital Herpes Research Group

CONTEXT

Recurrent genital herpes simplex virus (HSV) may be treated episodically, but this may not be sufficient for patients with frequent recurrences.

OBJECTIVE

To determine the efficacy and safety of famciclovir in the suppression of recurrent genital HSV infection.

DESIGN

A randomized, double-blind, placebo-controlled, parallel-group study.

SETTING

Thirty university, hospital, or private outpatient referral centers in Canada and Europe.

PATIENTS

A total of 455 patients (223 men, 232 women) aged 18 years or older with a history of 6 or more episodes of genital herpes during 12 of the most recent 24 months, in the absence of suppressive therapy, received study medication.

INTERVENTION

Oral famciclovir, 125 mg or 250 mg 3 times daily or 250 mg twice daily, or placebo for 52 weeks.

MAIN OUTCOME MEASURES

Time to the first recurrence of genital HSV infection; the proportion of patients remaining free of HSV recurrence at 6 months; frequency of adverse events.

RESULTS

In an intent-to-treat analysis, famciclovir significantly delayed the time to the first recurrence of genital herpes at all dose regimens (hazard ratios, 2.9-3.3; P<.001); median time to recurrence for famciclovir recipients was 222 to 336 days compared with 47 days for placebo recipients. The proportion of patients remaining free of HSV recurrence was approximately 3 times higher in famciclovir recipients (79%-86%) than in placebo recipients (27%) at 6 months (relative risks, 2.9-3.1; P<.001); efficacy was maintained at 12 months. Famciclovir was well tolerated with an adverse experience profile comparable to placebo.

CONCLUSIONS

Oral famciclovir (125 mg or 250 mg 3 times daily or 250 mg twice daily) is an effective, well-tolerated treatment for the suppression of genital HSV infection in patients with frequent recurrences.

Famciclovir: new preparation. Slightly helpful in herpes zoster

A comparative placebo-controlled trial involving 419 adults showed that a one-week course of famciclovir started within 3 days of onset of skin lesions had no effect on the acute phase of zoster, the time required for scabs to fall, the end of skin lesion progression, or pain. In this trial famciclovir failed to reduce the incidence of post-zoster pain, but it did reduce its median duration by approximately 2 months. According to a subgroup analysis (not planned for by the protocol), only patients over 50 benefited from this effect. Three other trials suggest that the approved dose regimen in France (500 mg 3 times a day) may not be optimal. The dose recommended in the United Kingdom (750 mg in one daily intake or 250 mg 3 times a day) seems to be more in line with the clinical assessment file. The three available comparative trials show no statistically significant difference between famciclovir and aciclovir in terms of efficacy or tolerability. An indirect comparison suggests that the risk-benefit ratio of famciclovir and valaciclovir are probably similar. However, the effects of famciclovir on post-zoster pain were observed in a clinical trial, while those of aciclovir were found only in meta-analyses.

A review of famciclovir in the management of genital herpes

The frequent occurrence of genital herpes continues to be a serious clinical problem. Although not life threatening, the physical symptoms of the disease, and the ensuing psychosocial complications, can be overwhelming to patients. The life cycle of the herpes simplex virus is complex, comprising multiple stages. Following infection, the virus establishes life-long latency in its host and can reactivate at any time as a recurrent infection. Successful management of genital herpes simplex infections involves patient education and psychological support, as well as antiviral agents. The antiviral agent famciclovir has been shown to shorten the course and decrease the severity of episodes of recurrent genital herpes. In addition, famciclovir has been shown to be effective in suppressing recurrent genital herpes. A review of the clinical experience with famciclovir in the treatment of genital herpes is presented.

A review of famciclovir in the management of genital herpes

The frequent occurrence of genital herpes continues to be a serious clinical problem. Although not life threatening, the physical symptoms of the disease, and the ensuing psychosocial complications, can be overwhelming to patients. The life cycle of the herpes simplex virus is complex, comprising multiple stages. Following infection, the virus establishes life-long latency in its host and can reactivate at any time as a recurrent infection. Successful management of genital herpes simplex infections involves patient education and psychological support, as well as antiviral agents. The antiviral agent famciclovir has been shown to shorten the course and decrease the severity of episodes of recurrent genital herpes. In addition, famciclovir has been shown to be effective in suppressing recurrent genital herpes. A review of the clinical experience with famciclovir in the treatment of genital herpes is presented.

Pretransplant famciclovir as prophylaxis for hepatitis B virus recurrence after liver transplantation

Liver transplantation in patients with detectable hepatitis B virus (HBV) DNA is associated with a high rate of HBV recurrence and detectable HBV DNA is often considered a contraindication for liver transplantation. Famciclovir, an oral form of the purine nucleoside penciclovir, has been shown to inhibit HBV replication. This pilot study was conducted to determine whether a 6-month course of famciclovir, administered before transplantation, was effective in inhibiting HBV replication in patients with end-stage liver disease caused by HBV and detectable HBV DNA and to assess the posttransplant clinical and virologic outcome of patients becoming HBV DNA negative with famciclovir prior to transplantation. All eight patients enrolled were hepatitis B surface antigen (HBsAg) positive; their HBV DNA levels at baseline ranged from 4.3 to 25,321 pg/ml (mean 3,661 pg/ml). Six of the eight patients were also seropositive for HBeAg. An initial decline in HBV DNA titers occurred in all patients; however, only 25% (two of eight) of the patients became HBV DNA negative before transplantation and underwent liver transplantation. Seroconversion to hepatitis B surface antibody (HBsAb) (and HBeAb in HBeAg-positive patient) was demonstrated at the conclusion of famciclovir in the transplanted patients. Both patients remain HBV DNA negative at nearly 2 years of follow-up after transplantation. HBV DNA remained detectable in 63% (five of eight) of the patients. The mean HBV DNA level for patients who became HBV DNA negative was 5.1 pg/ml versus 424 pg/ml in nonresponders. Adverse effects attributable to famciclovir were not observed in any of the patients. Future studies should assess the predictors of response to famciclovir so that patients likely to achieve good virologic outcome can be targeted for such a therapy.

Oral famciclovir for suppression of recurrent genital herpes simplex virus infection in women. A multicenter, double-blind, placebo-controlled trial. Collaborative Famciclovir Genital Herpes Research Group

OBJECTIVE

To evaluate the efficacy and safety of oral famciclovir in the suppression of genital herpes.

METHODS

In this randomized, double-blind, placebo-controlled trial that was performed at 11 university and 9 private ambulatory care referral centers, 375 women who were 18 years of age or older and had a history of 6 or more episodes of genital herpes during 12 of the last 24 months in the absence of suppressive therapy were treated for 4 months with oral famciclovir, 125 mg once daily or twice daily, 250 mg once daily or twice daily, 500 mg once daily, or placebo. The primary outcome measures included the time to first clinically and virologically confirmed recurrences, and safety as measured by clinical laboratory tests and adverse experiences.

RESULTS

The median time to first recurrence was 82 days in the placebo group, 114 days in those receiving famciclovir, 125 mg once daily, and more than 120 days in the other treatment groups. When compared with placebo recipients, the time to the first clinical recurrence was significantly prolonged in subjects who received famciclovir, 125 mg twice daily (hazard ratio, 1.8; 95% confidence interval, 1.0-3.0; P = .03), and in those who received famciclovir, 250 mg twice daily (hazard ratio, 3.6; 95% confidence interval, 1.9-6.9; P < .001). Treatment was well tolerated, and there was no evidence of emergence of resistance during or after suppressive famciclovir therapy.

CONCLUSIONS

Oral famciclovir, 250 mg, given twice daily for 4 months is an effective, well-tolerated treatment for the suppression of genital herpes in women with frequent recurrences, but single daily doses produced less complete suppression of genital herpes.

Patient-initiated, twice-daily oral famciclovir for early recurrent genital herpes. A randomized, double-blind multicenter trial. Canadian Famciclovir Study Group

OBJECTIVE

To compare the efficacy and safety of episodic patient-initiated oral famciclovir with placebo in recurrent genital herpes.

DESIGN

Randomized, double-blind, frequent-observation, dose-ranging study comparing twice-daily 125-mg, 250-mg, or 500-mg oral famciclovir with placebo. Patients initiated therapy after self-culturing, reported to the clinic within 12 hours, and were assessed twice daily for at least 5 days.

SETTING

Fifteen Canadian university, private practice, or public outpatient clinics.

PATIENTS

A total of 692 patients with culture-proven recurrent genital herpes were randomized; 467 patients experienced a symptomatic episode and commenced treatment.

MAIN OUTCOME MEASURE

Time to complete healing of all lesions.

RESULTS

Famciclovir (all doses) was significantly more effective than placebo in reducing time to healing, time to cessation of viral shedding, and durations of lesion edema, vesicles, ulcers, and crusts. Times to cessation of all symptoms and of moderate to severe lesion tenderness, pain, and burning were also reduced. Patients who initiated famciclovir prior to viral shedding were more likely to not shed virus throughout. All doses were equally effective, safe, and well tolerated.

CONCLUSIONS

Oral famciclovir reduced the onset and duration of viral shedding, lesion persistence, and uncomfortable symptoms. Several individual symptoms and lesion stages were also reduced in duration by this episodic therapy. Additionally, our twice-daily observation trial design proved to be a helpful tool for studying recurrent disease. Episodic oral famciclovir provides a convenient and effective alternative for those patients with recurrent genital herpes whose frequency rates do not require continuous antiviral suppression.

Famciclovir: review of clinical efficacy and safety

Famciclovir is the well-absorbed oral form of penciclovir, an antiviral agent with potent activity against varicella-zoster virus (VZV) and herpes simplex virus (HSV-1) and 2 (HSV-2). After oral administration, famciclovir is rapidly converted to penciclovir with a bioavailability of 77%. penciclovir is efficiently phosphorylated to the active metabolite, penciclovir-triphosphate, and has a prolonged intracellular half-life of approximately 9-10 h in VZV-infected cells, and 10 and 20 h in cells infected with HSV-1 and HSV-2, respectively. Two multicenter clinical trials have shown that famciclovir given during the acute zoster phase accelerated healing of cutaneous lesions. More importantly, in a placebo-controlled study, famciclovir reduced the duration of postherpetic neuralgia (PHN), particularly in elderly patients. Famciclovir has also been proven effective in treating recurrent genital herpes, as demonstrated by a reduction in times to cessation of viral shedding, complete healing, and loss of all symptoms. One study showed that suppressive therapy with famciclovir was effective in reducing genital herpes episodes in patients with frequent recurrences. A promising new area of investigation for famciclovir is controlling virus replication in patients with chronic hepatitis B virus (HBV) or HBV reinfections after liver transplant. Results from a double-blind, placebo-controlled, pilot study and several case reports have shown that famciclovir, alone or in combination with other agents, decreased HBV-DNA levels and was tolerated with long-term treatment. Available clinical data indicate that famciclovir is an effective agent for treating herpes and holds significant promise for the treatment of chronic HBV infection HBV reinfection after liver transplantation.

Famciclovir for the treatment of acute herpes zoster: effects on acute disease and postherpetic neuralgia. A randomized, double-blind, placebo-controlled trial. Collaborative Famciclovir Herpes Zoster Study Group

OBJECTIVE

To document the effects of treatment with famciclovir on the acute signs and symptoms of herpes zoster and postherpetic neuralgia.

DESIGN

A randomized, double-blind, placebo-controlled, multicenter trial.

SETTING

36 centers in the United States, Canada, and Australia.

PATIENTS

419 immunocompetent adults with uncomplicated herpes zoster.

INTERVENTION

Patients were assigned within 72 hours of rash onset to famciclovir, 500 mg; famciclovir, 750 mg; or placebo, three times daily for 7 days.

MEASUREMENTS

Lesions were assessed daily for as long as 14 days until full crusting occurred and then weekly until the lesions healed. Viral cultures were obtained daily while vesicles were present. Pain was assessed at each of the visits at which lesions were examined and then monthly for 5 months after the lesions healed. Safety was assessed throughout the study.

RESULTS

Famciclovir was well tolerated, with a safety profile similar to that of placebo. Famciclovir accelerated lesion healing and reduced the duration of viral shedding. Most importantly, famciclovir recipients had faster resolution of postherpetic neuralgia (approximately twofold faster) than placebo recipients; differences between the placebo group and both the 500-mg famciclovir group (hazard ratio, 1.7 [95% CI, 1.1 to 2.7]) and the 750-mg famciclovir group (hazard ratio, 1.9 [CI, 1.2 to 2.9]) were statistically significant (P = 0.02 and 0.01, respectively). The median duration of postherpetic neuralgia was reduced by approximately 2 months.

CONCLUSIONS

Oral famciclovir, 500 mg or 750 mg three times daily for 7 days, is an effective and well-tolerated therapy for herpes zoster that decreases the duration of the disease's most debilitating complication, postherpetic neuralgia.

Safety of famciclovir in patients with herpes zoster and genital herpes

Safety reporting from individual ongoing and completed clinical studies has demonstrated that famciclovir, the well-absorbed oral form of the antiherpesvirus agent penciclovir, has been well tolerated by more than 3,000 individuals worldwide. An integrated safety evaluation has been performed and includes over 1,600 patients from 11 completed, randomized, double-blind clinical trials and 2 open trials. The famciclovir population consisted of 816 herpes zoster patients (four trials), 409 patients with acute genital herpesvirus infections (seven trials), and 382 patients from two genital herpes suppression studies. Overall, the famciclovir-treated patient population was 57.7% female and ranged in age from 15 to 102 years (mean, 42.6 years), with 31.2% aged 50 years or more and 15.7% aged 65 years or more. The mean duration of exposure to famciclovir was 28.8 days (5.8 days excluding suppression studies). The total daily doses ranged from 125 mg to 2.25 g. The most common adverse experiences reported as related to study medication (famciclovir and placebo) were headache, nausea, and diarrhea. The frequencies of adverse experiences and laboratory abnormalities (hematology, clinical chemistry, and urinalysis parameters) were similar in both famciclovir and placebo recipients. Thus, safety data from the analysis of 13 completed clinical studies demonstrate that famciclovir is tolerated well by patients with either herpes zoster or genital and has a safety profile comparable to that of placebo.

Linear pharmacokinetics of penciclovir following administration of single oral doses of famciclovir 125, 250, 500 and 750 mg to healthy volunteers

Twenty healthy male volunteers received single oral doses of famciclovir (125-750 mg), in a randomized, single-blind, crossover study. Plasma and urine concentrations of penciclovir and its 6-deoxy precursor, BRL 42359, were determined and penciclovir plasma concentration-time data submitted to model-independent pharmacokinetic analysis. Peak plasma concentrations of penciclovir were obtained at median times of 0.5-0.75 h after dosing. The areas under the concentration versus time curves (AUC) and the peak penciclovir concentration (Cmax) increased linearly with dose of famciclovir. Time to Cmax, elimination half-life, urinary recovery and renal clearance of penciclovir did not change with increasing dose. Famciclovir was excreted via the kidneys as penciclovir (60%) and BRL 42359 (5%), respectively. Famciclovir was well tolerated by all subjects with a low incidence of adverse effects. In conclusion, penciclovir thus displays linear pharmacokinetics in the anticipated therapeutic dose range of famciclovir.