Famciclovir clinical studies

Famciclovir
FAMVIR® FDA Package Insert
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Clinical Pharmacology
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Clinical Studies
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Clinical Studies

herpes labialis (Cold Sores)

A randomized, double-blind, placebo-controlled trial was conducted in 701 immunocompetent adults with recurrent herpes labialis. Patients self-initiated therapy within 1 hour of first onset of signs or symptoms of a recurrent herpes labialis episode with FAMVIR 1500 mg as a single dose (n=227), FAMVIR 750 mg twice daily (n=220) or placebo (n=254) for 1 day. The median time to healing among patients with non-aborted lesions (progressing beyond the papule stage) was 4.4 days in the FAMVIR 1500 mg single-dose group (n=152) as compared to 6.2 days in the placebo group (n=168). The median difference in time to healing between the placebo and FAMVIR 1500 mg treated groups was 1.3 days (95% CI: 0.6-2.0). No differences in proportion of patients with aborted lesions (not progressing beyond the papule stage) were observed between patients receiving FAMVIR or placebo: 33% for FAMVIR 1500 mg single dose and 34% for placebo. The median time to loss of pain and tenderness was 1.7 days in FAMVIR 1500 mg single dose-treated patients vs. 2.9 days in placebo-treated patients.

genital herpes

Recurrent episodes: A randomized, double-blind, placebo-controlled trial was conducted in 329 immunocompetent adults with recurrent genital herpes. Patients self-initiated therapy within 6 hours of the first sign or symptom of a recurrent genital herpes episode with either FAMVIR 1000 mg twice daily (n=163) or placebo (n=166) for 1 day. The median time to healing among patients with non-aborted lesions (progressing beyond the papule stage) was 4.3 days in FAMVIR-treated patients (n=125) as compared to 6.1 days in placebo-treated patients (n=145). The median difference in time to healing between the placebo and FAMVIR-treated groups was 1.2 days (95% CI: 0.5 to 2.0). Twenty-three percent of FAMVIR-treated patients had aborted lesions (no lesion development beyond erythema) vs. 13% in placebo-treated patients. The median time to loss of all symptoms (e.g., tingling, itching, burning, pain, or tenderness) was 3.3 days in FAMVIR-treated patients vs. 5.4 days in placebo-treated patients.

A randomized (2:1), double-blind, placebo-controlled trial was conducted in 304 immunocompetent black and African American adults with recurrent genital herpes. Patients self-initiated therapy within 6 hours of the first sign or symptom of a recurrent genital herpes episode with either FAMVIR 1000 mg twice daily (n=206) or placebo (n=98) for 1 day. The median time to healing among patients with non-aborted lesions was 5.4 days in FAMVIR-treated patients (n=152) as compared to 4.8 days in placebo-treated patients (n=78). The median difference in time to healing between the placebo and FAMVIR-treated groups was -0.26 days (95% CI: -0.98 to 0.40).

Suppressive therapy: Two randomized, double-blind, placebo-controlled, 12-month trials were conducted in 934 immunocompetent adults with a history of 6 or more recurrences of genital herpes episodes per year. Comparisons included FAMVIR 125 mg three times daily, 250 mg twice daily, 250 mg three times daily, and placebo. At 12 months, 60% to 65% of patients were still receiving FAMVIR and 25% were receiving placebo treatment. Recurrence rates at 6 and 12 months in patients treated with the 250 mg twice daily dose are shown in Table 6.

FAMVIR-treated patients had approximately 1/5 the median number of recurrences as compared to placebo-treated patients. Higher doses of FAMVIR were not associated with an increase in efficacy.

Recurrent Orolabial or genital herpes in HIV-Infected Patients

A randomized, double-blind trial compared famciclovir 500 mg twice daily for 7 days (n=150) with oral acyclovir 400 mg 5 times daily for 7 days (n=143) in HIV-infected patients with recurrent orolabial or genital herpes treated within 48 hours of lesion onset. Approximately 40% of patients had a CD4+ count below 200 cells/mm3, 54% of patients had anogenital lesions and 35% had orolabial lesions. Famciclovir therapy was comparable to oral acyclovir in reducing new lesion formation and in time to complete healing.

herpes zoster (Shingles)

Two randomized, double-blind trials, 1 placebo-controlled and 1 active-controlled, were conducted in 964 immunocompetent adults with uncomplicated herpes zoster. Treatment was initiated within 72 hours of first lesion appearance and was continued for 7 days.

In the placebo-controlled trial, 419 patients were treated with either FAMVIR 500 mg three times daily (n=138), FAMVIR 750 mg three times daily (n=135) or placebo (n=146). The median time to full crusting was 5 days among FAMVIR 500 mg-treated patients as compared to 7 days in placebo-treated patients. The times to full crusting, loss of vesicles, loss of ulcers, and loss of crusts were shorter for FAMVIR 500 mg-treated patients than for placebo-treated patients in the overall study population. The effects of FAMVIR were greater when therapy was initiated within 48 hours of rash onset; it was also more profound in patients 50 years of age or older. Among the 65.2% of patients with at least 1 positive viral culture, FAMVIR treated patients had a shorter median duration of viral shedding than placebo-treated patients (1 day and 2 days, respectively).

There were no overall differences in the duration of pain before rash healing between FAMVIR- and placebo-treated groups. In addition, there was no difference in the incidence of pain after rash healing (postherpetic neuralgia) between the treatment groups. In the 186 patients (44.4% of total study population) who developed postherpetic neuralgia, the median duration of postherpetic neuralgia was shorter in patients treated with FAMVIR 500 mg than in those treated with placebo (63 days and 119 days, respectively). No additional efficacy was demonstrated with higher dose of FAMVIR.

In the active-controlled trial, 545 patients were treated with 1 of 3 doses of FAMVIR three times daily or with acyclovir 800 mg five times daily. Times to full lesion crusting and times to loss of acute pain were comparable for all groups and there were no statistically significant differences in the time to loss of postherpetic neuralgia between FAMVIR and acyclovir-treated groups.

References

Adapted from the FDA Package Insert.