Purpose: The intralesional administration of recombinant interferon alpha has led to resolution of genital warts in 50 to 70 percent of cases. However, continuous warts do not respond to such treatment, and human papillomavirus (HPV) infection of other anatomic sites remains untreated, so infection may continue to be transmitted. Since interferons have shown promise as effective therapies for genital warts, we decided to investigate the tolerance and efficacy of recombinant human interferon gamma in the treatment of refractory genital warts.
Patients and methods: Nineteen women and nine men with refractory genital warts were treated in an open-label, dose-response trial of intramuscular recombinant human interferon gamma.
Results: Complete responses were seen in two (7 percent) and partial responses were seen in 13 (46 percent). Of 12 women with concomitant cervical HPV infection, eight demonstrated resolution with therapy. Response rates were higher in those patients who had warts less than nine months (73 percent) prior to therapy and in women (63 percent). Responses were not associated with HPV type. Flu-like symptoms during treatment were frequent but well tolerated. Transient abnormal laboratory results were more frequent with daily administration than with three times weekly therapy. Eleven of 16 subjects treated with cryotherapy after treatment with interferon experienced long-term remissions.
Conclusions: In ambulatory patients with refractory genital warts, recombinant human interferon gamma appears to be biologically active and to have few adverse effects. The high efficacy rate achieved in subjects treated with cryotherapy after treatment with interferon suggests that further studies of combination therapy with these modalities are warranted.