Topical imiquimod - A review of its use in genital warts

Imiquimod is a topically active immunomodulatory agent that is formulated a s a 5% cream for application by the patient. It is the first agent of its c lass, the immune response modifiers, to be used in the treatment of genital warts. In immunocompetent patients with genital warts, imiquimod stimulate s the production of interferon-alpha and various other cytokines, and has i ndirect antiviral activity. In randomised, double-blind, vehicle-controlled clinical trials, complete c learance of warts occurred in 37 to 50% of immunocompetent patients with ge nital warts treated with imiquimod 5% cream 3 times a week for up to 16 wee ks; partial clearance of warts (defined as a reduction in wart area of grea ter than or equal to 50%) was observed in 76% of recipients of imiquimod 5% cream. Rates of complete or partial clearance of warts were significantly higher in patients who applied imiquimod 5% cream 3 times a week than in re cipients of imiquimod 1 % or vehicle cream, each applied 3 times a week. A between-gender difference in clinical response to imiquimod 5% cream has be en reported, with female patients experiencing higher rates of complete cle arance of warts than males. Recurrence(s) of greater than or equal to 1 wart occurred in 13 to 19% of i mmunocompetent patients in whom complete clearance of warts had been achiev ed with imiquimod 5% cream. Imiquimod 5% cream also shows some clearance of warts in immunosuppressed H N-infected patients with genital warts. preliminary results of a vehicle-co ntrolled study showed that the rate of partial clearance of warts (defined as a reduction in baseline wart area of >50%) [38%] was significantly highe r with imiquimod 5% cream than with vehicle cream; however, the rate of com plete clearance was not significantly higher than with vehicle cream. Imiquimod 5% cream is generally well tolerated by immunocompetent and HN-in fected patients. Local skin reactions (mainly mild or moderate), including erythema, itching and burning, are the most commonly reported adverse event s, occurring in less than or equal to 67% of patients applying imiquimod 5% cream 3 times a week. The incidence of adverse events is lower in patients applying the cream 3 times a week than with daily application. The inciden ce of systemic adverse events with imiquimod 5% cream (applied daily or 3 t imes a week) is similar to that of vehicle cream. The tolerability profile of imiquimod cream appears favourable compared with that of podophyllotoxin . Conclusion: Imiquimod 5% cream is a new therapeutic option for patients wit h genital warts. It produces clearance rates broadly similar to those of ot her treatment approaches and rates of wart recurrence compare favourably wi th those reported for established treatments. In contrast to most alternati ve treatment strategies, which are administered in the physician's office, imiquimod cream is a self-administered therapy for outpatient use.