Mary L. Owens

Therapeutic response of basal cell carcinoma to the immune response modifier imiquimod 5% cream

BACKGROUND Basal cell carcinoma (BCC) responds to interferon therapy. Imiquimod is a cytokine and interferon inducer. OBJECTIVE This randomized, double-blind pilot trial evaluated the safety and efficacy of imiquimod 5% cream versus vehicle in the treatment of BCC. METHODS In this population of 35 patients with BCC, 24 received imiquimod 5% cream and 11 received vehicle cream in 1 of 5 dosing regimens for up to 16 weeks. Six weeks after treatment, an excisional biopsy of the target site was performed. RESULTS BCC cleared (on the basis of histologic examination) in all 15 patients (100%) dosed twice daily, once daily, and 3 times weekly; in 3 of 5 (60%) patients dosed twice weekly; 2 of 4 (50%) dosed once weekly; and in 1 of 11 (9%) treated with vehicle. Adverse events were predominantly local reactions at the target tumor site, with the incidence and severity of local skin reactions declining in groups dosed less frequently. CONCLUSION Imiquimod 5% cream shows clinical efficacy in the treatment of BCC.

Treatment of genital warts with an immune-response modifier (imiquimod)

BACKGROUND Genital warts are a common sexually transmitted disease caused by human papillomavirus. Imiquimod is a novel immune-response modifier capable of inducing a variety of cytokines, including interferon alfa, tumor necrosis factor-alpha, as well as interleukins 1, 6, and 8. In animal models imiquimod has demonstrated antiviral, antitumor, and adjuvant activity. In vitro, imiquimod has no antiviral or antitumor activity. OBJECTIVE Our purpose was to determine the safety and efficacy of topical imiquimod for the treatment of external genital warts. METHODS This prospective double-blind, placebo-controlled, parallel design clinical trial was performed in three outpatient centers, a public health clinic, a university-based clinic, and a private practice. One hundred eight patients with external genital warts (predominantly white men) were entered into the trial. Fifty-one patients were randomly selected to receive 5% imiquimod cream; 57 patients were randomly chosen to receive placebo cream. Study medication was applied three times weekly for up to 8 weeks. Patients whose warts cleared completely were observed for up to 10 weeks to determine recurrence rates. RESULTS In the intent-to-treat analysis, the warts of 37% (19 of 51) of the imiquimod-treated patients and 0% (0 of 57) of the placebo group cleared completely (p < 0.001). In addition, many patients experienced a partial response. A reduction in baseline wart area of 80% or more was observed in 62% of imiquimod-treated patients (28 of 45) and 4% of the placebo group (2 of 50) (p < 0.001); a 50% reduction or more in wart area was noted in 76% of imiquimod-treated patients (34 of 45) and 8% of placebo recipients (4 of 50) (p < 0.001). Of imiquimod-treated patients whose warts cleared completely and who finished the 10-week follow-up period, 19% (3 of 16) experienced recurrences of warts. Imiquimod-treated patients experienced a significantly greater number of local inflammatory reactions than the placebo group. Symptoms and signs associated with the local inflammatory reactions included itching (54.2%), erythema (33.3%), burning (31.3%), irritation (16.7%), tenderness (12.5%), ulceration (10.4%), erosion (10.4%), and pain (8.3%). There were no differences in systemic reactions or laboratory abnormalities between treatment groups. CONCLUSION Topical 5% imiquimod cream appears to have a significant therapeutic effect in the treatment of external genital warts.

Topical imiquimod 5% cream as an effective treatment for external genital and perianal warts in different patient populations.

Background Genital infection with human papillomavirus, the cause of genital warts, is one of the most common sexually transmitted diseases. Goal The aim of this analysis was to determine whether patients’ demographic variables affect the efficacy of imiquimod 5% cream versus vehicle cream for the treatment of external genital and perianal warts. Study Design Male and female immunocompetent patients applied imiquimod 5% cream topically to external genital warts 3 times a week until wart clearance or for up to 16 weeks. Results As previously published, the intent-to-treat (ITT) clearance rate was 50% (54/109) in the imiquimod-treated group and 11% (11/100) in the vehicle-treated group (P < 0.0001). The ITT clearance rate in the imiquimod-treated group was higher in females (72%) than in males (33%). We have examined the clearance rates for subgroups based on variables of gender, baseline wart area, duration of current outbreak of warts, previous wart treatment, and tobacco use. For each of these subgroups, imiquimod was statistically more effective than vehicle in eradicating external genital and perianal warts. Conclusion Imiquimod 5% cream is an effective treatment for external genital and perianal warts and provides a significant benefit in comparison with vehicle cream, independent of gender, initial wart size, duration of current outbreak of warts, previous wart treatment, or tobacco use.

Treatment of external genital warts in men using 5% imiquimod cream applied three times a week, once daily, twice daily, or three times a day.

Background Medical therapy for genital warts remains suboptimal. The topical interferon and cytokine inducer, imiquimod, has been proved effective for the treatment of external genital and perianal warts, but there is a substantial difference in the response rates between men and women. When 5% imiquimod cream is applied three times a week up to 16 weeks, approximately two thirds of women treated with imiquimod achieve complete clearance of genital warts, whereas only about one third of men clear completely. Goal This study was undertaken to determine whether more frequent application of topical imiquimod cream would improve the rate of genital wart clearance in men. Study Design A randomized treatment trial involving adult men with biopsy-proven genital warts was conducted at nine centers in the United States and Canada using four different application frequencies. Results Complete clearance rates during the 16-week treatment period were as follows for the different imiquimod treatment frequencies: three times a week (35%), once daily (28%), twice daily (24%), and three times a day (27%)(P = 0.88). The four treatment groups all showed comparable reductions in the total lesion area, with a median of more than a 90% reduction in the lesion area by the end of treatment. There was a significant increase in the incidence and severity of local skin reactions including erythema, vesicle formation, ulceration, and excoriation as the dosing frequency increased from three times a week to three times a day. Conclusions In this study, the optimal dosage regimen was the approved three times a week regimen. More frequent application (up to three times a day) did not improve clearance and was associated with an increase in local adverse events.

Two‐year interim results from a 5‐year study evaluating clinical recurrence of superficial basal cell carcinoma after treatment with imiquimod 5% cream daily for 6 weeks

Imiquimod 5% cream is approved in the USA, Europe and Australia to treat superficial basal cell carcinoma, using a regimen of once daily, 5 times per week for 6 weeks. Vehicle‐controlled, phase III clinical trials show that imiquimod is safe and effective for treating superficial basal cell carcinoma with dosing 5 or 7 times per week for 6 weeks. This phase III, open‐label study evaluates the long‐term (5 years) clinical efficacy and safety of dosing once daily, for which this manuscript reports the 2‐year time point in the follow‐up period. For the 169 enrolled subjects, the tumour selected for treatment was assessed clinically to determine initial clearance at the 12‐week post‐treatment visit. If clinically clear of superficial basal cell carcinoma, subjects entered a 5‐year, long‐term follow‐up period. Subjects were evaluated for recurrence at the 3‐, 6‐, 12‐ and 24‐month follow‐up visits. The initial clearance rate at 12 weeks post treatment was 94.1%. The proportion of subjects who were clinically clear at the 2‐year follow‐up visit was estimated to be 82.0%. Imiquimod was tolerated when applied daily, with erythema reported for all subjects participating in the study. The recurrence rate observed suggests that once daily dosing and 5×/week dosing yield similar clearance rates, but daily dosing increases local skin reactions.

Percutaneous penetration of Aldara™ cream, 5% during the topical treatment of genital and perianal warts

Objective: The objective of this single-center, open-label trial was to evaluate the percutaneous penetration of Aldara (imiquimod) cream, 5% when applied topically to patients with anogenital warts using a more frequent/aggressive dosing regimen.Methods: Ten otherwise healthy males and six otherwise healthy, nonpregnant, nonlactating females with histology results suggestive of, or diagnostic of, human papilloma virus/condyloma acuminata were enrolled. Females were required to be practicing an acceptable form of contraception control. Patients applied cream daily (8 +/- 2 hours) until complete wart clearance, or for a maximum of 16 weeks. Following the initial dose, at approximately week 4, and at the end-of-treatment, patients were confined for 42 hours in order to obtain a series of blood and urine samples. These samples were analyzed for levels of imiquimod and two metabolites, S-26704 and S-27700. Biological marker levels were not included as a part of this trial.Results: No quantifiable (>/=5 ng/mL) levels of imiquimod or the two metabolites were observed in any of the serum samples collected. Five patients had quantifiable (>/=10 ng/mL) imiquimod, S-26704, or both in urine. No quantifiable levels of S-27700 were observed. Complete clearance of warts occurred in 40% of male patients and 83% of female patients. Erythema was the most frequently observed local skin reaction and was moderate in intensity, although 6 of 16 patients reported a severe erythema reaction at some point in the study. Application site reactions (itching, burning and pain) were the most frequently reported adverse events.Conclusion: The lack of quantifiable levels of imiquimod or metabolites in serum, together with sporadically occurring quantifiable but low levels in urine, indicate that systemic exposure, after daily application of Aldara cream to genital/perianal skin, may occur but is minimal; however, pharmacological (immune marker) effects were not evaluated because cytokine measurements were not obtained. A future trial assessing cytokine levels after topical Aldara therapy with minimal systemic levels of imiquimod would help assess systemic drug and pharmacological effects and utility of this product in pregnant women.

Safety studies of topical imiquimod 5% cream on normal skin exposed to ultraviolet radiation

BACKGROUND Imiquimod 5% topical cream is an immune response modifier that induces interferon alpha and interleukin-12, and exhibits antiviral and tumor-inhibiting properties. It is currently available for treatment of genital and perianal warts. Three randomized, open-label or assessor-blinded, placebo-controlled studies were carried out to assess its safety on normal white skin exposed to ultraviolet radiation (UVR). METHODS Healthy white volunteer adult subjects between the ages of 18 and 60 years with skin types I, II or III (Fitzpatrick Scale, US Federal Register 43:38260, 1978) were invited to participate. Imiquimod 5% cream (each dose approximately 0.1-0.2 ml) was compared with placebo cream. Two preliminary studies assessed the potential photosensitizing properties of the drug, and the third study added measurement of sunburn cell counts (SBC) and deoxyribonucleic acid (DNA) pyrimidine dimer (PD) formation. The three studies were: a 6-week standard photocontact allergenicity bioassay; a 4-day standard phototoxicity bioassay; and a 4-week photodamage study using biopsy sample analyses to determine SBC or PD frequency. RESULTS Imiquimod had no detectable potential for inducing either photocontact allergy (n=115) or phototoxicity (n=20). The final study further assessing photodamage potential of imiquimod included 44 subjects. There were no significant differences between imiquimod vs. the control (no drug+UVB) for SBC counts (mean 0.88 vs. 0.93), or PD frequency (mean 60.86 vs. 70.03). CONCLUSIONS Results from the two preliminary safety studies suggest that imiquimod 5% cream does not possess a detectable photosensitizing potential in humans. Furthermore, topical imiquimod did not enhance UVR-induced damage to epidermal cells or DNA.