Pharmacokinetics of daily self-application of imiquimod 3.75% cream in adult patients with external anogenital warts.

Imiquimod 3.75% cream is a new formulation intended for daily self-application. The objective of this study was to characterize serum imiquimod pharmacokinetics under maximal use conditions. Adults with ≥8 warts or total wart area ≥100 mm² applied up to 1 packet of imiquimod 3.75% cream (250 mg cream, 9.375 mg imiquimod) once daily for 3 weeks. Blood was obtained prior to doses 1, 7, 14, and 21 and at selected time points after doses 1 and 21. Eighteen patients (13 men and 5 women) with a median wart count of 16 and total wart area of 60 mm² were enrolled. Day 21 mean (SD) serum C(max) was 0.49 (0.37) ng/mL, AUC0₋24 6.80 (3.59) ng·h/mL, and t(1/2) 24.1 (12.4) hours. Steady state was achieved by day 7 with ~2-fold increase in C(max) and AUC after multiple dosing. Overall, C(max) was higher and t(max) shorter in women, with comparable AUC0₋24. Imiquimod metabolites were sporadically quantifiable. No patients discontinued for adverse events; 1 interrupted dosing for an application site ulcer. Treatment-related adverse events occurred in 16.7% of the patients. In conclusion, serum imiquimod concentrations were low after daily self-application to external anogenital warts of up to 1 packet of imiquimod 3.75% cream for 21 days.

Complete clearance is sustained for at least 12 months after treatment of actinic keratoses of the face or balding scalp via daily dosing with imiquimod 3.75% or 2.5% cream.

OBJECTIVE: Assess long-term, sustained, complete clearance of actinic keratoses after treatment with imiquimod 3.75% or 2.5% cream using two two-week or three-week cycles of daily dosing. METHODS: Adults with five to 20 baseline actinic keratoses who achieved complete clearance at the eight-week post-treatment visit in four phase 3 placebo-controlled treatment studies were followed for an additional 12 months. RESULTS: For imiquimod 3.75% and 2.5% cream, respectively, complete clearance was sustained for 12 months in 17/42 (40.5%) and 13/39 (33.3%) subjects from the two-week cycle studies, and in 23/48 (47.9%) and 16/37 (43.2%) subjects from the three-week cycle studies. There were no safety concerns during the follow-up. CONCLUSION: In subjects with a median of eight to nine baseline actinic keratoses who achieved complete clearance after treatment of the full face or balding scalp with topical imiquimod 3.75% cream, complete clearance of all lesions (baseline, recurrent or new) was sustained in ≥ 40 percent of subjects for at least 14 months after the last dose. Clinicaltrials.gov identifier NCT00668733.

A randomized, double-blinded, placebo-controlled, multicenter, efficacy and safety study of 3.75% imiquimod cream following cryosurgery for the treatment of actinic keratoses.

OBJECTIVE: Evaluate cryosurgery followed by 3.75% imiquimod cream to treat actinic keratoses (AK). METHODS: Adults with > or =10 AKs on the face underwent cryosurgery of five to 14 lesions. Subjects with > or =5 lesions remaining were randomized to 3.75% imiquimod or placebo cream applied to the entire face daily for two two-week cycles. Efficacy was assessed through week 26. RESULTS: For the cryosurgery/3.75% imiquimod (n=126) and cryosurgery/placebo (n=121) groups, respectively, median total AK reductions were 86.5 and 50 percent, and proportions of subjects with complete clearance were 30.2 and 3.3 percent (P < 0.0001, both). Analyzing cryosurgery-treated lesions only, median reductions were 100 and 80 percent (P = 0.0008), and subject complete clearance rates were 59.5% and 29.8% (P < 0.001), respectively. Only one subject discontinued for a treatment-related adverse event (cryosurgery/3.75% imiquimod group). LIMITATIONS: Cryosurgery was performed per usual study center practice and not standardized. CONCLUSION: A short, cyclical treatment course of field-directed daily 3.75% imiquimod cream following lesion-directed cryosurgery was well tolerated and provided additional therapeutic benefits to cryosurgery alone.

Pharmacokinetics of imiquimod 3.75% cream applied daily for 3 weeks to actinic keratoses on the face and/or balding scalp.

Imiquimod 3.75% cream is a topical formulation of imiquimod intended for daily application to treat actinic keratoses of the entire face or balding scalp. The objective of the study was to characterize serum imiquimod and metabolite pharmacokinetics. Nineteen subjects with actinic keratoses applied two packets of imiquimod 3.75% cream (18.75 mg imiquimod total) once daily for 21 days to a treatment area approximately 200 cm(2) in size on the face and/or balding scalp. Blood samples were obtained prior to application of doses 1, 7, 14 and 21, and at selected timepoints after application of doses 1 and 21. After multiple dosing (day 21) serum imiquimod mean C (max) was 0.323 (standard deviation 0.159) ng/mL, mean AUC(0-24) 5.974 (3.088) ng h/mL, and mean T(1/2) 29.3 (17.0) h. Steady-state was achieved by day 14; multiple dose accumulation ratios were 2.8 based on imiquimod C (max) and 3.9 based on AUC. Serum concentrations of imiquimod metabolites were only sporadically quantifiable in three subjects. One subject discontinued from study for adverse events of body aches and fatigue that were attributed to study drug. Treatment-related adverse events occurred in 42.1% (8/19) of the subjects. Systemic imiquimod exposure, as reflected by serum drug concentration, was low after daily application of two packets of imiquimod 3.75% cream for 21 days. Steady state was achieved by day 14, and the observed half-life of approximately 29 h supports daily dosing of the product.

Imiquimod 2.5% and 3.75% for the treatment of actinic keratoses: results of two placebo-controlled studies of daily application to the face and balding scalp for two 2-week cycles.

BACKGROUND: The approved imiquimod 5% cream regimen for treating actinic keratoses requires a long treatment time and is limited to a small area of skin. OBJECTIVE: We sought to evaluate imiquimod 2.5% and 3.75% for short-course treatment of the full face or balding scalp. METHODS: In two identical studies, adults with 5 to 20 lesions were randomized to placebo, imiquimod 2.5%, or imiquimod 3.75% (1:1:1). Up to two packets (250 mg each) were applied per dose once daily for two 2-week treatment cycles, with a 2-week, no-treatment interval between cycles. Efficacy was assessed at 8 weeks posttreatment. RESULTS: A total of 479 patients were randomized to placebo, or imiquimod 2.5% or 3.75%. Complete and partial clearance (> or =75% lesion reduction) rates were 6.3% and 22.6% for placebo, 30.6% and 48.1% for imiquimod 2.5%, and 35.6% and 59.4% for imiquimod 3.75%, respectively (P < .001 vs placebo, each; P = .047, 3.75% vs 2.5% for partial clearance). Median reductions from baseline in lesion counts were 25.0% for placebo, 71.8% for imiquimod 2.5%, and 81.8% for imiquimod 3.75% (P < .001, each active vs placebo; P = .048 3.75% vs 2.5%). There were few treatment-related discontinuations. Patient rest period rates were 0% for placebo, 6.9% for imiquimod 2.5%, and 10.6% for imiquimod 3.75%. LIMITATIONS: Local pharmacologic effects of imiquimod, including erythema, may have limited concealment of treatment assignment in some patients. CONCLUSIONS: Both imiquimod 2.5% and 3.75% creams were more effective than placebo and were well tolerated when administered daily as a 2-week on/off/on regimen to treat actinic keratoses.