Imiquimod Drug Information

• The following clinically significant adverse reactions are described elsewhere in the labeling:
• Local Skin Reactions [see Warnings and Precautions ( 5.1 )]
• Local Hypopigmentation Reactions [see Warnings and Precautions ( 5.2 )]
• Systemic Reactions [see Warnings and Precautions ( 5.3 )] Most common application site or local skin adverse reactions (incidence >28%) are erythema, flaking/scaling/dryness, scabbing/crusting, edema, erosion/ulceration, induration, itching, burning, excoriation, vesicles. Other reported systemic adverse reactions (≥1%): fatigue, fever, and headache. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Padagis ® at 1-866-634-9120 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. Actinic Keratosis The data described below reflect exposure to Imiquimod Cream or vehicle in 436 subjects with AK enrolled in two double-blind, vehicle-controlled trials (Studies AK1 and AK2) [see Clinical Studies (14.1)] . Subjects applied Imiquimod Cream, 5% or vehicle topically, to a 25 cm 2 contiguous treatment area on the face or scalp once daily 2 times per week for 16 weeks. The incidence of selected adverse reactions reported by ≥1% of subjects during the trials is presented in Table 2. Table 2: Selected Adverse Reactions Occurring in ≥1% of Imiquimod-Treated Subjects with AK and at a Greater Frequency than Vehicle in Studies AK1 and AK2 Imiquimod Cream (n= 215) Vehicle (n= 221) Application Site Reaction 71 (33%) 32 (14%) Upper Respiratory Tract Infection 33 (15%) 27 (12%) Sinusitis 16 (7%) 14 (6%) Headache 11 (5%) 7 (3%) Carcinoma Squamous 8 (4%) 5 (2%) Diarrhea 6 (3%) 2 (1%) Eczema 4 (2%) 3 (1%) Back Pain 3 (1%) 2 (1%) Fatigue 3 (1%) 2 (1%) Fibrillation Atrial 3 (1%) 2 (1%) Infection Viral 3 (1%) 2 (1%) Dizziness 3 (1%) 1 (<1%) Vomiting 3 (1%) 1 (<1%) Urinary Tract Infection 3 (1%) 1 (<1%) Fever 3 (1%) 0 (0%) Rigors 3 (1%) 0 (0%) Alopecia 3 (1%) 0 (0%) The incidence of application site reactions reported by >1% of subjects during the trials is presented in Table 3. Table 3: Application Site Reactions Reported by >1% of Imiquimod-Treated Subjects with AK and at a Greater Frequency than Vehicle in Studies AK1 and AK2 Imiquimod Cream (n= 215) Vehicle (n= 221) Itching 44 (20%) 17 (8%) Burning 13 (6%) 4 (2%) Bleeding 7 (3%) 1 (<1%) Stinging 6 (3%) 2 (1%) Pain 6 (3%) 2 (1%) Induration 5 (2%) 3 (1%) Tenderness 4 (2%) 3 (1%) Irritation 4 (2%) 0 (0%) Local skin reactions were collected independently of the adverse reaction "application site reaction". The incidence and severity of local skin reactions that occurred during controlled trials are shown in Table 4. Table 4: Local Skin Reactions in the Treatment Area of Imiquimod-Treated Subjects with AK as Assessed by the Investigator in Studies AK1 and AK2 Imiquimod Cream (n= 215) Vehicle (n= 220) All Grades* Severe All Grades* Severe Erythema 209 (97%) 38 (18%) 206 (93%) 5 (2%) Flaking/Scaling/Dryness 199 (93%) 16 (7%) 199 (91%) 7 (3%) Scabbing/Crusting 169 (79%) 18 (8%) 92 (42%) 4 (2%) Edema 106 (49%) 0 (0%) 22 (10%) 0 (0%) Erosion/Ulceration 103 (48%) 5 (2%) 20 (9%) 0 (0%) Weeping/Exudate 45 (22%) 0 (0%) 3 (1%) 0 (0%) Vesicles 19 (9%) 0 (0%) 2 (1%) 0 (0%) *Mild, Moderate, or Severe The adverse reactions that most frequently resulted in clinical intervention (e.g., rest periods, withdrawal from trial) were local skin and application site reactions. In the trials, 2% (5/215) of subjects discontinued for local skin/application site reactions. Of the 215 subjects treated, 35 subjects (16%) on imiquimod cream and 3 of 220 subjects (1%) on vehicle had at least one rest period. Of the imiquimod-treated subjects, 32 (91%) resumed therapy after a rest period. In the AK trials, 22 of 678 (3.2%) of imiquimod-treated subjects developed treatment site infections that required a rest period off imiquimod cream and were treated with antibiotics (19 with oral and 3 with topical). Of the 206 imiquimod-treated subjects with both baseline and 8-week post-treatment scarring assessments, 6 (2.9%) had a greater degree of scarring scores at 8 weeks post-treatment than at baseline. Superficial Basal Cell Carcinoma The data described below reflect exposure to imiquimod cream or vehicle in 364 subjects with sBCC enrolled in two double-blind, vehicle-controlled trials (sBCC1 and sBCC2) [see Clinical Studies ( 14.2 )] . Subjects applied imiquimod cream, 5% or vehicle topically 5 times per week for 6 weeks. The incidence of selected adverse reactions reported by ≥1% of subjects during the trials is summarized in Table 5. Table 5: Selected Adverse Reactions Reported by ≥1% of Imiquimod-Treated Subjects with sBCC and at a Greater Frequency than Vehicle in Studies sBCC1 and sBCC2 Imiquimod Cream (n= 185) N % Vehicle (n= 179) N % Application Site Reaction 52 (28%) 5 (3%) Headache 14 (8%) 4 (2%) Back Pain 7 (4%) 1 (<1%) Upper Respiratory Tract Infection 6 (3%) 2 (1%) Rhinitis 5 (3%) 1 (<1%) Lymphadenopathy 5 (3%) 1 (<1%) Fatigue 4 (2%) 2 (1%) Sinusitis 4 (2%) 1 (<1%) Dyspepsia 3 (2%) 2 (1%) Coughing 3 (2%) 1 (<1%) Fever 3 (2%) 0 (0%) Dizziness 2 (1%) 1 (<1%) Anxiety 2 (1%) 1 (<1%) Pharyngitis 2 (1%) 1 (<1%) Chest Pain 2 (1%) 0 (0%) Nausea 2 (1%) 0 (0%) The most frequently reported adverse reactions were local skin and application site reactions. The incidence of application site reactions reported by >1% of the subjects during the 6-week treatment period is summarized in Table 6. Table 6: Application Site Reactions Reported by > 1% of Imiquimod-Treated Subjects with sBCC and at a Greater Frequency than Vehicle in Studies sBCC1 and sBCC2 Imiquimod Cream (n= 185) Vehicle (n= 179) Itching 30 (16%) 1 (1%) Burning 11 (6%) 2 (1%) Pain 6 (3%) 0 (0%) Bleeding 4 (2%) 0 (0%) Erythema 3 (2%) 0 (0%) Papule(s) 3 (2%) 0 (0%) Tenderness 2 (1%) 0 (0%) Infection 2 (1%) 0 (0%) Local skin reactions were collected independently of the adverse reaction “application site reaction”. The incidence and severity of local skin reactions that occurred during the controlled trials are shown in Table 7. Table 7: Local Skin Reactions in the Treatment Area of Imiquimod-Treated Subjects with sBCC as Assessed by the Investigator in Studies sBCC1 and sBCC2 Imiquimod Cream (n= 184) Vehicle (n= 178) All Grades* Severe All Grades* Severe Erythema 184 (100%) 57 (31%) 173 (97%) 4 (2%) Flaking/Scaling 167 (91%) 7 (4%) 135 (76%) 0 (0%) Induration 154 (84%) 11 (6%) 94 (53%) 0 (0%) Scabbing/Crusting 152 (83%) 35 (19%) 61 (34%) 0 (0%) Edema 143 (78%) 13 (7%) 64 (36%) 0 (0%) Erosion 122 (66%) 23 (13%) 25 (14%) 0 (0%) Ulceration 73 (40%) 11 (6%) 6 (3%) 0 (0%) Vesicles 57 (31%) 3 (2%) 4 (2%) 0 (0%) *Mild, Moderate, or Severe The adverse reactions that most frequently resulted in clinical intervention (e.g., rest periods, withdrawal from trial) were local skin and application site reactions; 10% (19/185) of imiquimod-treated subjects received rest periods. The average number of doses not received per imiquimod-treated subject due to rest periods was 7 doses with a range of 2 to 22 doses; 79% of subjects (15/19) resumed therapy after a rest period. Overall, in the clinical trials, 2% (4/185) of imiquimod-treated subjects discontinued for local skin/application site reactions. In the sBCC trials, 17 of 1266 (1.3%) imiquimod-treated subjects developed treatment site infections that required a rest period and treatment with antibiotics. External Genital Warts In controlled clinical trials for EGW, including a double-blind, vehicle-controlled clinical trial in 209 adult subjects with EGW (Study EGW1) [see Clinical Studies ( 14.3 )] , imiquimod cream, 5% was applied topically to EGW in 109 subjects. Selected adverse reactions in imiquimod-treated subjects are listed below (see Table 8). Table 8: Selected Adverse Reactions in Imiquimod-Treated Subjects with EGW in Vehicle-Controlled Clinical Trials Females Males Imiquimod Cream (n=117) Vehicle (n=103) Imiquimod Cream (n=156) Vehicle (n=158) Wart Site Itching 38 (32%) 21 (20%) 34 (22%) 16 (10%) Burning 30 (26%) 12 (12%) 14 (9%) 8 (5%) Pain 9 (8%) 2 (2%) 3 (2%) 1 (1%) Soreness 3 (3%) 0 (0%) 0 (0%) 1 (1%) Fungal Infection 13 (11%) 3 (3%) 3 (2%) 1 (1%) Systemic Reactions Headache 5 (4%) 3 (3%) 8 (5%) 3 (2%) Influenza-like Symptoms 4 (3%) 2 (2%) 2 (1%) 0 (0%) Myalgia 1 (1%) 0 (0%) 2 (1%) 1 (1%) The most frequently reported adverse reactions were local skin and application site reactions. Overall, 1.2% (4/327) of the subjects discontinued treatment due to local skin/application site reactions. The incidence and severity of local skin reactions during controlled clinical trials are shown in Table 9. Table 9: Local Skin Reactions in the Treatment Area of Imiquimod-Treated Subjects with EGW as Assessed by the Investigator in Vehicle-Controlled Clinical Trials Imiquimod Cream Vehicle Females (n=114) Males (n=156) Females (n=99) Males (n=157) All Grades* Severe All Grades* Severe All Grades* Severe All Grades* Severe Erythema 74 (65%) 4 (4%) 90 (58%) 6 (4%) 21 (21%) 0 (0%) 34 (22%) 0 (0%) Erosion 35 (31%) 1 (1%) 47 (30%) 2 (1%) 8 (8%) 0 (0%) 10 (6%) 0 (0%) Excoriation/ Flaking 21 (18%) 0 (0%) 40 (26%) 1 (1%) 8 (8%) 0 (0%) 12 (8%) 0 (0%) Edema 20 (18%) 1 (1%) 19 (12%) 0 (0%) 5 (5%) 0 (0%) 1 (1%) 0 (0%) Scabbing 4 (4%) 0 (0%) 20 (13%) 0 (0%) 0 (0%) 0 (0%) 4 (3%) 0 (0%) Induration 6 (5%) 0 (0%) 11 (7%) 0 (0%) 2 (2%) 0 (0%) 3 (2%) 0 (0%) Ulceration 9 (8%) 3 (3%) 7 (4%) 0 (0%) 1 (1%) 0 (0%) 1 (1%) 0 (0%) Vesicles 3 (3%) 0 (0%) 3 (2%) 0 (0%) 0 (0%) 0 (0%) 0 (0%) 0 (0%) *Mild, Moderate, or Severe Remote site skin reactions were also reported. The severe remote site skin reactions reported for females were erythema (3%), ulceration (2%), and edema (1%); and for males, erosion (2%), and erythema, edema, induration, and excoriation/flaking (each 1%). Other adverse reactions reported by more than 1% of imiquimod-treated subjects included: Application Site Disorders: hypopigmentation, irritation, rash, sensitivity, stinging, tenderness Body as a Whole: fatigue, fever Gastrointestinal System Disorders: diarrhea Remote Site Reactions: bleeding, burning, itching, pain, tenderness, tinea cruris 6.2 Postmarketing Experience The following adverse reactions have been identified during post-approval use of imiquimod cream. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Application Site Disorders: tingling at the application site Body as a Whole: angioedema Cardiovascular: capillary leak syndrome, cardiac failure, cardiomyopathy, pulmonary edema, arrhythmias (tachycardia, atrial fibrillation, palpitations), chest pain, ischemia, myocardial infarction, syncope Endocrine: thyroiditis Gastrointestinal System Disorders: abdominal pain Hematological: decreases in red cell, white cell, and platelet counts (including idiopathic thrombocytopenic purpura), lymphoma Hepatic: abnormal liver function Infections and Infestations: herpes simplex Musculoskeletal System Disorders: arthralgia Neuropsychiatric: agitation, cerebrovascular accident, convulsions (including febrile convulsions), depression, insomnia, multiple sclerosis aggravation, paresis, suicide Respiratory: dyspnea Urinary System Disorders: proteinuria, dysuria, urinary retention Skin and Appendages: exfoliative dermatitis, erythema multiforme, hypertrophic scar, hyperpigmentation, hypopigmentation, including complete depigmentation. Vascular: Henoch-Schönlein purpura syndrome

Pregnancy Risk Summary Available data from case reports and case series of use with imiquimod during pregnancy have not identified a drug-associated risk of major birth defects, miscarriage or adverse maternal or fetal outcomes. There are no controlled or large-scale epidemiologic studies and no exposure registries with imiquimod use in pregnant women. In animal reproduction studies, there were no adverse developmental effects observed after oral administration of imiquimod in pregnant rats and intravenous administration of imiquimod in pregnant rabbits during organogenesis at doses up to 98 times and 407 times, respectively, the maximum recommended human dose (MRHD) (see Data). The background risk of major birth defects and miscarriage for the indicated population is unknown.

All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively. Data Animal Data The MRHD was set at 2 packets per treatment of Imiquimod Cream (25 mg imiquimod) for the animal multiples of human exposure presented in this label.

Systemic embryofetal development studies were conducted in rats and rabbits. Oral doses of 1, 5, and 20 mg/kg/day imiquimod were administered during the period of organogenesis to pregnant female rats. In the presence of maternal toxicity, fetal effects noted at 20 mg/kg/day (577 times the MRHD based on AUC comparison) included increased resorptions, decreased fetal body weights, delays in skeletal ossification, bent limb bones, and two fetuses in one litter (2 of 1567 fetuses) demonstrated exencephaly, protruding tongues and low-set ears.

No treatment-related effects on embryofetal toxicity or malformation were noted at 5 mg/kg/day (98 times the MRHD based on AUC comparison). Intravenous doses of 0.5, 1, and 2 mg/kg/day imiquimod were administered during the period of organogenesis to pregnant female rabbits. No treatment-related effects on embryofetal toxicity or malformation were noted at 2 mg/kg/day (1.5 times the MRHD based on BSA comparison), the highest dose evaluated in this study, or 1 mg/kg/day (407 times the MRHD based on AUC comparison). A combined fertility and peri- and postnatal development study was conducted in rats. Oral doses of 1, 1.5, 3, and 6 mg/kg/day imiquimod were administered to male rats from 70 days prior to mating through the mating period and to female rats from 14 days prior to mating through parturition and lactation.

No effects on growth, fertility, reproduction, or postnatal development were noted at doses up to 6 mg/kg/day (87 times the MRHD based on AUC comparison), the highest dose evaluated in this study. In the absence of maternal toxicity, bent limb bones were noted in the F1 fetuses at a dose of 6 mg/kg/day (87 times the MRHD based on AUC comparison). This fetal effect was also noted in the oral rat embryofetal development study conducted with imiquimod. No treatment-related malformations were noted at 3 mg/kg/day (41 times the MRHD based on AUC comparison).

Pediatric Use Actinic Keratosis and Superficial Basal Cell Carcinoma The safety and effectiveness of Imiquimod Cream for the treatment of AK or sBCC in pediatric patients have not been established. External Genital Warts The safety and effectiveness of Imiquimod Cream for the treatment of EGW in pediatric patients 12 years of age and older have been established. Use of Imiquimod Cream for this indication is supported by evidence from adequate and well controlled trials in adults . The safety and effectiveness of Imiquimod Cream for the treatment of EGW in pediatric patients less than 12 years of age have not been established.

Molluscum Contagiosum The safety and effectiveness of Imiquimod Cream for the treatment of molluscum contagiosum (MC) in pediatric patients have not been established. Safety and effectiveness of Imiquimod Cream was not demonstrated in two randomized, vehicle-controlled, double-blind trials involving 702 pediatric subjects with MC (470 exposed to Imiquimod Cream; median age 5 years, range 2–12 years). Adverse reactions reported in pediatric subject with MC (and not previously reported) included otitis media (5% Imiquimod Cream vs. 3% vehicle) and conjunctivitis (3% Imiquimod Cream vs. 2% vehicle). In a pharmacokinetics trial in subjects aged 2 to 12 years with extensive MC involving at least 10% of total body surface area; among the 20 subjects with evaluable laboratory assessments, the median white blood cell (WBC) count decreased by 1.4 x 10 9 /L and the median absolute neutrophil count decreased by 1.42 x 10 9 /L.

Topical overdosing of Imiquimod Cream could result in an increased incidence of severe local skin reactions and may increase the risk for systemic reactions. The most clinically serious adverse reaction reported following multiple oral imiquimod doses of >200 mg (equivalent to imiquimod content of >16 packets of Imiquimod Cream) was hypotension, which resolved following oral or intravenous fluid administration. Consider contacting the Poison Help line (1-800-222-1222) or a medical toxicologist for additional overdosage management recommendations.