A Phase II, Open‐Label Study of the Efficacy and Safety of Imiquimod in the Treatment of Superficial and Mixed Infantile Hemangioma

Objectives: To explore the efficacy and safety of imiquimod 5% cream as a treatment for infantile hemangioma. Design: Phase II, open‐label, noncomparative study of imiquimod applied during 16 weeks, with posttherapy follow‐up 16 weeks later (8 months total). Setting: Outpatient pediatric tertiary care referral center in Quebec, Canada. Participants: Healthy infants up to 8.8 months of age with previously untreated, nonulcerated, proliferative superficial or mixed infantile hemangioma, excluding periorbital, or perineal localization, ≥100 cm 2 in size. Intervention: Topical imiquimod applied three to seven times per week for 16 weeks to infantile hemangioma. Main Outcome Measures: Lesion area, volume, depth (Doppler ultrasound), and color (erythema), serum drug, and interferon‐alpha levels. Results: Sixteen infants (11 girls, 5 boys) with a mean age at entry of 4.1 months and mean lesion area of 32.89 cm 2 , and volume of 39.98 cm 3 were enrolled. Two participants discontinued treatment early, one for an adverse event (crying upon application), the other because of the lack of compliance. Local skin reactions were consistent with those reported in adults. Two cases had a decrease and three had an increase in lesion parameters; otherwise no meaningful changes in lesion area, volume, or depth were observed. At the 4‐month posttreatment visit, 11 of 14 subjects had improvement in erythema (marginal homogeneity test = 2.668, p = 0.008). Measured serum drug and interferon‐alpha levels were low or undetectable. Conclusions: Treatment of infants with infantile hemangioma with imiquimod up to seven times per week for 16 weeks was generally well tolerated with low systemic exposure. Improvement was observed in hemangioma coloration, but not lesion size, suggesting effects were limited to the superficial component.