Cumulative Irritation Potential and Contact Sensitization Potential of Tazarotene Foam 0.1% in 2 Phase 1 Patch Studies

We performed 2 phase 1 patch studies to evaluate tazarotene foam 0.1% for cumulative irritation potential (study A) and contact sensitization potential (study B). Study A participants wore patches containing active study product, vehicle foam, and positive and negative controls for 24 +/- 1 hours for 21 consecutive days. Irritation scores were statistically higher with tazarotene foam 0.1% than vehicle foam and both controls. Fourteen participants (36%) experienced product-related, application-site adverse events (AEs); all of the AEs were mild and transient. Study B participants were exposed to active product and vehicle foam for an induction and challenge phase. At the investigators discretion, participants were administered a rechallenge to evaluate for contact sensitization. Three participants demonstrated questionable sensitization reactions and underwent a rechallenge; none of the participants displayed conclusive contact sensitization. Three application-site AEs were considered to be product related; none of the AEs led to study discontinuation. Tazarotene foam 0.1% showed potential to induce irritation but a low potential for contact sensitization and an acceptable tolerability and safety profile.