Phototoxic and photoallergic potential of tazarotene foam 0.1% in 2 phase 1 patch studies.

Two phase 1 patch studies were conducted to evaluate tazarotene foam 0.1% for phototoxic (study A) and photoallergic (study B) potential. In study A, 38 participants were exposed to patches containing tazarotene foam 0.1%, vehicle foam, or no foam (blank patch) over 24 hours. One set each was exposed to UV irradiation, UV and visible (VIS) light, and no irradiation. In study B, 59 participants received patches containing tazarotene foam 0.1% and vehicle foam; sites were exposed to UVB irradiation and VIS light after each application during the induction phase. After 10 to 17 days, participants received both UVA and UVA/UVB irradiation, UVA/UVB plus VIS irradiation, or no irradiation during the challenge phase. Erythema grades and local skin reactions did not differ systematically by study product or across patch sites, and no pattern of increased reactivity at tazarotene foam 0.1% sites was observed. None of the participants demonstrated conclusive photoallergic reactions. Findings suggest that tazarotene foam 0.1% is not a major photoirritant and has a low potential for phototoxic or photoallergic reactions.

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.