FDA Approves Difamilast Ointment for Atopic Dermatitis
The FDA has approved topical difamilast, a PDE4 inhibitor, for treating mild-to-moderate atopic dermatitis in adults and children aged 2 years or older, marking the third PDE4 inhibitor approval for this indication.
The FDA has approved topical difamilast for treating mild-to-moderate atopic dermatitis in adults and children aged 2 years or older. Difamilast, a topical phosphodiesterase 4 (PDE4) inhibitor that will be marketed as Adquey, in a 1% ointment formulation, is applied twice daily.
The US approval marks the third approval of a PDE4 inhibitor for atopic dermatitis. Crisaborole was approved in 2017, and topical roflumilast (Zoryve) 0.15% was approved in 2024 for adults and children aged 6 years or older. In 2025, the FDA approved topical roflumilast 0.05% for treating mild-to-moderate atopic dermatitis in children aged 2-5 years.
Approval was supported by studies that included several phase 3, randomized, controlled trials, which found that after 4 weeks, a higher proportion of patients treated with difamilast achieved Investigator's Global Assessment success than those who received a vehicle. In pivotal studies, significantly more patients achieved clear or almost clear skin after 4 weeks of twice-daily difamilast compared with vehicle.
The most common adverse reactions associated with treatment have been nasopharyngitis, reported by 6% of patients. Difamilast was approved for atopic dermatitis in Japan in 2021 where it is marketed as Moizerto.
No date has been identified for when difamilast will be available for clinical use in the US. The individual studies were funded by Otsuka Pharmaceutical Company and Acrotech Biopharma.