Difamilast Ointment Shows Week 4 Benefits in Pediatric and Adult Atopic Dermatitis Trials
Key Takeaways
- In separate phase 3, randomized, double-blind, vehicle-controlled trials, difamilast 1% ointment achieved higher week 4 Investigator’s Global Assessment (IGA) success rates than vehicle in adults and children with atopic dermatitis.
- At week 4, IGA success was 38.5% with difamilast 1% versus 12.6% with vehicle in adults, and 47.1% versus 18.1%, respectively, in children aged 2 to 14 years. Pediatric patients receiving difamilast 0.3% had a 44.6% success rate.
- No serious adverse events were reported in the summarized trials, although the four-week treatment period limits conclusions about longer-term safety and efficacy.
Difamilast 1% ointment was associated with higher rates of Investigator’s Global Assessment (IGA) success than vehicle at week 4 in separate phase 3 studies involving adults and children with atopic dermatitis (AD), according to an integrated review presented at the 2026 Fall Clinical Dermatology Conference.
Lisa Swanson, MD, and Joshua Zeichner, MD, summarized randomized, double-blind, vehicle-controlled trials of the topical phosphodiesterase 4 inhibitor in patients with mild-to-moderate AD. Treatment was applied twice daily for four weeks.
The adult trial enrolled 364 participants, evenly assigned to difamilast 1% or vehicle. The pediatric trial enrolled 251 children aged 2 to 14 years, assigned to difamilast 1% (n = 85), difamilast 0.3% (n = 83), or vehicle (n = 83).
Week 4 Efficacy and Safety Across Age Groups
At week 4, IGA success occurred in 38.5% of adults receiving difamilast 1%, compared with 12.6% receiving vehicle (P < .0001). Among pediatric participants, IGA success rates were 47.1% with difamilast 1% and 44.6% with difamilast 0.3%, versus 18.1% with vehicle (both P < .001).
The investigators also reported improvements in Eczema Area and Severity Index scores and pruritus as early as week 1, sustained through week 4. Most treatment-emergent adverse events were mild or moderate, and no serious adverse events were reported. Common events included AD and nasopharyngitis in adults, and impetigo and nasopharyngitis in children.
The authors concluded that the results support difamilast as a nonsteroidal topical option across pediatric and adult AD populations.