RESUMEN
Importance: Atopic dermatitis (AD) and plaque psoriasis are inflammatory skin diseases with unmet need for effective topical treatments with few application site reactions. Objective: To assess the efficacy and safety of the topical phosphodiesterase 4 inhibitor PF-07038124 in patients with AD and plaque psoriasis. Design, Setting, and Participants: This phase 2a, randomized, double-blind clinical trial was conducted from December 21, 2020, to August 18, 2021, at 34 sites across 4 countries. Eligible patients (aged 18-70 years) had mild to moderate AD (covering 5%-20% body surface area) or plaque psoriasis (covering 5%-15% body surface area). Data were analyzed until December 15, 2021. Interventions: Patients were randomized (1:1) to PF-07038124, 0.01%, topical ointment or vehicle once daily for 6 weeks. Main Outcomes and Measures: The primary end point was the percent change from baseline (CFB) in the Eczema Area and Severity Index (EASI) total score among patients with AD and in the Psoriasis Area and Severity Index (PASI) score among patients with plaque psoriasis at week 6. Safety measures included treatment-emergent adverse events, including application site reactions. Results: Overall, 104 patients were randomized (mean [SD] age, 43.0 [15.4] years; 55 [52.9%] women; 4 [3.8%] Asian, 13 [12.5%] Black, and 87 [83.7%] White), including 70 with AD (41 women [58.6%]; mean [SD] ages, 41.4 [16.6] years in the PF-07038124 group and 36.1 [13.9] years in the vehicle group) and 34 with plaque psoriasis (20 men [58.8%]; mean [SD] ages, 51.8 [12.3] years in the PF-07038124 group and 51.2 [10.8] years in the vehicle group). Baseline characteristics were generally balanced. At week 6, the PF-07038124 groups showed significantly greater improvements compared with vehicle groups in EASI (least-squares mean CFB, -74.9% vs -35.5%; difference, -39.4% [90% CI, -58.8% to -20.1%]; P < .001) and PASI scores (CFB, -4.8 vs 0.1; difference, -4.9 [90% CI, -7.0 to -2.8]; P < .001). The number of patients with treatment-emergent adverse events was comparable between treatment groups in patients with AD (PF-07038124, 9 [25.0%]; vehicle, 9 [26.5%]) and plaque psoriasis (PF-07038124, 3 [17.6%]; vehicle, 6 [35.3%]). There were no application site reactions with PF-07038124 treatment. Conclusions and Relevance: Topical PF-07038124 was well tolerated and demonstrated superior efficacy compared with vehicle in patients with mild to moderate AD and plaque psoriasis. Trial Registration: ClinicalTrials.gov Identifier: NCT04664153.